ANTI-BACTERIAL DITERPENES FROM BORNEAN SOFT CORALS SINULARIA FLEXIBILIS

Two new compounds, (13Z,16E)-fuscol (1) and (13E,16Z)-fuscol (2), along with five known and related metabolites fuscol (3), 18-methoxyloba-8,10,13(15),16(17)-tetraene (4), isofuscol (5), 17,18-epoxyloba- 8,10,13(15)-trien-l6-ol (6) and loba-8,10,13(15)-triene-16,17,18-triol (7) were isolated from the methanolic extract of Bornean soft coral Sinularia flexibilis (Dinawan Island). Meanwhile, one new compound, (3E,5E)-2- methyl-6-[(2'R*,4a'S*,8a'R*)-4a'-methyl-8'-methylene-trans-perhydronaphthalen-2'-yl]hepta-3,5-dien-2- methoxy (8) together with a known compound, (3E,5E)-2-methyl-6-[(2'R*,4a'S*,8a'R*)-4a'-methyl-8'- methylene-trans-perhydronaphthalen-2'-yl]hepta-3,5-dien-2-ol (9) were isolated from the methanolic extract of another populations of Bornean S. flexibilis from Banggi Island. The structures of these three new molecules were elucidated based on spectroscopic methods (NMR, HR-ESI-MS and IR). In addition, their anti-bacterial activity was evaluated.