Norisoprenoids from red alga Gymnogongrus flabelliformis / 中国中药杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the chemical constituents of the red alga Gymnogongrus flabelliformis Harv.</p><p><b>METHOD</b>Compounds were isolated by normal phase silica gel and Sephadex LH - 20 gel column chromatography and reverse phase HPLC. Their structures were elucidated by spectroscopic methods including MS, 1H-NMR, 13C-NMR. Cytotoxicity of the compounds was screened by using standard MIT method.</p><p><b>RESULT</b>Five compounds were isolated from G. flabelliforrmis, their structures were identified as(3S, 6R, 7E)-( + )-3-hydroxyl-4, 7-mega-stigmadien-9-one (1), (3S, 5R, 6S, 7E)-(-)-3-hydroxy-5, 6-epoxy-7-megastigmene-9-one (2), (3S, 5S, 6R, 7E)-(+)3-hydroxy-5, 6-epoxy-7-megastigmene-9-one (3), dehydrovomifoliol (4), (3R)-(-)4-[(2R, 4S)-4-acetoxy-2-hydroxy-2, 6, 6-trimethylcyclohexylidene] -3-buten-2-one (5).</p><p><b>CONCLUSION</b>All of the compounds were obtained from this species for the first time and compound 1 was a new natural product. These compounds were inactive (IC50 > 10 microg x mL(-1)) in the MTT assay against several human cancer cell lines.</p>