Anticonvulsant compounds from the wood of Caesalpinia sappan L.

80% Aqueous MeOH extracts from the wood of Caesalpinia sappan, which showed remarkable anticonvulsant activity, were fractionated using EtOAc, n-BuOH, and H2O. Among them, the EtOAc fraction significantly inhibited the activi ties of two GABA degradative enzymes, succinic semialdehyde dehydrogenase ( SSADH) and succinic semialdehyde reductase (SSAR). Repeated column chromato graphies for the fraction guided by activity test led to the isolation of t he two active principal components. Their chemical structures were determin ed to be sappanchalcone and brazilin based on spectral data. The pure compo unds, sappanchalcone (1) and brazilin (2), inactivated the SSAR activities in a dose dependent manner, whereas SSADH was inhibited partially by sappan chalcone and not by brazilin.