Gomotsang Bojase
Department of Chemistry, University of Botswana, Private Bag 00704, Gaborone, Botswana
Cornelius C.W. Wanjala
Department of Chemistry, University of Botswana, Private Bag 00704, Gaborone, Botswana
Runner R.T. Majinda
Department of Chemistry, University of Botswana, Private Bag 00704, Gaborone, Botswana
Abstract
. The structures of two new isoflavonoids from the combined ethyl acetate/methanolic extracts of the stem bark of Bolusanthus speciosus have been established as 4,7,2' -trihydroxy-4' -methoxyisoflavanol (1) and 5,7,3' ,4' -tetrahydroxy-5' -(2-epoxy-3-methylbutyl)isoflavanone (2). Five other known isoflavonoids, 5,7,3' -trihydroxy-4' -methoxy-5' -γγ; -dimethylallylisoflavanone, 5,7,2' -trihydroxy-4' -methoxy-6,5' -di)(γγ -dimethylallyl)isoflavanone, 5,7,2' ,4'-tetrahydroxy-8,5'2; -di(γγ -dimethylallyl)flavanone, 5,7,2' ,4' -tetrahydroxy-8,3' -di(γγ -dimethylallyl)-isoflavanone, and derrone were also isolated. Compound 2 showed moderate activity against gram positive bacteria and weak activity against gram negative bacteria, while compound 1 was weakly active against both organisms in a TLC bioautography assay.
(Received March 22, 2001; revised August 13 2001)
Bull.Chem.Soc.Ethiop. 2001, 15(2), 131-136