Maia L F, Epifanio R A, Fenical W
Núcleo de Pesquisas de Produtos Naturais, Universidade Federal do Rio de Janeiro, 21941-590, Rio de Janeiro, RJ, Brazil.
J Nat Prod. 2000 Oct;63(10):1427-30. doi: 10.1021/np9906323.
Two new steroidal glycosides, 3beta-O-(3'-O-acetyl-beta-D-arabinopyranosyl)-25xi-choles tan e-3beta, 5alpha,6beta,26-tetrol-26-acetate (riisein A, 2) and 3beta-O-(4'-O-acetyl-beta-D-arabinopyranosyl)-25xi-choles tan e-3beta, 5alpha,6beta,26-tetrol-26-acetate (riisein B, 3), were isolated from extracts of the Brazilian telestacean octocoral Carijoa (Telesto) riisei collected near Rio de Janeiro. The new glycosides co-occur with the polyhydroxy sterol, 25xi-cholestane-3beta,5alpha,6beta, 26-tetrol-26-acetate (1), an inseparable diastereomeric mixture previously reported from Telesto riisei collected in Micronesia. The structures of the new glycosides were assigned by spectroscopic methods and by comparison with spectral data for sterol 1. Riiseins A and B showed in vitro cytotoxicity toward HCT-116 human colon adenocarcinoma with IC(50) values of 2.0 microg/mL.
从里约热内卢附近采集的巴西远海八放珊瑚卡里霍阿（特莱斯托）里塞伊的提取物中，分离出两种新的甾体糖苷，3β - O -（3'-O - 乙酰基-β - D - 阿拉伯吡喃糖基）- 25ξ - 胆甾烷 - 3β，5α，6β，26 - 四醇 - 26 - 乙酸酯（里塞因A，2）和3β - O -（4'-O - 乙酰基-β - D - 阿拉伯吡喃糖基）- 25ξ - 胆甾烷 - 3β，5α，6β，26 - 四醇 - 26 - 乙酸酯（里塞因B，3）。这两种新糖苷与多羟基甾醇25ξ - 胆甾烷 - 3β，5α，6β，26 - 四醇 - 26 - 乙酸酯（1）共存，（1）是先前从密克罗尼西亚采集的卡里霍阿（特莱斯托）里塞伊中报道的一种不可分离的非对映异构体混合物。通过光谱方法并与甾醇1的光谱数据进行比较，确定了新糖苷的结构。里塞因A和B对HCT - 116人结肠腺癌显示出体外细胞毒性，IC（50）值为2.0微克/毫升。
