Three New Cytotoxic ent-Kaurane Diterpenes from Isodon excisoides.

ABSTRACT: Three types of ent-kaurane diterpenoids were isolated from the aerial parts of Isodon excisoides, including three new diterpenoids, 1?,7?,14?-trihydroxy-20-acetoxy-ent-kaur-15-one (1); 1?,7?,14?,18-tetrahydroxy-20-acetoxy-ent-kaur-15-one (2); and 1?-acetoxy-14?-hydroxy-7?,20-epoxy-ent-kaur-16-en-15-one (3); together with six known diterpenes henryin (4); kamebanin (5); reniformin C (6); kamebacetal A (7); kamebacetal B (8); and oridonin (9). The structures of the isolated compounds were elucidated by means of nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry in conjunction with published data for their analogs, as well as their fragmentation patterns. Compounds 5 and 9 were isolated from Isodon excisoides for the first time. To explore the structure-activity relationships of the isolated compounds, they were tested for their cytotoxic effects against five human cancer cell lines: HCT-116, HepG2, A2780, NCI-H1650, and BGC-823. Most of the isolated compounds showed certain cytotoxic activity against the five cancer cell lines with IC50 values ranging from 1.09-8.53 µM. Among the tested compounds, compound 4 exhibited the strongest cytotoxic activity in the tested cell lines, with IC50 values ranging from 1.31-2.07 µM. Compounds 1, 6, and 7 exhibited selective cytotoxic activity.

SUBMITTER: Dai LP 

PROVIDER: S-EPMC6332174 | biostudies-literature | 2015 Sep

REPOSITORIES: biostudies-literature