3-methylquercetin and 6-hydroxy-2-5-7-8-tetramethylchroman-2-carboxylic-acid

Chickpea (Cicer arietinum L.) genotypes, nine kabuli from Mexico and 9 desi from other countries, were investigated for their phenolic profiles and antioxidant activity (AA). Phenolics in methanol extracts (ME) were analyzed by ultra-performance liquid chromatography coupled to diode array detection and mass spectrometry (UPLC-DAD-MS), whereas the AA was measured as Trolox equivalents (TE) by ABTS, DPPH and FRAP methods. Twenty phenolic compounds were identified in the ME and their levels showed a great variability among the chickpea genotypes. Phenolic acids and flavonoids were the most abundant compounds in kabuli and desi genotypes, respectively. The AA values (μmol TE/ 100 g dw) by ABTS (278-2417), DPPH (52-1650), and FRAP (41-1181) were mainly associated with the content of sinapic acid hexoside, gallic acid, myricetin, quercetin, catechin, and isorhamnetin, suggesting they are the main compounds responsible for the AA. The sum of the AA obtained for standards of these compounds evaluated at the concentration found in the extracts accounted for 34.3, 69.8, and 47.0% of the AA in the extract by ABTS, DPPH, and FRAP, respectively. In the AA by DPPH, most of the mixtures of these compounds resulted in synergistic interactions. Three desi genotypes with black seeds (ICC 4418, ICC 6306, and ICC 3761) showed the highest AA and flavonoids content, whereas the most promising kabuli genotypes were Surutato 77, Bco. Sin. 92, and Blanoro that showed the highest values of phenolic acids. These genotypes represent good sources of antioxidants for the improvement of nutraceutical properties in chickpea.

Topics: Antioxidants; Catechin; Chromans; Chromatography, Liquid; Cicer; Flavonoids; Gallic Acid; Genotype; Hydroxybenzoates; Mass Spectrometry; Quercetin; Seeds

An analytical study was carried out on the presence of antioxidant constituents and the in vitro antioxidant capacity in the extracts of three species of Spanish red-skinned cactus pear fruits (Opuntia ficus-indica, Opuntia undulata and Opuntia stricta). The cactus pear fruit extracts were analyzed for determined constituents: ascorbic acid, flavonoids (quercetin, isorhamnetin, myricetin, kaempferol and luteolin), betalains, taurine, total carotenoids and total phenolics. The antioxidant capacity was assessed by means of two different methods: the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (Trolox equivalent antioxidant capacity) method and the 2,2-diphenyl-1-picrylhydrazyl radical method. Opuntia ficus-indica fruit extract had the strongest antioxidant capacity and taurine content. O. stricta fruits were the richest in ascorbic acid and total phenolics, whereas O. undulata fruits showed the highest carotenoid content. Quercetin and isorhamnetin were the main flavonoids detected. This study provides basic information on the presence of bioactive compounds and antioxidant capacity in extracts of cactus pear fruits, in order to consider these extracts as ingredient for the production of health-promoting food.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Carotenoids; Chromans; Flavonoids; Flavonols; Fruit; Opuntia; Phenols; Picrates; Plant Preparations; Polyphenols; Quercetin; Taurine