2016 Volume 64 Issue 10 Pages 1519-1522
A new 10-demethylated steroid, nephtheasteroid A (1), a new 19-oxygenated steroid, nephtheasteroid B (2) as well as five known steroids 3–7 were isolated from the organic extract of a Taiwanese soft coral Nephthea erecta. The structure was determined by means of IR, MS, and NMR techniques. Among these metabolites, 1 is rarely found in steroids possessing a 19-norergostane skeleton. In vitro cytotoxicity study using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay revealed that compounds 3 and 4 exhibited cytotoxicity against human chronic myelogenous leukemia (K562), human acute lymphoblastic leukemia (Molt-4), human T lymphoblastoid (Sup-T1), and human leukemic monocyte lymphoma (U937), with IC50 of 6.5–14.0 µM.
