A number of biosynthetically and chemically related compounds were isolated from the roasted seeds of Moringa oleifera. The micronucleus test, an in vivo method, using albino mice as the test system, was used for monitoring the mutagenicity of the isolated compounds. Structure-activity correlation studies showed that 4(α-L-rhamnosyloxy)phenylacetonitrile, 4-hydroxyphenylacetonitrile, and 4-hydroxyphenyl-acetamide exhibited mutagenic activity.