2-2--azino-di-(3-ethylbenzothiazoline)-6-sulfonic-acid and isoquercitrin

In this study, the phenolic profiles and bioactivities of five representative cultivars of okra collected in China were investigated. Noticeable variations of phenolic compounds and their bioactivities were observed among these different cultivars of okra. The contents of total flavonoids (TFC) in "Shuiguo", "Kalong 8", "Kalong 3", "Wufu", and "Royal red" ranged from 1.75 to 3.39 mg RE/g DW, of which "Shuiguo" showed the highest TFC. Moreover, five individual phenolic compounds were found in okra by high performance liquid chromatography analysis, including isoquercitrin, protocatechuic acid, quercetin-3-O-gentiobioside, quercetin, and rutin, while isoquercitrin and quercetin-3-O-gentiobioside were detected as the main phenolic compounds in okra. Moreover, all tested okra exhibited significant antioxidant activities (2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity, 2,2'-azino-bis (3-ethylenzthiazoline-6-sulphonic acid) radical scavenging capacity, and ferric reducing antioxidant power) and inhibitory effects on digestive enzymes (lipase, α-glucosidase, and α-amylase). Indeed, "Shuiguo" exhibited much better antioxidant activities and inhibitory activities on digestive enzymes, which might be attributed to its high TFC. Results suggested that okra, especially "Shuiguo", could be developed as natural antioxidants and inhibitors against hyperlipidemia and hyperglycemia in the fields of functional foods and pharmaceuticals, which could meet the increasing demand for high-quality okra with health-promoting properties in China.

Topics: Abelmoschus; alpha-Amylases; alpha-Glucosidases; Animals; Antioxidants; Benzothiazoles; Biphenyl Compounds; Disaccharides; Flavonoids; Fruit; Hydroxybenzoates; Lipase; Phenols; Picrates; Plant Extracts; Quercetin; Rutin; Sulfonic Acids; Swine; Thiazoles

The aim of this study was to determine the composition and content of phenolic compounds in the ethanol extracts of apple leaves and to evaluate the antioxidant activity of these extracts. The total phenolic content was determined spectrophotometrically, as well as the total flavonoid content in the ethanol extracts of apple leaves and the antioxidant activity of these extracts, by the ABTS, DPPH, and FRAP assays. The highest amount of phenolic compounds and flavonoids as well as the highest antioxidant activity was determined in the ethanol extracts obtained from the apple leaves of the cv. Aldas. The analysis by the HPLC method revealed that phloridzin was a predominant component in the ethanol extracts of the apple leaves of all cultivars investigated. The following quercetin glycosides were identified and quantified in the ethanol extracts of apple leaves: hyperoside, isoquercitrin, avicularin, rutin, and quercitrin. Quercitrin was the major compound among quercetin glycosides.

Topics: Antioxidants; Benzothiazoles; Biphenyl Compounds; Flavonoids; Malus; Oxidation-Reduction; Phenols; Picrates; Plant Extracts; Plant Leaves; Quercetin; Rutin; Sulfonic Acids