Three new α-pyrone derivatives from the plant endophytic fungus Penicillium ochrochloronthe and their antibacterial, antifungal, and cytotoxic activities

Abstract

Three new 3,4,6-trisubstituted α-pyrone derivatives, namely 6-(2′R-hydroxy-3′E,5′E-diene-1′-heptyl)-4-hydroxy-3-methyl-2H-pyran-2-one (1), 6-(2′S-hydroxy-5′E-ene-1′-heptyl)-4-hydroxy-3-methyl-2H-pyran-2-one (2), and 6-(2′S-hydroxy-1′-heptyl)-4 -hydroxy-3-methyl-2H-pyran-2-one (3), together with one known compound trichodermic acid (4), were isolated from the solid-substrate fermentation culture of Penicillium ochrochloronthe associated the roots of Taxus media. Compounds 1–4 displayed the antimicrobial activity selectively against tested fungal and bacterial strains with minimum inhibitory concentration (MIC) values ranging from 12.5 to 100 μg/ml. Furthermore, we found that only compound 4 exhibited moderate cytotoxicity against five human cancer cells (A549, LN229, MGC, LOVO, and MDA231) with IC₅₀ values of 51.45, 23.43, 39.16, 46.97, and 42.85 μg/ml, respectively.

Keywords:

• Plant endophytic fungi
• Penicillium ochrochloronthe
• Taxus media
• α-pyrone
• antimicrobial activity
• cytotoxic activity