Alkaloids from an algicolous strain of <Emphasis Type="Italic">Talaromyces</Emphasis> sp.

Compounds isolated and identified in a culture of the alga-endophytic fungus Talaromyces sp. cf-16 included two naturally occurring alkaloids, 2-[(S)-hydroxy(phenyl)methyl]-3-methylquinazolin-4(3H)-one (1a) and 2-[(R)-hydroxy(phenyl)methyl]-3-methylquinazolin-4(3H)-one (1b), that were identified for the first time. In addition, seven known compounds (2–8) were obtained from the culture. Following chiral column chromatography, compounds 1a and 1b were identified as enantiomers by spectroscopic analyses and quantum chemical calculations. Bioassay results showed that 5 was more toxic to brine shrimp than the other compounds, and that 3–6 could inhibit Staphylococcus aureus.