Spectrophotometric Determination of Hydroxycinnamic Acids in Herbal Drugs. Part 1. Direct Spectrophotometry (Review)

INTRODUCTION. Current scientific research aims to discover new plant sources of hydroxycinnamic acids for the development of novel medicinal products. Most commonly, the quantitative determination of hydroxycinnamic acids in herbal drugs involves testing procedures based on spectrophotometry and its modifications.AIM. This study aimed to establish the possibility of the quantification of hydroxycinnamic acids in herbal drugs by direct spectrophotometry.DISCUSSION. This review presents organised information on the use of direct spectrophotometry to quantify hydroxycinnamic acids in 70 plant species growing or cultivated in the Russian Federation. The review covers publications in Russian for the period from 2007 to 2023. According to the reviewed publications, direct spectrophotometry is an easy-to-use and highly reproducible method that does not require additional reagents or labour-intensive steps. Direct spectrophotometry may result in an overestimation of the hydroxycinnamic acid content due to overlapping absorption bands of polyphenolic compounds with different structures.CONCLUSIONS. Direct spectrophotometry can be considered as a method for measuring the total content of phenolic compounds (as well as hydroxycinnamic acids) in herbal drugs. Different approaches to direct spectrophotometric quantification of hydroxycinnamic acids in herbal drugs by can serve as a methodological basis for developing analytical procedures specific to the chemical compositions of biologically active compounds in herbal drugs and their extracts.