Diastereomeric Quinolinone Alkaloids from the Marine-Derived Fungus Penicillium janczewskii

From Penicillium janczewskii, obtained from a marine sample, two new diastereomeric quinolinones, 3S*,4R*-dihydroxy-4-(4‘-methoxyphenyl)-3,4-dihydro-2(1H)-quinolinone (<BO>1</BO>) and 3R*,4R*-dihydroxy-4-(4‘-methoxyphenyl)-3,4-dihydro-2(1H)-quinolinone (<BO>2</BO>), were identified, along with two known alkaloids, peniprequinolone (<BO>3</BO>) and 3-methoxy-4-hydroxy-4-(4‘-methoxyphenyl)-3,4-dihydro-2(1H)-quinolinone (<BO>4</BO>). Cytotoxicity testing on eight tumor cell lines revealed a moderate specificity of <BO>2 </BO>on SKOV-3 cells.