Antibacterial Compounds from Mushrooms I: A Lanostane-Type Triterpene and Prenylphenol Derivatives from Jahnoporus hirtus and Albatrellus flettii and Their Activities Against Bacillus cereus and Enterococcus faecalis

Antibacterial bioassay-guided fractionation of two American mushroom species, JAHNOPORUS HIRTUS and ALBATRELLUS FLETTII, led to the isolation and identification of their major antibacterial constituents: 3,11-dioxolanosta-8,24( Z)-diene-26-oic acid ( 1) from J. HIRTUS and confluentin ( 2), grifolin ( 3), and neogrifolin ( 4) from A. FLETTII. Compound 1 is a new lanostane-type triterpene. All purified compounds were evaluated for their ability to inhibit the growth of BACILLUS CEREUS and ENTEROCOCCUS FAECALIS using standard MIC assays. Compounds 1- 4 demonstrated MIC values of 40, 20, 10, and 20 μg/mL, respectively, against B. CEREUS and MIC values of 32, 1.0, 0.5, and 0.5 μg/mL, respectively, against E. FAECALIS. Thus, one novel compound and three others were shown to possess antimicrobial activities against these gram-positive bacteria employed as surrogates for more virulent and dangerous pathogens.