Volume And Acoustics Of The Interaction Between Drugs And Carbohydrates In Aqueous Solutions

The solvation behavior of drug molecules in solution is important for understanding the activity of drugs in living organisms.Carbohydrates on the cell surface are receptors for biologically active structures such as enzymes,viruses,antibodies,and hormones.Carbohydrates and their derivatives are involved in many biological processes due to their conformational flexibility,such as signal transmission,cell-cell recognition,and the like.Water is the main body of all life.Therefore,it is of great value to study the interaction between drug molecules and carbohydrates in aqueous solution.Gamma-aminobutyric acid is a rational drug for the treatment of neurological and psychiatric disorders as well as epilepsy,anxiety,insomnia and depression.6-Aminocaproic acid is suitable for bleeding caused by elevated plasmin activity.Dihydroxypropyl theophylline is suitable for asthmatic patients with tachycardia.In this thesis,volumetric and acoustic methods were systematically studied for the properties of drug(gamma-aminobutyric acid,6-aminocaproic acid,diproticophylline)in 4% carbohydrates(inositol,mannitol,sucrose,D-(+)-glucose,D-(+)-xylose)aqueous solutions.The main contents of the study are as follows:1.The DSA5000 was used to determine the density and sound velocity of the above system at four temperatures(293.15,298.15,303.15,308.15K).The apparent molar volume,standard partial molar volume of transfer,infinite dilute partial molar volume,limiting apparent molar expansivity,Hepler's constant of drugs in each aqueous solution of co-solute were calculated from the density value.From the sound velocity value,apparent molar isentropic compressibility,standard partial molar isentropic compression,standard partial molar isentropic compression of transfer of the drug in each cosolvent aqueous solution were calculated.Based on the experimental results obtained,various interactions between drugs and carbohydrate in aqueous solution were discussed.2.The transfer of gamma-aminobutyric acid and 6-aminocaproic acid from water to sugar solution in all study temperature ranges.Infinite dilution partial molar volume and transfer infinite dilution partial partial molar isentropic compression coefficient have the same order,glucose> sucrose > xylose(but 6-aminocaproic acid has a relatively small transfer meta-dilution partial molar volume),inositol > mannitol.The near-zero dilution of the two amino acids in mannitol dilutes the partial molar volume,indicating that the hydrophilic and hydrophobic interactions in the solution are balanced.The dilute partial molarity of the dihydroprophyl theophylline transferred is different from the size of the two amino acids because it is different from the amino acid structure.The infinite dilute partial molar volume of dihydroxypropyl theophylline shifts with the increase of sugar carbon chain,indicating that the enhancement of hydrophobic interaction in solution dominates.3.Transfer of the three drug molecules from water to co-solute solution.Infinite dilution The partial molar volume is positive,negative,and zero.Explain the prevalence of various hydrophilic and hydrophobic interactions in different solutions.4.The Hepler's constants of the three drug molecules calculated in the same co-solute solution are different,showing different structure promotion or destruction properties.Structure-promoting properties of ?-aminobutyric acid in mannitol solution,structural destruction properties in other solutions.The structure-promoting properties of 6-aminocaproic acid in water and xylose solutions and the structural destruction properties in other solutions are shown.Diprophylline is a structural disrupter in the studied solution.5.In the study temperature range,the infinite-dilution partial molar isentropic compression coefficient of ?-aminobutyric acid and 6-aminohexanoic acid is negative,and increases with temperature,indicating that the water molecules around the two amino acids are harder to compress than the bulk water.At high temperatures,diprophylline has a positive,infinite dilution of partial molar isentropic compression coefficients,indicating that it is a structural disrupter.