Quantitation of Protodioscin in Tribulus terrestris L. Fruit Powder by Reversed-Phase High-Performance Thin-Layer Chromatography

A sensitive, simple, and accurate reversed-phase high-performance thin-layer chromatographic method has been established for determination of protodioscin in fruit powder from Tribulus terrestris L. A methanol extract of the fruit powder was used for experimental work. Separation was performed on RP-18F254s HPTLC plates with 0.1 m KH2PO4-acetonitrile-methanol-triethylamine, 5 + 4 + 1 + 0.1 (v/v), as mobile phase. After development, plates were treated with 0.1 m H2SO4 and detection and quantification were performed by densitometry at λ = 366 nm. Detection and quantitation limits were 0.03 μg and 0.05 μg, respectively. Response was a linearly dependent on amount of protodioscin in the range 0.05 to 1.00 μg. The validated RP-HPTLC method can be used for a routine quality-control analysis of Tribulus terrestris L. fruit powder and quantitative determination of protodioscin.