Phytochemical Analysis of Polyphenols in Leaf Extract from Vernonia amygdalina Delile Plant Growing in Uganda

Abstract

Due to the presence of phytochemicals, plants have been known to be used in the treatment and management of various diseases. Vernonia amygdalina, belonging to the Asteraceae family, is a plant known for its many applications in traditional medicine for various purposes. Previous studies on the methanolic leaf extract of this plant have proved the antibacterial, cytotoxic, anticancer and antioxidant effects indicative of promising therapeutic potentials. In this work, chromatographic and spectroscopic techniques along with high-performance liquid chromatography quantitative analysis were adopted to isolate, identify and quantify polyphenolic compounds in V. amygdalina leaf extract. UHPLC-DAD-ESI-MS/MS and UHPLC-DAD methods were adopted for qualitative and quantitative analysis, respectively. In the case of polyphenol separation, some reference substances were isolated by preparative HPLC. Seven polyphenols were identified and quantified in this study: 5-O-caffeoylquinic acid, luteolin hexoside, 3,4-O-dicaffeoylquinic acid, 1,5-O-dicaffeoylquinic acid, 3,5-O-dicaffeoylquinic acid, 4,5-O-dicaffeoylquinic acid and luteolin dihexoside, with 3,5-O-dicaffeoylquinic acid being isolated in the highest quantity of 27.49 mg g−1 extract.