School of Public Health, University of Sao Paulo, 715 Dr Arnaldo Avenue, Sao Paulo, Sao Paulo 01246-904, Brazil.
Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL A1B 3X9, Canada.
Molecules. 2020 Feb 5;25(3):679. doi: 10.3390/molecules25030679.
The Brazilian Food Supplement Law recently recognized that guarana ( ) contains bioactive substances, hence supporting its role as a functional food ingredient. The health benefits of guarana are associated, at least in part, to its phenolic compounds. However, to the best of our knowledge, there is no literature addressing the presence of phenolic compounds in the fraction containing insoluble-bound compounds and its contribution in terms of alpha-glucosidase inhibition. The concentration of phenolic extracts released from the insoluble-bound fraction required to inhibit 50% of alpha-glucosidase (IC) activity was 5.8-fold lower than that present in the soluble counterpart. Both fractions exhibited a mixed inhibition mode. Fourteen proanthocyanidins (dimers to tetramers) present in the insoluble-bound fraction were tentatively identified by MALDi-TOF-MS. Future studies aiming at increasing the concentration of the soluble counterpart are deemed necessary. The results presented here enhance the phenolic database of guarana and have a practical impact on the procurement of nutraceuticals and functional ingredients related to the prevention and/or management of type 2 diabetes. The Brazilian normative on food supplements has been recently revised. This study lends support to the future inclusion of guarana powder in the list of sources of proanthocyanidins for the industry of food supplements.
巴西食品补充剂法规最近承认瓜拉那（）含有生物活性物质，因此支持其作为功能性食品成分的作用。瓜拉那的健康益处至少部分与其酚类化合物有关。然而，据我们所知，没有文献涉及到含有不溶性结合物的部分中的酚类化合物及其对α-葡萄糖苷酶抑制的贡献。从不溶性结合物部分释放的酚类提取物抑制 50%α-葡萄糖苷酶（IC）活性所需的浓度比可溶性部分低 5.8 倍。这两个部分都表现出混合抑制模式。通过 MALDi-TOF-MS 暂定鉴定了不溶性结合物部分中存在的 14 种原花青素（二聚体到四聚体）。认为有必要增加可溶性部分的浓度。这里提出的结果增强了瓜拉那的酚类数据库，并对采购与预防和/或管理 2 型糖尿病相关的营养品和功能性成分具有实际影响。巴西食品补充剂的规范最近已经修订。这项研究支持未来将瓜拉那粉末列入食品补充剂行业原花青素来源的清单。
