Iridoids, Flavonoids, and Antioxidant Capacity of Cornus mas, C. officinalis, and C. mas × C. officinalis Fruits

Abstract

The fruits of <i>Cornus mas</i> and <i>Cornus officinalis</i> have been known and appreciated in folk medicine for years and have a high biological value, which is mainly connected with their polyphenols and iridoids content. However, hybrids of <i>C. mas</i> × <i>C. officinalis</i> have not been investigated. The aim of this study was to evaluate the iridoids, anthocyanins, and flavonols content, and antioxidant capacity of <i>Cornus mas</i>, <i>Cornus officinalis</i>, and <i>C. mas</i> × <i>C. officinalis</i>. Iridoids and flavonoids were quantified by the High-Performance Liquid Chromatography (HPLC) method. Antioxidant capacity (AC) was measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH^•), 2,2'-azino-bis (3-ethyl benzothiazoline-6-sulfonic acid (ABTS^•+), and ferric reducing antioxidant power (FRAP) tests. Total phenolic content (TPC) was evaluated using the Folin-Ciocalteu reagent. Among the <i>C. mas</i> cultivars and <i>C. officinalis</i> genotypes, there was considerable variation in the content of iridoids, flavonoids, and AC. Interspecific hybrids <i>C. mas</i> × <i>C. officinalis</i> contained more iridoids than <i>C. mas</i> and more anthocyanins than <i>C. officinalis</i> and additionally had higher AC and TPC than <i>C. officinalis</i> and most <i>C. mas</i>. AC, TPC, and the presence of iridoids, anthocyanins, and flavonols in hybrids <i>C. mas</i> × <i>C. officinalis</i> are reported for the first time. The <i>Cornus</i> species deserve special attention due to their highly biologically active substances, as well as useful medicinal properties.