Six cycloartanes were isolated from ethanol extract of marine green alga Cladophora fas-cicularis by column chromatography. Procedure of isolation and description of these compounds are given in this paper. The structures were elucidated as (1). 24-hydroperoxycycloart-25(26)-en-3β-ol; (2). cycloart-25(26)-en-3β 24-diol; (3). 25-hydroperoxycycloart-23-en-3β-ol; (4). cycloart-23-en-3β, 25-diol; (5). cycloart-23, 25(26)-dien-3β-ol; and (6). cycloart-24-en-3β-ol by spectroscopic (MS, 1D and 2D NMR) data analysis. Cycloartane derivatives are widely distributed in terrestrial plants, but only few were ob-tained in the alga. All these compounds that have been isolated from terrestrial plants, were found in the marine alga for the first time.
A new compound named 13b (S )-hydroxy-17c-ethoxypheaophorbide a (2) together witha known compound 17c-ethoxypheaophorbide a (1) were isolated from marine sponge Dysidea sp.collected in South China sea. The structures were elucidated by spectroscopic analysis as well ascomparison with those reported in literatures.
Two new compounds, namely 7α, 10α-dimethyl-3β-isopropene-1, 2-ene-octahydro- naphthalene (1) and ethyl 5Z,8Z,11Z,14Z-nonadecatetraenoate (2) were isolated from the soft coral Nephthea hainansis. Compound 1 was a pseutosesquiterpene and 2 was a polyunsaturated fatty acid ethylate. Their structures were established on the basis of spectroscopic methods.
From the marine sponge Jaspis sp., a new isomalabaricane triterpenoid 22, 23- dihydrostellettin D (1) was isolated, and its structure was established on the basis of IR, MS and extensive 2D NMR spectroscopic analysis. It is a unique skeleton compound rarely obtained from Chinese marine organisms.
