Three sesquiterpenes from the marine-alga-epiphytic fungus Trichoderma hamatum Z36-7

Abstract

Abstract Two new cyclonerane sesquiterpenes, 5-hydroxyepicyclonerodiol oxide (1) and 4-hydroxyepicyclonerodiol oxide (2), and one new naturally occurring halogenated trichothecane derivative, trichodermol chlorohydrin (3), were isolated from Trichoderma hamatum Z36−7, an epiphytic fungal strain obtained from the marine red alga Grateloupia sp. Their structures and relative configurations were assigned on the basis of spectroscopic techniques, including 1D/2D NMR and IR as well as MS. Compound 2 features an unusual 4-hydroxy group on the five-membered ring of cycloneranes, and 3 is the first natural isolate of halogenated trichothecanes. These isolates represent the first occurrence of terpenes in T. hamatum and exhibit growth inhibition of several bacteria and phytoplankton species.