Cytotoxic diterpenoids from the roots of Salvia lachnocalyx

Salvia lachnocalyx Hedge, Lamiaceae, is an endemic sage which grows naturally in the Fars Province of Iran. The phytochemical analyses of the roots of S. lachnocalyx led to the isolation of five known diterpenoids: ferruginol (1), taxodione (2), sahandinone (3), 4-dehydrosalvilimbinol (4) and labda-7,14-dien-13-ol (5). Their chemical structures were elucidated using one (H-1 and C-13) and two dimensional (COSY, HSQC and HMBC) NMR spectroscopic data as well as electron impact mass spectra. The cytotoxicity of the purified compounds was evaluated against three human cancer cell lines; MOLT-4 (acute lymphoblastic leukemia), HT-29 (colorectal adenocarcinoma) and MCF7 (breastadenocarcinoma) and all of the isolated compounds showed considerable cytotoxic activity against these cell lines. Compounds 2 and 3 (IC50 range: 0.413.87 mu g/ml) with endocyclic alpha,beta-unsaturated carbonyl functional group, exhibited the highest cytotoxic activities compared to the other compounds (IC50 range: 6.8517.23 mu g/ml). In conclusion, compounds 2 and 3 are presented as compounds that deserve further investigation of their biological activities (c) 2017 Sociedade Brasileira de Farmacognosia. Published by Elsevier Editora Ltda.