Anti-microbial activity of the alkaloid extract of Genista microcephala: isolation and complete 1H and 13C chemical shifts assignments of lupanine and S-calycotomine.

Abstract

Chemical investigation of the aerial parts of G. microcephala (collected in June 2000 in Khenchla, Algeria) afforded 2 alkaloids, identified as lupanine (2-oxosparteine) and S-calycotomine. The complete 1H and 13C chemical shifts assignments of the 2 compounds were determined using 1D and 2D NMR spectroscopy (COSY, DEPT, HMQC, HMBC). The alkaloid extract of G. microcephala was tested against strains of bacteria (Escherichia coli, Staphylococcus sp., Pseudomonas aeruginosa, Enterobacter sp., Proteus mirabilis, P. vulgaris and Serratia sp.) and fungi (Aspergillus fumigatus, A. ramosus, Rhizoctonia solani, Alternaria alternata, Rhizopus sp. and Gliocladium sp.), which showed a strong sensitivity. The minimum inhibitory concentration and minimum bactericide concentration of the alkaloid extract were determined.