Isolation and Characterization of Flavonoids in Urena lobata Leaves

Aim: Urena lobata L. a member of Malvaceae family, is widely used as famine food in Africa. It is also
used in traditional medicine system to cure gonorrhea, fever, wounds, toothache & rheumatism. The
plant has already been tested for its antioxidant activity. The work was extended to investigate and
identify the flavonoid glycosides present in the plant.
Methodology: Urena lobata leaves were dried, powdered and extracted with petroleum ether
followed by methanol. The methanolic extract, after processing through different solvents, was used to
obtain the Chemically active constituents .Column Chromatography and Thin Layer Chromatography
(TLC) were used to isolate four compounds which were, in turn, subjected to spectroscopic analysis.
Results: The spectroscopic studies indicated that the four isolated compounds are (1) Quercetin, (2)
Kaempferol, (3) Quercetin 3-0-rutinoside and (4) Kaempferol 3-0- β glucopyranoside.
Conclusion: The presence of flavonoids in the plant makes it an important ingredient of the traditional
medicinal system. Since flavonoids are associated with antioxidant activity, their presence in the plant
makes it an important food material.