ABSTRACT
A new abeo-abietane diterpenoid, 12-methoxy-6,11,14,16-tetrahydroxy-17(15â16)-abeo-5,8,11,13-abietatetraen-3,7-dione (8), was isolated from the hydroalcoholic extract of the herb of Clerodendrum kiangsiense along with seven known diterpenoids (1-7). Their structures were identified on the basis of spectroscopic analyses including two-dimensional NMR and comparison with literature data. All of these compounds were evaluated for their cytotoxic activities against the growth of human cancer cells lines HL-60, SMMC-7721, A-549 and MCF-7 by the MTT assay. The results showed that cryptojaponol (4), fortunin E (6) and 8 exhibited significant cytotoxicity against four human cancer cell lines.
Subject(s)
Abietanes/pharmacology , Antineoplastic Agents, Phytogenic/pharmacology , Clerodendrum/chemistry , Diterpenes/pharmacology , Abietanes/chemistry , Abietanes/isolation & purification , Antineoplastic Agents, Phytogenic/chemistry , Antineoplastic Agents, Phytogenic/isolation & purification , Cell Line, Tumor , Cell Survival/drug effects , Diterpenes/chemistry , Diterpenes/isolation & purification , HL-60 Cells , Humans , Inhibitory Concentration 50 , MCF-7 Cells , Plant Stems/chemistry , Structure-Activity RelationshipABSTRACT
Bioassay-guided fractionation of the culture extract of Pestalotiopsis adusta, an endophytic fungus isolated from the medicinal plant Clerodendrum canescens, led to the isolation of one new, (10S)-12,16-epoxy-17(15â16)-abeo-3,5,8,12,15-abietapentaen-2,7,11,14-tetraone (1), and four known diterpenoids, teuvincenone F (2), uncinatone (3), coleon U (4), coleon U-12-methyl ether (5). These structures were identified by using spectroscopic methods, including UV, MS, 1D and 2D NMR experiments. This is the first report of these compounds being isolated from a Pestalotiopsis species. The cytotoxic activities of the compounds were evaluated, and compounds 1 and 3 demonstrated cytotoxic activities against the HL-60 tumour cell line (IC50 ï¼ 20 µM).