- Wittig reaction of unprotected D-aldopentoses with stabilized ylides: Metal-ion effects
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Each of the four D-aldopentoses (1-4) reacts in the unprotected form withg Ph3PCHCO2Me (5) in THF to given stereoselectively the corresponding trans-α,β-unsaturated C7 Wittig adducts, isolated as the corresponding 4,5,6,7-tetraacetates (7-10) or 4,5:6,7-di-O-isopropylidene derivatives (11-14). Concurrently formed are also bicyclic, 1,4-lactone derivatives, isolated as their 5,7-diacetates (15-18) or 5,7-O-isopropylidene derivatives (19), arising through intramolecular Michael addition from the initial acyclic adducts. Formation of the cyclized products is suppressed by incorporation of Cu(OAc)2 in the reaction mixture, permitting preparative isolation of the hept-3-enonate derivatives 7-10, useful as dienophiles in Diels-Alder carbocyclizations with chirality transfer. Optimized yields were 25% (D-ribo), 50% (D-arabino), 49% (D-xylo), and 61% (D-lyxo). Under Cu(OAc)2-catalyzed conditions, the formation of small proportion of 3,7-anhydroheptonic acid esters (21 and 23) was observed in the D-arabino and D-xylo series, but not with the other two pentoses. Each of the four D-aldopentoses (1-4) reacts in the unprotected form with Ph3PCHCO2Me (5) in THF to give stereoselectively the corresponding trans-α,β-unsaturated C7 Wittig adducts, isolated as the corresponding 4,5,6,7-tetraacetates (7-10) or 4,5:6,7-di-O-isopropylidene derivatives (11-14). Concurrently formed are also bicyclic, 1,4-lactone derivatives, isolated as their 5.7-diacetates (15-18) or 5,7-O-isopropylidene derivatives (19), arising through intramolecular Michael addition from the initial acyclic adducts. Formation of the cyclized products is suppressed by incorporation of Cu(OAc)2 in the reaction mixture, permitting preparative isolation of the hept-3-enonate derivatives 7-10, useful as dienophiles in Diels-Alder carbocyclizations with chirality transfer. Optimized yields were 25% (D-ribo), 50% (D-arabino), 49% (D-xylo), and 61% (D-lyxo). Under Cu(OAc)2-catalyzed conditions, the formation of small proportions of 3,7-anhydroheptonic acid esters (21 and 23) was observed in the D-arabino and D-xylo series, but not with the other two pentoses.
- Horton,Koh
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- Synthesis and property of alkyl dioxyethyl α-D-xyloside
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Due to the inherent defects of the long alkyl chain in the related hydrophilicity and water solubility, alkyl α-D-xylosides (7) had hardly the practical application as sugar-based surfactants and should be reconstructed to obtain alkyl dioxyethyl α-D-xylosides (5) with dioxyethylene fragment (?(OCH2CH2)2-)) as the hydrophilic spacer to increase the related TPSA value. With D-xylose as the raw material, 1,2-cis alkyl dioxyethyl α-D-xylosides (5a-5f, n = 6–12) were stereoselectively synthesized. Their physicochemical properties including water solubility, surface tension, foamability, emulsification, thermotropic liquid crystal, and hygroscopicity had been investigated. Their water solubility was found to decrease gradually whereas their calculated HLB numbers were 14.72 → 11.67 (n = 6 → 12) with increasing alkyl chain length (n). Dodecyl dioxyethyl α-D-xyloside (5f) had not water solubility because the HLB number was low. Furthermore, their CMC values decreased with increasing the alkyl chain length, and the CMC value of decyl dioxyethyl α-D-xyloside (5e) was as low as 9.21 × 10?5 mol·L?1. Octyl dioxyethyl α-D-xyloside (5c) had the lowest surface tension (27.25 mN·m?1) at the CMC. Both of nonyl and decyl dioxyethyl α-D-xylosides (5d & 5e) possessed good foaming power and foam stability. Decyl dioxyethyl α-D-xyloside (5e) had the strongest emulsifying property either in the toluene/water system or in the octane/water system. Nonyl dioxyethyl α-D-xylosides (5d) had the most stylish SA texture. Hexyl dioxyethyl α-D-xyloside (5a) possessed the strongest hygroscopicity. Therefore, the alkyl dioxyethyl α-D-xylosides as a class of novel sugar-based surfactants will be widely considered as promising candidates for various practical applications.
- Wu, Xiubing,Kuang, Na,Chen, Langqiu,Fan, Yulin,Fu, Fang,Li, Jiping,Zhang, Jing
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- Glycosylation of Nα-lauryl-O-(β-d-xylopyranosyl)-l- serinamide as a saccharide primer in cells
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Nα-Lauryl-O-(β-d-xylopyranosyl)-l-serinamide (Xyl-Ser-C12) was synthesized as a saccharide primer to obtain oligosaccharides of glycosaminoglycan using the glycan biosynthetic potential of mouse osteosarcoma FBJ-S1 cells and Chinese hamster ovary (CHO) cells. The glycosylated products secreted into the culture medium were collected and analyzed by liquid chromatography-mass spectrometry and glycosidase digestion. The structure of the Xyl-Ser-C12 derivatives was investigated. Several glycosaminoglycan-type oligosaccharides, such as GalNAc-(GlcA-GlcNAc) n-GlcA-Gal-Gal-Xyl-Ser-C12, were detected, and identified as intermediates of the biosynthesis of heparan sulfate glycosaminoglycans. Xyl-Ser-C12 exhibited greater acceptor activity for the glycosylation of glycosaminoglycan-type oligosaccharides than p-nitrophenyl-β-d- xylopyranoside.
- Wang, Yinan,Kumazawa, Tomoaki,Shiba, Keisuke,Sato, Toshinori,Osumi, Kenji,Mizuno, Mamoru
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- Water Solubility and Surface Property of Alkyl Di-/Tri-/Tetraoxyethyl β- D -Xylopyranosides
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Alkyl di-/tri-/tetraoxyethyl β-d-xylopyranosides as derivatives of alkyl xylosides are a class of non-ionic sugar-based surfactants. They were stereoselectively synthesized by the Helferich method. Their properties including hydrophilic-lipophilic balance number, water solubility, surface property, foam property, emulsifying property, and thermotropic liquid crystal property were mainly investigated. The results showed that their water solubility decreased with increasing the alkyl chain length and increasing the number of the oligooxyethyl fragment. The critical micelle concentration had a monotonous decreasing trend with increasing the alkyl chain length. Nonyl di-/tri-/tetraoxyethyl β-d-xylopyranosides [-(OCH2CH2)m-, where m = 2, 3, and 4] exhibited the most excellent foaming ability and foam stability. In the n-octane/water system, dodecyl tetraoxyethyl β-d-xylopyranosides and tetradecyl tetraoxyethyl β-d-xylopyranosides had the strongest emulsion ability. In addition, some alkyl di-/tri-/tetraoxyethyl β-d-xylopyranosides had thermotropic liquid crystal properties. Such sugar-based surfactants, alkyl di-/tri-/tetraoxyethyl β-d-xylopyranosides, will be expected to develop for a variety of practical application.
- Wu, Xiubing,Chen, Langqiu,Fan, Yulin,Fu, Fang,Li, Jiping,Zhang, Jing
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- Design, Synthesis, biological investigations and molecular interactions of triazole linked tacrine glycoconjugates as Acetylcholinesterase inhibitors with reduced hepatotoxicity
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Tacrine is a known Acetylcholinesterase (AChE) inhibitors having hepatotoxicity as main liability associated with it. The present study aims to reduce its hepatotoxicity by synthesizing tacrine linked triazole glycoconjugates via Huisgen's [3 + 2] cycloaddition of anomeric azides and terminal acetylenes derived from tacrine. A series of triazole based glycoconjugates containing both acetylated (A-1 to A-7) and free sugar hydroxyl groups (A-8 to A-14) at the amino position of tacrine were synthesized in good yield taking aid from molecular docking studies and evaluated for their in vitro AChE inhibition activity as well as hepatotoxicity. All the hybrids were found to be non-toxic on HePG2 cell line at 200 μM (100 % cell viability) as compared to tacrine (35 % cell viability) after 24 h of incubation period. Enzyme kinetic studies carried out for one of the potent hybrids in the series A-1 (IC50 0.4 μM) revealed its mixed inhibition approach. Thus, compound A-1 can be used as principle template to further explore the mechanism of action of different targets involved in Alzheimer's disease (AD) which stands as an adequate chemical probe to be launched in an AD drug discovery program.
- Ahmed, Ajaz,Bhagat, Kavita,Choudhary, Sushil,Kaur Gulati, Harmandeep,Kumar, Ajay,Kumar, Nitish,Mukherjee, Debaraj,Singh Bedi, Preet Mohinder,Singh, Atamjit,Singh, Harbinder,Vir Singh, Jatinder
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- Synthesis and biological evaluation of 3β-O-neoglycosides of caudatin and its analogues as potential anticancer agents
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In order to study the structure–activity relationship (SAR) of C21-steroidal glycosides toward human cancer cell lines and explore more potential anticancer agents, a series of 3β-O-neoglycosides of caudatin and its analogues were synthesized. The results revealed that most of peracetylated 3β-O-monoglycosides demonstrated moderate to significant antiproliferative activities against four human cancer cell lines (MCF-7, HCT-116, HeLa, and HepG2). Among them, 3β-O-(2,3,4-tri-O-acetyl-β-L-glucopyranosyl)-caudatin (2k) exhibited the highest antiproliferative activity aganist HepG2 cells with an IC50 value of 3.11 μM. Mechanical studies showed that compound 2k induced both apoptosis and cell cycle arrest at S phase in a dose dependent manner. Overall, these present findings suggested that glycosylation is a promising scaffold to improve anticancer activity for naturally occurring C21-steroidal aglycones, and compound 2k represents a potential anticancer agent deserved further investigation.
- Li, Xiao-San,Chen, Tang-Ji,Xu, Zhi-Peng,Long, Juan,He, Miao-Ying,Zhan, He-Hui,Zhuang, Hai-Cai,Wang, Qi-Lin,Liu, Li,Yang, Xue-Mei,Tang, Jin-Shan
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- Patentiflorin A Analogs as Antiviral Agents
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The present disclosure relates to patentiflorin A analogs that are useful as antivirals, such as anti-HIV, anti-coronaviral, anti-Ebola viral, and anti-influenza viral agents and methods of use thereof.
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Paragraph 0111; 0353-0354
(2021/03/05)
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- Synthesis of Glycosyl Fluorides by Photochemical Fluorination with Sulfur(VI) Hexafluoride
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This study describes a new convenient method for the photocatalytic generation of glycosyl fluorides using sulfur(VI) hexafluoride as an inexpensive and safe fluorinating agent and 4,4′-dimethoxybenzophenone as a readily available organic photocatalyst. This mild method was employed to generate 16 different glycosyl fluorides, including the substrates with acid and base labile functionalities, in yields of 43%-97%, and it was applied in continuous flow to accomplish fluorination on an 7.7 g scale and 93% yield.
- Bannykh, Anton,Khomutnyk, Yaroslav,Kim, Sungjin,Nagorny, Pavel
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supporting information
p. 190 - 194
(2021/01/13)
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- Synthesis of podophyllotoxin-glycosyl triazoles via click protocol mediated by silver (I)-N-heterocyclic carbenes and their anticancer evaluation as topoisomerase-II inhibitors
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Herein we report the regioselective synthesis of podophyllotoxin-Glycosyl triazole hybrids catalysed by Ag(I)-N-heterocyclic carbene (Ag(I)-NHC) in a short reaction time (~30 min) at ambient conditions. In principle, it is the first report of Click alkyne-azide cycloaddition catalysed by Ag(I)-NHC catalyst and moreover, this new methodology yielded good results when compared with traditional CuAAC in terms of reaction time and selectivity. The synthesised compounds were further explored for in vitro anticancer activity against four human cancer cell lines Du145, HeLa, A-549, and MCF-7 and found that these synthesised compounds possess significant anticancer activity. Further, the compounds 5a and 5e were identified as promising leads due to their better activity across all cell lines than that of the standard drug etoposide. Molecular docking studies of 5a & 5e with DNA Topoisomerase-II were revealed that the free energy calculations of active compounds were in good agreement with observed IC50 values.
- Nerella, Srinivas,Kankala, Shravankumar,Gavaji, Brahmeshwari
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supporting information
p. 9 - 16
(2019/06/27)
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- Total Synthesis of (+)-Erogorgiaene and the Pseudopterosin A?F Aglycone via Enantioselective Cobalt-Catalyzed Hydrovinylation
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Due to their pronounced bioactivity and limited availability from natural resources, metabolites of the soft coral Pseudopterogorgia elisabethae, such as erogorgiaene and the pseudopterosines, represent important target molecules for chemical synthesis. We have now developed a particularly short and efficient route towards these marine diterpenes exploiting an operationally convenient enantioselective cobalt-catalyzed hydrovinylation as the chirogenic step. Other noteworthy C?C bond forming transformations include diastereoselective Lewis acid-mediated cyclizations, a Suzuki coupling and a carbonyl ene reaction. Starting from 4-methyl-styrene the anti-tubercular agent (+)-erogorgiaene (>98 % ee) was prepared in only 7 steps with 46 % overall yield. In addition, the synthesis of the pseudopterosin A aglycone was achieved in 12 steps with 30 % overall yield and, surprisingly, was found to exhibit a similar anti-inflammatory activity (inhibition of LPS-induced NF-κB activation) as a natural mixture of pseudopterosins A?D or iso-pseudopterosin A, prepared by β-D-xylosylation of the synthetic aglycone.
- Movahhed, Sohajl,Westphal, Julia,Kempa, Alexander,Schumacher, Christian Eric,Sperlich, Julia,Neud?rfl, J?rg-Martin,Teusch, Nicole,Hochgürtel, Matthias,Schmalz, Hans-Günther
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supporting information
p. 11574 - 11579
(2021/07/02)
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- Protecting carbohydrates with ethers, acetals and orthoesters under basic conditions
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Chlorinated ethyl and vinyl ethers are introduced at various positions of carbohydrates. Depending on the relative stereochemistry, vinylethers, acetals or orthoesters are formed under basic conditions. The products are stable, but are easily deprotected
- Liang, Yang,Pedersen, Christian M.
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supporting information
p. 7598 - 7601
(2021/09/22)
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- Sugar-Based Polymers from d-Xylose: Living Cascade Polymerization, Tunable Degradation, and Small Molecule Release
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Enyne monomers derived from D-xylose underwent living cascade polymerizations to prepare new polymers with a ring-opened sugar and degradable linkage incorporated into every repeat unit of the backbone. Polymerizations were well-controlled and had living character, which enabled the preparation of high molecular weight polymers with narrow molecular weight dispersity values and a block copolymer. By tuning the type of acid-sensitive linkage (hemi-aminal ether, acetal, or ether functional groups), we could change the degradation profile of the polymer and the identity of the resulting degradation products. For instance, the large difference in degradation rates between hemi-aminal ether and ether-based polymers enabled the sequential degradation of a block copolymer. Furthermore, we exploited the generation of furan-based degradation products, from an acetal-based polymer, to achieve the release of covalently bound reporter molecules upon degradation.
- Rizzo, Antonio,Peterson, Gregory I.,Bhaumik, Atanu,Kang, Cheol,Choi, Tae-Lim
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supporting information
p. 849 - 855
(2020/12/03)
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- Isolation and characterization of triterpenoid saponins from leaves of Aralia nudicaulis L
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Three new oleanolic glycosides (1–3), along with seven known saponins from various plants (4–10) were isolated for the first time from the leaves of Aralia nudicaulis. Their structures were elucidated on the basis of spectroscopic evidence, including 1D and 2D NMR, and HRESIMS. Nudicauloside A and B (1–2) have shown moderate anti-inflammatory activity, as demonstrated by inhibition of LPS-induced NO production in raw 264.7 murine macrophages (IC50 = 74–101 μM).
- Lavoie, Serge,Pierra, Julie,Legault, Jean,Raminoson, Diamondra,Lion, Quentin,Mshvildadze, Vakhtang,Pichette, André
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p. 184 - 189
(2021/04/23)
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- Tea leaf perfumery precursor glucoside and synthesizing method thereof
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The invention relates to a tea leaf perfumery precursor glucoside and a synthesizing method thereof. The synthesizing method comprises the following steps of synthesizing ten glucosides including aromatic alcohol ( alkanol )-beta -D-glucosides and aromatic alcohol (alkanol )-beta -D-primrose indicans. The synthesizing method disclosed by the invention is a glucoside synthesizing method which is good in selectivity, high in production rate and low in cost.
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Paragraph 0067-0077
(2020/07/02)
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- Design, synthesis and biological evaluation of carbohydrate-based sulphonamide derivatives as topical antiglaucoma agents through selective inhibition of carbonic anhydrase II
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A series of new carbohydrate-based sulphonamide derivatives were designed, synthesised by employing the so-call ‘sugar-tail’ approach. The compounds were evaluated in vitro against a panel of CAs. Compared to their parent compound p-sulfamoylbenzoic acid, these compounds showed nearly 100-fold improvement in their binding affinities against hCA II in vitro. All of compounds showed great water solubility and the pH value of their water solutions of compounds is 7.0. Such properties are advantageous to make them much less irritating to the eye when applied topical glaucomatous drugs, compared to the relatively highly acidic dorzolamide preparations (pH 5.5). Notably, compounds 7d, 7 g, 7 h demonstrated to topically lower intraocular pressure (IOP) in glaucomatous animals better than brinzolamide when applied as a 1% solution directly into the eye. Low cytotoxicity on human cornea epithelial cell was observed in the tested concentrations by the MTT assay.
- Fan, Zhanfang,Guo, Chun,Hou, Zhuang,Li, Chuanchao,Lin, Bin,Liu, Yang,Liu, Yichuang,Wang, Yitong,Zhang, Miao
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p. 383 - 390
(2019/12/30)
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- Synthesis and Antiproliferative Activities of OSW-1 Analogues Bearing 2”-O-p-Acylaminobenzoyl Residues?
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OSW-1 is a well-known natural saponin with potent antitumor activities. We have designed and prepared a small library of 22 OSW-1 analogues with a variety of p-acylamino-benzoyl groups installed at C2” of the xylose residue, wherein a regioselective (1→3)
- Sun, Lijun,Zhu, Di,Beverborg, Laura Olde Groote,Wang, Ruina,Dang, Yongjun,Ma, Mingming,Li, Wei,Yu, Biao
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p. 1091 - 1097
(2020/07/25)
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- Non-naturally Occurring Regio Isomer of Lysophosphatidylserine Exhibits Potent Agonistic Activity toward G Protein-Coupled Receptors
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Lysophosphatidylserine (LysoPS), an endogenous ligand of G protein-coupled receptors, consists of l-serine, glycerol, and fatty acid moieties connected by phosphodiester and ester linkages, respectively. An ester linkage of phosphatidylserine can be hydrolyzed at the 1-position or at the 2-position to give 2-acyl lysophospholipid or 1-acyl lysophospholipid, respectively. 2-Acyl lysophospholipid is in nonenzymatic equilibrium with 1-acyl lysophospholipid in vivo. On the other hand, 3-acyl lysophospholipid is not found, at least in mammals, raising the question of whether the reason for this might be that the 3-acyl isomer lacks the biological activities of the other isomers. Here, to test this idea, we designed and synthesized a series of new 3-acyl lysophospholipids. Structure-activity relationship studies of more than 100 "glycol surrogate"derivatives led to the identification of potent and selective agonists for LysoPS receptors GPR34 and P2Y10. Thus, the non-natural 3-acyl compounds are indeed active and appear to be biologically orthogonal with respect to the physiologically relevant 1-and 2-acyl lysophospholipids.
- Nakamura, Sho,Sayama, Misa,Uwamizu, Akiharu,Jung, Sejin,Ikubo, Masaya,Otani, Yuko,Kano, Kuniyuki,Omi, Jumpei,Inoue, Asuka,Aoki, Junken,Ohwada, Tomohiko
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p. 9990 - 10029
(2020/10/18)
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- Studies on the stereoselective synthesis and immunosuppressive activity of dihydroartemisinin-O-glycoside derivatives
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Eight new dihydroartemisinin-O-glycosides were synthesized with their relative configurations were determined based on NMR spectrum. In vitro immunosuppressive assay showed that 10α-dihydroartemisinin-β-O-D-mannoside (19a) demonstrate 88percent inhibition towards T cells proliferation and 98percent reduction in IFN-γ levels in cell media. These results suggest that dihydroartemisinin-O-glycoside as a potential lead for further in vivo evaluation.
- Bian, Hongzhu,Dong, Xun,Shen, Zhengwu,Xu, Wei,Yu, Jingfeng,Yu, Yu,Zhang, Jinghua,Zou, Xiaosu
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supporting information
(2020/07/21)
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- Synthesis of xylal- and arabinal-based crown ethers and their application as asymmetric phase transfer catalysts
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New xylal- and arabinal-based monoaza-15-crown-5 ethers were synthesized starting from l- and d-xylose, and l- and d-arabinose, respectively. These monosaccharide-based chiral macrocycles were tested as phase transfer catalysts in a few asymmetric reactions. The xylal-based crown compounds proved to be efficient catalysts in a few liquid-liquid phase reactions. The epoxidation of trans-chalcone and the Darzens condensation of α-chloroacetophenone with benzaldehyde took place with complete diastereoselectivity and up to 77% ee and 58% ee, respectively. It was found that the substituents in the aromatic ring of the chalcone and the α-chloroacetophenone had an influence on the enantioselectivity. The highest ee values were obtained in the epoxidation of 4-chlorochalcone (81% ee) and in the reaction of a 2-naphthyl analogue (96% ee), while in the Darzens condensation of 4-phenyl-α-chloroacetophenone with benzaldehyde, a maximum ee of 91% was detected. The configuration of the monosaccharide unit in the crown ring influenced the absolute configuration of the epoxyketones synthesized.
- Nemcsok, Tamás,Rapi, Zsolt,Bagi, Péter,Keglevich, Gy?rgy,Bakó, Péter
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p. 107 - 119
(2019/11/16)
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- Substituted pyrazole compound, preparation method, pharmaceutical composition and applications thereof
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The invention discloses a substituted pyrazole compound represented by a formula I, and a preparation method, a pharmaceutical composition and applications thereof, wherein the compound has characteristics of good stability, excellent solubility, low cytotoxicity and remarkable neuroprotective effect, can effectively prevent and treat nerve cell injury, and is an ideal medicinal compound for preventing or treating cerebral stroke, cerebral embolism, cerebral stroke sequelae, cerebral stroke dyskinesia, mitochondrial encephalomyopathy and amyotrophic lateral sclerosis of spinal cord.
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Paragraph 0362-0366
(2020/03/12)
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- XYLOSIDE DERIVATIVES OF RESVERATROL FOR USE THEREOF IN COSMETICS
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The present invention relates to the use of a compound of formula (I): in which R1, R2 and R3 independently denote: -a group of formula (II), or -a hydrogen atom H, it being understood that at least one of the radicals R1, R2, R3 denotes a group of formul
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Page/Page column 22
(2019/07/13)
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- XYLOSE DERIVATIVES AND PROCESS FOR PREPARATION THEREOF
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Disclosure of the present invention relates to a method for synthesis of a xylose derivative, which comprises protecting a xylose with a protective group, followed by incorporating to a halogen atom as a leaving group removing the protective groups and using water-soluble ligands to carry out a Suzuki cross-couplings reaction with a palladium catalyst in a water solution. Ten new xylose derivatives as obtained by the method are also provided.
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Paragraph 0061-0062; 0103; 0105
(2020/04/10)
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- Synthesis and O-Glycosidic Linkage Conformational Analysis of 13C-Labeled Oligosaccharide Fragments of an Antifreeze Glycolipid
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NMR studies of two 13C-labeled disaccharides and a tetrasaccharide were undertaken that comprise the backbone of a novel thermal hysteresis glycolipid containing a linear glycan sequence of alternating [βXylp-(1→4)-βManp-(1→4)]n dimers. Experimental trans-glycoside NMR J-couplings, parameterized equations obtained from density functional theory (DFT) calculations, and an in-house circular statistics package (MA'AT) were used to derive conformational models of linkage torsion angles φ and ψ in solution, which were compared to those obtained from molecular dynamics simulations. Modeling using different probability distribution functions showed that MA'AT models of φ in βMan(1→4)βXyl and βXyl(1→4)βMan linkages are very similar in the disaccharide building blocks, whereas MA'AT models of ψ differ. This pattern is conserved in the tetrasaccharide, showing that linkage context does not influence linkage geometry in this linear system. Good agreement was observed between the MA'AT and MD models of ψ with respect to mean values and circular standard deviations. Significant differences were observed for φ, indicating that revision of the force-field employed by GLYCAM is probably needed. Incorporation of the experimental models of φ and ψ into the backbone of an octasaccharide fragment leads to a helical amphipathic topography that may affect the thermal hysteresis properties of the glycolipid.
- Zhang, Wenhui,Meredith, Reagan,Yoon, Mi-Kyung,Wang, Xiaocong,Woods, Robert J.,Carmichael, Ian,Serianni, Anthony S.
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p. 1706 - 1724
(2019/02/14)
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- Ni-Catalyzed Suzuki-Miyaura Cross-Coupling of α-Oxo-vinylsulfones to Prepare C-Aryl Glycals and Acyclic Vinyl Ethers
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We demonstrate that readily available and bench-stable α-oxo-vinylsulfones are competent electrophiles in Ni-catalyzed Suzuki-Miyaura cross-coupling reactions. The C-sulfone bond in the α-oxo-vinylsulfone motif is cleaved chemoselectively in these reactions, furnishing C-aryl glycals or acyclic vinyl ethers in high yields. These reactions proceed under mild conditions and tolerate a remarkable scope of heterocycles and functional groups. Preliminary mechanistic studies revealed the importance of an α-heteroatom in facilitating these transformations.
- Gong, Liang,Sun, Hong-Bao,Deng, Li-Fan,Zhang, Xia,Liu, Jie,Yang, Shengyong,Niu, Dawen
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supporting information
(2019/05/22)
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- Ni-Catalyzed Suzuki-Miyaura Cross-Coupling of α-Oxo-vinylsulfones to Prepare C-Aryl Glycals and Acyclic Vinyl Ethers
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We demonstrate that readily available and bench-stable α-oxo-vinylsulfones are competent electrophiles in Ni-catalyzed Suzuki-Miyaura cross-coupling reactions. The C-sulfone bond in the α-oxo-vinylsulfone motif is cleaved chemoselectively in these reactions, furnishing C-aryl glycals or acyclic vinyl ethers in high yields. These reactions proceed under mild conditions and tolerate a remarkable scope of heterocycles and functional groups. Preliminary mechanistic studies revealed the importance of an α-heteroatom in facilitating these transformations.
- Gong, Liang,Sun, Hong-Bao,Deng, Li-Fan,Zhang, Xia,Liu, Jie,Yang, Shengyong,Niu, Dawen
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supporting information
p. 7680 - 7686
(2019/05/22)
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- Triterpenoids and their glycosides from Glinus oppositifolius with antifungal activities against Microsporum gypseum and Trichophyton rubrum
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Four new triterpenoids, 3β,12β,16β,21β,22-pentahydroxyhopane (1), 12β,16β,21β,22-tetrahydroxyhopan-3-one (2), 3-oxo-olean-12-ene-28,30-dioic acid (3), and 3β-hydroxyoleana-11,13(18)-diene-28,30-dioic acid 30-methyl ester (4); 21 new triterpenoid saponins, glinusopposides A–U (5–25); and 12 known compounds (26–37) were isolated from the whole plants of Glinus oppositifolius. The structures of the new compounds were elucidated based on the analysis of one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) and mass spectrometry (MS) data. All compounds from the plants were measured for antifungal activities against Microsporum gypseum and Trichophyton rubrum. Glinusopposide B (6), glinusopposide Q (21), glinusopposide T (24), and glinusopposide U (25) showed strong inhibitory activities against M. gypseum (MIC50 7.1, 6.7, 6.8, and 11.1 μM, respectively) and T. rubrum (MIC50 14.3, 13.4, 11.9, and 13.0 μM, respectively). For those active compounds with an oleanane skeleton, glycosylation (21–26) or oxidation (3) of 3-OH was helpful in increasing the activity; replacement of the 30-methyl group (29) by a carboxymethyl group (26) enhanced the activity; the presence of 11,13(18) double bonds (20) decreased the activity.
- Zhang, Dongdong,Fu, Yao,Yang, Jun,Li, Xiao-Nian,San, Myint Myint,Oo, Thaung Naing,Wang, Yuehu,Yang, Xuefei
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- Design, synthesis of oleanolic acid-saccharide conjugates using click chemistry methodology and study of their anti-influenza activity
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The development of entry inhibitors is an emerging approach to the inhibition of influenza virus. In our previous research, oleanolic acid (OA) was discovered as a mild influenza hemagglutinin (HA) inhibitor. Herein, as a further study, we report the preparation of a series of OA-saccharide conjugates via the CuAAC reaction, and the anti-influenza activity of these compounds was evaluated in vitro. Among them, compound 11b, an OA-glucose conjugate, showed a significantly increased anti-influenza activity with an IC50 of 5.47 μM, and no obvious cytotoxic effect on MDCK cells was observed at 100 μM. Hemagglutination inhibition assay and docking experiment indicated that 11b might interfere with influenza virus infection by acting on HA protein. Broad-spectrum anti-influenza experiments showed 11b to be robustly potent against 5 different strains, including influenza A and B viruses, with IC50 values at the low-micromole level. Overall, this finding further extends the utility of OA-saccharide conjugates in anti-influenza virus drug design.
- Su, Yangqing,Meng, Lingkuan,Sun, Jiaqi,Li, Weijia,Shao, Liang,Chen, Kexuan,Zhou, Demin,Yang, Fan,Yu, Fei
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- Synthesis of Arabinoxylan Oligosaccharides by Preactivation-Based Iterative Glycosylations
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A concise synthetic strategy has been developed for assembling densely substituted arabinoxylan oligosaccharides, which are valuable substrates for characterizing hemicellulose-degrading enzymes. The xylan backbone has been prepared by an iterative preact
- Underlin, Emilie N.,B?hm, Maximilian,Madsen, Robert
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p. 16036 - 16054
(2019/12/27)
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- BIARYL AMIDES WITH MODIFIED SUGAR GROUPS FOR TREATMENT OF DISEASES ASSOCIATED WITH HEAT SHOCK PROTEIN PATHWAY
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Provided are biaryl amides and coumarin-based compounds with modified sugar groups for treatment of diseases associated with heat shock protein pathway. The compounds having the following formulas, wherein variables are as defined herein. Formulae (I), (II), (III), (IV), and (V), Pharmaceutical compositions of the compounds are also provided. These biaryl amides and coumarin-based derivatives with modified sugar groups are useful for treatment and prevention of diseases and disorders, including neurological disorders, such as neurodegenerative diseases and nerve damaging disorders, for example, diabetic peripheral neuropathy.
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Page/Page column 174; 246
(2019/12/04)
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- S-Adamantyl Group Directed Site-Selective Acylation: Applications in Streamlined Assembly of Oligosaccharides
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The site-selective functionalization of carbohydrates is an active area of research. Reported here is the surprising observation that the sterically encumbered adamantyl group directed site-selective acylation at the C2 position of S-glycosides through dispersion interactions between the adamantyl C?H bonds and the π system of the cationic acylated catalyst, which may have broad implications in many other chemical reactions. Because of their stability, chemical orthogonality, and ease of activation for glycosylation, the site-selective acylation of S-glycosides streamlines oligosaccharide synthesis and will have wide applications in complex carbohydrate synthesis.
- Blaszczyk, Stephanie A.,Xiao, Guozhi,Wen, Peng,Hao, Hua,Wu, Jessica,Wang, Bo,Carattino, Francisco,Li, Ziyuan,Glazier, Daniel A.,McCarty, Bethany J.,Liu, Peng,Tang, Weiping
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supporting information
p. 9542 - 9546
(2019/06/10)
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- Monosaccharide Analogues of Anticancer Peptide R-Lycosin-I: Role of Monosaccharide Conjugation in Complexation and the Potential of Lung Cancer Targeting and Therapy
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Glycoconjugation is a promising modification strategy for the optimization of peptide drugs. In this study, five different monosaccharide derivatives (7a-e) were covalently linked to the N-terminal of R-lycosin-I, which yielded five glycopeptides (8a-e). They demonstrated increased or reduced cytotoxicity depending on monosaccharide types, which might be explained by the changes of physicochemical properties. Among all synthesized glycopeptides, only 8a exhibited increased cytotoxicity (IC50 = 9.6 ± 0.3 μM) and selectivity (IC50 = 37.4 ± 5.9 μM). The glucose transporter 1 (GLUT1) with high expression in cancer cells was approved to be involved in the cytotoxicity and selectivity enhancement of 8a. Furthermore, 8a but not R-lycosin-I inhibited tumor growth in the nude mice xenograft model without generating side effects intraperitoneally. Taken together, this study reveals the different monosaccharide roles in peptide modification and also provides an optimized anticancer peptide with high activity and selectivity, that is, 8a might be a promising lead for developing anticancer drugs.
- Zhang, Peng,Ma, Jing,Zhang, Qianqian,Jian, Shandong,Sun, Xiaoliang,Liu, Bobo,Nie, Liqin,Liu, Meiyan,Liang, Songping,Zeng, Youlin,Liu, Zhonghua
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p. 7857 - 7873
(2019/10/11)
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- Phosphotungstic acid as a novel acidic catalyst for carbohydrate protection and glycosylation
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This work demonstrates the utilization of phosphotungstic acid (PTA) as a novel acidic catalyst for carbohydrate reactions, such as per-O-acetylation, regioselective O-4,6 benzylidene acetal formation, regioselective O-4 ring-opening, and glycosylation. These reactions are basic and salient during the synthesis of carbohydrate-based bioactive oligomers. Phosphotungstic acid's high acidity and eco-friendly character make it a tempting alternative to corrosive homogeneous acids. The various homogenous acid catalysts were replaced by the phosphotungstic acid solely for different carbohydrate reactions. It can be widely used as a catalyst for organic reactions as it is thermally stable and easy to handle. In our work, the reactions are operated smoothly under ambient conditions; the temperature varies from 0 °C to room temperature. Good to excellent yields were obtained in all four kinds of reactions.
- Chen, Jyun-Siao,Sankar, Arumugam,Lin, Yi-Jyun,Huang, Po-Hsun,Liao, Chih-Hsiang,Wu, Shen-Shen,Wu, Hsin-Ru,Luo, Shun-Yuan
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p. 33853 - 33862
(2019/11/11)
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- Design, synthesis and molecular docking analysis of flavonoid derivatives as potential telomerase inhibitors
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Based on the structural scaffolds of natural products, two series of flavonoid derivatives, for a total of twelve compounds, were designed and synthesized as potential human telomerase inhibitors. Using a modified TRAP-PCR assay, compound 5c exhibited the most potent inhibitory activity against human telomerase with an IC50 value of less than 50 μM. In vitro, the results demonstrated that compound 5c had potent anticancer activity against five classes of tumor cell lines. The molecular docking and molecular dynamics analyses binding to the human telomerase holoenzyme were performed to elucidate the binding mode of active compound 5c. This finding helps the rational design of more potent telomerase inhibitors based on the structural scaffolds of natural products.
- Cheng, Mao-Sheng,Fan, Zhan-Fang,Fu, Ya,Ho, Sai-Tim,Hu, Chun,Liu, Yang,Shaw, Pang-Chui,Wang, Jian,Wen, Rui,Zhang, Lei
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- Preparation method and application of xylose carbon glycoside drug
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The invention provides an xylose carbon glycoside drug. A structural formula of the compound is as follows as show in the specification, wherein Ar comprises Ph-, 3-F-Ph- or 3,5-F2-Ph-; and R comprises n-Pr-, PhCH2CH2- or i-Pr-. A preparation method of th
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Paragraph 0029-0030
(2018/07/06)
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- Synthesis of C3-Neoglycosides of digoxigenin and their anticancer activities
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Cardiac glycosides exhibit significant anticancer effects and the glycosyl substitution at C3 position of digoxigenin is pivotal for their biological activity. In order to study the structure-activity relationship (SAR) of cardiac glycosides toward cancers and explore more potent anticancer agents, a series of C3-O-neoglycosides and C3-MeON-neoglycosides of digoxigenin were synthesized by the Koenigs-Knorr and neoglycosylation method, respectively. In addition, digoxigenin bisdigitoxoside and monodigitoxoside were prepared from digoxin by sodium periodate (NaIO4) oxidation and 6-aminocaproic acid hydrolysis. The SAR analysis revealed that C3-O-neoglycosides of digoxigenin exhibited stronger cytotoxicity and induction of Nur77 expression of tumor cells than C3-MeON-neoglycosides. Also, 3β-O-glycosides exhibited stronger anticancer effects than 3α-O-glycosides. Among them, 3β-O-(β-L-fucopyranosyl)-digoxigenin (3i) showed the highest activity on induction of Nur77 expression and translocation from the nucleus to cytoplasm, leading to cancer cell apoptosis.
- Li, Xiao-san,Ren, Yi-chang,Bao, Yu-zhou,Liu, Jie,Zhang, Xiao-kun,Zhang, You-wei,Sun, Xue-Long,Yao, Xin-sheng,Tang, Jin-Shan
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supporting information
p. 252 - 262
(2018/01/12)
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- Synthesis and Properties of Alkoxyethyl β-d-Xylopyranoside
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In order to improve the water solubility of sugar-based surfactants, alkyl β-d-xylopyranosides, novel sugar-based surfactants, 1,2-trans alkoxyethyl β-d-xylopyranosides, with alkyl chain length n = 6–12 were stereoselectively prepared by the trichloroacetimidate method. Their properties including hydrophilic–lipophilic balance (HLB) number, water solubility, surface tension, emulsification, foamability, thermotropic liquid crystal, and hygroscopicity were investigated. The results indicated that their HLB number decreased with increase of alkyl chain, the water solubility improved since the hydrophilic oxyethene (─OCH2CH2─) fragment was introduced. The dissolution process was entropy driven at 25–45 °C for alkyl chain length n = 6–10. Octyloxyethyl β-d-xylopyranoside had the best foaming ability. Nonyloxyethyl β-d-xylopyranoside had the best foam stability and the emulsifying ability was better in toluene/water system than in rapeseed oil/water system. The surface tension of in aqueous solution dropped to 27.8 mN m?1 at the critical micelle concentration, and it also showed the most distinct thermotropic liquid phases with cross pattern texture upon heating and the fan schlieren texture on cooling. Hexyloxyethyl β-d-xylopyranoside possessed the strongest hygroscopicity. Based on the effective improvement of water solubility, the prepared alkoxyethyl β-d-xylopyranosides showed excellent surface activity and are expected to develop their practical application as a class of novel sugar-based surfactants.
- Shen, Wangzhen,Ji, Shanwei,Chen, Langqiu,Zhang, Yanhua,Wu, Xiubing
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p. 255 - 267
(2018/02/09)
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- Tailormade Polysaccharides with Defined Branching Patterns: Enzymatic Polymerization of Arabinoxylan Oligosaccharides
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The heterogeneous nature of non-cellulosic polysaccharides, such as arabinoxylan, makes it difficult to correlate molecular structure with macroscopic properties. To study the impact of specific structural features of the polysaccharides on crystallinity
- Senf, Deborah,Ruprecht, Colin,Kishani, Saina,Matic, Aleksandar,Toriz, Guillermo,Gatenholm, Paul,W?gberg, Lars,Pfrengle, Fabian
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supporting information
p. 11987 - 11992
(2018/09/10)
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- ANTICANCER COMPOUNDS
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The present invention discloses compounds for inhibition of uncontrolled cell proliferation particularly in cancer stem cells. Particularly, the invention relates to compounds of Formula III to XIV for the treatment of cancer, such as breast and prostate cancer.
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Page/Page column 36; 38; 39; 40
(2018/11/22)
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- MULTIBIOTIC AGENTS AND METHODS OF USING THE SAME
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Multibiotic agents are disclosed. The multibiotic agents may contain two or more moieties linked through bonds cleavable in vivo. The bonds cleavable in vivo can be ester bonds, amide bonds, azo bonds, glycosidic bonds, carbonate linkers, or carbamate linkers. The moieties can be alcohol cores, amine cores, and/or acyls. Also disclosed are compositions containing multibiotic agents and methods of using the multibiotic agents.
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Page/Page column 137; 138
(2019/01/06)
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- ADENOSINE ANALOG AND ITS USE IN REGULATING THE CIRCADIAN CLOCK
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Provided are a kind of nucleoside analogue compounds, and compositions comprising these compounds and pentostatin, their use for modulating circadian rhythm, preferably, for shifting circadian phase, and methods for modulating circadian rhythm, preferably, for shifting circadian phase via these compounds or the compositions.
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Paragraph 0149; 0150; 0151
(2018/08/12)
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- Ruthenium(II)- and copper(I)-catalyzed synthesis of click-xylosides and assessment of their glycosaminoglycan priming activity
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Xylosides are small molecules that serve as primers of glycosaminoglycan biosynthesis. Xyloside mediated modulation of biological functions depends on the extent of priming activity and fine structures of primed GAG chains. In earlier studies, copper (Cu)
- Mencio, Caitlin P.,Garud, Dinesh R.,Doi, Yosuke,Bi, Yiling,Vankayalapati, Hariprasad,Koketsu, Mamoru,Kuberan, Balagurunathan
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p. 5027 - 5030
(2017/10/18)
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- Xylose compound with terminal group containing HS-(PEG)-2-O branch chain and synthesis method of xylose compound
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The invention discloses a xylose compound with a terminal group containing a HS-(PEG)-2-O branch chain and a synthesis method of the xylose compound with the terminal group containing the HS-(PEG)-2-O branch chain. The compound is shown as the formula I (
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Paragraph 0036-0040
(2017/04/27)
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- THERAPEUTIC COMPOUNDS
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The invention provides compounds of formula (I): and salts thereof, wherein R1, R2, R3, B, X, Y, and Z have any of the values defined herein. The invention also provides pharmaceutical compositions comprising a compound of formula (I) or a pharmaceutically acceptable salt thereof, processes for preparing compounds of formula (I) and salts thereof, intermediates useful for preparing compounds of formula (I) and salts thereof, and therapeutic methods for treating cancer using a compound of formula (I) or a pharmaceutically acceptable salt thereof.
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Page/Page column 26
(2017/06/30)
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- Synthetic transformations of higher terpenoids: XXXVI. Synthesis of furanolabdanoid glycoconjugates with a 1,2,3-triazole linker
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Procedures have been developed for the synthesis of 16-[(propargyloxy)methyl]- and 7- and 18-(propargyloxy)labda-8(9),13,14-trienes from phlomisoic acid. Copper-catalyzed cycloaddition of the labdanoid alkynes to azido derivatives of α-D-glucose, D-galactose, D-xylose, and L-arabinose afforded the corresponding N-glycosyl-1,2,3-triazole conjugates.
- Kremenko,Kharitonov, Yu. V.,Shul’ts
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- Potent Inhibitor of Drug-Resistant HIV-1 Strains Identified from the Medicinal Plant Justicia gendarussa
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Justicia gendarussa, a medicinal plant collected in Vietnam, was identified as a potent anti-HIV-1 active lead from the evaluation of over 4500 plant extracts. Bioassay-guided separation of the extracts of the stems and roots of this plant led to the isolation of an anti-HIV arylnaphthalene lignan (ANL) glycoside, patentiflorin A (1). Evaluation of the compound against both the M-and T-Tropic HIV-1 isolates showed it to possess a significantly higher inhibition effect than the clinically used anti-HIV drug AZT. Patentiflorin A and two congeners were synthesized, de novo, as an efficient strategy for resupply as well as for further structural modification of the anti-HIV ANL glycosides in the search for drug leads. Subsequently, it was determined that the presence of a quinovopyranosyloxy group in the structure is likely essential to retain the high degree of anti-HIV activity of this type of compounds. Patentiflorin A was further investigated against the HIV-1 gene expression of the R/U5 and U5/gag transcripts, and the data showed that the compound acts as a potential inhibitor of HIV-1 reverse transcription. Importantly, the compound displayed potent inhibitory activity against drug-resistant HIV-1 isolates of both the nucleotide analogue (AZT) and non-nucleotide analogue (nevaripine). Thus, the ANL glycosides have the potential to be developed as novel anti-HIV drugs.
- Zhang, Hong-Jie,Rumschlag-Booms, Emily,Guan, Yi-Fu,Wang, Dong-Ying,Liu, Kang-Lun,Li, Wan-Fei,Nguyen, Van H.,Cuong, Nguyen M.,Soejarto, Djaja D.,Fong, Harry H. S.,Rong, Lijun
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p. 1798 - 1807
(2017/06/28)
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- Stereoselective acetylation of hemicellulosic C5-sugars
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The stereoselective peracetylation of α-D-xylose (1) and α-L-arabinose (4) using a combination of triethylamine and acetic anhydride in the presence or absence of a catalytic amount of dimethylaminopyridine (DMAP) is described. The peracetylated D-xylose and L-arabinose alpha pyranose anomers 2α and 5α are obtained in 97% and 56% yields respectively. The peracetylated D-xylose beta pyranose anomer 2β is obtained in 71% yield through simple modification of the reaction conditions. Details regarding synthesis and isolation optimization studies under different conditions are presented below. The stereoselective peracetylation reactions disclosed here have been used to separate mixtures of D-xylose and L-arabinose as their peracetylated derivatives 2β and 5α in 47% and 42% yields and can provide pure pentoses after deacetylation.
- Herde, Zachary D.,John, Prathap D.,Alvarez-Fonseca, Dania,Satyavolu, Jagannadh,Burns, Christopher T.
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- Synthesis of β-D-xylopyranoside thiophosphate derivatives
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A method of synthesis of β-D-xylopyranoside thiophosphate derivatives was developed. Biological testing revealed a high insecticidal activity in the synthesized compounds.
- Belakhov,Garabadzhiu,Boikova,Antonova
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p. 456 - 462
(2017/05/01)
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- Sequential Dy(OTf)3-Catalyzed Solvent-Free Per-O-Acetylation and Regioselective Anomeric De-O-Acetylation of Carbohydrates
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Dysprosium(III) trifluoromethanesulfonate-catalyzed per-O-acetylation and regioselective anomeric de-O-acetylation of carbohydrates can be tuned by adjusting the reaction medium. In this study, the per-O-acetylation of unprotected sugars by using a near-stoichiometric amount of acetic anhydride under solvent-free conditions resulted in the exclusive formation of acetylated saccharides as anomeric mixtures, whereas anomeric de-O-acetylation in methanol resulted in a moderate-to-excellent yield. Reactions with various unprotected monosaccharides or disaccharides followed by a semi-one-pot sequential conversion into the corresponding acetylated glycosyl hemiacetal also resulted in high yields. Furthermore, the obtained hemiacetals could be successfully transformed into trichloroimidates after Dy(OTf)3-catalyzed glycosylation.
- Yan, Yi-Ling,Guo, Jiun-Rung,Liang, Chien-Fu
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p. 2471 - 2479
(2017/09/06)
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- Novel xylosidesurfactant
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The invention belongs to the technical field of surfactants for fine chemistry and discloses a novel sugar-based surfactant, namely, alkoxyethyl-beta-D-xylopyranoside in order to solve the problem of limitation to application of traditional alkyl glycoside as the surfactant due to the fact water solubility of traditional alkyl glycoside is gradually reduced with increase of carbon chain length. Compared with traditional alkyl glycoside with the same carbon chain length, the surfactant has better water solubility and surface activity as well as selectable and controllable foaming capacity and emulsifying property. Besides, raw materials for synthesis comprisexylose obtained from waste crop leftovers and naturally-sourced fatty alcohol and have rich sources. The glycoside can be widely applied to application industries such as biochemical engineering, pharmacy, pesticides, food processing, cosmetics, scientific research and the like.
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Paragraph 0026; 0028
(2017/08/31)
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- Synthesis of some monosaccharide-related ester derivatives as insecticidal and acaricidal agents
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To develop natural-product-based pesticidal agents, a series of monosaccharide-related ester derivatives (17a–q and 18a–f), glucose (xylose)-piperic acid/piperic acid-like conjugates, were synthesized. Three-dimensional structures of compounds 17b, 17g, 17h, and 17n were unambiguously determined by single-crystal X-ray diffraction. Especially compounds 18e and 18f exhibited the most potent insecticidal and acaricidal activities against Mythimna separata and Tetranychus cinnabarinus. Their structure-activity relationships were also discussed.
- Huang, Xiaobo,Zhang, Bingchuan,Xu, Hui
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p. 4336 - 4340
(2017/09/12)
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- Efficient and selective N-, S- and O-acetylation in TEAA ionic liquid as green solvent. Applications in synthetic carbohydrate chemistry
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Background: The ionic liquid triethylammonium acetate (TEAA) was found to be an efficient solvent in the acetylation of alcohols, amines, oximes and thiols to their corresponding acetyl compounds using only a 10% excess of acetic anhydride under mild conditions. Moreover TEAA is not only an inexpensive and recyclable solvent but also an anomeric selective catalyst in the per-O-acetylation of sugar moieties. Methods: Simple and effective organic synthesis protocols were provided for the selective acetylation of several substrates. The products were fully characterized by 1H and 13C NMR spectroscopy and the anomeric ratios were obtained from the 1H spectra. Results: Structurally diverse alcohols, phenols, thiols, amines, carbohydrates and oximes underwent acylation under mild conditions by this procedure to provide the corresponding acetates in excellent yields. TEAA ionic liquid is unique in its capability to act as both, solvent and high selective catalyst. As expected, the reaction proceeds with high b anomeric selectivity for sugars derivatives. Moreover, the ionic liquid was regenerated, recycled and reused for three times without apparent loss of reactivity and selectivity in all cases. Conclusions: The present procedure provides a powerful and versatile acylation method for alcohols, phenols, thiols, amines, oximes and carbohydrates. This protocol is endowed with several unique merits: selectivity, cost-efficiency, atom-economy and mild reaction conditions tolerable to acid sensitive functionalities. With these features, this method may be considered as a better alternative for the acetylation of a wide range of substrates.
- Lafuente, Leticia,Díaz, Gisela,Bravo, Rodolfo,Ponzinibbio, Agustín
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p. 195 - 200
(2016/02/26)
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- The application of aryl substituted derivatives of xylose as environmentally friendly multipurpose pesticides
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A series of aryl substituted derivatives of xylose have been synthesized. Biological tests have revealed high fungicidal activity of the resulting compounds against various phythopathogenic fungi. Additional biological studies have demonstrated high plant growth regulatory activity of the compounds synthesized.
- Belakhov,Garabadzhiu
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p. 3002 - 3007
(2017/07/07)
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