2280-44-6Relevant articles and documents
Dipeptidyl peptidase-IV inhibitory activity of dimeric dihydrochalcone glycosides from flowers of Helichrysum arenarium
Morikawa, Toshio,Ninomiya, Kiyofumi,Akaki, Junji,Kakihara, Namiko,Kuramoto, Hiroyuki,Matsumoto, Yurie,Hayakawa, Takao,Muraoka, Osamu,Wang, Li-Bo,Wu, Li-Jun,Nakamura, Seikou,Yoshikawa, Masayuki,Matsuda, Hisashi
, p. 494 - 506 (2015)
A methanol extract of everlasting flowers of Helichrysum arenarium L. Moench (Asteraceae) was found to inhibit the increase in blood glucose elevation in sucrose-loaded mice at 500 mg/kg p.o. The methanol extract also inhibited the enzymatic activity against dipeptidyl peptidase-IV (DPP-IV, IC50 = 41.2 μg/ml), but did not show intestinal α-glucosidase inhibitory activities. From the extract, three new dimeric dihydrochalcone glycosides, arenariumosides V-VII (2-4), were isolated, and the stereostructures were elucidated based on their spectroscopic properties and chemical evidence. Of the constituents, several flavonoid constituents, including 2-4, were isolated, and these isolated constituents were investigated for their DPP-IV inhibitory effects. Among them, chalconaringenin 2′-O-β-D-glucopyranoside (16, IC50 = 23.1 μM) and aureusidin 6-O-β-D-glucopyranoside (35, 24.3 μM) showed relatively strong inhibitory activities.
A new ursane-type triterpenoid glycoside from Centella asiatica leaves modulates the production of nitric oxide and secretion of TNF-α in activated RAW 264.7 cells
Nhiem, Nguyen Xuan,Tai, Bui Huu,Quang, Tran Hong,Kiem, Phan Van,Minh, Chau Van,Nam, Nguyen Hoai,Kim, Jun-Ho,Im, Lee-Rang,Lee, Young-Mi,Kim, Young Ho
, p. 1777 - 1781 (2011)
One new ursane-type triterpenoid glycoside, asiaticoside G (1), five triterpenoids, asiaticoside (2), asiaticoside F (3), asiatic acid (4), quadranoside IV (5), and 2α,3β,6β-trihydroxyolean-12-en-28-oic acid 28-O-[α-l-rhamnopyranosyl-(1→4)-β-d-glucopyranosyl- (1→6)-β-d-glucopyranosyl] ester (6), and four flavonoids, kaempferol (7), quercetin (8), astragalin (9), and isoquercetin (10) were isolated from the leaves of Centella asiatica. Their chemical structures were elucidated by mass, 1D- and 2D-nuclear magnetic resonance (NMR) spectroscopy. The structure of new compound 1 was determined to be 2α,3β,23,30-tetrahydroxyurs-12-en-28- oic acid 28-O-[α-l-rhamnopyranosyl-(1→4)-β-d-glucopyranosyl- (1→6)-β-d-glucopyranosyl] ester. The anti-inflammatory activities of the isolated compounds were investigated on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Asiaticoside G (1) potently inhibited the production of nitric oxide and tumor necrosis factor-α with inhibition rates of 77.3% and 69.0%, respectively, at the concentration of 100 μM.
Reductive splitting of cellulose in the ionic liquid 1-butyl-3-methylimidazolium chloride
Ignatyev, Igor A.,Doorslaer, Charlie Van,Mertens, Pascal G. N.,Binnemans, Koen,De Vos, Dirk E.
, p. 91 - 96 (2010)
The depolymerization of cellulose is carried out in the ionic liquid 1-butyl-3-methylimidazolium chloride in the presence of hydrogen gas. First, the ketal 1,1-diethoxycyclohexane and cel-lobiose were used as model substrates. For the depolymerization of cellulose itself, the combination of a heterogeneous metal catalyst and a homogeneous ruthenium catalyst proved effective. One of the possible roles of the ruthenium compound is to enhance the transfer of hydrogen to the metallic surface. The cellulose is fully converted under relatively mild conditions, with sorbitol as the dominant product in 51-74% yield.
Phenylbutanoids and stilbene derivatives of Rheum maximowiczii
Shikishima, Yasuhiro,Takaishi, Yoshihisa,Honda, Gisho,Ito, Michiho,Takeda, Yoshio,Kodzhimatov, Olimjon K,Ashurmetov, Ozodbek
, p. 377 - 381 (2001)
The methanol extract of the dried roots of Rheum maximowiczii afforded four phenylbutanoid and two stilbene derivatives. Their structures were established on the basis of chemical and spectroscopic studies.
New direct production of gluconic acid from polysaccharides using a bifunctional catalyst in hot water
Onda, Ayumu,Ochi, Takafumi,Yanagisawa, Kazumichi
, p. 421 - 425 (2011)
Gluconic acid was produced from polysaccharides, such as starch and cellobiose, in water media at 393 K under air by a one-pot process using a bifunctional sulfonated activated-carbon supported platinum (Pt/AC-SO 3H) catalyst. Pt/AC-SO3H was prepared by the impregnation of platinum on activated-carbon (AC) and the sulfonation of the prepared Pt/AC. It was highly water-tolerant under hot aqueous solutions even including organic acids.
Which controls the depolymerization of cellulose in ionic liquids: The solid acid catalyst or cellulose?
Rinaldi, Roberto,Meine, Niklas,vom Stein, Julia,Palkovits, Regina,Schüth, Ferdi
, p. 266 - 276 (2010)
Cellulose is a renewable and widely available feedstock. It is a biopolymer that is typically found in wood, straw, grass, municipal solid waste, and crop residues. Its use as raw material for biofuel production opens up the possibility of sustainable biorefinery schemes that do not compete with food supply. Tapping into this feedstock for the production of biofuels and chemicals requires-as the first-step-its depolymerization or its hydrolysis into intermediates that are more susceptible to chemical and/or biological transformations. We have shown earlier that solid acids selectively catalyze the depolymerization of cellulose solubilized in 1-butyl-3-methylimidazolium chloride (BMIMCl) at 100°C. Here, we address the factors responsible for the control of this reaction. Both cellulose and solid acid catalysts have distinct and important roles in the process. Describing the depolymerization of cellulose by the equivalent number of scissions occurring in the cellulosic chains allows a direct correlation between the product yields and the extent of the polymer breakdown. The effect of the acid strength on the depolymerization of cellulose is discussed in detail. Practical aspects of the reaction, concerning the homogeneous nature of the catalysis in spite of the use of a solid acid catalyst, are thoroughly addressed. The effect of impurities present in the imidazolium-based ionic liquids on the reaction performance, the suitability of different ionic liquids as solvents, and the recyclability of Amberlyst 15DRY and BMIMCl are also presented.
Isatindigodiphindoside, an alkaloid glycoside with a new diphenylpropylindole skeleton from the root of Isatis indigotica
Meng, Ling-Jie,Guo, Qing-Lan,Zhu, Cheng-Gen,Xu, Cheng-Bo,Shi, Jian-Gong
, p. 119 - 122 (2018)
A novel indole alkaloid glycoside with an unprecedented 2-(diphenylpropyl)indole skeleton, isatindigodiphindoside (1), was isolated from an aqueous extract of the roots of Isatis indigotica. The structure was determined by extensive spectroscopic studies, especially by 2D NMR data analysis combined with enzymatic hydrolysis and ECD calculations. Plausible biosynthetic pathways of compound 1 are also discussed.
Tetra-aryl cyclobutane and stilbenes from the rhizomes of Rheum undulatum and their α-glucosidase inhibitory activity: Biological evaluation, kinetic analysis, and molecular docking simulation
Choi, Jae Sue,Ha, Manh Tuan,Kim, Chung Sub,Kim, Jeong Ah,Kim, Minji,Min, Byung Sun,Park, Se-Eun,Woo, Mi Hee
, (2020)
One achiral tetra-aryl cyclobutane [rheundulin A (1)] and three stilbene glycosides [rheundulins B–D (2–4)] were isolated from the methanol extract of Rheum undulatum L., along with eight known compounds (5–12). Structural determination of the new compounds (1–4) was accomplished using comprehensive spectroscopic methods. Compound 1 represents the first example of a dimeric stilbene linked via a cyclobutane ring from the Rheum genus. All isolates were screened for their inhibition against α-glucosidase. Among them, stilbene derivatives (5 and 6) showed strong inhibitory effects on α-glucosidase with IC50 values of 0.5 and 15.4 μM, respectively, which were significantly higher than that of the positive control, acarbose (IC50 = 126.8 μM). Rheundulin A (1) showed moderate α-glucosidase inhibition with an IC50 value of 80.1 μM. In addition, kinetic analysis and molecular docking simulation of the most active compound (5) with α-glucosidase were performed for the first time. Kinetic studies revealed that compound 5 competitively inhibited the active site of α-glucosidase (Ki = 0.40 μM), while 6 had a mixed-type inhibitory effect against α-glucosidase (Ki = 15.34 μM). Molecular docking simulations of 5 and 6 demonstrated negative-binding energies, indicating high proximity to the active site and tight binding to α-glucosidase enzyme.
F-/Cl- mediated microwave assisted breakdown of cellulose to glucose
Shaveta,Bansal, Neha,Singh, Palwinder
, p. 2467 - 2470 (2014)
Microwave irradiation of aqueous solution of cellulose in the presence of NaF/NaCl resulted into disintegration of cellulose to its monomeric unit, glucose (55%) in 20 min.
Indole alkaloids from the leaves of nauclea officinalis
Fan, Long,Liao, Cheng-Hui,Kang, Qiang-Rong,Zheng, Kai,Jiang, Ying-Chun,He, Zhen-Dan
, (2016)
Three new indole alkaloids, named naucleamide G (1), and nauclealomide B and C (5 and 6), were isolated from the n-BuOH-soluble fraction of an EtOH extract of the leaves of Nauclea officinalis, together with three known alkaloids, paratunamide C (2), paratunamide D (3) and paratunamide A (4). The structures with absolute configurations of the new compounds were identified on the basis of 1D and 2D NMR, HRESIMS, acid hydrolysis and quantum chemical circular dichroism (CD) calculation. According to the structures of isolated indole alkaloids, their plausible biosynthetic pathway was deduced.
