Study On Determination Of Carnosine Content And Chiral Separation

L-Camosine（β-alanyl-L-histidine）,a dipeptide composed ofβ-alanine and L-histidine, widely distributed in tissues including the animal and human muscle brain and lens,at concen trations up to 20 mmol/L,It have been postulated to have numerous biological roles including pH buffering,chelate prooxidative metals,inhibition of oxidative reactions and scavenge free radical.Resengly it is used as medicine to cure Premedicine,cataract,relieve asthenopia.It also can be used to cure gastr-ulcer.A rather unusual reported about Carnosine used for ischemia of brain,kidney,heart and diabetes.Carnosine can used as food additive,roboirans,skin-protective agent etc.Comparative study of Carnosine" s biological functions and mechanism of action was carried out,while the method for the determination was seldom in our country,there was no report about chiral seperation.To establish a method with 2,4-Dinitrochlorobenzene as precolumn derivatization agent for the determination of Carnosine by RP-HPLC.The research use a Diamonsil^TMC₁₈analytical column（200 mm×4.6 mm,5μm）with the mobile phase consisting of 0.15 mol/L sodium acetate solution:acetonitrile 5:1（v/v）at the flow rate of 1.0 mL/min.The detection was set at 360 nm.The column tempreture was 35 C.The standard curves were linear over the range of 2.0 20.0μg/mL（r = 0.9999）;The average recovery was 99.7%（RSD = 0.4%）.The method is simple and accurate with a good reproducibility and can be used as a quality control method for Carnosine.To establish a method for the determination of Carnosine by HPCE.This research use flows:Quartz microcapillary（utility length 55cm）,the running electrolyte was 100 mmol/L boracic acid solution.The detection was set at 200 nm.The voltage was 10 kV.The column tempreture was 20℃.The standard curves were linear over the range of 40.0～100.0μg/mL（r = 0.9991）;The average recovery was 105.7%（RSD = 1.2%）.The method is simple and economical and can be used to detect trace quantity Carnosine.To establish a method with o-phthaldialdehyde and N-acetyl-L-cysteine as precolumn derivatization agent to separate D,L-Carnosine by RP-HPLC.The separation was performed on Cromasil C₁₈analytical column（250 mm×4.6 mm,5μm）with the mobile phase consisting of 0.05 mol/L ammonium acetate solution:methanol 7:3（v/v）at the flow rate of 1.0 mL/min.The detection was set at 345 nm.The column tempreture was 25℃.The standard curve of D-Camosine was linear over the range of 2.0～20.0μg/mL（r = 1）;The average recovery was 96.8%,RSD = 0.04%（n = 9）.By this method L,D-Carnosine can be separated and chirality impurity can be detected.The method with good sensitive and reproducibility and can be used to detect the content of D-Carnosine in Carnosine crude drug.