In vitro antifungal activity of sanguinarine and chelerythrine derivatives against phytopathogenic fungi

Abstract

In order to understand the antifungal activity of some derivatives of sanguinarine (S) and chelerythrine (C) and their structure-activity relationships, sixteen derivatives of S and C were prepared and evaluated for in vitro antifungal activity against seven phytopathogenic fungi by the mycelial growth rate method. The results showed that S, C and their 6-alkoxy dihydro derivatives S 1-S 4, C 1-C 4 and 6-cyanodihydro derivatives S 5, C 5 showed significant antifungal activity at 100 μg/mL against all the tested fungi. For most tested fungi, the median effective concentrations of S, S 1, C and C 1 were in a range of 14-50 μg/mL. The structure-activity relationship showed that the C=N + moiety was the determinant for the antifungal activity of S and C. S 1-S 5 and C 1-C 5 could be considered as the precursors of S and C, respectively. Thus, the present results strongly suggested that S and C or their derivatives S 1-S 5 and C 1-C 5 should be considered as good lead compounds or model molecules to develop new anti-phytopathogenic fungal agents. © 2012 by the authors.