Naphthoquinones from the Roots of Onosma argentatum Hub.-Mor. (Boraginaceae)

Authors: UFUK ÖZGEN, MAKSUT COŞKUN, CAVİT KAZAZ, HASAN SEÇEN

Abstract: Onosma argentatum Hub.-Mor. is an endemic species growing in Turkey. In this study, the roots of O. argentatum were extracted with n-hexane-dichloromethane (1:1). The extract was separated on a silica gel column eluting with n-hexane-ethyl acetate by gradient elution. New naphthoquinone compounds (3 known and 1 new) were isolated and their structures were elucidated by spectroscopic methods as deoxyshikonin, acetyl shikonin, 3-hydroxy-isovaleryl shikonin, and 5,8-O-dimethyl acetyl shikonin.

Keywords: Onosma argentatum, natural naphthoquinones, shikonin derivatives, Boraginaceae, 5,8-O-dimethyl acetyl shikonin

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