Three abietane diterpenes and two diterpenes incorporated sesquiterpenes from the bark of Cryptomeria japonica

Abstract

Three new abietane diterpenes, sugikurojins D (1), E (2), and F (3), and two new abietanes which incorporate cadinane, sugikurojins G (4) and H (5) were isolated from the bark of Cryptomeria japonica. These structures were elucidated primarily by extensive NMR experiments. The structure of sugikurojin D (1) was deduced to be 6α-acetoxy-7β,11-dihydroxy-12-methoxy-8,11,13- abietatriene. Sugikurojin E (2) was deduced to be 6α-acetoxy-7β,12- dihydroxy-8,11,13-abietatriene. Sugikurojin F (3) was 7α-methoxy-8,13- abietadien-11,12-dione. Sugikurojins G (4) and H (5) had a unique skeleton incorporating an α-cadinol or a 1α-hydroxy-T-cadinol in ferruginol, respectively. Also obtained in this investigation were the known diterpenes (6-14). An antibacterial activity of ten among these against Staphylococcus aureus and Escherichia coli was inactive at the (MIC: 125 μg/ml) level. Meanwhile, in the cytotoxic activity against HL-60, compounds 4, 8, and 11 showed moderate (IC50: 4, 35.4; 8, 28.0; 11, 52.4 μM) though weak (IC50: 4, 100; 8, 80.8; 11, 100 μM) activity against HCT-15. © 2006 Pharmaceutical Society of Japan.