Bioassay guided isolation of naphthoquinones from Onosma aksoyii, investigation of their cytotoxic properties

Abstract

The genus Onosma L. (Boraginaceae) includes about 230 species, distributed mainly in the Mediterranean region and Central Asia. Major constituents of Onosma species are alkaloids, naphthoquinones, polyphenols, phytosterols, terpenoids and fatty acids [1], [2]. Naphthoquinones are naturally widespread secondary metabolites deriving from some higher plants, fungi and bacteria. They exhibit significant biological activities such as cytotoxicity, antimalarial, antibacterial, antifungal and wound healing [2], [3]. Recently naphthoquinone derivatives have also been recognized as potent topoisomerase inhibitors [4].