Enoxapin sodium is a low molecular weight heparin sodium derived from pig intestinal mucosa, which is esterified to obtain benzyl ester sodium derivative of heparin. Structurally, it is composed of many complex and undefined oligosaccharides. According to current knowledge, most oligosaccharides have 4-enolpyranose acid at the non-reducing end of the sugar chain, and 1. 6-dehydrating structure at the reducing end of the sugar chain accounts for 15-25% of the total sugar.

　　Enoxaparin sodium is a low molecular weight heparin that was chemically lysed from the parent heparin by phenylmethyl ester β- elimination. The active site of enoxaparin is a unique 1. 6-dehydrated cyclic two-ring structure, which makes it different from other low molecular weight heparin pharmacological properties. Enoxaparin catalyzes the inactivation of the clotting factors IIa, Xa, IXa, XIa and XIIa by binding to antithrombin III (AT-III), among which it acts as an anticoagulant primarily by inhibiting Xa.

　　The effect of low molecular weight heparin on Xa and IIa is mainly related to the length of the molecular chain. Usually, the molecular chain of heparin reaches more than 18 sugar units and inactivates IIa and Xa at the same time, while most of the molecular chain of low molecular weight heparin is less than 18 sugar units, and the inactivating effect of Xa is stronger, while the effect on the coagulation factor IIa is less. Therefore, the Xa/IIa ratio of enoxaparin sodium with an average molecular weight of 4500Da was 41. which was significantly higher than that of ordinary heparin with an average molecular weight of 15000Da.