Validated thin-layer chromatographic method for the identification and monitoring of the effect of the extraction method on the yield and phytochemical constituents of Egyptian Withania somnifera leaves.

A sensitive, reliable, simple and rapid thin-layer chromatographic method has been developed for routine analysis of withanolide S content for the purpose of quality control assessment of chemotype III of Withania somnifera. The new method was used first to compare the accumulation of withanolide S in different parts of the plant, which was found to be the highest in the leaves extract (0.21% w/w). Second, to investigate different extraction parameters that improve the extraction efficiency of withanolides from the leaves using conventional and ultrasound-assisted extraction methods. The extraction efficiency was expressed via total withanolide content and withanolide S content.
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