Pyran Rings Containing Polyketides from Penicillium raistrickii.

Five new pyran rings containing polyketides, penicipyrans A-E (-), together with the known pestapyrone A (), were isolated from the saline soil-derived . Their structures were determined by interpretation of NMR and HRESIMS data. The absolute configurations of compounds and were established by the modified Mosher's method and single-crystal X-ray diffraction analysis, respectively. These compounds possessed high structural diversity including two α-pyrones (, ), three isocoumarins (, , ), and one dihydropyran derivative (). Among them, Compound exhibited cytotoxicity against HL-60 and K562 cell lines with IC values of 4.4 and 8.5 μM, respectively.