Simultaneous quantification of stemocurtisine, stemocurtisinol and stemofoline in Stemona curtisii (Stemonaceae) by...

Stemona curtisii Hook. F. (Family Stemonaceae), a prominent species distributed in the south and southwest of Thailand, has widely been used as a natural pesticide and as treatment for head lice and skin diseases. This study developed a thin-layer chromatography (TLC)-densitometric method for the simultaneous quantification of major components--stemocurtisine, stemocurtisinol and stemofoline--in the extracts from the roots of S. curtisii collected from 10 locations in Thailand. Components were found in the ranges of 0.0353-0.1949, <0.0121-0.0859 and 0.0733-0.1689 percent dry weight, respectively. The method was validated for linearity, precision, accuracy, robustness, limit of detection and limit of quantitation. The linearity was found over the range of 40-320 ng/spot with a good correlation coefficient (r > 0.9866). Intra-day and inter-day precision showed a relative standard deviation of less than 6%. The accuracy of the method was determined by a recovery study, and the average recoveries were 100.4, 100.2 and 100.3% for stemocurtisine, stemocurtisinol and stemofoline, respectively. The proposed TLC-densitometric method was found to be simple, precise, specific and inexpensive, and can be used simultaneously for the routine quality control of raw materials of S. curtisii roots, extracts and their products, and also other products containing these markers.