Pyrrole alkaloids from the fruiting bodies of edible mushroom Lentinula edodes

Nine pyrrole alkaloid derivatives, including four new ones (1–4), were isolated from the wild mushroom Lentinula edodes for the first time. Their chemical structures were determined using UV-Vis spectroscopy, IR spectroscopy, MS, NMR spectroscopy, and single-crystal X-ray diffraction techniques. Compound 1, a previously unreported bicylo-pyrrole aldehyde homologue, was found to be a major component, approximately 8.2 μg g (−1) in the dry powder of L. edodes. Compound 1 showed cytotoxicity against SMMC-772 (IC(50) 15.8 μM) without any cytotoxic effect on LO2, a normal hepatic cell line; compounds 1 and 2 displayed weak immunosuppressive activities by inhibiting the proliferation of induced T cells; compound 3 showed inhibition activity on the proliferation of HaCaT cell line (IC(50) 25.4 μM) and weak antioxidant activity at a concentration of 50 μM.