Total Phenolics and Total Flavonoid Contents, Antioxidant Activity and Flavonoids Identification by High-Performance Liquid Chromatography – Tandem Mass Spectrometry of Odontonema strictum (Acanthaceae) Leaves

Different extracts of Odontonema strictum leaves are investigated for their total phenolic content, total flavonoid content and antioxidant properties using the DPPH (2,2-diphenyl-1-picryl-hydrazyl) radical scavenging capacity assay. The flavonoid diversities in the ethyl acetate and butanol extracts are also investigated by high-performance liquid chromatography– tandem mass spectrometry (LC-MS/MS). Total phenolic contents varies from 27.7 ± 1.5 mg GAE/g to 102.6 ± 0.9 mg GAE/g (GAE=Gallic Acid Equivalent) of dried extract and total flavonoid contents from 5.2 ± 0.2 mg QE/g to 170.7 ± 7.3 mg QE/g (QE=Quercetin Equivalent) of dried extract. The IC50 of DPPH inhibition is measured from 1.1 ± 0.1 to 3.9 ± 1.7 μg/mL. The antioxidant capacity correlates quite well with the total phenolic and the total flavonoid contents, indicating that phenolic compounds are major contributors to the antioxidant properties of the extracts. Lastly, based on LC-MS/MS analysis, we demonstrate that the flavonoid glycosides are constructed on the luteolin structure as aglycone.

Author(s): Jean Claude W Ouédraogo, Moumouni Koala, Noufou Ouédraogo, Félix B Kini, Pascal Gerbaux and Yvonne L Bonzi-Coulibaly

Abstract | PDF

Share This Article