Cussonia arborea Hochst (Araliaceae): Ethnobotany, Pharmacology and Phytochemistry

Background: C. arborea belonging to Araliaceae family is used traditionally to cure many alien diseases including gonorrhoeae infection, diarrhea, malaria, and diabetes mellitus. The plant has been examined on the basis of scientific in vitro and in vivo evaluations possessing the major pharmacological activities including antimicrobial, antibacterial, antihyperglycemic, antiplasmodial and anticancer properties. Aim of the study: In the present paper, we reported the isolation and characterization of secondary metabolites from the methanol extract of the stem bark of Cussonia arborea Hochst after a short review of the traditional and pharmacological studies done on this important medicinal plant. Materials and methods: MeOH extract of stem bark of C. arborea was suspended in water and successively extracted with EtOAc and n-BuOH. The EtOAc extract (18 g) was subjected to repeated column chromatography to yield seven (1-7) compounds. Their structures were determined by means of NMR, and published data. Results: The isolated compounds were identified as: protocatechuic acid (1), mixture of 3,23-dihydroxyolean-12-en-28-oic acid (2a) and 3,23-dihydroxyurs-12-en-28-oic acid (2b) in ratio 5/4, 3-O-β-D-xylopyranosylolean-12-en-28-oic acid (3), 3-O-α-L-arabinopyranosylolean-12-en-28-oic acid (4), β-resorcylic acid (5), mixture of 3-O-β-D-glucopyranosyl-23-hydroxyolean-12-en-28-oic acid (6a) and 3-O-β-D-glucopyranosyl-23-hydroxyurs-12-en-28-oic acid (6b) in ration 4/1, 3-O-β-D-glucopyranosyl-(1→2)-α-L-arabinopyranosyl-3β-hydroxyolean-12-en-28-oic acid (7). Compounds 3, 4, 5, 7, 2b and 6b are herein reported for the first time in this plant