Quantification of the bioactive (-)-Pseudosemiglabrin at different growth stages of <i>Tephrosia purpurea</i> L. (Pers.) growing in Gizan, Saudi Arabia

Recently the prenylated 5-deoxyflavonoid (-)-pseudosemiglabrin has demonstrated interesting biological activities. The compound presents in Tephrosia purpurea with a significant yield. In the current study, the amounts of (-)-pseudosemiglabrin were quantified by high-performance liquid chromatography (HPLC) method at different stages of plant growth. Also, various solvents and different extraction conditions were applied for optimizing the extraction process. The HPLC method was developed using Poroshell 120 EC-C18 (4.6 mm x 150 mm, 4 µm) HPLC column (Agilent). The used mobile phase composition was water and methanol, both containing 0.05% formic acid in gradient mode. The flow rate was fixed at 1.0 mL/min, and a 256 nm wavelength was selected for detection. The method was validated for specificity, linearity, accuracy, precision, robustness, limit of detection (LOD) and limit of quantification (LOQ) in compliance with the ICH guidelines. The correlation coefficient was R 2 = 0.9995 in the concentration range of 15.63-200 ppm. The analysis results indicated that the highest yield (186±5.7 mg/10 g) for (-)-pseudosemiglabrin was obtained from the plant extracted with 95% ethanol (ethanolic cold extract- ECE) in the flowering stage (FLS) (1.86%) relative to dry plant weight. The chloroform extract obtained by maceration at room temperature was not efficient in the complete extraction of (-)-pseudosemiglabrin. However, it was the most selective method as the yield was 16.5% relative to the dry extract weight and selectivity index (SI) 0.165. The study results indicate that the developed HPLC method is ideal for the determination and quantification of (-)-pseudosemiglabrin in different plant extracts or pharmaceutical products.