Extraction optimization of gallic acid, (+)-catechin, procyanidin-B2, (−)-epicatechin, (−)-epigallocatechin gallate, and (−)-epicatechin gallate: their simultaneous identification and quantification in Saraca asoca

The objective of the present investigation was to optimize extraction conditions for maximum recovery of bioactive phenolics from different parts of Saraca asoca. Extraction recovery was optimized using a mixture of methanol and water in different proportions. For identification and quantification of six analytes, a rapid reversed phase ultra-performance liquid chromatography (UPLC) photo diode array detection method was developed. UPLC separation was achieved in a gradient elution mode on a C(18) column with acetonitrile and aqueous phosphoric acid (0.1%, pH = 2.5). Extraction solvent for maximum recovery of analytes varied depending on the nature of matrices. The developed UPLC method was validated in accordance with International Council for Harmonisation (ICH) guidelines. Wide linearity range, sensitivity, accuracy, short retention time, and simple mobile phase composition implied that the method could be suitable for routine analysis of all six analytes with high precision and accuracy. The uniqueness of this study is the determination of the distribution of these compounds in the various parts of S. asoca.