10036-64-3Relevant articles and documents
Isolation and structures of erylosides from the carribean sponge Erylus formosus
Antonov, Alexandr S.,Kalinovsky, Anatoly I.,Stonik, Valentin A.,Afiyatullov, Shamil S.,Aminin, Dmitry L.,Dmitrenok, Pavel S.,Mollo, Ernesto,Cimino, Guido
, p. 169 - 178 (2007)
Nine new triterpene glycosides, erylosides F1-F4 (1-4), M (5), N (6), O (7), P (8), and Q (9), along with previously known erylosides F (10) and H (11) were isolated from the sponge Erylus formosus collected from the Mexican Gulf (Puerto Morelos, Mexico). Structures of 1-4 were determined as the corresponding biosides having aglycons related to penasterol with additional oxidation patterns in their side chains. Erylosides 5-9 contain new variants of carbohydrate chains with three (5, 6), four (7), and six (8, 9) sugar units, respectively. Erylosides 5, 7, 8, and 6, 9 contain 14-carboxy-24-methylenelanost-8(9)-en-3β-ol and penasterol as aglycons, respectively. In contrast with its epimer 2, the compound 3 induced the early apoptosis of Ehrlich carcinoma cells at a concentration of 100 μg/mL, while 1 and 10 activated the Ca2+ influx into mouse spleenocytes (130% of the control) at the same doses.
Effect of sub- and supercritical water pretreatment on enzymatic degradation of chitin
Osada, Mitsumasa,Miura, Chika,Nakagawa, Yuko S.,Kaihara, Mikio,Nikaido, Mitsuru,Totani, Kazuhide
, p. 308 - 312 (2012)
We examined the effect of sub- and supercritical water pretreatment (300-400 °C, 0.5-15 min) on enzymatic degradation of chitin to N,N′-diacetylchitobiose (GlcNAc)2. The yield of (GlcNAc) 2 by enzymatic degradation of supercritical water pretreated chitin at 400 °C for 1.0 min was up to 37%, compared to 5% without the pretreatment. X-ray diffraction (XRD) analysis revealed that the d-spacing and the crystallite size increased by sub- and supercritical water pretreatment, which is indicative of swelling of the chitin. The swelling of the chitin crystal structure improved enzymatic degradation by allowing the enzymes easy access to the chitin.
Kinetics of acid hydrolysis of acetylglucosamine
Gizatulina,Chebotok,Novikov,Konovalova
, p. 791 - 793 (2005)
The kinetics of acid hydrolysis of N-acetylglucosamine at different temperatures and reagent concentrations was studied. A mathematical model of the hydrolysis was proposed. The rate constant and activation energy of deacetylation were calculated.
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Inouye,Y. et al.
, p. 1265 - 1267 (1960)
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Jordaan
, p. 69,75 (1970)
Mapping out the Degree of Freedom of Hosted Enzymes in Confined Spatial Environments
Sun, Qi,Pan, Yanxiong,Wang, Xiaoliang,Li, Hui,Farmakes, Jasmin,Aguila, Briana,Yang, Zhongyu,Ma, Shengqian
, p. 3184 - 3195 (2019)
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MODEL STUDIES PERTAINING TO THE HYDRAZINOLYSIS OF GLYCOPEPTIDES AND GLYCOPROTEINS: HYDRAZINOLYSIS OF THE 1-N-ACETYL AND 1-N-(L-β-ASPARTYL) DERIVATIVES OF 2-ACETAMIDO-2-DEOXY-β-D-GLUCOPYRANOSYLAMINE
Saeed, May S.,Williams, J. Michael
, p. 83 - 94 (1980)
The products of hydrazinolysis of the 1-N-acetyl and 1-N-(L-β-aspartyl) derivatives of 2-acetamido-2-deoxy-β-D-glucopyranosylamine could not be converted quantitatively into 2-amino-2-deoxy-D-glucose under mild conditions.Proton and (13)C-n.m.r. measurements indicated that the hydrazone of 2-amino-2-deoxy-D-glucose was a major product of the hydrazinolysis of 2-acetamido-1-N-acetyl-2-deoxy-β-D-glucopyranosylamine.Control experiments showed that acetohydrazide is slowly converted into 4-amino-3,5-dimethyl-1,2,4-triazole under the conditions of hydrazinolysis, and hat 2-amino-2-deoxy-D-glucose reacts slowly with acetohydrazide in dilute acetic acid.The implications of these results in relation to the hydrazinolysis of glycopeptides and glycoproteins are discussed.
Production of N-acetyl-D-glucosamine from alpha-chitin by crude enzymes from Aeromonas hydrophila H-2330.
Sashiwa, Hitoshi,Fujishima, Shizu,Yamano, Naoko,Kawasaki, Norioki,Nakayama, Atsuyoshi,Muraki, Einosuke,Hiraga, Kazumi,Oda, Kohei,Aiba, Sei-ichi
, p. 761 - 763 (2002)
The selective and efficient production of N-acetyl-D-glucosamine (GlcNAc) was achieved from flake type of alpha-chitin by using crude enzymes derived from Aeromonas hydrophila H-2330.
Enzymatic Discrimination of 2-Acetamido-2-deoxy-D-mannopyranose-Containing Disaccharides Using β-N-Acetylhexosaminidases
Hu?áková, Lucie,Herkommerová-Rajnochová, Eva,Semeňuk, Tomá?,Kuzma, Marek,Rauvolfová, Jana,P?ikrylová, Věra,Ettrich, Rüdiger,Plíhal, Ond?ej,Bezou?ka, Karel,K?en, Vladimír
, p. 735 - 742 (2003)
β-N-Acetylhexosaminidase from Aspergillus oryzae selectively discriminates mixture of the disaccharides GlcNAcβ(1→4)GlcNAc (1) and GlcNAcβ(1→4)ManNAc (2). N,N′-Diacetylchitobiose (1) was selectively hydrolyzed by β-N-acetylhexosaminidase, whereas its C-2 epimer (2) was completely resistant to the enzyme hydrolysis. Analogous discrimination was observed also with GalNAcβ(1→4)GlcNAc (3) and GalNAcβ(1→ 4)ManNAc (4). β-N-Acetylhexosaminidases from A. terreus, A. flavus, bovine kidney and bovine epididymis displayed the same selectivity, whereas the enzymes from A. sojae, A. tamarii, Penicillium brasilianum, P. oxalicum, P. funiculosum, P. multicolor, Talaromyces flavus and jack beans hydrolyzed both types of disaccharides. Molecular modelling of β-N-acetylhexosaminidase from A. oryzae CCF 1066 and docking experiments with both types of disaccharides revealed that the ManNAc residue causes distortion of disaccharide molecule resulting in a steric conflict with a Trp482 that causes diminished stabilization of the oxazolinium transition state by extending the distance of Asp345 in the active site. Both ManNAc-containing disaccharides 2 and 4 dock with similar steric energies into the active site but without cleaving and also without notable inhibition. This novel phenomenon enables also the preparative production of both disaccharides 2 and 4 starting from N, N′-diacetylchitobiose (1) or GalNAcβ(1→ 4)GlcNAc (3) followed by Lobry de Bruyn-Albreda van Ekenstein C-2 epimerization catalyzed by Ca(OH)2. The resultant mixture of the respective epimers 1, 2 or 3, 4 that is hardly separable by, e.g., analytical HPLC can be treated with the β-N-acetylhexosaminidase from A. oryzae and the mixture of monosaccharides and target disaccharide can be easily separated using gel filtration.
Comparative analysis of glycoside hydrolases activities from phylogenetically diverse marine bacteria of the genus Arenibacter
Bakunina, Irina,Nedashkovskaya, Olga,Balabanova, Larissa,Zvyagintseva, Tatyana,Rasskasov, Valery,Mikhailov, Valery
, p. 1977 - 1998 (2013)
A total of 16 marine strains belonging to the genus Arenibacter, recovered from diverse microbial communities associated with various marine habitats and collected from different locations, were evaluated in degradation of natural polysaccharides and chromogenic glycosides. Most strains were affiliated with five recognized species, and some presented three new species within the genus Arenibacter. No strains contained enzymes depolymerizing polysaccharides, but synthesized a wide spectrum of glycosidases. Highly active β-N- acetylglucosaminidases and α-N-acetylgalactosaminidases were the main glycosidases for all Arenibacter. The genes, encoding two new members of glycoside hydrolyses (GH) families, 20 and 109, were isolated and characterized from the genomes of Arenibacter latericius. Molecular genetic analysis using glycosidase-specific primers shows the absence of GH27 and GH36 genes. A sequence comparison with functionally-characterized GH20 and GH109 enzymes shows that both sequences are closest to the enzymes of chitinolytic bacteria Vibrio furnissii and Cellulomonas fimi of marine and terrestrial origin, as well as human pathogen Elisabethkingia meningoseptica and simbionts Akkermansia muciniphila, gut and non-gut Bacteroides, respectively. These results revealed that the genus Arenibacter is a highly taxonomic diverse group of microorganisms, which can participate in degradation of natural polymers in marine environments depending on their niche and habitat adaptations. They are new prospective candidates for biotechnological applications due to their production of unique glycosidases.
Synthesis, characterization, and biological evaluation of some novel glycosyl 1,3,4-thiadiazole derivatives as acetylcholinesterase inhibitors
Liu, Wei-Wei,Li, Qu-Xiang,Shi, Da-Hua,Cao, Zhi-Ling,Cheng, Feng-Chang,Tao, Chuan-Zhou,Yin, Long,Wang, Xuan
, p. 275 - 286 (2015)
The corresponding 4-substituted glycosyl thiosemicarbazide derivatives (6a-6l) were obtained by the reaction of glycosyl isothiocyanate 4 with various hydrazides. Further cyclization with the system of p-TsCl/TEA led to the formation of N-glycosyl-5-substituted 1,3,4-thiadiazole-2-amine (7a-7l). Subsequent removal of the acetyl groups were conducted using the system of NaOMe/MeOH. The chemical structures of all new products were confirmed by IR, 1H NMR and ESI-HRMS. The acetylcholinesterase (AChE) inhibitory activities of those compounds were tested by Ellman's method. Among them, the compound 8h possessed the best acetylcholinesterase-inhibition activity with IC50 of 18.38 ± 0.89 μM.
An ammonium sulfate sensitive chitinase from Streptomyces sp. CS501
Rahman, Md. Arifur,Choi, Yun Hee,Pradeep,Yoo, Jin Cheol
, p. 1522 - 1529 (2014)
A chitinase from Streptomyces sp. CS501 was isolated from the Korean soil sample, purified by single-step chromatography, and biochemically characterized. The extracellular chitinase (Ch501) was purified to 4.60 fold with yield of 28.74 % using Sepharose Cl-6B column. The molecular mass of Ch501 was approximately 43 kDa as estimated by SDS-PAGE and zymography. The enzyme (Ch501) was found to be stable over a broad pH range (5.0-10.0) and temperature (up to 50 °C), and have an optimum temperature of 60 °C. N-terminal sequence of Ch501 was AAYDDAAAAA. Intriguingly, Ch501 was highly sensitive to ammonium sulfate but it's completely suppressed activity was recovered after desalting out. TLC analysis of Ch501 showed the production of N-acetyl d-glucosamine (GlcNAc) and Diacetylchitobiose (GlcNAc)2, as a principal hydrolyzed product. Ch501 shows antifungal activity against Fusarium solani and Aspergillus brasiliensis, which can be used for the biological control of fungus. As has been simple in purification, stable in a broad range of pH, ability to produce oligosaccharides, and antifungal activity showed that Ch501 has potential applications in industries as for chitooligosaccharides production used as prebiotics and/or for the biological control of plant pathogens in agriculture.
Enzymatic characterization and molecular modeling of an evolutionarily interesting fungal β-N-acetylhexosaminidase
Ryslava, Helena,Kalendova, Alzbeta,Doubnerova, Veronika,Skocdopol, Premysl,Kumar, Vinay,Kukacka, Zdenek,Pompach, Petr,Vanek, Ondrej,Slamova, Kristyna,Bojarova, Pavla,Kulik, Natallia,Ettrich, Rudiger,Kren, Vladimir,Bezouska, Karel
, p. 2469 - 2484 (2011)
Fungal β-N-acetylhexosaminidases are inducible extracellular enzymes with many biotechnological applications. The enzyme from Penicillium oxalicum has unique enzymatic properties despite its close evolutionary relationship with other fungal hexosaminidases. It has high GalNAcase activity, tolerates substrates with the modified N-acyl group better and has some other unusual catalytic properties. In order to understand these features, we performed isolation, biochemical and enzymological characterization, molecular cloning and molecular modelling. The native enzyme is composed of two catalytic units (65 kDa each) and two propeptides (15 kDa each), yielding a molecular weight of 160 kDa. Enzyme deglycosylated by endoglycosidase H had comparable activity, but reduced stability. We have cloned and sequenced the gene coding for the entire hexosaminidase from P. oxalicum. Sufficient sequence identity of this hexosaminidase with the structurally solved enzymes from bacteria and humans with complete conservation of all catalytic residues allowed us to construct a molecular model of the enzyme. Results from molecular dynamics simulations and substrate docking supported the experimental kinetic and substrate specificity data and provided a molecular explanation for why the hexosaminidase from P. oxalicum is unique among the family of fungal hexosaminidases. Enzymes hexosaminidase, β-N-acetyl-d-hexosaminide N-acetylhexosaminhydrolase, Fungal β-N-acetylhexosaminidases are inducible extracellular enzymes with many biotechnological applications. The enzyme from Penicillium oxalicum has unique enzymatic properties despite its close evolutionary relationship with other fungal hexosaminidases. Results from molecular dynamics simulations and substrate docking supported the experimental kinetic and substrate specificity data, and identified a secondary binding site for the substrate close to the catalytic site. 2011 The Authors Journal compilation
From glycals to glycopeptides: A convergent and stereoselective total synthesis of a high mannose N-linked glycopeptide
Wang, Zhi-Guang,Zhang, XuFang,Live, David,Danishefsky, Samuel J.
, p. X3652-3656 (2000)
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Structure and activity of the streptomyces coelicolor A3(2) β-N-acetylhexosaminidase provides further insight into GH20 family catalysis and inhibition
Thi, Nhung Nguyen,Offen, Wendy A.,Shareck, Francìois,Davies, Gideon J.,Doucet, Nicolas
, p. 1789 - 1800 (2014)
β-N-acetylhexosaminidases (HEX) are glycosidases that catalyze the glycosidic linkage hydrolysis of gluco- and galacto-configured N-acetyl-β-d-hexosaminides. These enzymes are important in human physiology and are candidates for the biocatalytic production of carbohydrates and glycomimetics. In this study, the three-dimensional structure of the wild-type and catalytically impaired E302Q HEX variant from the soil bacterium Streptomyces coelicolor A3(2) (ScHEX) were solved in ligand-free forms and in the presence of 6-acetamido-6-deoxy-castanospermine (6-Ac-Cas). The E302Q variant was also trapped as an intermediate with oxazoline bound to the active center. Crystallographic evidence highlights structural variations in the loop 3 environment, suggesting conformational heterogeneity for important active-site residues of this GH20 family member. The enzyme was investigated for its β-N-acetylhexosaminidase activity toward chitooligomers and pNP-acetyl gluco- and galacto-configured N-acetyl hexosaminides. Kinetic analyses confirm the β(1-4) glycosidic linkage substrate preference, and HPLC profiles support an exoglycosidase mechanism, where the enzyme cleaves sugars from the nonreducing end of substrates. ScHEX possesses significant activity toward chitooligosaccharides of varying degrees of polymerization, and the final hydrolytic reaction yielded pure GlcNAc without any byproduct, promising high applicability for the enzymatic production of this highly valued chemical. Thermostability and activation assays further suggest efficient conditions applicable to the enzymatic production of GlcNAc from chitooligomers.
Comparison of physicochemical characteristics and anticoagulant activities of polysaccharides from three sea cucumbers
Luo, Lan,Wu, Mingyi,Xu, Li,Lian, Wu,Xiang, Jingying,Lu, Feng,Gao, Na,Xiao, Chuang,Wang, Shengmin,Zhao, Jinhua
, p. 399 - 417 (2013)
In order to search for sulfated polysaccharides in different invertebrate connective tissues and to examine their biological activities, we have isolated three types of polysaccharides from the body wall of the three sea cucumbers Holothuria edulis, Apostichopus japonicas and Holothuria nobilis. The physicochemical properties and anticoagulant activities of these polysaccharides were examined and compared. The chemical composition analysis and nuclear magnetic resonance (NMR) analysis indicate that two types of polysaccharides, sulfated fucan and fucosylated chondroitin sulfate (FuCS), were found in all of the three species and in addition a neutral glycan was observed in H. edulis. The neutral a-glucan was firstly obtained from sea cucumber. The same type of polysaccharides from different species of sea cucumbers have similar physicochemical properties and anticoagulant activities, but those of different types of glycans are significantly different, possibly due to their different monosaccharide compositions, electric charges and average molecular weights. The FuCSs have stronger anticoagulant activities than the sulfated fucans, although the molecular sizes of the FuCSs are lower than those of the sulfated fucans, whereas the neutral glucan has no activity, as expected from the absence of sulfate. Thus, anticoagulant activities of the different type of polysaccharides are likely to relate to monosaccharide composition and sulfate content. Preliminary analysis suggests that the sulfation patterns of the FuCSs may result in the difference in anticoagulant activities. Our data could help elucidate the structure-activity relationship of the sea cucumber polysaccharides.
Hydrazinolysis-N-reacetylation of glycopeptides and glycoproteins. Model studies using 2-acetamido-1-N-(L-aspart-4-oyl)-2-deoxy-beta-D-glucopyranosy lamine.
Bendiak,Cumming
, p. 1 - 12 (1985)
2-Acetamido-1-N-(L-aspart-4-oyl)-2-deoxy-beta-D-glucopyranosyla mine (1) was used as a model glycopeptide to study the hydrazinolysis-N-reacetylation procedure. The major, initial product was the beta-acetohydrazide derivative of 2-acetamido-2-deoxy-D-glucose (2) which gave 2-acetamido-2-deoxy-D-glucose (5) after exposure to acidic conditions. Very mild conditions of hydrolysis of 2 gave a 75-80% overall yield of 5 from 1 after the hydrazinolysis-N-reacetylation procedure. Several other minor compounds were detected which were not converted into 5 upon mild acid hydrolysis, indicating that 20-25% of product cannot be recovered as 5 at the reducing end of oligosaccharides.
Synthesis and anticholinesterase activities of novel glycosyl benzoxazole derivatives
Cao, Zhi-Ling,Liu, Shu-Hao,Liu, Wei-Wei,Ren, Shu-Ting,Shi, Da-Hua,Wang, Lei,Wang, You-Xian,Wu, Yu-Ran
, p. 363 - 366 (2020)
Eight glycosyl benzoxazole derivatives are synthesized by nucleophilic addition reactions of glycosyl isothiocyanate with o-aminophenol in tetrahydrofuran. The reaction conditions are optimized, and good yields (86%–94%) were obtained. The structures of all new products are confirmed by infrared, 1H nuclear magnetic resonance, and high-resolution mass spectrometry (electrospray ionization). In addition, the in vitro cholinesterase inhibitory activities of these new compounds are tested by Ellman’s method.
A short and economical synthesis of orthogonally protected C-linked 2-deoxy-2-acetamido-α-D-galactopyranose derivatives
Bouvet, Vincent R.,Ben, Robert N.
, p. 3619 - 3622 (2006)
A short and high-yielding synthesis has been devised to prepare C-linked 2-deoxy-2-acetamido-α-D-galactopyranose derivative 3. One of the main advantages of this approach is that it employs commercially available and inexpensive D-glucosamine as the starting material. The key steps include a highly stereoselective C-allylation followed by epimerization of the C-4 hydroxyl group. Building block 3 and orthogonally protected C-linked 2-deoxy-2-acetamido-α-D-galactopyranose derivative 2 were obtained in 44% overall yield (six steps) and 29% overall yield (eight steps), respectively. This represents a significant improvement over previously reported syntheses.
Chitooligosaccharide Synthesis Using an Ionic Tag
Gillard, Laura,Tran, Anh-Tuan,Boyer, Fran?ois-Didier,Beau, Jean-Marie
, p. 1103 - 1109 (2016)
An environmentally improved synthesis of the N-differentiated chitotetrasaccharide CO-IV-(NH2), a key intermediate for the preparation of lipochitooligosaccharides and the TMG-chitotriomycin, is reported based on a chromatography-free ionic-liquid tagging approach. The method involves the glycosylation of ionic-liquid-tagged acceptors with thioglucosamine donors leading to the stereoselective formation of β-(1→4)-linked glucosamine-containing oligomers.
Structures of triterpenoids from the leaves of Lansium domesticum
Matsumoto, Takahiro,Kitagawa, Takahiro,Ohta, Tomoe,Yoshida, Tatsusada,Imahori, Daisuke,Teo, Stephen,Ahmad, Haji Sapuan bin,Watanabe, Tetsushi
, p. 727 - 734 (2019)
From the methanolic extract of the leaves of Lansium domesticum, three new onoceranoid-type triterpenoids, lansium acids X–XII and a new cycloartane-type triterpene, lansium acid XIII, were isolated. The chemical structures of the isolated new compounds were elucidated on the basis of chemical/physicochemical evidence. For new onoceranoid-type triterpenoids, the absolute configurations were established by comparison of experimental and predicted electronic circular dichroism (ECD) data. The isolated onoceranoid-type triterpenoids showed antimutagenic effects in the Ames assay against 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1).
Substrate specificity of chitinases from two species of fish, greenling, Hexagrammos otakii, and common Mackerel, Scomber japonicus, and the insect, tobacco hornworm, Manduca sexta
Matsumiya, Masahiro,Arakane, Yasuyuki,Haga, Atsunobu,Muthukrishnan, Subaratnam,Kramer, Karl J.
, p. 971 - 979 (2006)
Three chitinase isozymes, HoChiA, HoChiB, and HoChiC, were purified from the stomach of the greenling, Hexagrammos otakii, by ammonium sulfate fractionation, followed by column chromatography on Chitopearl Basic BL-03 and CM-Toyopearl 650S. The molecular masses and pIs of HoChiA, HoChiB, and HoChiC are 62 kDa and pH 5.7, 51 kDa and pH 7.6, and 47 kDa and pH 8.8, respectively. Substrate specificities of these chitinases were compared with those of another fish stomach chitinase from the common mackerel, Scomber japonicus (SjChi), as well as two from the tobacco hornworm, Manduca sexta (MsChi535 and MsChi386). The efficiency parameters, kcat/Km, toward glycolchitin for HoChiA and SjChi were larger than those for HoChiB and HoChiC. The relative activities of HoChiA and SjChi toward various forms of chitin were as follows: shrimp shell or crab shell -chitin > β-chitin ? silkworm cuticle -chitin. On the other hand, the relative activities of HoChiB and HoChiC were β-chitin ? silkworm -chitin > shrimp and crab -chitin. MsChi535 preferred silkworm -chitin to shrimp and crab -chitins, and no activity was observed toward β-chitin. MsChi386, which lacked the C-terminal linker region and the chitin-binding domain, did not hydrolyze silkworm -chitin. These results demonstrate that fish and insect chitinases possess unique substrate specificities that are correlated with their physiological roles in the digestion of food or cuticle.
Sialic acid biosynthesis: Stereochemistry and mechanism of the reaction catalyzed by the mammalian UDP-N-acetylglucosamine 2-epimerase
Chou, Wayne K.,Hinderlich, Stephan,Reutter, Werner,Tanner, Martin E.
, p. 2455 - 2461 (2003)
The bifunctional enzyme, UDP-N-acetylglucosamine 2-epimerase/ManNAc kinase, catalyzes the first two steps in the biosynthesis of the sialic acids in mammals. The epimerase domain converts UDP-GlcNAc into ManNAc and UDP. This paper demonstrates that α-ManNAc is the first formed anomer and therefore the reaction proceeds with a net retention of configuration at C-1. Studies in deuterated buffer show that solvent-derived deuterium is quantitatively incorporated into the C-2 position of the product during catalysis, but it is not incorporated into the remaining pool of substrate. This indicates that the inversion of stereochemistry is ultimately brought about by the removal and replacement of a proton at C-2 and is consistent with a two-base mechanism. Studies with 18O-labeled UDP-GlcNAc show that the anomeric oxygen of the glycosyl phosphate bond departs with the UDP product and therefore the net hydrolysis reaction involves C-O bond cleavage. Incubation of the putative intermediate, 2-acetamidoglucal, with the enzyme resulted in a slow hydration reaction to give the product, ManNAc. Additional kinetic isotope effect and positional isotope exchange (PIX) experiments address the nature of the rate-determining step of the reaction and show that C-H bond cleavage is not rate limiting. Overall, these results support a reaction mechanism involving an anti-elimination of UDP to give 2-acetamidoglucal, followed by a synaddition of water.
Isopimarane diterpene glycosides, isolated from endophytic fungus Paraconiothyrium sp. MY-42
Shiono, Yoshihito,Kikuchi, Miwako,Koseki, Takuya,Murayama, Tetsuya,Kwon, Eunsang,Aburai, Nobuhiro,Kimura, Ken-Ichi
, p. 1400 - 1405 (2011)
Six isopimarane diterpenes, compounds 1-6, were isolated from the endophytic fungus Paraconiothyrium sp. MY-42. Compound 1 possesses a 19-glucopyranosyloxy group. Its structure was first elucidated by spectroscopic data analysis and finally confirmed by X-ray crystallography, whereas structures 2-6 were mainly elucidated based on the analysis of spectroscopic evidence. Compounds 2 and 3 showed moderate cytotoxicities against the human promyelocytic leukemia cell line HL60 (IC50 6.7 μM value for 2 and 9.8 μM for 3).
Polarized light-stimulated enzymatic hydrolysis of chitin and chitosan
Konieczna-Molenda, Anna,Fiedorowicz, Maciej,Zhong, Wei,Tomasik, Piotr
, p. 3117 - 3119 (2008)
Illumination with white linearly polarized light (WLPL) stimulated chitinase and chitosanase in their degradation of chitin and chitosan, respectively. Enzymes were illuminated at room temperature in separate vessels, then admixed in reactors containing polysaccharides. Hydrolysis of chitosan to glucosamine followed first order kinetics whereas hydrolysis of chitin to N-acetylglucosamine deviated from the first order kinetics. In both cases, an increase in the rate of hydrolysis depended on the illumination time. Efficient degradation required up to 60 min exposure of the enzyme to WLPL.
Synthesis and Anti-Cholinesterase Activity of Novel Glycosyl Benzofuranylthiazole Derivatives
Cao, L.,Cao, Zh.,Chen, Ch.,Jiang, K.,Liu, Sh.,Liu, W.,Lu, X.,Shao, Zh.,Shi, D.,Su, Z.,Wang, L.,Wang, Y.,Wu, Y.
, p. 1513 - 1518 (2021/10/26)
Abstract: A new series of glycosyl benzofuranylthiazole derivatives were designed, synthesized, characterized, and evaluated as potential candidates to treat Alzheimer’s disease. The compounds have been synthesized by the cyclocondensation of glycosyl thiourea with a variety of 2-(bromoacetyl)benzofurans. The reaction conditions have been optimized, and good yields (79–95%) have been obtained. The synthesized compounds showed different degrees of cholinesterase inhibitory activity.
