Secondary metabolite production in cell cultures of artocarpus lakoocha

Abstract

A study on the secondary metabolite production in cell cultures of Artocarpus lakoocha Roxb. was initiated by inducing callus formation from aerial part explants on Woody Plant Medium (WPM), which contained 1 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D), 1 mg/l benzyladenine (BA) and 20 g/l sucrose. A chemical study of the callus cultures of A. lakoocha led to the isolation of thirteen pure compounds, including four new compounds, namely, 5,7,4'-trihydroxy-2'-methoxy-3-(y,y-dimethylallyl)-flavone, 7,2',4'-trihydroxy-3",4"-dehydropyrano [1",4":5,6] flavone, trans-2,4,5'-trihydroxy-3'-methoxy-4'-(3-methyl-E-but-1-enyl)-stilbene and 3-geranyl-2,4,3',5'-tetrahydroxystilbene together with nine known compounds including aesculin, (--)-catechin, albanin A, isoartocarpesin, norartocarpin, cudraflavone B, cudraflavone C, artotonkin and chlorophorin. Their structures were elucidated through analysis of their spectroscopic data and by comparison with previously reported data. The isolated compounds were evaluated for free radical scavenging and antityrosinase activities. Stilbenoids showed potent free radical scavenging activity and tyrosinase inhibitory activity. A thin-layer chromatography (TLC) densitometric method was also developed for the determination of oxyresveratrol content in A. lakoocha heartwood and in the traditional drug ‘Puag-Haad’, and the secondary metabolites in plant cell cultures of A. lakoocha. A study on the growth-product relationship during the 25-day growth of A. lakoocha callus cultures showed that all the isolated compounds were formed over the peroid of the culture growth. The obtained chemical profiles appeared to proceed parallelly to the growth curve of the callus, with the maximum content in the period of progressive decleration phase (day 15-day 17) followed by a rapid decline in the stationary phase (day 20-day 25).