Pyrrolidine Alkaloids and Polyketide Derivatives from the Marine-Derived Fungus Trichoderma harzianum ZN-4

Two unusual alkaloids with furanopyrrolidine skeleton, harzianopyrrolidones A-B (1-2), four new compounds, harzianopyridone B (3), harzianopyrone (4), (R)-1-(3,5-dihydroxy-4-methylphenyl)-1-hydroxyhept-5E-en-2-one (5), and harzianopyrrolidone C (6), together with two known compounds (7-8) were isolated from a marine-derived fungus Trichoderma harzianum ZN-4. Structures of the isolated compounds were elucidated based on their HRESIMS data, extensive NMR spectroscopic analyses, NMR calculation in combination with DP4+, ECD calculations, and a single-crystal X-ray diffraction experiment. New compounds 1, 4, and 5 exhibited potential cardiomyocyte protective activity at concentrations ranging from 5 to 20 μM. In addition, 7 showed moderate inhibitory activity against Pestalotiopsis theae with an MIC value of 25 μg/mL.