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As part of our continuing efforts to discover new bioactive compounds from endophytic fungal sources, we have investigated the extract of the Paraphaeosphaeria sporulosa F03 strain. The study led to the isolation of four new 3-methyl-isoquinoline alkaloids (1 – 4) and four known polyketides (5 – 8). The structures of compounds 1 – 4 were elucidated by 1D and 2D NMR experiments and HRMS analysis. The absolute configuration of 4 was determined by comparison of its experimental electronic circular dichroism spectrum with calculated data. Compounds 1 – 4 exhibited antifungal activity with minimal inhibitory concentration values ranging from 6.25 – 50 µg/mL against six Candida species but they did not present any cytotoxic activity against the human tumor cell lines A549 (lung), MCF-7 (breast), and HepG2 (hepatocellular). In addition, compound 4 exhibited antiplasmodial activity in the low micromolar range (IC50 = 4 µM). [ABSTRACT FROM AUTHOR]

Three new benzaldehyde derivatives, sporulosaldeins A – C (1 – 3), and 3 new benzopyran derivatives, sporulosaldeins D – F (4 – 6), were discovered from an endophytic fungus, Paraphaeosphaeria sp. F03, which was isolated from Paepalanthus planifolius leaves. Compounds 1 – 6 were elucidated by 1- and 2-dimensional nuclear magnetic resonance experiments and high-resolution mass spectrometry analysis. The absolute configuration of compound 5 was determined through the comparison of experimental and calculated electronic circular dichroism data. Compounds 1 – 6 were found to exhibit antifungal activity with minimum inhibitory concentration (MIC) values of 7.8 – 250 µg/mL and racemic mixture of compound 6 exhibited weak cytotoxicity against MCF-7 and LM3 with IC50 values of 34.4 and 39.2 µM, respectively. [ABSTRACT FROM AUTHOR]