ABSTRACT
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.
Subject(s)
Anthozoa/chemistry , Antineoplastic Agents, Phytogenic/pharmacology , Steroids/pharmacology , Sterols/pharmacology , Animals , Antineoplastic Agents, Phytogenic/chemistry , Antineoplastic Agents, Phytogenic/isolation & purification , Cell Line, Tumor , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Humans , Molecular Conformation , Steroids/chemistry , Steroids/isolation & purification , Sterols/chemistry , Sterols/isolation & purification , Structure-Activity RelationshipABSTRACT
Chemical investigation of a Formosan sponge Axinyssa sp. has led to the isolation of five nitrogenous bisabolene-type sesquiterpenes 1-5, including two new compounds axinysalines A (1) and B (2). The structures of new compounds were elucidated by analysis of high resolution (HR)-MS and two dimensional (2D)-NMR spectra and comparison of its NMR data with those of known analogues. Compound 1 exhibited moderate to weak cytotoxicity against Molt 4 and K562 cancer cell lines.
Subject(s)
Antineoplastic Agents/chemistry , Porifera/chemistry , Sesquiterpenes/chemistry , Animals , Antineoplastic Agents/pharmacology , Cell Line, Tumor/drug effects , Drug Screening Assays, Antitumor , Humans , K562 Cells/drug effects , Magnetic Resonance Spectroscopy , Molecular Structure , Sesquiterpenes/isolation & purification , Sesquiterpenes/pharmacologyABSTRACT
Three new 4-methylenesterols, theonellasterol K (1), acetyltheonellasterol (2) and acetyldehydroconicasterol (3), along with two known sterols, theonellasterol (4) and theonellasterone (5), were isolated from the sponge Theonella swinhoei. The structures of these compounds were elucidated on the basis of their spectroscopic data and comparison of the NMR data with those of known analogues. Compound 1 exhibited significant cytotoxic activity against HCT-116, K562 and Molt 4 cancer cell lines.