INDUCTION OF BENZOQUINONE FORMATION BY ACTIVATED CARBON IN LITHOSPERMUM ERYTHRORHIZON CELL SUSPENSION CULTURES

Article abstract of DOI:10.1016/S0031-9422(00)80322-2

Cultured cells of Lithospermum erythrorhizon which were capable of producing red naphthoquinone (shikonin) derivatives on Linsmaier-Skoog's agar medium stopped synthesizing these compounds when grown in liquid medium without agar.However, when the liquid medium was supplemented with a small amount of activated carbon, the cells produced a new orange benzoquinone derivative, echinofuran B, which may be considered an abnormal metabolite of geranylquinol, the key intermediate in the biosynthesis of shikonin.A similar effect of activated carbon was also observed with a variant cell line incapable of producing shikonin derivatives even on the agar medium.By contrast, the callus cultures grown on the agar medium as well as the dried roots of the intact plant were found to contain a small amount of echinofuran C, another new benzoquinone related to echinofuran B, in addition to shikonin derivatives.Key Word Index - Lithospermum erythrorhizon; Boraginaceae; plant cell culture; activated carbon; biosynthesis; echinofuran; shikonin; benzoquinone; naphthoquinone.