- EFFECT OF PRESSURE ON THE RATES OF OXIDATION OF MONOSACCHARIDES WITH VANADIUM(V)
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The effect of pressure on the rates of the oxidation of D-galactose, D-glucose, D-mannose, D-fructose, L-sorbose, L-arabinose, D-ribose, and D-xylose with vanadium(V) in perchloric acid was studied.The activation volumes for the monosaccharides were positive and approximately equal (7.5+/-1.3 mL*mol-1), with negligible dependence on pressure up to 200 MPa at least.These observations indicate the same mechanism for the formation of the activated complexes.A mechanism involving formation of a radical by hydrogen atom transfer in the rate-determining decomposition of a monosaccharide-vanadium(V) complex is proposed.
- Virtanen, Pentti O. I.,Koukkanen, Toivo,Rauma, Touko
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- Isolation and structure determination of acetylated triterpenoid saponins from the seeds of Centratherum anthelminticum
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Phytochemical investigation of Centratherum anthelminticum seeds resulted in the isolation of two novel glycosides. The pentacyclic triterpenoid saponins were shown to contain hederagenin and sugar residues forming two glycosyl chains. The structural analysis of its acetylated derivative was determined using a combination of homo- (1D 1H NMR, 13C NMR and 13C NMR-DEPT) and heteronuclear 2D NMR techniques ( 1H-1H-COSY, total correlated spectroscopy (TOCSY), heteronuclear multiple quantum coherence (HMQC)), heteronuclear multiple bond correlation (HMBC) and chemical methods. The structure of the saponins were established to be 3-O-[β-D-glucopyranosyl-(1 → 2)- α- L-rhamnopyranosyl-(1 → 2)-α - L-arabinopyranosyl]-28-O-[β-D- xylopyranosyl-(1 → 4)- α - L-rhamnopyranosyl-(1 → 3)- β - D-glucopyranosyl]-23-hydroxyolean-12-en-28-oic acid and 3-O-[β-D- glucopyranosyl-(1 → 2)- α - L-rhamnopyranosyl-(1 → 2)- α - L-arabinopyranosyl]-28-O-[β-D-glucoyranosyl-(1 → 3)- β - D-glucopyranosyl]-23-hydroxyolean-12-en-28-oic acid. Different extracts and compounds were also tested for antifilarial and antimicrobial activities. Methanolic, acetone and aqueous extracts of seeds exhibited some pronounced pharmacological activity under study.
- Mehta,Mehta, Darshana,Itoriya, Amrita
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- Extraction, purification, characterization and hypoglycemic activity of a polysaccharide isolated from the root of Ophiopogon japonicus
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In this research, a water-soluble polysaccharide (OJP1) extracted with hot water from the roots of Ophiopogon japonicus which is a traditional Chinese medicinal herb was precipitated with 95% ethanol and purified by DEAE-52 cellulose anion-exchange and Sephadex G-100 gel filtration chromatography. The high performance gel permeation chromatography (HPGPC) analysis showed that the average molecular weight (Mw) of OJP1 was 35.2 kDa. Monosaccharides analysis revealed that the OJP1 is composed of Ara, Glc, Gal with a relative molar ratio of 1:16:8. Pharmaceutical experiments showed OJP1 can significantly reduce blood glucose level, increase the insulin level and remediating destruction of pancreatic islets in STZ-induced diabetic rats compared with the diabetic control group. The study shows that OJP1 has an anti-diabetic effect on STZ-induced diabetic rats, and has potential use as an anti-diabetic agent. Copyright
- Chen, Xiaoming,Jin, Jing,Tang, Jia,Wang, Zhongfu,Wang, Junjun,Jin, Liqin,Lu, Jianxin
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- Antibacterial Activity of a New Flavone Glycoside from the Stems of Holmskioldia sanguinea Retz.
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A new flavone glycoside was isolated from ethanolic extract of stem parts of Holmskioldia sanguinea Retz. Its structure was characterized as 3,4′-dihydroxy-5,7-dimethoxyflavone-3-O-β-D-galactopyranosyl(1→4)-O-β-D-arabinopyranosyl-4′-O-α-L-rhamnopyranoside (1) by colour reactions, chemical degradation and spectroscopic analysis. Antibacterial activity of compound 1 was evaluated against various Gram positive and Gram negative bacteria showing a significant effects.
- Yadava,Raghuvansi, Jyotsna
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- A new kaempferol trioside from Farsetia aegyptia
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A new kaempferol trioside, kaempferol-3-O-(2-α-L-arabinopyranosyl)- α-L-rhamnopyranoside-7-O-α-L-rhamnopyranoside, along with eight known flavonoid compounds were isolated from the methanolic extract of Farsetia aegyptia Turra. growing in Egypt. The struc
- Marzouk,Kawashty,Saleh,Al-Nowaihi, Abdel Salam M.
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- Kaempferol glycosides from Lobularia maritima and their potential role in plant interactions
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Six kaempferol glycosides, four of them characterized for the first time, were isolated from the leaf extract of Lobularia maritima. The structural elucidation was performed by a combined approach using Electrospray-Ionization Triple-Quadrupole Mass-Spect
- Fiorentino, Antonio,Ricci, Andreina,D'Abrosca, Brigida,Golino, Annunziata,Izzo, Angelina,Pascarella, Maria Teresa,Piccolella, Simona,Esposito, Assunta
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- Selective electrocatalytic oxidation of sorbitol to fructose and sorbose
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A new electrocatalytic method for the selective electrochemical oxidation of sorbitol to fructose and sorbose is demonstrated by using a platinum electrode promoted by p-block metal atoms. By the studying a range of C4, C5 and C6 polyols, it is found that the promoter interferes with the stereochemistry of the polyol and thereby modifies its reactivity.
- Kwon, Youngkook,De Jong, Ed,Van Der Waal, Jan Kees,Koper, Marc T. M.
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- Antitumor and immunomodulatory activities of a polysaccharide from Artemisia argyi
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A water-soluble polysaccharide (FAAP-02), composed of N-acetyl-d- glucosamine, glucose, mannose, galactose, rhamnose arabinose, xylose and ribose, with an average molecular weight of 5169 Da, was isolated from Artemisia argyi. The antitumor and immunomodulatory activities of FAAP-02 were evaluated in Sarcoma 180 (S180) tumor-bearing mice by intraperitoneal administration. As a result, FAAP-02 significantly inhibited the growth of the S180 transplanted tumors and prolonged the survival time of the tumor-bearing mice. Moreover, FAAP-02 could obviously increase the thymus and spleen indices, the levels of serum Interleukin 2 (IL-2), Interleukin 6 (IL-6), Interleukin 12 (IL-12) and tumor necrosis factor- α (TNF-α) and the expression of CD4+ and CD8+ splenic T lymphocytes which were suppressed by the transplanted tumor or/and 5-fluorouracil (5-FU) in the mice. These results indicated that the antitumor activity of FAAP-02 might be associated with its immunostimulatory effects.
- Bao, Xiaoli,Yuan, Huihui,Wang, Chengzhong,Liu, Jinjin,Lan, Minbo
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- Four new triterpenoids isolated from the resin of Garcinia hanburyi
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Four new triterpenoids, 2-O-acetyl-3-O-(4′-O-acetyl)-α-l- arabinopyranosylmaslinic acid (1), 2-O-acetyl-3-O-(3′-O-acetyl)-α-l- arabinopyranosylmaslinic acid (2), 2-O-acetyl-3-O-(3′,4′-O-diacetyl) -α-l-arabinopyranosylmaslinic acid (3), and 3-O-(3′-O-acety
- Wang, Hong-Min,Liu, Qun-Fang,Zhao, Yi-Wu,Liu, Shuang-Zhu,Chen, Zhen-Hua,Zhang, Ru-Jun,Wang, Zhen-Zhong,Xiao, Wei,Zhao, Wei-Min
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- Adjuvant effect of Atractylodis macrocephalae Koidz. Polysaccharides on the immune response to foot-and-mouth disease vaccine
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Present study was designed to investigate the polysaccharide (RAMPS) extracted from the rhizome of Atractylodis macrocephalae Koidz. (RAM) for its effect on the immune responses to foot-and-mouth (FMD) vaccine. Thirty-five ICR mice were randomly distributed into 5 groups with 7 mice in each. After oral administration of RAMPS for 4 days at a dose of 0, 0.025, 0.05, 0.1 g or 0.25 g of RAM, respectively, the animals were immunized twice with FMD vaccine at 2-week intervals. Three weeks later, serum IgG, IFN-γ/IL-5, splenocyte proliferation, and mRNA expression of cytokines by splenocytes were measured. Results indicated that RAMPS and RAM significantly enhanced IgG titers, IgG subclasses, IFN-γ, IL-5 and the splenocyte proliferations stimulated by concanavalin A, lipopolysacharide, and FMDV (P 0.05). Therefore, RAMPS and RAM increased both cellular and humoral immune responses to vaccination, and may have a potential as an oral adjuvant to improve vaccination.
- Xie, Feng,Li, Yutao,Su, Fei,Hu, Songhua
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- 7,2''-DI-O-GLYCOSYL-6-C-GLYCOSYLFLAVONES FROM CERASTIUM ARVENSE
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Four 7,2''-di-O-glycosyl-6-C-glycosylflavones were isolated from Cerastium aravense, including two new compounds: isomollupentin 7-O-glucoside-2''-O-arabinoside and isomollupentin 7-O-glucoside-2''-O-xyloside.The known compounds are isovitexin 7-O-glucoside-2''-O-arabinoside and isomollupentin 7,2''-di-O-glucoside. - Key Word Index: Cerastium arvense; Caryopyllaceae; C-glycosylflavonoids; isovitexin 7-O-glucosie-2''-O-arabinoside; isomollupentin 7,2''-di-O-glucoside; isomollupentin 7-O-glucoside-2''-O-xyloside; isomollupentin 7-O-glucoside-2''-O-arabinoside.
- Dubois, Marie-Aleth,Zoll, Anne,Chopin, Jean
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- Photocatalytic Solar Light H2 Production by Aqueous Glucose Reforming
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A series of tungsten and nitrogen doped Pt-TiO2 samples were prepared with the aim to extend the TiO2 absorption to the visible light region and to enhance the separation efficiency of the photogenerated electron/hole pairs. The physicochemical features of the powders were characterized by X-ray diffraction (XRD), UV/Vis reflectance spectra, specific surface area (SSA) determinations, and transmission electron microscopy (TEM) analyses. The influence of the presence of different doping agents was evaluated, under anaerobic conditions, in the aqueous photo-reforming of glucose to form H2 at ambient pressure and temperature under a halogen lamp or natural solar light irradiation. Arabinose, erythrose, and formic acid were the main glucose partial oxidation products observed in the liquid phase, whilst H2 and CO2 were measured in the gaseous phase. The highest H2 production was observed in the presence of the Pt-TiO2-W0.25 sample.
- Bellardita, Marianna,García-López, Elisa Isabel,Marcì, Giuseppe,Nasillo, Giorgio,Palmisano, Leonardo
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- The catalysis of the Ruff oxidative degradation of aldonic acids by copper(II)-containing solids
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The catalysis of the Ruff oxidative degradation of calcium D-gluconate to D-arabinose by aqueous diluted hydrogen peroxide was investigated using copper(II)-containing solids: zeolites and resins. Among zeolites, copper(II)-exchanged Y faujasite has given
- Hourdin, Gwenaelle,Germain, Alain,Moreau, Claude,Fajula, Francois
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- Selective conversion of aqueous glucose to value-added sugar aldose on TiO2-based photocatalysts
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We describe here a photocatalytic process for direct conversion of glucose to value-added chemicals (arabinose and erythrose) and H2 in water under mild reaction conditions without additional acid or base. The total selectivity for the production of arabinose and erythrose on rutile TiO 2-based photocatalyst reaches 91% at 65% conversion. More importantly, it has been demonstrated for the first time that the photodegradation of glucose initially involves C1-C2 bond cleavage (α-scission) to produce arabinose in the presence of water as solvent. To unravel the high selectivity on rutile TiO2, EPR and glucose reaction were carried out on rutile TiO2 in the presence of H 2O2. It was found that the selectivity of the products is mainly dependent on the reactive oxygen species: the hydroxyl radicals (OH) may lead to low selectivity, while the peroxy species lead to a high selectivity. The advantages of the photocatalytic approach for conversion of biomass to value-added chemicals include (1) operation at low reaction temperature, (2) benign environmental effects due to using only water as both solvent and oxidant precursor, and (3) being wasteless due to high selectivity with H2 as the by-product.
- Chong, Ruifeng,Li, Jun,Ma, Yi,Zhang, Bao,Han, Hongxian,Li, Can
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- Three new steroidal glycosides from roots of Reineckia carnea
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Two new spirostanols and a new furostanol, reinocarnoside A (1), B (2) and C (3), were isolated from the roots of Reineckia carnea, together with two known compounds, (25S)-1β,3β,4β-trihydroxyspirostan-5β-yl-O- β-D-glucopyranoside (4), kitigenin-5β-O-β-D-glucopyranoside (5). The structures of three new compounds were elucidated by spectroscopic methods including 1-D NMR, 2-D NMR and MS spectrums, and their anticancer activities were evaluated by MTT method.
- Wang, Qian,Hou, Qune,Guo, Zhiyong,Zou, Kun,Xue, Yanhong,Huang, Nianyu,Cheng, Fan,Zhou, Yuan
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- Photocatalytic conversion of glucose in aqueous suspensions of heteropolyacid-TiO2 composites
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Commercial and home prepared TiO2 samples were functionalized with a commercial Keggin heteropolyacid (HPA) H 3PW12O 40 (PW12) or with a hydrothermally home prepared K 7PW11O 39 salt (PW11). All the materials were characterized by specific surface area measurements (BET), XRD analyses, Raman, DRS along with SEM observations and they have been used for glucose photocatalytic conversion in an aqueous suspension. Different reaction extents and distribution of intermediate oxidation products were observed depending on the photocatalyst. Gluconic acid, arabinose, erythrose and formic acid were observed as oxidation products when bare TiO2 or HPA/TiO2 composite materials were used. Glucose isomerization to form fructose was also observed and in some runs traces of glucaric acid and glyceraldehyde were also found. The carbon mass balance was accomplished in the presence of the commercial Evonik P25 TiO2 powder and the composites where TiO2 was present, whereas the presence of the solvothermically prepared TiO2 gave rise to a carbon unbalance, due to strong adsorption of the products on the photocatalyst surface. No reactivity was observed in the presence of PW12 alone while PW11 induced only isomerization of the glucose.
- Bellardita,García-López,Marcì,Megna,Pomilla,Palmisano
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- Synthesis and properties of crosslinked chiral nanoparticles via RAFT miniemulsion polymerization
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Crosslinked chiral nanoparticles were successfully synthesized via reversible addition-fragmentation chain transfer (RAFT) miniemulsion polymerization of 6-O-p-vinylbenzyl-1,2:3,4di-O-isopropylidene-D-galactopyranose (VBPG) using linear poly(VBPG) as the macro-RAFT agent. The polymerization of VBPG in the absence of crosslinker was first studied and the kinetic results showed that the molecular weights of the obtained poly(VBPG) increased linearly with the monomer conversion and was in good consistency with the corresponding theoretical ones while there remained a relative narrow polydisperslty. The effect of the amount of crosslinker, divlnylbenzene, on the nanoparticle size and chiral separation properties of the obtained nanoparticles were investigated in detail using four racemates ±-3-Amino-1,2propanediol, D,L-arablnose, D,L-tartaric acid, and D,L-mandelic acid.
- Xu, Wenliang,Cheng, Zhenping,Zhang, Lifen,Zhang, Zhengbiao,Zhu, Jian,Zhou, Nianchen,Zhu, Xiulin
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- SYNTHESIS OF MONOSACCHARIDES WITH THE AID OF A NEW SYNTHETIC EQUIVALENT FOR THE GLYCOLALDEHYDE ANION
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The synthesis and characterization of previously unknown B-aryl- and B-alkyl-1,3,2-dioxaboroles is reported.These compounds can act as synthetic equivalents for the glycolaldehyde anion, because they undergo an aldol-type reaction with aldehydes yielding mono, and large amounts of multiple, addition products.By immobilizing the 1,3,2-dioxaboroles on a polymeric support, which accomplishes the site separation of the enediolate intermediates, further addition beyond the primary stage could be inhibited.As a first example of a synthetic application, the synthesis of the otherwise arduously accesible l-ribose was undertaken. 2,3-O-Cyclohexyliden-L-glyceraldehyde reacted with polymer-bound 1,3,2-dioxaborole to give a mixture of pentoses in good yield, from which 54percent of enantiomerically pure L-ribose could be isolated.This work provides a general methodology for the lengthening of sugar chains by two C-atoms, thus furnishing a novel route for the synthesis of rare sugars.
- Wulff, Gunther,Hansen, Achim
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- Optimization of ultrasound-assisted extraction of okra (Abelmoschus esculentus (L.) Moench) polysaccharides based on response surface methodology and antioxidant activity
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This study determined the optimal conditions for ultrasound-assisted extraction of a water-soluble polysaccharide, Raw Okra Polysaccharide, from the fruit of okra using response surface methodology. The optimal extraction temperature, extraction time and ultrasonic power were 59 °C, 30 min and 522 W, respectively, giving a yield of 10.35 ± 0.11%. ROP was further isolated, lyophilized and purified using a DEAE-Sepharose Fast Flow column and Sepharose CL-6B column, revealing three elution peaks subsequently designated ROP ?1, ?2, and ?3, respectively. Of these, ROP-2 showed the highest yield, and was therefore selected for physicochemical analysis and evaluation of antioxidant activity. Gas chromatography, fourier transform infrared spectroscopy, and high-performance liquid chromatography were used to characterize the primary structural features and molecular weight, revealing that ROP-2 is composed of glucose, mannose, galactose, arabinose, xylose, fructose, and rhamnose (molar percentages: 28.8, 12.5, 13.1, 15.9, 9.2, 13.7, and 6.8%, respectively) and has an average molecular weight of 1.92 × 105 Da. A superoxide radical scavenging assay and DPPH radical scavenging assay further revealed the significant in vitro antioxidant activity of ROP-2. These findings present an effective technique for extraction of the natural antioxidant ROP-2, warranting further analysis of its potential application in the food industry.
- Wang, Kunli,Li, Mo,Wen, Xin,Chen, Xiaosong,He, Zhengyu,Ni, Yuanying
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- Towards efficient synthesis of sugar alcohols from mono- and poly-saccharides: Role of metals, supports & promoters
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Biomass derived sugar alcohols (xylitol, arabitol) find numerous uses in the food, oral hygiene and pharmaceutical industries. Their direct synthesis from poly-saccharides, however, still remains an immense challenge. In this study, we demonstrate in detail the effects of metals, supports and promoters in enhancing the yields of sugar alcohols from mono- and poly-saccharides. We undertook synthesis of bimetallic catalysts, M-M′/S (M, metal = Pt, Ru; M′, promoter = Sn, Ga, Fe; S, support = γ-Al2O3 (AL), SiO2-Al2O3 (SA), carbon (C)) with varying metal loadings (Pt/Ru = 2, 3.5 wt%; Sn = 0.22, 0.43, 0.87, 1.5, 3.5 wt%; Ga/Fe = 0.25 wt%) by a co-impregnation method. The catalytic activities of these catalysts were evaluated in the synthesis of sugar alcohols from xylose (mono-saccharide) and hemicellulose (xylan, poly-saccharide) at 130-190 °C. Among all of the bimetallic catalysts, the Pt(3.5)Sn(0.43)/AL catalyst (50%) showed 2.8 times improvement in the yield of sugar alcohols compared to a monometallic Pt(3.5)/AL catalyst (18%). Similarly, in the xylose reaction a 2.4 times enhancement in the yield of sugar alcohols over Pt(3.5)Sn(0.43)/AL (79%) was observed compared to the 33% yield obtained with Pt(3.5)/AL. By conducting several experiments it is confirmed that the residual Cl-, which remained on the catalyst even after calcinations and reductions carried out at 400 °C, does not play any role in catalysis. The stability of the Pt(3.5)Sn(0.43)/AL catalyst confirmed by XRD and ICP analysis was responsible for achieving reproducible activity in at least 5 consecutive runs. Formation of electron deficient Sn confirmed by XPS analysis helped to polarize the carbonyl group, which in turn enhanced the sugar alcohols' yields. Formation of PtSn and Pt3Sn species was observed when Sn loading was more than 0.87%.
- Tathod, Anup P.,Dhepe, Paresh L.
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- Determination of the absolute configuration of sialic acids in gangliosides from the sea cucumber Cucumaria echinata
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Enantiomeric pairs of sialic acid, D- and L-NeuAc (N-acetylneuraminic acid), were converted to D- and L-arabinose, respectively, by chemical degradation. Using this method, the absolute configuration of the sialic acid residues, NeuAc and NeuGc (N-glycolylneuraminic acid), in the gangliosides from the sea cucumber Cucumaria echinata was determined to be the D-form. Although naturally occurring sialic acids have been believed to be the D-form on the basis of biosynthetic evidence, this is the first report of the determination of the absolute configuration of the sialic acid residues in gangliosides using chemical methods.
- Kisa, Fumiaki,Yamada, Koji,Miyamoto, Tomofumi,Inagaki, Masanori,Higuchi, Ryuichi
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- Steroids glycosylated with both d- and l-arabinoses from the South China Sea gorgonian Dichotella gemmacea
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Three new 19-hydroxy steroidal glycosides, namely, junceellosides E-G (2-4), were isolated together with the known analogue junceelloside C (1) from the South China Sea gorgonian Dichotella gemmacea. The structures of these compounds were elucidated by a combination of detailed spectroscopic analyses, chemical methods, and comparison with reported data. These glycosides are found to have sugar moieties of both β-l- and β-d-arabinopyranoses by HPLC analysis of their thiocarbamoyl-thiazolidine derivatives and those of authentic d- and l-arabinoses, leading to the structure revision of junceelloside C (1). This is the first report of steroidal glycosides from the gorgonian D. gemmacea and the first report of glycosides with β-l-arabinopyranose from marine sources.
- Jiang, Mei,Sun, Peng,Tang, Hua,Liu, Bao-Shu,Li, Tie-Jun,Li, Cui,Zhang, Wen
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- Three new triterpenoid saponins from Ardisia crenata
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Three new triterpenoid saponins, ardisicrenoside I (1), ardisicrenoside J (2), and ardisicrenoside M (3), along with eight known compounds, were isolated from the roots of Ardisia crenata Sims. Their structures were elucidated as 16α-hydroxy-30,30-dimethoxy-3β-O-{β-D-xylopyranosyl-(1→2) -β-D-glucopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→2)] -α-L-arabinopyranosyl}-13β,28-epoxyoleanane (1), 16α-hydroxy- 30,30-dimethoxy-3β-O-{α-L-rhamnopyranosyl-(1→2) -β-D-glucopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→2)] -α-L-arabinopyranosyl}-13β,28-epoxyoleanane (2), 30,30-dimethoxy-16- oxo-3β-O-{β-D-xylopyranosyl-(1→2)-β-D-glucopyranosyl- (1→4)-[β-D-glucopyranosyl-(1→2)]-α-L-arabinopyranosyl} -13β,28-epoxyoleanane (3), ardisiacrispin A (4), ardisiacrispin B (5), ardisicrenoside B (6), ardisicrenoside A (7), ardisicrenoside H (8), ardisicrenoside G (9), cyclamiretin A-3β-O-β-D-xylopyranosyl- (1→2)-β-D-glucopyranosyl-(1→4)-α-L-arabinopyranoside (10), and cyclamiretin A-3β-O-α-L-rhamnopyranosyl-(1→2)-β-D- glucopyranosyl-(1→4)-α-L-arabinopyranoside (11) by means of chemical and spectral analysis, and their cytotoxicities were evaluated in vitro. Copyright
- Liu, Dai-Lin,Wang, Nai-Li,Zhang, Xue,Yao, Xin-Sheng
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- Structural properties of polysaccharides from cultivated fruit bodies and mycelium of Cordyceps militaris
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The structural properties of polysaccharides, respectively, obtained from the fermented mycelium and cultivated fruiting bodies of the Cordyceps militaris were investigated and compared in this paper. First, the crude polysaccharides were extracted from the mycelium and the fruiting bodies, respectively. The polysaccharides were successively purified by Sevag and chromatography on Sephadex G-100 column to produce two polysaccharides fractions termed CMPS-II and CBPS-II, respectively. The average molecular weights of CMPS-II and CBPS-II were 1.402 × 103 kDa and 1.273 × 103 kDa, respectively, and they were mainly composed of mannose, glucose and galactose in the mole ratios of 1:28.63:1.41 and 1:12.41:0.74, respectively, for CMPS-II and CBPS-II. Afterward, the structural features of CMPS-II and CBPS-II were investigated by a combination of chemical and instrumental analysis, such as FT-IR, periodate oxidation-Smith degradation, GC-MS, NMR and methylation analysis. The results indicated that structurally, both CMPS-II and CBPS-II were 1,3-branched-galactomannoglucan that had a linear backbone of (1 → 4)-linked α-d-glucopyranose (Glcp). Congo-red test revealed that CMPS-II and CBPS-II existed as triple-helical chains in 0.05-0.15 M NaOH solution.
- Liu, Xiao-Cui,Zhu, Zhen-Yuan,Tang, Ya-Li,Wang, Ming-Fei,Wang, Zheng,Liu, An-Jun,Zhang, Yong-Min
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- Triterpene glycosides from the leaves of pittosporum angustifolium
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Phytochemical investigation of the leaves of Pittosporum angustifolium resulted in the isolation and structural elucidation of nine new triterpene saponins, named pittangretosides A-I (1-9), together with a known compound (10). Mainly by NMR and HRESIMS experiments, eight compounds were identified as A1-barrigenol glycosides (1-7, 10), whereas two compounds exhibited an unusual 17,22-seco-backbone of oleanolic acid (8, 9). All compounds were evaluated for their in vitro cytotoxicities against human urinary bladder carcinoma cells (5637). Only compounds with an angeloyl-residue at C-22 of the aglycone (1-4 and 10) showed antiproliferative effects with IC50 values of 4.1, 5.2, 2.1, 17.9, and 2.4 M, respectively. Georg Thieme Verlag KG Stuttgart.
- Baecker, Christian,Jenett-Siems, Kristina,Siems, Karsten,Wurster, Martina,Bodtke, Anja,Chamseddin, Chamseddin,Cruesemann, Max,Lindequist, Ulrike
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- Kinetic and chemical studies on the isomerization of monosaccharides in N-methylmorpholine-N-oxide (NMMO) under Lyocell conditions
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The Lyocell process is a modern and environmentally fully compatible industrial fiber-making technology. Cellulosic pulp is dissolved without chemical derivatization in a melt of N-methylmorpholine-N-oxide monohydrate (NMMO). In the present work, the reactions of monosaccharides under Lyocell conditions were investigated in detail, using capillary zone electrophoresis as the analytical technique to clarify the composition of reaction mixtures and to follow the kinetics. Under Lyocell conditions, xylose and glucose undergo two competitive reactions: rapid conversion to nonreducing products, and complete isomerization involving the whole carbohydrate backbone, via ketose intermediates. Sugar acids are present in minor amounts only, as demonstrated by employing isotopically labeled material for NMR techniques.
- Adorjan, Immanuel,Sjoeberg, John,Rosenau, Thomas,Hofinger, Andreas,Kosma, Paul
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- Isolation and structural characterization of a polysaccharide LRP4-A from Lycium ruthenicum Murr.
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A complex polysaccharide, termed LRP4-A, was isolated from the fruit of Lycium ruthenicum Murr. and its structure was characterized. The crude polysaccharide LRP was obtained from the fruit of L. ruthenicum Murr. using hot water extraction followed by ethanol precipitation. The water-soluble polysaccharide LRP4-A was purified from LRP by anion-exchange chromatography and gel filtration chromatography. Its molecular weight was 1.05 × 10 5 Da. Monosaccharide composition analysis revealed that LRP4-A mainly consisted of rhamnose, arabinose, glucose, and galactose in the molar ratio of 1:7.6:0.5:8.6, with a trace of xylose. Structure of the polysaccharide LRP4-A was characterized using a series of analytical techniques, including methylation analysis, partial acid hydrolysis, IR, NMR, and ESI-MS. LRP4-A was identified to be a highly branching polysaccharide with a backbone of β-(1→6)- linked galactose partially substituted at O-3 position. The branches were composed of (1→3)-linked-Gal, (1→3)-linked-Ara, (1→5)-linked-Ara, and (1→2,4)-linked-Rha. Arabinose, galactose, and glucose were located at the termini of the branches.
- Lv, Xiaopeng,Wang, Chengjian,Cheng, Yang,Huang, Linjuan,Wang, Zhongfu
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- New chemical constituents from oryza sativa straw and their algicidal activities against blue-green algae
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Five new constituents, 5,4′-dihydroxy-7,3′-dimethoxyflavone- 4′-O-β-d-xylopyranosyl-(2a→1b)-2a-O-β-d-xylopyranosyl- (2b→1c)-2b-O-β-d-xylopyranosyl-2c-octadecanoate (1), 5,4′-dihydroxy-7,3′-dimethoxyflavone-4′-O-α-d- xylopyranosyl-(2a→1b)-2a-O-α-d-xylopyranosyl-(2b→1c) -2b-O-α-d-xylopyranosyl-(2c→1d)-2c-O-α-d-xylopyranosyl-2d- octadecanoate (2), kaempferol-3-O-α-d-xylopyranosyl-(2a→1b)-2a-O- α-d-xylopyranosyl-(2b→1c)-2b-O-α-d-xylopyranosyl-(2c→1d) -2c-O-α-d-xylopyranosyl-2d-hexadecanoate (3), methyl salicylate-2-O- α-d-xylopyranosyl-(2a→1b)-2a-O-α-d-xylopyranosyl-(2b→1c) -2b-O-α-d-xylopyranosyl-(2c→1d)-2c-O-α-d-xylopyranosyl- (2d→1e)-2d-O-α-d-xylopyranosyl-(2e→1f)-2e-O-α-d- xylopyranosyl-(2f→1g)-2f-O-α-d-xylopyranosyl-(2g→1h) -2g-O-α-d-xylopyranosyl-2h-geranilan-8′,10′-dioic acid-1′-oate (4), and oleioyl-β-d-arabinoside (5), along with eight known compounds, were isolated from a methanol extract of Oryza sativa straw. The structures of the new compounds were elucidated using one- and two-dimensional NMR spectroscopies in combination with IR, ESI/MS, and HR-ESI/FTMS. In bioassays with blue-green algae, the efficacies of the algicidal activities of the five new compounds (1-5) were evaluated at concentrations of 1, 10, and 100 mg/L. Compound 5 had the highest growth inhibition (92.6 ± 0.3%) for Microcystis aeruginosa UTEX 2388 at a concentration of 100 ppm (mg/L). Compound 5 has high potential for the ecofriendly control of weeds and algae harmful to water-logged rice.
- Ahmad, Ateeque,Kim, Seung-Hyun,Ali, Mohd,Park, Inmyoung,Kim, Jin-Seog,Kim, Eun-Hye,Lim, Ju-Jin,Kim, Seul-Ki,Chung, Ill-Min
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- The effect of microwave irradiation on Mo(VI) catalyzed transformations of reducing saccharides
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Efficient microwave-assisted Mo(VI)-catalyzed transformations of the 10 most common aldoses are described. Both pentoses and hexoses were converted to the corresponding epimers in considerably shorter reaction times. The yields were comparable, or better compared to conventional synthetic methods.
- Hricoviniova, Zuzana
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- Production of keto-pentoses: Via isomerization of aldo-pentoses catalyzed by phosphates and recovery of products by anionic extraction
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Xylulose and ribulose are rare keto-pentoses which are in high demand for the synthesis of commodities and fine chemicals. The production of keto-pentoses via isomerization of aldo-pentoses presents a carbon-efficient synthetic method. However, the isomerizations are equilibrium processes with thermodynamically limited yields of the products. In this work we examined isomerization of aldo-pentoses into keto-pentoses in the presence of NaH2PO4 + Na2HPO4 as a soluble catalyst at pH 7.5. A reaction network was proposed based on product distribution with d-(1-13C)-ribose as a substrate. Additionally, kinetics of the isomerization reactions was addressed. Selectivity for the keto-pentoses dramatically depends on the structure of the substrate. Arabinose and xylose give rise to a number of isomeric pentoses with low selectivities for the target products. Investigation of the reaction kinetics suggests that xylose and arabinose slowly isomerize into xylulose and ribulose, respectively. The latter react further significantly quicker to produce a number of isomers as subsequent products. This causes a complex mixture of products with low selectivity for the keto-pentoses. In contrast, ribose and lyxose as substrates yield ribulose and xylulose with rather high selectivities of 68-79% at 20% conversion. Ribose and lyxose quickly isomerize into ribulose and xylulose, respectively, whereas the subsequent processes are relatively slow. This results in a high selectivity for the keto-pentoses based on ribose and lyxose. Moreover, the isolation of xylulose from the reaction mixture was also studied. Xylulose can be selectively recovered after the isomerization of lyxose using anionic extraction with o-hydroxymethyl phenylboronic acid (HMPBA). After extraction, the aqueous phase containing phosphates and remaining lyxose can be recycled. After four cycles, the yield of xylulose reached 37% though only 19% can be achieved under batch conditions. Xylulose can be further recovered from the organic phase by back extraction using an acidified solution. Ribulose can also be extracted as an anionic complex with HMPBA, though ribose is co-extracted in this case and a separation of ribulose from ribose cannot be achieved. Extraction of the keto-pentoses occurs due to formation of β-xylulose-HMPBA and α-ribulose-HMPBA anionic complexes, whose molecular structures were established by NMR and MS.
- Delidovich, Irina,Gyngazova, Maria S.,Sánchez-Bastardo, Nuria,Wohland, Julia P.,Hoppe, Corinna,Drabo, Peter
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- Isolation and structural characterization of a polysaccharide FCAP1 from the fruit of Cornus officinalis
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A water-soluble polysaccharide, FCAP1, was isolated from an alkaline extract from the fruits of Cornus officinalis. Its molecular weight was 34.5 kDa. Monosaccharide composition analysis revealed that it was composed of fucose, arabinose, xylose, mannose, glucose, and galactose in a molar ratio of 0.29:0.19:1.74:1:3.30:1.10. On the basis of partial acid hydrolysis and methylation analysis, FCAP1 was shown to be a highly branched polysaccharide with a backbone of β-(1→4)-linked-glucose partially substituted at the O-6 position with xylopyranose residues. The branches were composed of (1→3)-linked-Ara, (1→4)-linked-Man, (1→4,6)-linked-Man, (1→4)-linked-Glc, and (1→2)-linked-Gal. Arabinose, fucose, and galactose were located at the terminal of the branches. The structure was further elucidated by a specific enzymatic degradation with an endo-β-(1→4)-glucanase and MALDI-TOF-MS analysis. Oligosaccharides generated from FCAP1 indicated that FCAP1 contained XXXG-type and XXG-type xyloglucan fragments.
- Yang, Liyan,Wang, Zhongfu,Huang, Linjuan
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- Antitumor and immunomodulatory activities of a water-soluble polysaccharide from Chaenomeles speciosa
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Abstract In this study, a water-soluble polysaccharide (CSP) was successfully purified from Chaenomeles speciosa by DEAE-Sepharose and Sephadex G-100 column chromatography. CSP had a weight-average molecular weight of about 6.3 × 104 Da and was composed of glucose (Glc), galactose (Gal), rhamnose (Rha) and arabinose (Ara) with a relative molar ratio of 4.6:1.3:0.8:0.5. CSP could not only inhibit the growth of S180 tumor transplanted in mice, but also increase the relative spleen index and body weight of tumor bearing mice. Moreover, concanavalin A (ConA) and lipopolysaccharide (LPS) induced splenocyte proliferation and peritoneal macrophage phagocytosis were also enhanced after CSP administration. Furthermore, CSP treatment could improve delayed type hypersensitivity (DTH) and promote the secretion of IL-2, TNF-α and IFN-γ in serum. The overall findings suggest that the antitumor effect of CSP is might be associated with its potent immunostimulatory activity.
- Xie, Xianfei,Zou, Guolin,Li, Chenghai
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- OXIDATIVE DEGRADATION OF MONOSACCHARIDES BY IRON(III) CHLORIDES WITH A NEAR-UV TO VISIBLE LIGHT UNDER AEROBIC ATMOSPHERE.
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Monosaccharides were oxidatively degraded by FeCl//3 with irradiation of a near-UV to visible light under aerobic atmosphere. D-Fructose and D-arabinose were degraded to D-erythrose in a yield of more than 80 mol%. D-Glucose and D-mannose were at first degraded to D-arabinose, which was subsequently degraded to D-erythrose, while d-ribose was directly degraded to d-erythrose and D-glyceraldehyde. The degradation processes were selective, and these reactions were shown to proceed via formation of an Fe(III)-monosaccharide complex. The kinetic data and other features of these reactions are also discussed.
- Araki,Sakuma,Shiraishi
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- Acylphloroglucinol derivatives from Decaspermum gracilentum and their antiradical and cytotoxic activities
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Two new acylphloroglucinol derivatives, 1-(hexanoyl)phloroglucinol-α-d-arabinopyranoside (1) and 1-(hexanoyl)phloroglucinol-β-d-glucopyranoside (2), along with two known ones, 1-(acetyl)phloroglucinol-β-d-glucopyranoside (3) and ethyl 2,4,6-trihydroxybenzoate (4), were isolated from the EtOAc soluble fraction of EtOH extract of Decaspermum gracilentum. The structures of the new compounds were determined by extensive spectroscopic analyses including HRESIMS, 1D and 2D NMR data. Interestingly, all of the compounds showed ABTS·+ radical scavenging activity with the IC50 values less than 10 M. Furthermore, compounds 3 and 4 displayed moderate cytotoxicity on human non-small-cell lung carcinoma cell line A549 (IC50 = 50.9 μ) and human renal carcinoma cell line 786-O (IC50 = 38.6 μ), respectively.
- Sun, Meng,Gobu, Fekadu-Roge,Pan, Dong,Li, Ya,Gao, Kun
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- Effects of polysaccharide on chicks co-infected with Bordetella avium and Avian leukosis virus
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Chicks' co-infection with immunosuppressive virus and bacteria seriously threaten the development of the poultry industry. In this study, a model was established in which chicks were injected with either subgroup B ALV (ALV-B) + Bordetella avium (B. avium), or ALV-B + B. avium + Taishan Pinus massoniana pollen polysaccharide (TPPPS), or B. avium only, or B. avium + TPPPS. The data showed that the group injected with ALV-B and B. avium exhibited significant inhibition of the immune function and therefore increased pathogenicity compared with the group injected with B. avium-only. Application of TPPPS effectively alleviated immunosuppression, and body weights increased sharply in the TPPPS groups compared with non-TPPPS groups. To some extent, TPPPS may reduce the proliferation of ALV-B. These results suggest that Pinus pollen polysaccharides are beneficial treating co-infections with immunosuppressive virus and bacteria and therefore have potential for development into safe and effective immunoregulator.
- Guo, Fanxia,Xue, Cong,Wu, Cun,Zhao, Xue,Qu, Tinghe,He, Xiaohua,Guo, Zhongkun,Zhu, Ruiliang
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- In vitro and in vivo antioxidant activity of a water-soluble polysaccharide from dendrobium denneanum
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The water-soluble crude polysaccharide (DDP) obtained from the aqueous extracts of the stem of Dendrobium denneanum through hot water extraction followed by ethanol precipitation, was found to have an average molecular weight (Mw) of about 484.7 kDa. Monosaccharide analysis revealed that DDP was composed of arabinose, xylose, mannose, glucose and galactose in a molar ratio of 1.00:2.66:8.92:34.20:10.16. The investigation of antioxidant activity both in vitro and in vivo showed that DDP is a potential antioxidant.
- Luo, Aoxue,Ge, Zhongfu,Fan, Yijun,Luo, Aoshuang,Chun, Ze,Jin He, Xing
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- Chemical Components in Hedera rhombea Leaves and Their Cytotoxicity
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Two novel triterpene glycosides (1 and 2), 17 known triterpene glycosides (3-19), two known flavonoid glycosides (20 and 21), and two known norsesquiterpene glucosides (22 and 23) were isolated from Hedera rhombea (Araliaceae) leaves. The structures of 1
- Mimaki, Yoshihiro,Miyake, Katsunori,Oguro, Airi,Shimomura, Tatsuya,Yokogawa, Shohei,Yokosuka, Akihito
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p. 175 - 181
(2022/02/05)
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- Comparative study on the structural characterization and α-glucosidase inhibitory activity of polysaccharide fractions extracted from Sargassum fusiforme at different pH conditions
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Sargassum fusiforme polysaccharides (SFPs), including SFP-3-40, SFP-3-60, SFP-3-80, SFP-7-40, SFP-7-60, SFP-7-80, SFP-10-40, SFP-10-60, and SFP-10-80, were extracted at different pH (3, 7, and 10), and then precipitated with graded precipitation of 40%, 60% and 80% (v/v) ethanol solution, respectively. Their physicochemical properties and α-glucosidase inhibitory activity were determined. Results showed that SFPs significantly differed in the contents of total sugar, protein, uronic acid, sulfate, the zeta potential, and molecular weight distribution. SFPs, including SFP-10-40, SFP-10-60, and SFP-10-80, had bigger absolute zeta potential value and higher respective average molecular weight in the same ethanol concentration precipitate. All samples were mainly composed of fucose, glucuronic acid, and mannose with different molar ratios. The extraction pH and precipitation ethanol solution concentration caused little changes in functional groups, but significantly altered surface morphology of SFPs. Congo red test revealed that all polysaccharides were not helical polysaccharides. Rheological measurements indicated that SFPs were pseudoplastic fluids and showed elastic behavior of the gel. Except SFP-3-40 and SFP-3-60, all other samples had a stronger α-glucosidase inhibitory activity than that of acarbose. The inhibition type of SFPs against α-glucosidase varied owing to different extraction pH and precipitation ethyl concentration. This study shows that extraction pH can significantly affect the structure and hypoglycemic activity of SFPs and provide a data support for the scientific use of Sargassum fusiforme in industrial production.
- Jia, Rui-Bo,Li, Zhao-Rong,Lin, Lianzhu,Luo, Donghui,Ou, Zhi-Rong,Zhao, Mouming,Zheng, Qianwen
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p. 602 - 610
(2021/11/30)
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- Photocatalytic hydrogenation of nitrobenzene to aniline over titanium(iv) oxide using various saccharides instead of hydrogen gas
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Bare TiO2 photocatalyst almost quantitatively converted nitrobenzene to aniline with various saccharides without the use of hydrogen gas. Although aniline was formed when any saccharide was used, the use of disaccharides (lactose, maltose, and sucrose) de
- Aono, Yushiro,Ikeuchi, Kazuma,Imamura, Kazuya,Onda, Ayumu,Oto, Takahiro,Sakamoto, Yuki
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p. 32300 - 32304
(2021/12/02)
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- Chemical composition and biological activity of salicornia fruticosa L.
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Plants have been used as a source of traditional medicine to treat many diseases and conditions for many years. They considered as excellent source of phytochemicals which showed antioxidant and anticancer activities. The aim of the present study is to investigate the chemical composition and to determine the anticancer activity of Salicornia fruticosa (Chenopodiaceae) methanolic extract. S. fruticosa proved to be a source of isorhamnetin and its glycosides and showed anticancer activities. Seven major flavonoids were isolated and identified from the cytotoxic methanolic extract. The isolated compounds were identified, as quercetin 3',4'-dimethyl ether (1), isorhamnetin (2), isorhamnetin 3-O-rhamnoside (3), isorhamnetin 3-O-glucoside (4), isorhamnetin 3-O-rutinoside (5), isorhamnetin 3-O-neohesperidoside (6), isorhamnetin 3-O-rhamnosyl(1-2)arabinoside (7), by chromatographic analysis, chemical and spectroscopic tools (acid hydrolysis, UV, 1H and 13C NMR). Compounds 1 and 3-7 were isolated for the first time from the plant under investigation. The evaluation of cytotoxic activity of the methanolic extract against HCT-116, HepG2, A549 and MCF-7 human cancer cells, by MTT assay, revealed the higher potency of S. Fruticosa extract with IC50 [2.6. 10.9, 37.9, 5.4 (mg/ml)] respectively, comparable to that of doxorubicin. The obtained results suggested that the investigated plant could be used for future development of naturally occurring anticancer agent. Subclinical and clinical trials on polar fractions of S. fruticosa are mandatory to pave the way for its use in treatment of cancer diseases (HCT-116, HepG2, A549 and MCF-7).
- Abdel Elatif,Shabana,Ibrahim,Mansour,Awad,Sharaf
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p. 1713 - 1721
(2020/09/01)
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- Insecticidal and α-glucosidase inhibitory activities of chemical constituents from Viburnum fordiae Hance
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The ethanolic extract of the stems of Viburnum fordiae Hance showed insecticidal and α-glucosidase inhibitory activities and then was fractionated by bioactivity-guided fractionation to obtain a rare C13-norisoprenoid (1), together with a new phenolic glycoside (2), and seven known compounds, alangionoside C (3), pisumionoside (4), koaburaside (5), 3,5-dimethoxy-benzyl alcohol 4-O-β-d-glucopyranoside (6), 3,4,5-trimethoxybenzyl-β-d-glucopyranoside (7), arbutin (8), and salidroside (9). The previously undescribed compounds were elucidated as (3R,9R)-3-hydroxy-7,8-didehydro-β-ionyl 9-O-α-d-arabinopyranosyl-(1→6)-β-d-glucopyranoside (1) and 2-(4-O-β-d-glucopyranosyl)syringylpropane-1,3-diol (2) by spectroscopic data (1H and 13C NMR, HSQC, HMBC, 1H-1H COSY, HSQC-TOCSY, HRESIMS, IR and ORD) and chemical methods. Compound 1 showed potent insecticidal effect against Mythimna separata with LD50 value of 140 μg g?1. Compounds 2, 5, 6, 8 and 9 showed varying α-glucosidase inhibitory activity with IC50 values ranging from 148.2 to 230.9 μM.
- Shao, Jian-Hua,Chen, Jia,Zhao, Chun-Chao,Shen, Jie,Liu, Wen-Yan,Gu, Wen-Yan,Li, Ke-Huan
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p. 2662 - 2667
(2018/05/03)
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- Visible-light-driven selective oxidation of glucose in water with H-ZSM-5 zeolite supported biomimetic photocatalyst
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A new iron tetra(2,3-bis(butylthio)maleonitrile)porphyrazine (FePz(SBu)8)has been synthesized, then it was loaded on H-ZSM-5 zeolite to obtain a supported biomimetic photocatalyst H-ZSM-5/FePz(SBu)8. Using H2O2 as oxidant, the photocatalytic selective oxidation of glucose in water under visible light (λ ≥ 420 nm)irradiation was carried out in presence of H-ZSM-5/FePz(SBu)8. Under such conditions, the glucose can be efficiently converted into value-added chemicals such as glucaric acid, gluconic acid, arabinose, glycerol and formic acid. More importantly, in comparison with pure FePz(SBu)8 and pure H-ZSM-5 zeolite, the H-ZSM-5/FePz(SBu)8 exhibited a higher photocatalytic activity for glucose oxidation and the formation of glucaric acid was observed only when H-ZSM-5/FePz(SBu)8 was used, deriving from the synergistic effect between FePz(SBu)8 and H-ZSM-5 zeolite. Some reaction parameters of glucose oxidation catalyzed by the H-ZSM-5/FePz(SBu)8 were discussed, such as loading amount of FePz(SBu)8, H2O2:glucose ratio, glucose concentration, and so on. It was demonstrated that the Soret-band of FePz(SBu)8 contributed more to the visible light photocatalytic activity than the Q-band during the photocatalytic process. The stability of H-ZSM-5/FePz(SBu)8 during the photocatalytic process was further evaluated by the reusability test. In addition, the generation of reactive oxygen species was determined by electron spin resonance (ESR)technology and scavenger experiments. A possible reaction pathway of glucose oxidation was also discussed.
- Chen, Rui,Yang, Changjun,Zhang, Quanquan,Zhang, Bingguang,Deng, Kejian
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p. 297 - 305
(2019/05/24)
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- Successive C1-C2 bond cleavage: The mechanism of vanadium(v)-catalyzed aerobic oxidation of d-glucose to formic acid in aqueous solution
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Vanadium(v)-catalyzed aerobic oxidation in aqueous solution shows high selectivity in the field of C-C bond cleavage of carbohydrates for chemicals with less carbon atoms. However, the pathway of C-C bond cleavage from carbohydrates and the conversion mechanism are unclear. In this work, we studied the pathway and the mechanism of d-glucose oxidation to formic acid (FA) in NaVO3-H2SO4 aqueous solution using isotope-labeled glucoses as substrates. d-Glucose is first transformed to FA and d-arabinose via C1-C2 bond cleavage. d-Arabinose undergoes similar C1-C2 bond cleavage to form FA and the corresponding d-erythrose, which can be further degraded by C1-C2 bond cleavage. Dimerization and aldol condensation between carbohydrates can also proceed to make the reaction a much more complicated mixture. However, the fundamental reaction, C1-C2 bond cleavage, can drive all the intermediates to form the common product FA. Based on the detected intermediates, isotope-labelling experiments, the kinetic isotope effect study and kinetic analysis, this mechanism is proposed. d-Glucose first reacts with a vanadium(v) species to form a five-membered-ring complex. Then, electron transfer occurs and the C1-C2 bond weakens, followed by C1-C2 bond cleavage (with no C-H bond cleavage), to generate the H3COO-vanadium(iv) complex and d-arabinose. FA is generated from H3COO that is oxidized by another vanadium(v) species. The reduced vanadium species is oxidized by O2 to regenerate to its oxidation state. This finding will provide a deeper insight into the process of C-C bond cleavage of carbohydrates for chemical synthesis and provide guidance for screening and synthesizing new highly-efficient catalyst systems for FA production.
- Niu, Muge,Hou, Yucui,Wu, Weize,Ren, Shuhang,Yang, Ru
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p. 17942 - 17951
(2018/07/14)
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- Effect of polyphenols from Vicia faba L on lipase activity and melanogenesis
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Two new flavonoid glycosides, kaempferol 3-O-α-L-rhamnopyranosyl (1→6) (3′′-acetyl)-β-D-galactopyranoside 1 and kaempferol 3-O-α-L-arabinopyranosyl-5-O-α-L-rhamnopyranoside 2, along with six known ones 3–8 were isolated from the flowers of Vicia faba L. (Fabaceae). Methanol extract and the isolated compounds were tested against lipase and melanogenesis inhibition activities and resulted in that compound 2 showed 53 and 77% lipase inhibition activity in concentrations of 400 and 800?μg/mL, respectively. For melanogenesis, compounds 2, 3 and 4 exhibited potent melanogenesis inhibition activity where the melanin content in melanoma cells was decreased to be about 57.5, 56 and 61%, respectively, with no obvious melanocytotoxicity. The rest of compounds showed weak to moderate activity. The results of melanogenesis inhibition activity of this study suggested the potential use of Vicia faba flowers as a skin-whitening agent and reveal the flowers to be a rich source of important phytochemicals with antilipase and melanogenesis inhibitory activity.
- Allam, Ahmed E.,Nafady, Alaa M.,Nakagawa, Toshinori,Takemoto, Naomichi,Shimizu, Kuniyoshi
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p. 1920 - 1925
(2017/10/06)
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- Preparation method of high-concentration D-arabinose
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The invention provides a preparation method of high-concentration D-arabinose. The method comprises the following steps: adding a catalyst into sodium gluconate, feeding hydrogen peroxide and sodium gluconate in a flowing manner, oxidizing, preparing D-arabinose liquid, and the like, wherein the feeding rate of the sodium gluconate is determined according to an oxygen content in reaction tail gas. By adopting the method, high-concentration conversion from the sodium gluconate to D-arabinose is realized, and the concentration of the obtained D-arabinose can reach 35 to 80 percent of the total mass of a dry matter, so that the subsequent extraction and crystallizing step is simple; and the production cost of the D-arabinose is reduced.
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Paragraph 0034-0038
(2017/06/13)
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- New minor spirostanol glycosides from Helleborus thibetanus
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Phytochemical reinvestigation of the dried roots and rhizomes of Helleborus thibetanus afforded four new minor spirostanol glycosides (1–4) and four known spirostanol glycosides (5–8). Their structures were determined on the basis of spectroscopic analyse
- Zhang, Hui,Su, Yan-Fang,Yang, Feng-Ying,Gao, Xiu-Mei
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p. 925 - 931
(2017/01/28)
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- Unusual Cytotoxic Steroidal Saponins from the Gorgonian Astrogorgia dumbea
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Three steroidal saponins, including astrogorgiosides A (1) and B (2) bearing acetamido-glucose moieties, and astrogorgioside C (3) with a 19-nor and bearing an aromatized B ring steroid aglycone, together with a known major saponin dimorphoside A (4), were obtained from the gorgonian Astrogorgia dumbea collected near Dongshan Island in East China Sea. Structures of these compounds were elucidated by in-depth spectral and chemical methods, including 2D-NMR, HR-ESI-MS spectra, and acidic hydrolysis. For the first time, acetamido-glucose moiety is being reported from a gorgonian. The B-ring aromatized steroid aglycone of compound 3 is also rare in marine natural products. Compounds 1-3 exhibited moderate cytotoxic activity with IC50 values of 26.8-45.6 μM against human tumor cells Bel-7402 and K562.
- Lu, Ya-Nan,Cui, Ping,Tian, Xiao-Qing,Lou, Li-Guang,Fan, Cheng-Qi
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p. 882 - 887
(2016/07/11)
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- Molecular structure, chemical properties and biological activities of Pinto bean pod polysaccharide
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Pinto bean pod polysaccharide (PBPP) was successfully extracted with yield of 38.5 g/100 g and the PBPP gave total carbohydrate and uronic acid contents of 286.2 mg maltose equivalent/g and 374.3 mg Gal/g, respectively. The Mw of PBPP was 270.6 kDa with intrinsic viscosity of 0.262 dm3/g, which composed of mannose (2.5%), galacturonic acid (15.0%), rhamnose (4.0%), glucose (9.0%), galactose (62.2%), xylose (2.9%) and arabinose (4.3%) with trace amount of ribose and fucose. The result suggested that PBPP has a spherical conformation with a highly branched structure. Fourier Transform Infrared analysis showed that PBPP has a similar structure as commercial pectin with an esterification degree of 59.9%, whereas scanning electron microscopy study showed that the crude polysaccharide formed a thin layer of film that was made of multiple micro strands of fibre. PBPP exhibited substantial free radical scavenging activity (7.7%), metal reducing capability (2.04 mmol/dm3) and α-amylase inhibitory activity (97.6%) at a total amount of 1 mg. PBPP also exhibited high water- and oil-holding capacities (3.6 g/g and 2.8 g/g, respectively). At a low concentration, PBPP exhibited emulsifying activity of 39.6% with stability of 38.6%. Apart from that, PBPP was able to show thickening capability at low concentration (0.005 kg/dm3).
- Kamarudin, Fazlina,Gan, Chee-Yuen
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p. 280 - 287
(2016/04/19)
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- A selective oxidation of glucose method of preparing high-value added chemical
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The invention provides a novel method for preparing high value-added chemicals by selectively photo-catalytically oxidizing glucose. The method is characterized in that glucose is directly converted into arabinose and erythrose by using rutile TiO2 loaded with a metallic promoter as a photocatalyst by a photo-catalytic dehydrogenating and oxidizing way under room temperature. The prepared arabinose and erythrose prepared by the method have the yields respectively reaching more than 45mol% and 26mol%; the reaction conditions are mild; no acid, alkali and organic solvents are added; and high-temperature and high-pressure conditions are not needed.
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Paragraph 0052; 0053; 0054
(2017/05/27)
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- Arabinogalactan hydrolysis and hydrolytic hydrogenation using functionalized carbon materials
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Hydrolysis of the hemicellulose arabinogalactan was studied in this work over several functionalized carbon materials, which were specifically treated to increase their acidities. Hydrolytic hydrogenation of arabinogalactan was investigated using the same materials in a mechanical mixture with ruthenium supported on active carbon. Application of these mixtures resulted in formation of polyols, suppressing simultaneously the generation of side products hydroxymethylfurfural (HMF) and furfural. Formation of high molecular weight compounds (aggregates of sugars and humins) was still quite substantial with a mechanical mixture of Ru/C and a carbon material prepared from sucrose by activation with zinc chloride to increase porosity. Post-treatment of this carbonaceous material with sulphuric acid significantly influenced kinetics of high molecular weight products formation resulting also in elevation of sugar alcohols yields.
- Murzin, D.Yu.,Murzina,Tokarev,Shcherban,W?rn?,Salmi
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p. 169 - 176
(2015/02/19)
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- Characterization and biological activities of a novel polysaccharide isolated from raspberry (Rubus idaeus L.) fruits
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Abstract A water-soluble polysaccharide namely RCP-II from raspberry fruits was obtained by complex enzyme method followed by successive purification using macroporous resin D4020 and Sephadex G-100 columns. RCP-II was an acidic heteropolysaccharide and the characteristic structure of polysaccharide was determined. The carbohydrate of RCP-II was composed with galacturonic acid, rhamnose, arabinose, xylose, glucose and galactose in a molar ratio of 1.00:0.55:1.19:0.52:0.44:1.90 and the average molecular weight was estimated to be 4013 Da, based on dextran standards. RCP-II presented high scavenging activity toward DPPH?, HO?, O2?- in a concentration-dependent manner. The determination of the inhibitory activity on protein glycation showed that in 14 days of incubation the inhibitory ability of RCP-II was more effective on the development of non-enzymatic glycation reaction at early phase than that at the following two phases.
- Yu, Zeyuan,Liu, Lu,Xu, Yaqin,Wang, Libo,Teng, Xin,Li, Xingguo,Dai, Jing
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p. 180 - 186
(2015/07/15)
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- Bioactive chemical constituents from the leaves of Lantana Camara L
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New compound 1 (Gautin), a new flavone glycoside with a unique aglycone moiety, with five flavone, acacetin-7-O-β-D-rutinoside 2, Tricin 3, Hispidulin 4, 3,5,7,8-tetra hydroxyl-6,3′-dimethoxy flavones 5 and Pectolinarigenin 10 and also six terpenoids (25S)-spirostan-5-ene-3β-21-diol-3-O-α-L-rhamnopyranosyl-(1,2)-[α-L-rhamnopyranosyl-(1,4)]-β-D-glucopyranoside 6, Ursolic acid 7, Lantanilic acid 8, Icterogenin 9, Bemlonic acid 11 and Betulinic acid 12 have been isolated from the dried leaves of Lantana camara L. The structure of compound 1 (Gautin) assessed by spectroscopial analysis as 5,7-dihydroxy-6,3′,4′-trimethoxy isoflavone-5-O-α-L-rhamnopyrano-syl-7-O-β-D-arabinopyranosyl-(l→4)-O-β-D-xylopyranoside. Three flavones 1, 2, 5 and one terpenoid 11 are isolated for the first time from this plant.
- Patil, Gautam,Khare, Anand Bhushan,Huang, Keh-Feng,Lin, Fuh-Mei
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p. 691 - 697
(2015/05/27)
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- Stigmasterol-3-O-β-D-arabinopyranosyl(1→4)-O-β-D- glucopyranoside from the roots of Limonia crenulata (Roxb.)
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The methanol soluble part of the concentrated ethanolic extract of defatted roots of Limonia crenulata (Roxb) when worked up phytochemically yielded a saponin which on various chemical reactions and spectral analysis was identified as; Stigmasterol-3-O-β- D-arabinopyranosyl (1→4)-O-β-D- glucopyranoside.
- Shrivastava, Archana,Parihar, Sangeeta,Jadhav, Raina
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p. 171 - 175
(2013/07/19)
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- Yarrowia lipolytica dehydrogenase/reductase: An enzyme tolerant for lipophilic compounds and carbohydrate substrates
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Yarrowia lipolytica short chain dehydrogenase/reductase (YlSDR) was expressed in Escherichia coli, purified and characterized in vitro. The substrate scope for YlSDR mediated oxidation was investigated with alcohols and unprotected carbohydrates spectrophotometrically, revealing a preference for secondary compared to primary alcohols. In reduction direction, YlSDR was highly active on ribulose and fructose, suggesting that the enzyme is a mannitol-2-dehydrogenase. In order to explore substrate tolerance especially for space-demanding, lipophilic protecting groups, 5-O-trityl-d-ribitol and 5-O-trityl-α,β-d-ribose were investigated as substrates: YlSDR oxidized 5-O-trityl-d-ribitol and 5-O-trityl-α,β-d-ribose and reduced the latter at the expense of NADP(H).
- Napora, Kamila,Wrodnigg, Tanja M.,Kosmus, Patrick,Thonhofer, Martin,Robins, Karen,Winkler, Margit
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p. 3393 - 3395
(2013/06/27)
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- Hydrolysis of konjac glucomannan by Trichoderma reesei mannanase and endoglucanases Cel7B and Cel5A for the production of glucomannooligosaccharides
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In this paper we describe the enzymatic hydrolysis of konjac glucomannan for the production of glucomannooligosaccharides using purified Trichoderma reesei mannanase, endoglucanases EGI (Tr Cel7b) and EGII (Tr Cel5a). Hydrolysis with each of the three enzymes produced a different pattern of oligosaccharides. Mannanase was the most selective of the three enzymes in the hydrolysis of konjac mannan and over 99% of the formed oligosaccharides had mannose as their reducing end pyranosyl unit. Tr Cel5A hydrolysate shared similarities with mannanase and Tr Cel7B hydrolysates and the enzyme had the lowest substrate specificity of the studied enzymes. The hydrolysate of Tr Cel7B contained a series of oligosaccharides with non-reducing end mannose (M) and reducing end glucose (G) (MG, MMG, MMMG, and MMMMG). These oligosaccharides were isolated from the hydrolysate by size exclusion chromatography in relatively high purity (86-95%) and total yield (23% of substrate). The isolated oligosaccharides were characterized using acid hydrolysis and HPAEC-PAD (carbohydrate composition), HPLC-RI and HPAEC-MS (to determine the DP of purified oligosaccharides), enzymatic hydrolysis (determination of non-reducing end carbohydrate) and NMR (both 1D and 2D, to verify structure and purity of purified compounds). Hydrolysis of konjac mannan with a specific enzyme, such as T. reesei Cel7B or mannanase, followed by fractionation with SEC offers the possibility to produce glucomannooligosaccharides with defined structure. The isolated oligosaccharides can be utilised as analytical standards, for determination of bioactivity of oligosaccharides with defined structure or as substrates for defining substrate specificity of novel carbohydrate hydrolyzing enzymes.
- Mikkelson, Atte,Maaheimo, Hannu,Hakala, Terhi K.
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- New tetraterpene glycosides from the fruits of Lycium chinense
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Two new compounds lyciumtetraterpenic hexaarabinoside (1) and tetraterpenyl hexaarabinoside (2), along with two known compounds, were isolated from the methanol extract of the fruits of Lycium chinense Miller (Solanaceae), and their structures have been e
- Chung, Ill-Min,Ali, Mohd,Kim, Eun-Hye,Ahmad, Ateeque
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p. 136 - 144
(2013/04/23)
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- New triterpenoids from the leaves of Cyclocarya paliurus
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Six new triterpenoids including four new secodammarane triterpenoid glycosides (14), an epoxydammarane triterpenoid glycoside (5), and a new secodammarane triterpenoid (6) were isolated from the ethanolic extract of the leaves of Cyclocarya paliurus. The structures of these compounds were elucidated by spectroscopic analysis methods. Compounds 16 were evaluated for their inhibitory activities against α-glucosidase, lipase, DPP-IV, and aldose reductase. Georg Thieme Verlag KG Stuttgart - New York.
- Li, Shuai,Cui, Baosong,Liu, Quan,Tang, Li,Yang, Yongchun,Jin, Xiangju,Shen, Zhufang
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experimental part
p. 290 - 296
(2012/06/18)
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- A study on chemical constituents and sugars extraction from spent coffee grounds
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Spent coffee grounds (SCG), the residual materials obtained during the processing of raw coffee powder to prepare instant coffee, are the main coffee industry residues. In the present work, this material was chemically characterized and subsequently submitted to a dilute acid hydrolysis aiming to recover the hemicellulose sugars. Reactions were performed according to experimental designs to verify the effects of the variables H2SO 4 concentration, liquid-to-solid ratio, temperature, and reaction time, on the efficiency of hydrolysis. SCG was found to be rich in sugars (45.3%, w/w), among of which hemicellulose (constituted by mannose, galactose, and arabinose) and cellulose (glucose homopolymer) correspond to 36.7% (w/w) and 8.6% (w/w), respectively. Optimal conditions for hemicellulose sugars extraction consisted in using 100 mg acid/g dry matter, 10 g liquid/g solid, at 163 °C for 45 min. Under these conditions, hydrolysis efficiencies of 100%, 77.4%, and 89.5% may be achieved for galactan, mannan, and arabinan, respectively, corresponding to a hemicellulose hydrolysis efficiency of 87.4%.
- Mussatto, Solange I.,Carneiro, Livia M.,Silva, Jo?o P.A.,Roberto, Inês C.,Teixeira, José A.
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experimental part
p. 368 - 374
(2011/06/22)
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- HYBRID COMPOUNDS BASED ON POLYOL(S) AND AT LEAST ONE OTHER MOLECULAR ENTITY, POLYMERIC OR NON-POLYMERIC, IN PARTICULAR OF THE POLYORGANOSILOXANE TYPE, PROCESS FOR THE PREPARATION THEREOF, AND APPLICATIONS THEREOF
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The invention relates to novel hybrid compounds comprising at least one polyon entity (Po)—for example oligomer or polymer—in which at least one of the hydroxyl functions of Po is substituted by at least one entity A that can be of a variable nature, for example polymer (e.g. polyorganosiloxane-POS), hydrocarbonated or mineral. The bond Ro between the entity Po and the entity A is obtained by means of “click chemistry” and corresponds to formula (II.1) or (II.2), Z representing —CH— or —N—. A is an entity selected from the group comprising the various polyols of Po, polyorganosiloxanes (POS), polyalkylene glycols, polyamides, polyesters, polystyrenes, alkyls, alkenyls, alkynyls, aryls, and combinations thereof, in addition to mineral materials such as silica and the combinations thereof. Said hybrid components can be used as emulsifiers, especially for cosmetics.
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- Antioxidant activities of different fractions of polysaccharide purified from pulp tissue of litchi (Litchi chinensis Sonn.)
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Three fractions of water-soluble polysaccharide fractions, coded as LFP1, LFP2 and LFP3, were isolated and purified from litchi pulp by DEAE-52 cellulose anion-exchange column and Sephadex G-100 gel-permeation column. Their chemical and physical characteristics were determined by chemical methods, gas chromatography, IR spectrophotometer and gel-permeation chromatography (GPC) with a model 410 refractive index detector. Antioxidant activities of these fractions were investigated using various in vitro assay systems. Results indicated that LFP1 was composed of arabinose, ribose, galactose and glucose, while LFP2 comprised arabinose, rhamnose and glucose. LFP3 was a heteropolysaccharide bounded with protein (2.6%) and composed of arabinose, rhamnose, galactose and glucose. The molecular weights of LFP1, LFP2 and LFP3 were 11.6 × 104, 3.1 × 104 and 2.9 × 104 Da, respectively. LFP3 showed the highest antioxidant activities among the three fractions of polysaccharides, and could be explored as a novel potential antioxidant.
- Kong, Fan-Li,Zhang, Ming-Wei,Kuang, Rui-Bin,Yu, Shu-Juan,Chi, Jian-Wei,Wei, Zhen-Cheng
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experimental part
p. 612 - 616
(2011/11/12)
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- Three new aromatic glycosides from the ripe fruit of cherry tomato
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Three new aromatic glycosides were isolated from the ripe fruit of cherry tomato [Lycopersicon esculentum var. cerasiforme (Dunal) Alef. (Solanaceae)] along with six known aromatic glycosides and one known steroidal alkaloid glycoside. Their chemical structures were determined on the basis of spectroscopic data as well as chemical evidence.
- Ono, Masateru,Shiono, Yuki,Tanaka, Takayuki,Masuoka, Chikako,Yasuda, Shin,Ikeda, Tsuyoshi,Okawa, Masafumi,Kinjo, Junei,Yoshimitsu, Hitoshi,Nohara, Toshihiro
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experimental part
p. 500 - 505
(2011/11/29)
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