Comparison of quercetin and rutin inhibitory influence on Tartary buckwheat starch digestion in vitro and their differences in binding sites with the digestive enzyme

Libo Wang; Lijuan Wang; Tongtong Wang; Zaigui Li; Yanxiang Gao; Steve W Cui; Ju Qiu

doi:10.1016/j.foodchem.2021.130762

Comparison of quercetin and rutin inhibitory influence on Tartary buckwheat starch digestion in vitro and their differences in binding sites with the digestive enzyme

Food Chem. 2022 Jan 15:367:130762. doi: 10.1016/j.foodchem.2021.130762. Epub 2021 Aug 3.

Authors

Libo Wang¹, Lijuan Wang², Tongtong Wang³, Zaigui Li², Yanxiang Gao², Steve W Cui⁴, Ju Qiu⁵

Affiliations

¹ College of Food and Bioengineering, Henan University of Science and Technology, Luoyang, Henan 471023, China; College of Food Science and Nutritional Engineering, China Agricultural University, P. O. Box 40, No. 17 Qinghuadonglu, Haidian, Beijing 100083, China.
² College of Food Science and Nutritional Engineering, China Agricultural University, P. O. Box 40, No. 17 Qinghuadonglu, Haidian, Beijing 100083, China.
³ Institute of Quality Standard and Testing Technology for Agri-Products, Chinese Academy of Agricultural Sciences, Key Laboratory of Agro-Food Safety and Quality, Ministry of Agriculture and Rural Affairs, Beijing 100081, China.
⁴ Guelph Research and Development Centre, Agriculture and Agri-Food Canada, 93 Stone Road West, Guelph, Ontario N1G 5C9, Canada.
⁵ Institute of Food and Nutrition Development, Ministry of Agriculture and Rural Affairs, Haidian, Beijing 100081, China. Electronic address: [email protected].

PMID: 34390912
DOI: 10.1016/j.foodchem.2021.130762

Abstract

Inhibitory effects of flavonoids on starch digestibility were well known, but the structural mechanism was not clear. This study was focused on the diverse effect of quercetin and rutin on digestibility of Tartary buckwheat starch. Results showed that quercetin and rutin reduced the starch digestion by altering starch structure in bound forms and inhibiting digestive enzyme activity in free forms simultaneously, and quercetin showed a stronger effect than rutin. Molecular docking and saturation transfer difference-nuclear magnetic resonance (STD-NMR) revealed different binding site of rutin from quercetin was due to its hydroxyl and hydrogen on the glycoside structure. Rutin interacted with enzymes mainly by CH and OH on the glycoside structure which induced steric hindrance and restricted the inhibitory effect of quercetin fraction. The glycoside structure weakened inhibition of rutin on digestive enzymes in free forms rather than influence its anti-digestive effects in bound forms with starch.

Keywords: Binding site; Digestibility; Enzyme inhibition; Quercetin; Rutin; Tartary buckwheat starch.

MeSH terms

Binding Sites
Digestion
Fagopyrum*
Molecular Docking Simulation
Quercetin
Rutin*
Starch

Substances

Rutin
Starch
Quercetin