Study On Terpenoids And Activity Of Taraxacum Mongolicum

Taraxacum mongolium Hand-Mazz,also known as famous mother-in-law man,etc,which is a perennial herb of Compositae.It was first published in the famous book "Tang Materia Medica",and also detailed in medical books such as"Compendium of Materia Medica" and "New Materia Medica".Taraxacum is widely distributed,especially in the northeast and north of China,and other countries in the northern hemisphere are also distributed.Taraxacum medicinal value is very extensive.The function of taraxacum is gallbladder and diuretic swelling,cure poison sore swollen,clear hot detoxify,and anti-tumor.In this paper,the chemical constituents and pharmacological effects of taraxacum in recent years were summarized.It was found that there were few reports about tyrosinase inhibitory activity and DPPH(1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity of taraxacum.Therefore,tyrosinase inhibitory activity and DPPH radical scavenging activity were used as active guides in order to separate methanol-dichloromethane(1:1) extract and methanol extract.Macroporous resin column,SiO2 normal phase column chromatography,ODS reverse phase column chromatography and high performance liquid chromatography were used for separation and purification.Nine compounds were isolated from taraxacum.The molecular structures of three compounds were identified by mass spectrometry and nuclear magnetic resonance.They were identified respectively as taraxerol(1),stigmasterol(2),and taraxasterol(7),(3a,19a)-3,19-dihydroxywusu-12-ene-28-acid(8).Tyrosinase inhibitory activity and DPPH free radical scavenging activity of the four compounds were tested.The results showed that the DPPH free radical scavenging rate of the four compounds were above 90%.The IC50 values of the four compounds were 1.52 g/mL,1.25 g/mL,2.02 g/mL and 3.08 g/mL,respectively.which were lower than that of vitamin C(4.49 ?g/mL) in the positive control group.