Recent advances on preparative LC approaches for polyphenol separation and purification: Their sources and main activities

Preparative High Performance Liquid Chromatography (pre-HPLC) is one of the most modern instrumental liquid chromatography available today. The methodological development phase requires time and skills, especially when dealing with complex samples, as in the case of polyphenol-rich herbal matrices. Polyphenols are the most widely distributed constituents of secondary metabolism in plants of medicinal interest, presenting social and economic importance, contributing to the investigation of their complex structures and therapeutic properties. Considering the challenges of isolation of this class of bioactives, the bibliography of the last five years presented in Scopus, Science Direct and Wiley Online Library databases was discussed in this work, bringing together the methodological strategies of pre-HPLC, from sample preparation to post-isolation analysis, for the separation and recovery of polyphenols from crude extracts or enriched fractions. The impacts of obtaining isolated compounds were observed and addressed according to the contribution in building the identity of plant species, the establishment of model methodologies, the elucidation of structure-activity and correlation of isolates as responsible for the therapeutic properties of plant species, in processes involving the removal of free radicals, modulation of enzymatic pathways and inhibition of microbial growth. Results were observed that generate new perspectives on the deepening of knowledge of plant species, highlighting the importance of this as a primary step in the development of nutraceuticals, cosmetics and pharmaceutical products with the delivery of polyphenols, isolated, in concentrated fractions or even in their initial form present in the complex herbal matrices.