Antibiotics from Australian terrestrial invertebrates. Part 1: Antibacterial trinervitadienes from the termite Nasutitermes triodiae

The antibacterial activity of an extract of the Australian termite Nasutitermes triodiae (Isoptera: Termitidae) (Froggatt) is due to the presence of a group of trinervitanes, diterpenes unique to termite genera within the subfamily Nasutitermitinae. The major active components are novel hydroxylated 1(15),8(19)-trinervitadienes and the known 1(15),8(9)-trinervitadiene-2β,3α-diol. This constitutes the first observation of hydroxylation of the trinervitane skeleton at the 5- and 18-positions, and of the substantial antimicrobial activity of trinervitane diterpenes.