Simultaneous determination of three steroidal glycoalkaloids in Solanum xanthocarpum by high performance thin layer chromatography

A new high-performance thin-layer chromatographic (HPTLC) method has been developed for the simultaneous quantitation of three bioactive steroidal glycoalkaloid (SGA) markers, solasonine (SN), solamargine (SM) and khasianine (KN) in the plant Solanum xanthocarpum. Extraction efficiency of targeted SGAs from plant matrix using methanol and acidified methanol were studied using percolation, ultrasonication and microwave techniques. The separation was achieved on silica gel 60F254 TLC plates using chloroform–methanol–water as mobile phase. The quantitation of SGAs was carried out using the densitometric reflection/absorption mode at 520 nm after post chromatographic derivatization using Dragendorff's reagent. The method was validated for peak purity, precision, accuracy, robustness, limit of detection (LOD) and quantitation (LOQ). Method specificity was confirmed using retention factor (Rf), Vis spectral correlation and electrospray ionization mass spectra (ESI-MS) of marker compounds in the sample track.