Kaeswurm Julia A H, Könighofer Lisa, Hogg Melanie, Scharinger Andreas, Buchweitz Maria
Institute of Biochemistry and Technical Biochemistry, Department of Food Chemistry, University of Stuttgart, 70569 Stuttgart, Germany.
Chemisches und Veterinäruntersuchungsamt Karlsruhe, Weißenburger Str. 3, 76187 Karlsruhe, Germany.
Foods. 2020 Mar 21;9(3):367. doi: 10.3390/foods9030367.
An inhibitory effect on α-amylase and α-glucosidase is postulated for polyphenols. Thus, ingestion of those secondary plant metabolites might reduce postprandial blood glucose level (hyperglycemia), which is a major risk factor for diabetes mellitus type II. In addition to a previous study investigating structure-effect relationships of different phenolic structures, the effect of anthocyanins is studied in detail here, by applying an α-amylase activity assay, on the basis of the conversion of 2-chloro-4-nitrophenyl-4-O-ß-galactopyranosyl maltoside (GalGCNP) and detection of CNP release by UV/Vis spectroscopy and isothermal titration calorimetry (ITC). All anthocyanin-3-glucosides showed a mixed inhibition with a strong competitive proportion, K < 134 µM and K < 270 µM; however, the impact of the B-ring substitution was not statistically significant. UV/Vis detection failed to examine the inhibitory effect of acylated cyanidins isolated from black carrot ( ssp. var. ). However, ITC measurements reveal a much stronger inhibitory effect compared to the cyanidin-3-glucoside. Our results support the hypothesis that anthocyanins are efficient α-amylase inhibitors and an additional acylation with a cinnamic acid boosts the observed effect. Therefore, an increased consumption of vegetables containing acylated anthocyanin derivatives might help to prevent hyperglycemia.
多酚类物质被认为对α-淀粉酶和α-葡萄糖苷酶有抑制作用。因此，摄入这些次生植物代谢产物可能会降低餐后血糖水平（高血糖症），而高血糖症是II型糖尿病的主要风险因素。除了之前一项研究不同酚类结构的构效关系外，本文还通过应用α-淀粉酶活性测定法，基于2-氯-4-硝基苯基-4-O-β-吡喃半乳糖苷麦芽糖苷（GalGCNP）的转化以及通过紫外/可见光谱和等温滴定量热法（ITC）检测CNP释放，详细研究了花青素的作用。所有花青素-3-葡萄糖苷均表现出混合抑制作用，其中竞争性抑制比例较强，K<134µM且K<270µM；然而，B环取代的影响在统计学上并不显著。紫外/可见检测未能检测到从黑胡萝卜（ssp. var.）中分离出的酰化花青素的抑制作用。然而，ITC测量结果显示，与花青素-3-葡萄糖苷相比，其抑制作用要强得多。我们的结果支持了以下假设：花青素是有效的α-淀粉酶抑制剂，肉桂酸的额外酰化会增强所观察到的效果。因此，增加含有酰化花青素衍生物的蔬菜摄入量可能有助于预防高血糖症。
