Synthetic Studies of Complex Immunostimulants from Quillaja saponaria: Synthesis of the Potent Clinical Immunoadjuvant QS-21Aapi
摘要:
QS-21 is one of the most promising new adjuvants for immune response potentiation and dose-sparing in vaccine therapy given its exceedingly high level of potency and its favorable toxicity profile. Melanoma, breast cancer, small cell lung cancer, prostate cancer, HIV-1, and malaria are among the numerous maladies targeted in more than 80 recent and ongoing vaccine therapy clinical trials involving QS-21 as a critical adjuvant component for immune response augmentation. QS-21 is a natural product immunostimulatory adjuvant, eliciting both T-cell- and antibody-mediated immune responses with microgram doses. Herein is reported the synthesis of QS-21A(api) in a highly modular strategy, applying novel glycosylation methodologies to a convergent construction of the potent saponin immunostimulant. The chemical synthesis of QS-21 offers unique opportunities to probe its mode of biological action through the preparation of otherwise unattainable nonnatural saponin analogues.
The use of 2-O-acyl-1-O-sulfonyl-d-galactopyranose derivatives in β-d-galactopyranoside synthesis
作者:H. Fredrick Vernay、Eliezer S. Rachaman、Ronald Eby、Conrad Schuerch
DOI:10.1016/0008-6215(80)90007-5
日期:1980.1
Abstract Several 1-O-sulfonyl derivatives of d -galactopyranose having a participating benzoyl or p-methoxybenzoyl group at O-2 were synthesized from the corresponding d -galactopyranosyl chloride derivatives by use of silver p-toluenesulfonate or trifluoroethanesulfonate in acetonitrile. The reaction of the 1-O- sulfonyl- d -galactopyranose derivatives with several alcohols in various solvents at
Total Synthesis of Starfish Cyclic Steroid Glycosides. Part 2, Model Synthesis via Intramolecular Etherification
作者:Youxi Chen、Guozhi Xiao、Dapeng Zhu、Biao Yu
DOI:10.1002/cjoc.202200786
日期:2023.4.15
Sepositoside A (1) is a prototypical cyclic steroid glycoside bearing a hybrid 16-membered ring composed of the steroid skeleton and a 1,2-trans-linked trisaccharide. Herein, we report an expedient access toward two simplified analogues, in which the strained 16-membered ring is constructed via Au(I)-catalyzed intramolecular addition of alcohol to epoxide. A similar macroetherification in relevant
Sepositoside A ( 1 ) 是一种原型环状类固醇糖苷,带有由类固醇骨架和 1,2-反式连接的三糖组成的混合 16 元环。在此,我们报告了两种简化类似物的权宜之计,其中应变 16 元环是通过 Au(I) 催化的醇分子内加成环氧化物而构建的。相关类固醇三糖中的类似大醚化已得到深入研究,但未能提供 Sepositoside A 的大环骨架。