Pyran Rings Containing Polyketides from Penicillium raistrickii

Abstract

Five new pyran rings containing polyketides, penicipyrans A-E (<b>1</b>-<b>5</b>), together with the known pestapyrone A (<b>6</b>), were isolated from the saline soil-derived <i>Penicillium raistrickii</i>. Their structures were determined by interpretation of NMR and HRESIMS data. The absolute configurations of compounds <b>4</b> and <b>5</b> 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 (<b>1</b>, <b>2</b>), three isocoumarins (<b>3</b>, <b>4</b>, <b>6</b>), and one dihydropyran derivative (<b>5</b>). Among them, Compound <b>5</b> exhibited cytotoxicity against HL-60 and K562 cell lines with IC₅₀ values of 4.4 and 8.5 μM, respectively.