文摘
Six novel phototoxins, phaeosphaerins A鈥揊 (1鈥?b>6), together with six known perylenequinones were isolated from an endolichenic fungus Phaeosphaeria sp. Their structures were determined unequivocally on the basis of comprehensive analysis of MS and NMR data as well as electronic circular dichroism calculations. These toxins kill cancer cells in vitro with accumulation in lysosomes, and the killing effects were potently intensified in the presence of light.