Simultaneous quantification of two bioactive flavonoids, homoeriodictyol and persicogenin, in the methanol extract of the aerial parts of two different species of genus Rhus by a validated high-performance thin-layer chromatographic-densitometric method

A simple and sensitive high-performance thin-layer chromatographic (HPTLC)-densitometric method was developed for the simultaneous quantification of two flavonoid compounds, persicogenin and homoeriodictyol, in the methanol extracts of the aerial parts of two species (Rhus retinorrhoea and Rhus tripartita) of the genus Rhus grown in the Kingdom of Saudi Arabia. Chromatography was performed on glass-backed silica gel 60 F₂₅₄ HPTLC plates using toluene-ethyl acetate-methanol (8:2:0.5, v/v) as the mobile phase. Scanning and quantification were done at 293 nm. The system was found to give compact spot for homoeriodictyol and persicogenin at, R_F = 0.30 ± 0.01 and 0.48 ± 0.01, respectively. The linearity ranges for homoeriodictyol and persicogenin were found to be the same (100-800 ng spot_-1) with correlation coefficients (r² values) of 0.9989 and 0.9983, respectively. The limit of detection (LOD) for homoeriodictyol and persicogenin was found to be 26 and 31 ng band_-1, respectively, while the limit of quantification (LOQ) was found to be 77 and 92 ng band_-1, respectively. Homoeriodictyol (7.06%) and persicogenin (2.33%) were only found in R. retinorrhoea. The developed method was found to be accurate and precise; hence, it can be used as an important tool to assure the therapeutic dose of homoeriodictyol and persicogenin in herbal formulations as well as for the standardization and quality control of bulk drugs.