Tibetan Zhatuo Ba Hypoglycemic Active Ingredients

Leontopodium sinense Hemsl (Compositae) is a commonly-used Tibetan medicine. It tastes slightly bitter, cold in nature and belongs to the Kidney and Urinary bladder Channel. Its functions include dispelling wind to relieve exterior syndrome, clearing away heat and toxic material, removing heat from the blood to stop bleeding, replenishing kidney to induce diuresis and relieving inflammation to promote diuresis, being used for the treatment of influenza, epidemic disease, poisoning of mineral medicine, arsenic intoxication, acute or chronic nephritis, urethritis, proteinuria, hematuresis, diabetes, traumatic hemorrhage, etc.Researches on its chemical constituents indicate that it contains amino acid, polypeptide, protein, polysaccharide, monosaccharide, reductive sugar, organic acid, fatty oil, phenols, flavone, tannin, lignans, coumarin, triterpene, saponin, steroid.The present study screened many Leontopodium plants by the use of mice alloxan diabetes model to select plant with the strongest hypoglycemic activity and made further research on it to find out the active parts. Results showed that L. sinense Hemsl is the most effective and its active part is in the petroleum ether-extract.After separation with silica gel.(200-300 mesh) column chromatography and repeated recrystallization, seven monomers were obtained. Compounds Ⅰ-Ⅶ were identified as 3,5-dihydroxy-6,7-dimethoxy flavone, stigmasterol, n-tetracosanol, n-tetracosanic acid, 3,5,7-trihydroxy-8-methoxy flavone, β-sitosterol and quercetin. compound Ⅰ , Ⅲ, Ⅳ, Ⅴ, Ⅶ are isolated from this plant for the first time. Ⅰ and Ⅴ are novel constituents with ring B unsubstituted. Results of activity screening of these seven compounds by enzyme-inhibitor model showed that I could inhibit a-glucosidase indicating that I is the active hypoglycemic constituents in L. sinense Hemsl.Quality standard of L. sinense Hemsl crude drug was studied by HPLC and taking compound I as standard to establish controllable quality assessment system. Results showed the content of compound I in L. sinense Hemsl is higher than...