Agelasphins, novel antitumor and immunostimulatory cerebrosides from the marine sponge Agelas mauritianus
摘要:
New glycosphingolipids, named agelasphins (1-8), have been isolated by antitumor and immunostimulatory bioassay-guided purification from an extract of a marine sponge, Agelas mauritianus. Strongly active agents in agelasphins had characteristic ol-galactosylceramide structures, the isolation of which from natural products has not previously been reported. The absolute configurations of agelasphins were elucidated by the total synthesis.
was synthesized from naturally occurring cyclitol, L-quebrachitol via the conduramine derivative, which was prepared regio- and stereoselectively by the Pd-catalyzed azidation of the allyl carbonate derivative. Condensation of phytosphingosines with 2-acetoxy fatty acid residue, followed by glycosidation, furnished the total synthesis. This work established an effective synthetic pathway to a wide
描述了从海星中分离的新型脑苷脂、棘突脑苷脂 A (1) 和星形脑苷脂 A (2) 的手性和立体选择性全合成。1 和 2 中的植物鞘氨醇部分是通过二烷基镁试剂与常见的环氧化物中间体 2-(t-butoxycarbonyl)amino-1-O-(t-butyldiphenylsilyl)-2-deoxy-3-O-( 4-甲氧基苄基)-D-4,5-脱水核糖醇 (5)。环氧化物 (5) 是由天然存在的环醇、L-白木糖醇通过康杜拉明衍生物合成的,该衍生物是通过 Pd 催化的碳酸烯丙酯衍生物的叠氮化反应制备的。植物鞘氨醇与 2-乙酰氧基脂肪酸残基的缩合,然后是糖苷化,提供全合成。这项工作建立了一种有效的合成途径,可合成含有多种植物鞘氨醇和 2-羟基脂肪酸残基的多种脑苷脂;第一次全合成astrocerebroside A (2) 充分证实了所提出的结构。
Kawano, Yasuhiro; Higuchi, Ryuichi; Isobe, Ryuichi, Liebigs Annalen der Chemie, 1988, p. 19 - 24