Anti-Bacterial, Anti-Oxidant and Cytotoxic Activities of Nimbin Isolated from African Azadirachta Indica Seed Oil

Azadirachta indica (neem), belonging to Meliaceae family and native to Asia, has been used therapeutically in traditional Ayurveda, Unani, several local systems within Africa and Chinese medicine to treat different diseases for long times. The phytochemical screening of the seed oil of these plants grown in Nigeria resulted in the isolation of nimbin from the methanol soluble fraction of the hexane extract. The structure of this compound was established on the basis of nuclear magnetic resonance (NMR), Infrared (IR) and mass (MS) spectroscopy. The obtained 1H and 13C NMR data of the compound was compared with those reported already in the literature. Finally, the identity of the compound was further substantiated by employing the X-ray crystallography. The compound was also subjected to antioxidant, antibacterial and brine shrimp lethality bioassay for further analyses. The pure compound showed poor antioxidant activity and was only moderately active against Escherichia coli among all the organisms tested. Moreover, the compound shows no cytotoxicity.