Study On Chemical Constitutes And Anti-oxidant Activities Of Leontopodium Leontopodioides

Leontopodium leontopodioides (Willd) (Compositae) is a commonly-used Chinese 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 constitutes indicate it contains amino acid, protein, saccharide, organic acid, phenols,flavones,coumarin and saponin. In this study, the content of polyphenols, flavonoid and total alkaloids of Leontopodium leontopodioides extracts were determined. It was proved the contents of these active constitutes in ethanol extracts are twice or much more than in the water extracts.The antioxidant activities of Leontopodium leontopodioides water and ethanol extracts were evaluated by various established in vitro systems, including total reducing power, superoxide(O2-·) /hydroxyl (·OH) radical-scavenging assays, reducing lipid peroxidation, the effects of sodium nitrite scavenging and nitrosamine synthesis disconnecting. The extracts of Leontopodium leontopodioides had a strong reducing power and radical-scavenging effect. The capacity of ethanol extract was more effective than water extract, .When the concentration of both water and ethanol extracts were at 5mg/ml, hydroxyl (·OH) radical-scavenging rate was at 100%. When the concentration of water extracts,ethanol extracts and Vc was at 7.5mg/ml,4mg/ml and 0.4mg/ml separately, superoxide(O2-·) radical-scavenging was at 100%. Leontopodium leontopodioides water and ethanol extracts attained 60% and over for inhibition of the lipid peroxidation. Leontopodium extracts had strong capacity of sodium nitrite scavenging and nitrosamine synthesis disconnecting. Water extract was77.7% for the scavenging rate of sodium nitrite, and ethanol extract was 98% for the rate of nitrosamine synthesis disconnecting. The IC50 of Vc,ethanol extracts and water extracts for the rate of nitrosamine synthesis disconnecting was 10.867mg/ml, 1.186mg/ml, 6.860mg/ml separately.After separation and purification with silica gel (200-300mesh) column-chromatogaphy and PTLC,two monomers were obtained,compoundⅠand compoundⅡ. The concrete structures of compoundsⅠ,Ⅱhave to be further confirmed.