title: Antioxidant and α-glucosidase inhibitory phenolics isolated from highbush blueberry flowers.
abstract: Blueberries have been extensively researched, but there are limited studies on other parts of the plant. Here we report the first phytochemical examination of highbush blueberry (Vaccinium corymbosum) flowers, which yielded 21 phenolics. The compounds were identified from extensive NMR and mass spectral analyses and included five caffeic acid (1-5), three coumaric acid (6-8), and two cinnamyl alcohol (9-10) derivatives, eight flavonol glycosides (11-18), and three phenylpropanoid-substituted catechins (19-21). The isolates were evaluated for antioxidant and α-glucosidase inhibitory activities. Overall, the flavonol glycosides and phenylpropanoid-substituted catechins showed superior antioxidant activities compared to the positive controls, vitamin C (IC(50)=63μM) and butylated hydroxytoluene (IC(50)=1548μM). Similarly, these phenolic sub-classes were more potent α-glucosidase inhibitors than the clinical drug, acarbose (IC(50)=200μM). Thus, non-consumed parts of food plants may be exploited as sources of bioactive compounds beyond their edible parts alone for nutraceutical and functional food applications.
authors.affiliation: Bioactive Botanical Research Laboratory, Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, United States.
authors.forename: Chunpeng
authors.initials: C
authors.lastname: Wan
authors.forename: Tao
authors.initials: T
authors.lastname: Yuan
authors.forename: Amanda L
authors.initials: AL
authors.lastname: Cirello
authors.forename: Navindra P
authors.initials: NP
authors.lastname: Seeram
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D029798:Blueberry Plants / Q000737:chemistry*; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D035264:Flowers / Q000737:chemistry; D065089:Glycoside Hydrolase Inhibitors; D015394:Molecular Structure; D010636:Phenols / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000520:alpha-Glucosidases / Q000032:analysis
chemical_list: D000975:Antioxidants; D004791:Enzyme Inhibitors; D065089:Glycoside Hydrolase Inhibitors; D010636:Phenols; D010936:Plant Extracts; D000520:alpha-Glucosidases