Dolabrane-type diterpenes from the mangrove plant Ceriops tagal with antitumor activities

Abstract

Chemical examination of the barks of mangrove plant Ceriops tagal resulted in the isolation of six new dolabrane-type diterpenes with the trivial names of tagalenes A–F (1–6), together with 10 known analogues. The structures of new compounds were elucidated by extensive spectroscopic data analyses. Tagalenes A–C (1–3) are characterized by 18-nordolabrane scaffold, while tagalene F (6) featured by a 2,3-seco dolabrane derivative. Antitumor assay revealed that seven compounds exhibited potent inhibitory effects against a panel of tumor cell lines with IC50<10μM, while tagalsin C (8) exerted the most potent activities in comparison with the IC50 values of the rest compounds. The primary structure–activity relationship is discussed. Tagalsin C also exerted the potent effects against a panel of drug-resistant human tumor cell lines, indicating it to be a promising molecule for further evaluation as an antitumor lead compound.