Characterization of geographical variation in antioxidative active Eucalyptus camaldulensis extracts : for future use as biopesticides in Burkina Faso

Abstract: The current use of pesticides in Burkina Faso has been described as problematic. An alternative to synthetically produced pesticides is products based on naturally occurring substances, e.g. from plants, so-called biopesticides. In this study aqueous and ethanol extracts from Eucalyptus camaldulensis collected at three different geographical locations in Burkina Faso are investigated with regard to flavonoid and polyphenol content, TLC fingerprint profile, and antioxidant activity by DPPH-radical scavenging. The result show high yields, high polyphenolic content and strong antioxidant activity, especially for the aqueous extracts. The activity of the extracts derived from leaves collected in the north and south-west of Burkina Faso have approximately three times higher antioxidant activity than those from the central part of the country. Furthermore, clear differences between the extract can be seen on TLC, especially for the aqueous extracts. In conclusion, water extracts from E. camaldulensis contain high amounts of antioxidant active polyphenols and are promising as active ingredients for a biopesticide formulation. However, the geographical variation in content and activity is a clear example of the issues with working on natural products and must be taken into consideration in the future work.