Inhibition of wheat embryo calcium-dependent protein kinase and other kinases by mangostin and γ-mangostin

Abstract

The hull of the fruit of the mangosteen tree (Garcinia mangostana) contains four inhibitors of plant Ca²⁺-dependent protein kinase. Two of these inhibitors have been purified and identified as the xanthones 1,3,6-trihydroxy-7-methoxy-2,8-bis(3-methyl-2-butenyl)-9H-xanthen-9-one (mangostin) and 1,3,6,7-tetrahydroxy-2,8-bis(3-methyl-2-butenyl)-9H-xanthen-9-one (γ-mangostin). Both xanthones also inhibit avian myosin light chain kinase and rat liver cyclic AMP-dependent protein kinase. This is the first report of inhibition of plant and animal second messenger-regulated protein kinases by plant-derived xanthones.