Bioassay guided isolation of biologically active constituents from Prosopis seeds

MAZZUCA MARCIA; BALZARETTI V; KRAUS W

Praga

Congreso; 44 th. Annual Congress of Society for Medicinal Plant Research; 1996

Academia de Ciencias de la República Checa y Facultad de Farmacia de la Charles University Praga

Extracts of different polarities from four species and three varieties of the genera Prosopis (P. alpataco, P. flexuosa, P. alba, P. denudans var. denudans, P. denudans var. patagoni­ca, and P. denudans var. stenocarpa), collected in the Central and Southern parts of Argen­tina, were screened  in order to evaluate their antibacterial, antifungal, antifeedant, anthel­minthic, molluscicidal and toxical activities. The organisms used in these bioassays were: Bacillus subtilis and Pseudomona stutzeri for the antibacterial test, Cladosporium cucumeri­num and Aspergillus niger for the fungitoxical test, Meloidogyne incognita for the anthel­mintic test, Epilachna varivestis for the antifeedant test, Biomphalaria glabrata for the mol­luscicidal test and Artemia salina (brine shrimps) for the toxicity test. The extractions of the plant materials were carried out sucessively with petrol ether, ethyl acetate, dichloromethane, methanol, and water. The extracts showing significant response to the tests were subjected to a series of chromatographic separations guided by the respective bioassays. All the petrol ether extracts showed antibacterial activity. The dichloromethane extract of P. alpataco showed antibacterial and antifungal activities. The methanol and the aquous extracts of P. denudans var. patagonica and the aquous extract of Prosopis denu­dans var. denudans showed antifungal activities.The aquous extracts of P. denudans var. denudans and Prosopis denudans var. patagonica showed a slight activity against Artemia salina. No antifeedant and no molluscicidal activity was observed in the screened extracts.  Column chromatography, GC, GC-MS, HPLC, 1H-NMR, and 13C-NMR were the methods used in the separation and identification of the active principles. Fatty acids and a group of pentacyclic triterpenes with antibacterial activities were identified up to now.