Laurencia rigida: Chemical Investigations of Its Antifouling Dichloromethane Extract

Abstract

From the CH₂Cl₂ extract of the temperate marine red alga, Laurencia rigida, which has antifouling properties, eight sesquiterpenes (1−8) were isolated. Of these, four (3-acetoxy-E-γ-bisabolene (1), (−)-10α-bromo-9β-hydroxy-α-chamigrene (2), rigidol (3), and (+)-(10S)-10-bromo-β-chamigrene (4)), were shown to be new natural products. For the known compound deschloroelatol (5), reassignment of the ¹H- and ¹³C-NMR data was found to be necessary on the basis of extensive NMR measurements. For elatol (6), complete ¹H- and ¹³C-NMR data are also reported. The antimicrobial and antialgal activities of all isolates were assessed.