A simple colorimetric quantification of flavonoids in the flowers of Lonchocarpus cyanescens genus: Lonchocarpus.

As part of a continuing study of the Nigerian flora a chemical analysis of the flavonoids of some plants of the family Papilionaceae prominent in traditional medicine was undertaken. The flowers of the selected plants were extracted and the flavonoids were detected and identified by standard methods. In any such biochemical/chemotaxonomic study where a sizeable number of plants are analysed and in which small differences in type and quantity of each sample are critical, a fast and accurate method of determining the composition becomes paramount. In this work, the determination of the concentration of each flavonoid as a factor of absorbance on a simple single cell photoelectric colorimeter (Seagull Electric Institute Model-1) is reported. The results obtained for Lonchocarpus cyanescens genus Lonchocarpus were consistently satisfactory, sensitive and economical compared with the standard thin layer procedure. As far as the authors know, this is the first report of this method in flavonoid work.