Mechanistic Study On The Effect Of Flavonoids From Rosa Roxburghii Tratt On The Digestion Of Starch

Controlling diabetes,obesity and other chronic diseases has become a major challenge for scientists in the fields of food science and medicine.From the perspective of nutrition,type?diabetes can be prevented through diet,namely by lowering glucose absorption in the small intestine so as to avoid the rapid rise of blood sugar and insulin response frequence.This can be achieved by inhibiting the activity of key enzymes for carbohydrate digestion.The primary function of acarbose,a first-line diabetic medicine,is to control blood sugar levels by inhibiting the activity of?-glucosidase,but it has numerous side effects.Natural products are attracted by scientists because of their safety,antioxidant,anti-tumor and other biological activities.This study mainly investigated the effect of flavonoids in“cili?Rosa roxburghii Tratt?”on?-glucosidase activity and on the functional properties of starch,which has important guiding significance for the development of new?-glucosidase inhibitors and the design of functional food.The main conclusions are as follows:The n-butanol phase of the ethanol crude extract of“cili”showed a favorable inhibitory effect on?-glucosidase,the three main components of which were catechin,kaempferol hexose and rutin.The crude extract could act synergistically with acarbose and effectively reduce the dose of acarbose.After digestion in simulated gastric juice,the inhibitory effect of flavonoids in“cili”on?-glucosidase decreased,and HNO₂in gastric juice further decreased its inhibitory effect.UV-vis spectra showed that the structures of flavonoids in“cili”changed as a result of the gastrointestinal p H difference.Molecular docking was used to study the relationship between docking score of polyphenols and their in vitro IC₅₀ values of inhibiting?-glucosidase.The results showed that although the correlation coefficient was low,there was a negative correlation between them;apart from the deviation of some molecules,the docking scores were basically consistent with in vitro data,which could explain the enhancing/weakening effect of some groups.Galloyl and caffeoyl group can significantly enhance the inhibition under certain conditions,and can help pharmaceutical chemists design novel?-glucosidase inhibitors.Compound 7,a quercetin modified with caffeoyl group,might have favorable anti-diabetes and anti-obesity activities.Chestnut rose juice concentrate significantly increased slow digestion starch and resistant starch content.As for the structure-activity relationship of galloyllation and glycosylation,molecular dynamics study showed that the results were consistent with in vitro experimental results and in silico molecular docking results.The molecular dynamics results of the polyphenol-amylose interaction showed that the polyphenols with complex molecular structure,greater molecular weight,and more hydrogen bond donors?acceptors?bound more strongly with amylose,but this binding failed to form a long-term stable complex.