Isolation and Characterisation of Flavonoids From Ocimum Sanctum Leaves

Holy basil (Ocimum sanctum, tulsi) is used widely in Indian medicine, and its leaves hold a mixed population of flavonoids that are often credited with its antioxidant and anti-inflammatory reputation. This review draws on published phytochemical and analytical literature to describe how those flavonoids are extracted, enriched, separated and identified. It covers solvent choice, chromatographic strategies, spectroscopic and mass spectrometric structure work, and the quantitation methods used for quality control. The review reports no new experimental data. The literature shows that several flavones and flavone glycosides have been characterised, but isolation reports are uneven, reference standards are scarce, and bioactivity is rarely tested on purified compounds.