关键词: 香蕉, 多酚, 成分鉴定, α-淀粉酶, α-葡萄糖苷酶, 抑制作用

Abstract: Polyphenols are the important active ingredients of banana, which may be associated with the anti-hypoglycemic activity of unripe bananas. Banana polyphenols were extracted from unripe bananas and the chemical components in the extract were identified using ultraperformance liquid chromatography plus Q-Exactive Orbitrap tandem mass spectrometry (UPLC-Q-Exactive Orbitrap/MS). After that, the inhibitory effects of banana polyphenol extracts on α-amylase, α-glucosidase were estimated by in vitro studies. In total, 28 compounds were identified from the polyphenol extracts of banana, including 21 polyphenolics, 2 organic acids, 3 ellagitannin metabolites, vanillin and coumarin. Among them, three polyphenols including esculetin, hyperoside, and kaempferol-3-O-glucoside were identified in bananas pulp for the first time. In addition, dimethyl ellagic acid and urolithin A were the major peaks. The banana polyphenol extract exhibited excellent inhibitory effects on α-amylase and α-glucosidase. The inhibition rate of banana polyphenol extracts with a concentration of 1.0 mg/mL on α-amylase activity was 76.25%±3.79%, with an IC50 value of 0.53 mg/mL. At a concentration of 160 μg/mL of banana polyphenol extracts, the inhibition rate on α-glucosidase was 92.54%±0.69%, with an IC50 value of 35.75 μg/mL. Therefore, the polyphenols in banana may be one of the interpreted which contributed to the anti-hypoglycemic effects of banana.

Key words: banana, polyphenols, identification, α-amylase, α-glucosidase, inhibitory effect