CINNAMATE ESTERS OF CATALPOL FROM WESTRINGA-FRUTICOSA AND WESTRINGIA-VIMINALIS

Two cinnamate esters of catalpol were isolated from Westringia frutico sa and Westringia viminalis. They were identified as 6-O-([Z]-4-methox ycinnamoyl)-catalpol and 6-O-([E]-3,4-dimethoxycinnamoyl) catalpol by spectroscopic methods. The former appears to be novel. Each exhibited antifungal activity against the plant pathogenic fungus Cladosporium c ucumerinum. Minimum inhibitory doses were 10 and 25 mu g, respectively , with activity persisting for 48 h in the direct TLC bioautography as say. The concentration of 6-O-([Z]-4-methoxycinnamoyl) catalpol in the two species of Westringia was variable but detectable in all samples. Concentrations were significantly greater (P < 0.05) in W. fruticosa but there was overlap between the two taxa.