Chemical and biological investigation of the fungus Pulveroboletus ravenelii

Two new compounds, pulveraven A (1) and pulveraven B (2), as well as vulpinic acid (3) and its previously unreported polymorph were isolated from the fruiting body of Pulveroboletus ravenelii. The structures were determined using a combination of NMR, MS, IR, optical rotation, molecular modeling, and X-ray analysis. The isolates were evaluated for antimicrobial activity as well as their potential to inhibit cyclooxygenase (COX) activity and carcinogen-induced preneoplastic lesion formation with mouse mammary organ culture (MMOC).