African Journal of Biotechnology Vol. 6 (14), pp. 1685-1689, 18 July 2007   

ISSN 1684–5315 © 2007 Academic Journals        

Full Length Research Paper

In vitro assays for bioactivity-guided isolation of antisalmonella and antioxidant compounds in Thonningia sanguinea flowers

J. D. N’Guessan^{1, 3}*, A. P. Bidié¹, B. N. Lenta², B. Weniger³, P. André⁴, F. Guédé-Guina ¹

¹Laboratoire de Pharmacodynamie Biochimique, Université de Cocody Abidjan, 22 BP 582 Abidjan 22, Côte d’Ivoire.

²Department of Chemistry, Higher Teacher Training College, University of Yaounde´ I, P. O. Box 47 Yaoundé, Cameroon.

³Laboratoire de Pharmacognosie et Molécules Naturelles Bioactives, UMR 7175-LC1, Faculté de Pharmacie, Université Louis Pasteur Strasbourg BP 60024, 67401 Illkirch cedex, France.

⁴Laboratoire de Bactériologie et de Cryptogamie, Faculté de Pharmacie, Université Louis Pasteur Strasbourg BP 60024, 67401 Illkirch cedex, France.

*Corresponding author. E-mail: nguess100jd@yahoo.fr. Tel: (00225) 05-785-789.

Accepted 15 June, 2007

Bioguided fractionation of the aqueous extract of Thonningia sanguinea flowers, used traditionally in the treatment of microbial diseases, led to the isolation of two phenolic compounds. The structure of these compounds was elucidated by ¹H, ¹³C 1D NMR and mass spectrometry experiments. The antibacterial activity against Salmonella strains and antioxidant activity of the crude extract, fractions and isolated compounds was evaluated using the DPPH method. The isolated compounds identified as brevifolin carboxylic acid and gallic acid demonstrates moderate antibacterial activity against Salmonella enteritidis, Salmonella typhimurium, and Salmonella abony. The results indicated that the two isolated compounds, gallic acid (IC₅₀ = 13.5 µM) and brevifolin carboxylic acid (IC₅₀ = 18.0 µM) were mainly responsible for the good scavenging activity of the aqueous extract.

Key words: Thonningia sanguinea, antimicrobial activity, antioxidant activity, gallic acid, brevifolin carboxylic acid.