BIOLOGICAL ACTIVITY OF LEAVES OF SOME ORNAMENTAL PLANTS EXTRACTS WITH EMPHASIS ON CHEMICAL INVESTIGATION

Abstract

An experiment was conducted on biologically active substances in aqueous extracts of leaves of some ornamental plants viz., joba (Hibiscus rosa sinensis), kamini (Murraya exotica), sephali (Nyctanthes arbortristis), bokul (Mimusops elengi), polash (Butea monosperma), krishnachura (Caesalpinia pulcherrima), kantalichapa (Artabotrys odoratissimus), togor (Tabernaemontana coronaria), rongon (Jxora coccinia) and mouchanda (Mussaenda erythrephytta), for each vegetable crop such as, country bean (Lablab niger), kolmishak (Impoea aquatica), okra (Hibiscus esculentus) and borboti (Vigna unguiculata), with the attempt for chemical investigation on effective plant extract. The aqueous extract of kamini significantly reduced and delayed germination, growth of shoot length and root length of country bean, kolmishak, okra and borboti seeds compared with control whereas, polash increased and enhanced germination, growth of shoot length and root length ‘of these same vegetable crops. The aqueous extract of kamini showed the lowest germination were 70.67, 15, 12 and 34.67%, and minimum shoot length were 3.36, 1.44, 0.36 and 1.73 cm, and root length were 2.20, 0.73, 0.30 and 0.94 cm for country bean, okra, kolmishak and borboti seedlings respectively due to the presence of growth inhibiting substances or toxic compounds. The highest germination percentages of country bean, okra, kolmishsak and borboti seeds were consequently 100, 83.33, 67.33 and 100 respectively, treated with the leaves extract of polash compared with control. The aqueous extract of polash also significantly enhanced growth of shoot length and root length of these vegetable crops due to the presence of growth promoting substances. The thin layer chromatography (TLC) examination of chloroform extract of kamini showed four distinct compounds at Hexane: Ethyl acetate (9:1, ‘/,) whereas, polash showed three distinct compounds at Hexane: Ethyl acetate (5:1, ‘/,). The crude product of Kamini was purified by column chromatography. After column chromatography six distinct compounds were isolated. All indicated steroid type compounds by Salkowaski test. 'H-NMR and IR study indicated that the fractions were probably steroid or terpinoid type of compounds.