Study On The Extraction,Separation And Pharmacological Activity On α-Adrenoreceptor Of L-Synephrine In Fructus Citri Immaturi

Fructus Citri Immaturi is a traditional Chinese medicinal material with abound resources.It has been widely used for a long time. Synephrine is one of the major principles which have drug action in Fructus Citri Immaturi.So it has a huge market with big potential and wide prospect.Synephrine is an enantiomorph because there is a chiral carbon atom in its molecule.It has two configurations - laevoisomer (L-synephrine) and dextroisomer(D-synephrine).L-synephrine is the primary configuration in natural plants.Some reports indicated that L-synephrine is the active configuration which shows pharmacological activity in synephrine enantiomorph medicine.Therefore study on the extraction and separation of L-synephrine makes great sense for the development of chiral medicine with pharmacological higher activity and exploration of pharmacological mechanism.In this study synephrine enantiomorph was isolated by high performance liquid(HPLC) with chiral stationary phase.And a new method of determining the content of L-synephrine was developed. Optimized the extraction conditions of L-synephrine from Fructus Citri Immaturi.L-syneprine was obtained after extraction,ion exchanging and silica gel chromatography.It was structural identified using mass chromatography,nuclear magnetic resonance and optical rotation.Then its pharmacological activity onα-adrenoreceptor was determined.1,The development of a new method of determining L-synephrine content in samplesThe effects of modifying organic solvent concentration,acid and alkali addition,column temperature,flow on the isolation of synephrine enantiomorph were determined on ChiralPak AD-H chiral column by HPLC.Synephrine enantiomorph was isolated effectively.Basing on the above result,a new method of determining the content of L-synephrine was developed with the following conditions:①mobile phase: n-hexane-ethanol-diethylamine-trifluoroacetic acid(93:7:0.08:0.08);②flow:1.0mL/min;③column temperature:20℃;④wave length: 225nm.Methodology inspection showed simplicity,accuracy and good repeatability.The method can be used to determine L-synephrine quickly.2,Study on the extraction conditions of L-synephrine from Fructus Citri ImmaturiSdudy on the effects of several factors on extraction of L-synephrine fome Fructus Citri Immaturi,such as solution concentration,time,the rate of meteral and solution,temperature,times,etc.Ethanol refluxing extraction and HC1 ultrasonic extraction were compared by orthogonal experiment,and the result showed that the optimal condition was:60% ethanol,2h,the rate of meteral and solution 1:12,80℃.The extraction of L-synephrine is up to 6.28mg/g.3,Separation,purification and identification of L-synephrine Crude extract of L-synephrine was extracted by n-butyl alcohol, Separated by Resin 001×8,and purified by silica gel column.13.4g Lsynephrine was obtained and its purity was up to 95.2%.In the experiment process,compared the effects of separation conditions on isomerization of synephrine by cation-exchange chromatography of resin 001×8 when the loading sample's pH and the ammonia concentration of eluant were changed.It was identified to be L-synephrine by mass spectrum,nuclear magnetic resonance and optical rotation.4,Study on the pharmacological activity onα-adrenoreceptorThe ethanol extract of Fructus Citri Immaturi,synephrine enantiomorph and L-synephrine monomer were proofed to have pharmacological activity on a-adrenoreceptor by the rat isolated thoracic aorta tension experiment.L-synephrine has the highest activity,but there is not significant difference between synephrine enantiomers' pharmacological activity onα-adrenoreceptor and L-synephrine's.Further studies are necessary on pharmacological activity advantages and pharmacological mechanism.