Enzyme-catalyzed aldol condensation for asymmetric synthesis of azasugars: synthesis, evaluation, and modeling of glycosidase inhibitors
摘要:
A combined fructose 1,6-diphosphate aldolase reaction and catalytic reductive amination has been used in the asymmetric synthesis of azasugars structurally corresponding to N-acetylglucosamine, N-acetylmannosamine, and deoxyhexoses. The 6-deoxyazasugars were prepared by direct hydrogenolysis of the aldolase product without removal of the 6-phosphate group. Both (R)- and (S)-3-azido-2-acetamidopropanal used as substrates in the aldolase reactions were prepared from the corresponding lipase-resolved 2-hydroxy species followed by formation of an aziridine intermediate and opening of the aziridine with azide. Evaluation of these azasugars and their diastereomerically pure tertiary amine oxides as well as 5-thioglucose and its sulfoxide derivatives as glycosidase inhibitors was carried out. It was found that all synthetic azasugars and 5-thioglucose were strong inhibitors, but oxidation of the ring heteroatom weakened the inhibition. With the aid of molecular modeling and inhibition analysis, a structure-K(i) relation of inhibitors was established which provides useful information for the design of new glycosidase inhibitors.
A facile synthesis of 1,6-dideoxynojirimycin from l-sorbose
摘要:
A practical synthesis of 1,6-dideoxynojirimycin, a potent glycosidase inhibitor, starting from L-sorbose, is described. (c) 2006 Elsevier Ltd. All rights reserved.
A general approach to the synthesis of dideoxy and trideoxyiminoalditols from β-d-glycosides
作者:Gabriela Pistia、Rawle I. Hollingsworth
DOI:10.1016/s0008-6215(00)00124-5
日期:2000.10
Imino sugars (also called azasugars), a class of compounds of which the 1,5-dideoxy and 1,5,6-trideoxyiminoalditols are members, are important glycosidase inhibitors with very high potential as drugs. Their potential therapeutic applications range from the treatment of diabetes to cancer and AIDS. We present here a general method for the preparation of such compounds with the D-gluco and D-galacto
Organocatalytic<i>syn</i>-Aldol Reactions of Hydroxy Ketones with (<i>S</i>)-Isoserinal: Asymmetric Synthesis of 6-Deoxy-1,5-iminohexitols and Related Compounds
作者:Cyril Nicolas、Roman Pluta、Monika Pasternak-Suder、Olivier R. Martin、Jacek Mlynarski
DOI:10.1002/ejoc.201201413
日期:2013.3
intermediate was reacted through organocatalyzed aldol reaction or Wittig based chainextension and functionalization to give enantiopure 1,5,6-trideoxy-1,5-imino-hexitols such as 10a (L-manno) and 10b (D-gluco). These two compounds are of interest as glycosidase inhibitors. The elaborated organocatalytic process includes diastereoselective syn aldol reaction of (S)-isoserinal hydrate and hydroxyacetone or
Synthesis of 1,6-Dideoxynojirimycin, 1,6-Dideoxy-D-allo-nojirimycin, and 1,6-Dideoxy-D-gulo-nojirimycinvia Asymmetric Hetero-Diels-Alder Reactions
作者:Albert Defoin、Herv� Sarazin、Jacques Streith
DOI:10.1002/hlca.19960790223
日期:1996.3.20
Asymmetric Diels-Alder reaction of sorbaldehyde O-methyloxime 1d with chiral chloronitroso derivative 2 of D-mannose, followed by osmylation of the primary cycloadduct, led to diol 6a with excellent enantioselectivity (ee > 99%; Scheme 1). Catalytic hydrogenolysis of 6a gave 1,6-dideoxy-D-allo-nojirimycin (7a). Nucleophilic ring opening of cyclic sulfate 8 allowed a straightforward synthesis of 1,
An adjuvant composition comprises a Th1-activating alkaloid, optionally further comprising an auxiliary adjuvant selected from a type 2 adjuvant (e.g. alum and/or MF59), a type 1 adjuvant and/or a balanced adjuvant. Vaccines comprising the adjuvant composition include nucleic acid(s) which encode one or more antigenic protein(s); protein(s) or peptide(s); glycoprotein(s); polysaccharide(s) (e.g. carbohydrate(s)); fusion protein(s); lipid(s); glycolipid(s); peptide mimic(s) of polysaccharides carbohydrate(s) and a protein(s) in admixture; carbohydrate-protein conjugate(s); cells or extracts thereof; dead or attenuated cells or extracts thereof; tumour cells or extracts thereof; viral particles (e.g. attenuated viral particles or viral components); allergen(s) mixtures thereof.
Immunotherapy comprises administration of an alkaloid at a dose sufficient to induce IL-2 production in dendritic cells in a patient. The alkaloid induces the production of IL-2 in dendritic cells. The alkaloids need not be naturally occurring, and may be synthetic analogues or derivatives of naturally occurring counterparts. Such analogues or derivatives are preferably pharmaceutically acceptable analogues, salts, isomers or derivatives as herein defined. However, preferred alkaloids are phytochemicals. Such phytochemicals may be isolated from natural sources or synthesised in vitro. Particularly preferred are alkaloids is selected from piperidine alkaloids; pyrrolin alkaloids; pyrrolidine alkaloids; pyrolizidine alkaloids: indolizidine alkaloids and nortropane alkaloids.