Pyrrospirones K-Q, Decahydrofluorene-Class Alkaloids from the Marine-Derived Fungus sp. SCSIO 41512.

Seven new decahydrofluorene-class alkaloids, pyrrospirones K-Q (-), together with six known analogues (-) were isolated from the marine-derived fungal strain sp. SCSIO 41512. Their structures were determined by extensive spectroscopic analysis, and their absolute configurations were established by single-crystal X-ray diffraction analysis and quantum chemical calculations of electronic circular dichroism spectra. Compounds and possess a novel decahydrofluorene-class alkaloid skeleton with a 6/5/6/8/5/6/13 and a 6/5/6/5/6/13 polycyclic system, respectively. Biologically, displayed significant inhibitory activity against protein tyrosine phosphatases CD45, TCPTP, SHP1, and PTP1B with IC values of 8.1-17.8 μM, and , , , -, , and showed antibacterial activity against six pathogens. Their structure-activity relationship is also discussed.