Six new diterpene isonitriles from the sponge Acanthella cavernosa.

Six new diterpene isonitriles, 10-epi-isokalihinol F [1], 10-epi-isokalihinol H [2], 1-epi-kalihinene [4], 15-isothiocyanato-1-epi-kalihinene [5], 1,10-diepi-kalihinene [6], and kalihipyran [7] were isolated, together with the known compound isokalihinol B [3], from Acanthella cavernosa collected in the Seychelles. The structures of the new diterpenes were elucidated by interpretation of spectral data. The ring system of kalihipyran [7] differs from that of the kalihinols and kalihinenes.