Two undescribed indole alkaloids from the endophytic fungus Penicillium sp. KYJ-6 and their bioactivities.

Two undescribed indole alkaloids, one prenylated indole alkaloid penrhizovarin B (1) and one macfortine alkaloid penrhizovarin C (2), along with two known analogues (3-4), were characterized by Penicillium sp. KYJ-6. Structural elucidation was accomplished through comprehensive spectroscopic analyses, including high-resolution electrospray ionization mass spectrometry (HRESIMS) and electronic circular dichroism (ECD) calculations. Furthermore, in vitro bioactivity assays were conducted on compounds 1 and 2 across five human cancer cell lines, which revealed no significant cytotoxic effects. Concurrently, antifungal activity assessments were performed, and penrhizovarin B (1) demonstrated notable antifungal efficacy.