Antimicrobial drimane – phthalide derivatives from Hypoxylon fendleri BCC32408

Abstract

Fourteen new compounds including thirteen drimane – phthalide derivatives (fendlerals A – C, fendlerins A – D, fendlerols A – B, fendleric acids A – C, fendlerinine G) and one terphenyl derivative (fendleryl E) along with eight known compounds, fendlerinine A, rickenyls C – D, fendleryls C – D, atromentin, tetramethyl atromentin, and (±)-microsphaerophthalide F, were isolated from the wood fungus Hypoxylon fendleri BCC32408. Compared with the prior work, the results indicated the agitation effect on the production of bioactive drimane – phthalides. The chemical structures were determined based upon spectroscopic analyses and the absolute configurations were verified by comparison of the ECD spectral data with the calculated ECD spectra of the related compounds. Compounds 1–3 exhibited antimicrobial activity against Plasmodium falciparum (IC50 4.15–4.39 μM), Colletotrichum capsici (MIC 6.25–12.5 μg/mL), and Bacillus cereus (MIC 1.56–3.13 μg/mL). All tested compounds displayed broad cytotoxicity against cancerous (MCF-7, KB, and NCI-H187) and non-cancerous (Vero) cells.