High-performance thin-layer chromatography method development and validation for quantification of piperine in different extracts of Piper longum L. and its antioxidant activity.

A selective, simple, and sensitive high-performance thin-layer chromatography (HPTLC) method was developed and validated for identification and quantitative estimation of piperine in different extracts of Piper longum. A developing solvent, acetone‒toluene (3:7, V/V) was employed to attain good separation of bands. Densitometric estimation was performed at 343 nm. Linearity was reckoned to be in the range of 0.2–1.0 μg per spot. Ethanolic extract of P. longum revealed a higher content of piperine than dimethylformamide (DMF), acetone, and dimethyl sulphoxide (DMSO) extract during analysis. The method was further validated for robustness, accuracy, precision, specificity, and linearity. Furthermore, the antioxidant activity of P. longum extracts was scrutinized using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and the ethanolic extract showed the highest antioxidant potential, with 55.26% inhibition. [ABSTRACT FROM AUTHOR]