Bilirubin（635-65-4）

Chemical properties: except natural bilirubin IX α In addition, it also contains III{ α And XIII{ α Isomers. IX{ α The two vinyl groups on the pyrrole ring in the molecule are in the medial and lateral positions respectively. Under acidic conditions, the isomer III with both vinyl groups in the lateral position can be formed{ α Or isomer XIII in the medial position{ α。 In the production process, the type, concentration and operation of acid used for acidification are different, and the degree of isomerization is also different. This product mainly comes from the reduction product of heme in hemoglobin after the disintegration of aging red blood cells through a series of catabolism. It is golden yellow or dark reddish brown monoclinic crystal, odorless and tasteless. Soluble in organic solvents such as benzene, chloroform and carbon disulfide; It can also be dissolved in the mixture of hot ethanol and chloroform; Sodium salt is soluble in water, but calcium salt, magnesium salt and barium salt are insoluble in water. The dry solid is relatively stable; Chloroform solution is also stable in the dark; In alkaline solution (such as 0.1mmol/L sodium hydroxide) or in the presence of trivalent iron ions, it is unstable and quickly oxidized to biliverdin, which can be reduced to bilirubin through chemical reaction in vitro or biliverdin reductase. Bilirubin can combine with glycine, alanine or histidine. Bilirubin is a strong endogenous antioxidant at normal serum concentration. The molecular structure of bilirubin can be divided into ketone type and alcohol type. Since bilirubin has a specific curly structure, its hydrophobicity increases and it can enter into the lipid molecule. Bilirubin has an extended conjugated double bond system and active hydrogen atom, which can prevent oxidation. The experiment shows that bilirubin can inhibit the oxidative modification of LDL (low density lipoprotein in blood) to a certain extent in vitro, which can inhibit and alleviate the formation of atherosclerosis caused by oxidative modification of LDL, thus ultimately achieving the purpose of prevention and treatment of coronary heart disease.