A known triterpene glycoside, 3-O-[beta-D-glucopyranosyl-(1"-6')-2'-acetamido-2'-deoxy-beta-D-gluco pyranosyl]olean-12-en-28-oic acid [3], and new sulfated triterpene, echinocystic acid-3-O-sodium sulfate [4], have been isolated from the stem bark of Tetrapleura tetraptera. Compound 3 was 100% lethal to Biomphalaria glabrata at 20 ppm, while 4 was not molluscicidal at the same concentration. In a forward mutation assay utilizing Salmonella typhimurium strain TM677, T. tetraptera stem bark extracts were found to be mutagenic in the absence of a metabolic activating system (S-9). An MeOH extract of the fruit exhibited weak mutagenic activity only in the presence of S-9. The stem bark isolates, which included aridanin [1], 3-O-(2'-acetamido-2'-deoxy-beta-D-glucopyranosyl)echinocystic acid [2], and compounds 3 and 4, were not mutagenic either with or without metabolic activation.