Takahashi S, Matsunaga T, Hasegawa C, Saito H, Fujita D, Kiuchi F, Tsuda Y
Toyama Prefectural Institute for Pharmaceutical Research, Japan.
Chem Pharm Bull (Tokyo). 1998 Oct;46(10):1527-9. doi: 10.1248/cpb.46.1527.
Martefragin A (1), a novel indole alkaloid, was isolated from a red alga, Martensia fragilis, by repeated column chromatography. The structure of 1 was elucidated on the basis of spectral analysis of its methyl ester (2), including 1H- and 13C-NMR, 1H-1H correlation spectroscopy (COSY), and 13C-1H COSY. A single crystal X-ray analysis of the hydrochloride of 1 confirmed the assignment. Martefragin A (1) showed inhibitory activity on NADPH-dependent lipid peroxidation in rat liver microsomes. The IC50 values of 1, alpha-tocopherol and ascorbic acid were 2.8, 87 and 200 microM, respectively.
