Preparation Of Chromium Complex Of Propylene Glycol Alginate Sodium Sulfate (PSS) And Its Fractions And Study Of Their Hypoglycemic Effect

Propylene Glycol Alginate Sodium Sulfate (PSS) is the first marine carbohydrate new drug which is developed firstly in China, and it is a low-molecular-weight alginate propyl sulfate sodium salt resulting from the Laminaria Japonica-extract's molecule modification. It has been widely used in clinical practice for many years to reduce blood viscocity, anticoagulate blood, decrease serum lipids, improve microcirculation, etc. But up to now, there is no study on its gradation,preparation of the chromium complex of its fractions and their hypoglycemic effect.In this paper, PSS is taken for research object, and prepare its fractions and the complex of Cr3+ and PSS and its fractions. By the hypoglycemic biological study of PSS, its fractions and their chromium complex, their hypoglycemic effect are evaluated. The research may provide scientific basis for PSS'further medicine exploitation.Through ultra-filtration method, PSS is fractionated to 6 different samples which named PSS-C1, PSS-C2, PSS-C3, PSS-C4, PSS-C5 and PSS-C6 respectively. Their molecular weights are as followings: 21417Da,14316Da,11449Da,6221Da和4951Da. Screening results of PSS and its fractions by RIF-m and RIF-5F islet cells show that PSS-C4 and PSS-C5 have promoting insulin secretion effect. The antioxidation experiment display the free radical scavenging ability of PSS and its fractions is that Vc﹥PSS-C5﹥PSS-C4﹥PSS. For alloxan-induced diabetes mellitus mice, PSS and PSS-C5 can not decrease blood glucose, while in insulin resistance study, PSS and PSS-C5 all manifest some effect but just take on action slowly compared with metformin hydrochloride.The optimum conditions of orthogonal experiment are like this: pH value is 7, temperature is 50℃, the molar ratio of PSS monosaccharide and chromium is 2:1. The chromium content of PSS-Cr prepared under those conditions is 6.69%. And carboxyl group of PSS participates in coordination of PSS and Cr3+ is proved by IR, UV and conductivity titration. Under the opimum conditions, large quantity of PSS-Cr and PSS-C5-Cr are obtained, and their hypoglycemic effects are evaluated. Animal experiments show that PSS-Cr and PSS-C5-Cr can both improve insulin resistance, decrease blood glucose of alloxan-induced diabetes mellitus mice, especially PSS-Cr (P﹤0.05) . In the experiment of preliminary acute toxicity test, there is no death at dose of 20g/kg, and this proves that PSS-Cr is nontoxic. .