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Z. Naturforsch. 2013,
68b, 931 – 938
doi:10.5560/ZNB.2013-3106
Antimicrobial and Antioxidant Isoflavonoid Derivatives from the Roots of Amphimas pterocarpoides
1 Department of Organic Chemistry, Faculty of Science, University of Yaounde I, P. O. Box 812, Yaounde, Cameroon
2 Department of Biochemistry, Faculty of Science, University of Dschang, Cameroon
Reprint requests to Prof. Augustin E. Nkengfack. E-mail:
ankengf@yahoo.fr
Received March 27, 2013 / published online July 25, 2013
A new bis-isoflavone derivative, named amphiisoflavone (1), was isolated from the roots of Amphimas pterocarpoides, together with three known isoflavones, namely 8-methoxyisoformononetin (2), 6-methoxyisoformononetin (3) and isoformononetin (4). Chemical transformations carried out on compound 3 led to two new derivatives, 4′-acetoxy-6,7-dimethylisoflavone (3a) and 4′-O-prenyl-6,7-dimethylisoflavone (3p), along with a known compound, 4′,6,7-trimethoxyisoflavone (3m). The structures of all compounds were elucidated from spectroscopic evidence, in particular by 1D and 2D NMR spectroscopic methods. These compounds were evaluated for their antioxidant properties and for their antimicrobial activities against a wide range of bacteria and fungi.
Key words: Amphimas pterocarpoides, Isoflavones, Chemical Transformations, Antimicrobial Properties, Antioxidant Activities