One new coumarinolignan, cleomiscosin F (1) along with ten known compounds namely 3,4-secotirucalla-4(28),7,24-trien-21-hydroxy-21,23-epoxy-3-oic acid (2), 3,4-secotirucalla-4(28),7,24-trien-3,21-dioic acid (3),ceramid A (4),ceramid B (5), mayombensin (6),aridanin (7), stigmasterol and β-sitosterol and their glucosides were isolated from the seeds and roots of Leplaea mayombensis (Meliaceae).Thestructures of the compounds were elucidated based on the interpretation of their spectroscopic data. Some of the isolated compounds (3, 4 and 5) were tested in vitro against bacteria strains Escherichia coli, Bacillus subtilis, Pseudomonas agarici, and Micrococcus luteus. Compound 3 displayed good activity against Bacillus subtilis, Micrococcus luteus, and Pseudomonas agarici with MIC values of 1.7, 2.3 and 9.8µM, respectively; while compound 4 showed significant activity against Micrococcus luteus with MIC value of 11.9µM. تفاصيل المقالة