Harzianone (2), a new harziane diterpene, was isolated from an alga-endophytic isolate of Trichoderma longibrachiatum. The structure and absolute configuration of 2 were unambiguously identified by NMR and mass spectrometric methods as well as quantum chemical calculations. The absolute configuration of harziandione (1) was supported by calculation of optical rotation, and the structure of isoharziandione was revised to 1 on the basis of (13)C NMR data comparison and calculation.

Through addition of suberoylanilide hydroxamic acid, two new aromatic norditerpenes, aspewentins A (1) and B (2), along with an oxygenated derivative, aspewentin C (3), were obtained from the culture of an Aspergillus wentii strain (na-3) isolated from the tissue of the brown alga Sargassum fusiforme. The structures and absolute configurations were unambiguously elucidated by spectroscopic analyses and quantum chemical calculations. Aspewentins A-C were produced before sporulation and exhibited potent bioactivities against some marine-derived organisms.