Study On The Effect Of Phosphorylation On Biological Activity Of Chrysin

Chrysin,5,7-dihydroxy flavone, is one kind of natural synthetic flavonoids,which widely exists in oroxylum indicum and propolis. It has been known to have alot of biological activities consisting of antioxidant, antimicrobial, anticancery etc.Chrysin has low toxicity, but poor water-solubility. In the gastrointestinal tract, thehydroxyl group of chrysin can react with some kind of glucose and lose activity,which is not conducive to its metabolism and absorption in vivo. This feature to someextent limits its clinical efficacy. While in the life course, phosphorus is the centralrole, because most life activities depend on the participation of phosphoryl. As onekind small molecule of organic phosphorus compound, most of the phosphorus acidester derivatives have a wide range of biological activities. The relationship betweenstructure and biological activity has been taken seriously. Therefore, phosphorylatedchrysin was synthesized by Atherton-Todd reaction in this work. The influence ofphosphorylation on the biological activity and antioxidant properties in vitro wasstudied. The main contents of this paper are as follows:1. Effect of phosphorylation on antioxidant capacity of chrysin in vitroBy optimizing the experimental conditions, the luminol-hydrogen peroxide-carbonate buffer chemiluminescence system, luminol-hydrogen peroxide-coppersulfate-carbonate buffer chemiluminescence system, luminol-pyrogallol-Sodiumhydroxide chemiluminescence system,1,1-diphenyl-2-picrylhy-drazyl radical2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl (DPPH) detection system, and2,2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate)(ABTS) detection system wereestablished. The inhibition rate of chrysin, phosphorylated chrysin and ascorbic acidon H2O2·、·OH、O2·一、DPPH·、ABTS· was determined and their IC50were computed.The results showed that the scavenging ability of chrysin on O2·一and H2O2· isstronger than phosphorylated chrysin. Probably because the scavenging ability hasstrong correlation with the total phenol. While the scavenging ability ofphosphorylated chrysin on·OH and DPPH· is stronger than chrysin. It may be due to the poor correlation between scavenging ability and the total phenol. In addition, thescavenging ability of chrysin on ABTS· is stronger than phosphorylated chrysin andthe scavenging ability has a strong correlation with the total phenol. It is reasoned that7-hydroxy is substituted so that hydroxyl of phosphorylated chrysin less than chrysin.2. Effect of phosphorylation on peroxidation of human red blood cells (RBC)In this work, by determining the inhibition rate of phosphorylated chrysin,chrysin and5-OH flavonoid, the effect of phosphorylation on hydroperoxide-induced peroxidation of human RBC was evaluated. The results showed that thesethree flavonoids can inhibit erythrocyte hemolysis. The order for inhibition rate is asfollows: chrysin, phosphorylated chrysin,5-OH flavonoid. By contrastingphosphorylated chrysin and chrysin, the hemolysis inhibition rate may be related tothe number of hydroxyl groups.7-hydroxyl group has a stronger inhibition effect thanphosphoryl group. Compared phosphorylated chrysin and5-OH flavonoid,7-hydroxyl group has a certain inhibitory effect of hemolysis.3. Effect of phosphorylation on antibacterial properties of chrysinAs research subjects, the antibacterial effect of phosphorylated chrysin andchrysin on escherichia coli and staphylococcus aureus was studied by evaluating theeffect of phosphorylation on antibacterial properties of chrysin. The results showedthat both phosphorylated chrysin and chrysin have antibacterial effect on escherichiacoli and staphylococcus aureus and there is a good linear relationship between theantibacteria rate and concentration. Furthermore, the antibacteria rate ofphosphorylated chrysin is stronger than chrysin, providing a reference for furtherexploration on bactericidal effect of phosphorylated derivatives.4. Effect of phosphorylation on interaction between chrysin and solidsupport-phospholipid membraneIn the fourth part, cyclic voltammetry of phosphorylated chrysin and chrysin wasstudied by solid support-phospholipid membrane. The electrode modified withdigimon version pc (DMPC) was used to simulating phospholipid bilayer of plant andanimal cells and the electrode modified with dimyristoyl phosphatidylglycerole(DMPG) was used to simulating phospholipid bilayer of bacterial. The results are asfollows, through current increasing, both phosphorylated chrysin and chrysin make phospholipid membrane damaged or disintegrated. Chrysin has greater interactionwith electrode modified by DMPC than phosphorylated chrysin. It can be inferredthat compared with phosphorylated chrysin, chrysin may have higher toxicity and bemore likely to cause hemolysis of RBC. When the concentration was less than200μg/mL, the interaction between phosphorylated chrysin and chrysin with electrodemodified by DMPG was similar. Larger than200μg/mL, phosphorylated chrysinwas geater than chrysin. With concentration increasing, the interactions also showedan increasing trend. The bactericidal effect of phosphorylated chrysin could bestronger than chrysin.