Halogenated metabolites from the new Okinawan red alga Laurencia yonaguniensis.

Abstract

A novel brominated diterpene based on the rare neoirieane skeleton, named neoirietetraol (1), has been isolated along with a halogenated C15 acetogenin, (3Z)-laurenyne (2), from a new Laurencia species, L.yonaguniensis Masuda et Abe, species inedita, collected at Yonaguni Island, Okinawa Prefecture, Japan. The structures of these metabolites were elucidated by spectroscopic data (IR, 1H NMR, 13C NMR, 2D NMR, and MS). Neoirietetraol (1) was toxic to the brine shrimp (Altemia salina; LC50, 40.1 microM) and also showed weak antibacterial activities against two marine bacteria, Alcaligenes aquamarinus and Escherichia coli.