Determination of Melatonin Content in Different Types of Portulaca oleracea
Melatonin has biological activities such as regulating circadian rhythm and anti-oxidation,so the deter-mination of melatonin content in different Portulaca oleracea types can provide theoretical basis for the subsequent development of P.oleracea related functional products.Melatonin in P.oleracea was determined by HPLC,the column was Agilent 5 TC-C18(250 mm×4.6 mm,5 μm);the mobile phase was 50 mmol/L disodium hydrogen phosphate(pH=4.5)-acetonitrile(77∶23);the column temperature was 28℃;the flow rate was 1 mL/min;the injection volume was 10 pL;the detection wavelength was 223 nm.The results showed that there was a good linear relationship between melatonin concentration and peak area in the range of 100～4 000 ng/mL(R=0.999 9),the average recovery was 99.58％and the RSD value was 1.83％.The content of melatonin in the dried samples of P.oleracea was 0～35.917 ng/g and the content of melatonin in Hebei type was the highest.However,no melatonin was detected in Shandong,Sichuan and Jiangsu type.The content of melatonin in fresh leaves of P.oleracea was 0.493～139.911 ng/g and the content of melatonin in Netherlands type was the highest,while no melatonin component was detected in stems.In consequence,the difference of melatonin content in P.oleracea was not only influenced by different types,but also by different parts of the same sample,and the fresh sample of P.oleracea from Netherlands was the best.
万方数据
维普
