Liquid chromatographic fingerprints for the characterization of flavanol-rich nutraceuticals based on 4-dimethylaminocinnamaldehyde precolumn derivatization

Abstract

Flavanols consist of a great family of bioactive molecules displaying a wide range of health-promoting attributes for humans, including antioxidant, antimicrobial or an-ti-inflammatory effects. As a result, botanical species rich in this type of compounds are often used to develop nutraceutical products or dietary supplements with recognized healthy attrib-utes. This paper aims at characterizing nutraceutical products using liquid chromatographic fin-gerprints related to flavanol composition. Catechins and their oligomers were exploited to characterize and authenticate of various commercial products prepared with extracts of red ber-ries and medicinal plants. These compounds resulted in interesting descriptors of some fruits and vegetables, thus providing an additional perspective for the study of nutraceuticals. For such a purpose, a new method based on liquid chromatography with UV/Vis detection (HPLC-UV/Vis) with precolumn derivatization with 4-dimethylaminocinnamaldehyde was de-veloped. Results indicated that the separation of flavanols was very complex due to the degrada-tion of procyanidin derivatives. The resulting data sets were analyzed using chemometric methods such as principal component analysis and partial least square-discriminant analysis. Despite the complexity of chromatographic fingerprints, nutraceutical samples could be dis-criminated according to their main ingredients. In general, catechin and epicatechin were the most abundant compounds in the different samples and procyanidin A2 was highly specific of cranberry.