Sesquiterpenoids and a steroid from the algicolous Trichoderma brevicompactum

Six new sesquiterpenoids including three bisabolane derivatives, trichobisabolins O-1, O-2, and P (1-3), two nerolidol derivatives, trichonerolins A and B (4 and 5), one acorane, trichoacorin A (6), along with one new steroid, isoergokonin B (7), were isolated from the culture of Trichoderma brevicompactum A-DL-9-2 obtained from the inner tissue of the red alga Chondria tenuissima. Their structures and relative configurations were assigned by interpretation of 1D/2D NMR and MS data. As acyclic sesquiterpenoids, compounds 4 and 5 were discovered from Trichoderma for the first time. Compounds 1-7 were evaluated for the inhibition of some marine derived organisms, in which, 3 and 4/5 exhibited potent inhibition against Amphidinium carterae and Chattonella marina with IC50 of 1.8 mu g/mL and 1.2 mu g/mL, respectively. In addition, compound 7 could inhibit the growth of Pseudoalteromonas citrea with an MIC value of 64 mu g/mL.

Automated summary

Six new sesquiterpenoids, including three bisabolane derivatives, two nerolidol derivatives, one acorane, and one steroid, were isolated from the culture of Trichoderma brevicompactum obtained from the inner tissue of the red alga Chondria tenuissima. Compounds 4 and 5 were discovered from Trichoderma for the first time. Compounds 3, 4, and 5 exhibited potent inhibition against marine derived organisms, with compound 7 also showing inhibitory activity against Pseudoalteromonas citrea.