Pesimquinolones produced by Penicillium simplicissimum and their inhibitory activity on nitric oxide production

Eight undescribed quinolone alkaloids, pesimquinolones A−H, as well as six known compounds, were isolated from the solid culture broth of the fungus Penicillium simplicissimum. Their chemical structures were characterized by combined analyses of NMR spectroscopy and single-crystal X-ray crystallography. Pesimquinolones A−G are the first examples of naturally occurring quinolone alkaloids possessing a limonene moiety. Their anti-inflammatory activities on LPS-induced nitric oxide (NO) production in adherent cells were evaluated. Pesimquinolones A, E, G, and H showed promising suppressive effect on the production of NO with IC50 values of 1.94, 1.29, 1.20, and 1.23 μM, respectively. Eight undescribed quinolone alkaloids, pesimquinolones A−H, were isolated from the fungus Penicillium simplicissimum. Pesimquinolones A, E, G, and H showed promising suppressive effects on the production of NO, with IC50 values of 1.94, 1.29, 1.20, and 1.23 μM, respectively. [Display omitted] •Eight undescribed quinolone alkaloids were isolated from Penicillium simplicissimum.•Pesimquinolones A−G are the first example of quinolone alkaloids possessing a limonene moiety.•Pesimquinolones A, E, G, and H showed promising suppressive effect on the production of NO.