Deoxytrichodermaerin, a harziane lactone from the marine algicolous fungus Trichoderma longibrachiatum A-WH-20-2

Three metabolites deoxytrichodermaerin (a new harziane lactone), harzianol A and harzianone were obtained from Trichoderma longibrachiatum A-WH-20-2, an endophyte from marine red alga Laurencia okamurai. Their structures and relative configurations were unequivocally assigned by spectroscopic techniques, and the absolute configuration of deoxytrichodermaerin was established by analysis of the ECD curve aided by quantum chemical calculations. Deoxytrichodermaerin represents the second harziane lactone with an ester linkage between C-10 and C-11. Harzianol A occurs as a natural product of Trichoderma for the first time. Harzianone has been previously discovered from T. longibrachiatum cf-11. These isolates exhibited potent inhibition of some marine plankton species.

Automated summary

Three metabolites were isolated from Trichoderma longibrachiatum, an endophyte from marine red alga Laurencia okamurai. Among them, deoxytrichodermaerin represents the second harziane lactone with an ester linkage at a specific position, while harzianol A is a new natural product of Trichoderma. These isolates showed potent inhibition of some marine plankton species.