Variation in the phytochemical composition of Chromolaena odorata (L.) King and Robinson (Asteraceae) across climatic zones in Benin (West Africa)

Chromolaena odorata (L.) King and Robinson (Asteraceae) is a tropical shrub with interesting chemical potential widely used in agriculture and medical science and which can be affected by several geographic and climatic conditions. Therefore, we investigated the phytochemical composition of this plant across climatic zones in Benin. The plant material collected from different locations was phytochemically screened by staining and precipitation tests. The total phenolic, flavonoid and tannin contents were determined using, the colorimetric method of Folin-Ciocalteu, the method of aluminum chloride and the method of vanillin, respectively, then the obtained data were subjected to analysis of variance. The phytochemical analysis revealed the presence of the main chemical groups such as alkaloids, free anthracene, coumarins, flavonoids, mucilage, tannins, reducing compounds, saponins, quinone derivatives, steroids. There was a significant difference (P 0.05) in the phytochemical contents across geographical sites. In comparing the levels of phytochemicals among geographical locations, the raw material collected from the north climatic zone contained the highest phenolic and flavonoid contents, 147.59 ± 3.04 mg/g and 17.17 ±0.31 mg/g, respectively, compared to others. Overall, the study highlighted the potential of C. odorata as source of natural products. There was no difference in the phytochemical markers whereas the phytochemical contents vary across climatic zones. These results can be of use in the development of biopesticides from the raw material of C. odorata.