Randia dumetorum, family Rubiaceae is highly reputed ayurvedic medicinal tree commonly known as the Mainphal. A large deciduous thorny shrub grows upto 5 meters of height. It occurs in almost throughout India upto 4,000 ft attitude. It is found in Himalaya from Jammu east ward’s ascending to 1300 and from the Kashmir to east ward’s upto 4000 ft. Present study aimed at isolation of phytoconstituents from titled medicinal plant so as to validate its cytotoxic potential. α-L-Arabinosyl (1→3)-β-galactopyranosyl (1→3)-3-β-hydroxyolean-12-en-28-methyloate (compound 1) was isolated from the bark of this plant. The structure was characterized by using spectroscopic methods including 1D- 1H NMR, 13C-NMR, FABMS, experiments and hydrolytic studies. Compound (1) was subjected to cytotoxic activity against MDA-MB-231 (Breast cancer cell line) and SK-MEL-2 (Human Skin Melanoma cell line), BE(2)C (Neuroblastoma cell line derived from human bone marrow) and U87MG (Human Neuronale Glioblastoma (Astrozytom) cell-Line showed appreciable cytotoxic effect with IC50 value 93.33 μg/mL concentration for SK-MEL-2 (Human Skin Melanoma cell line).