Non-halogenated new sesquiterpenes from Bornean Laurencia snackeyi

Abstract

Two new non-halogenated sesquiterpenes, snakeol (1) and snakediol (2) were isolated together with 9 known sesquiterpenes such as (R,Z)-33-dimethyl-5-methylene-4-(3-methylpenta-24-dien-1-yl)cyclohex-1-ene (3), palisol (4), pacifigorgiol (5), palisadin D (6), palisadin A (7), palisadin B (8), 5-acetoxypalisadin B (9), debromolaurinterol (10) and α-bromocuparane (11) from the red algae Laurencia snackeyi. The structures of two new metabolites were determined from their spectroscopic data (IR, 1D and 2D NMR and MS). Compounds 1, 2, 10 and 11 showed strong antibacterial activity against selected human clinical bacterial pathogens.

Keywords:

• Red alga
• rhodomelaceae
• Laurencia snackeyi
• sesquiterpene
• chemical race
• antibacterial activity

Acknowledgements

The authors would like to thank the Sabah Parks for the support and assistance during field survey and Grant GL0070 from Sabah Biodiversity Center, Sabah State Government.