Antimicrobial screening of ethyl ether and alcoholic extracts of leaves of four selected exotic tree species growing in Rajasthan Desert was carried out. Colophospermum mopane, Holoptelea integrifolia, Kigelia pinnata and Putranjiva roxburghii showed positive reactions against bacterial pathogens i.e. Staphylococcus aureus, Escherichia coli and a fungal pathogen Candida albicans.

Evaluation of flavonoid contents from four selected exotic tree species like Colophospermum mopane, Holoptelea integrifolia, Kigelia pinnata and Putranjiva roxburghii growing in Rajasthan Desert was carried out. The leaves of selected trees were analysed for flavonoid contents i.e. Quercetin and Kaempferol. Flavonoid contents like Quercetin and Kaempferol were isolated and identified. The maximum total flavonoid contents (17.10mg./gdw) was found in leaves of Putranjiva roxburghii while minimum (9.20mg./gdw) in leaves of Holoptelea integrifolia.

Ascorbic acid contents of stems, leaves and fruits from four selected exotic tree species like Colophospermum mopane, Holoptelea integrifolia, Kigelia pinnata and Putranjiva roxburghii have been analysed. Maximum ascorbic acid contents were found in the fruits of Colophospermum mopane (42.10mg/100g.d.w.) while, minimum in the stems of Kigelia plnnata (22.15mg/100g.d.w).