| Lignans are one of the largest natural phenolic substances present in plants.Most of them exist in angiosperms and gymnosperms in a free state.It is reported that lignans is characterized by a series of biological and pharmacological properties,such as anti-tumor,anti-inflammatory,liver protection,antibacterial activities.Lignans are the main active ingredients in Chinese herbal medicine such as Schisandra and Magnolia officinalis.It is of great significance to study the separation and extraction of active ingredients of traditional Chinese medicine for drug development,selection of dosage form and quality monitoring.However,due to the shortcomings of traditional extraction techniques such as low sensitivity,large consumption of organic solvent,long extraction time and low recovery.It is very necessary to establish a simple,efficient,environment-friendly sample pretreatment technique with strong enrichment ability for the extraction of active ingredients of traditional Chinese medicine.In this paper,according to the structural characteristics and physicochemical properties of different types of lignans,a suitable extraction solvent is selected to develop the liquid-liquid microextraction systems.And high-performance liquid chromatography-mass spectrometry(HPLC-MS)was used for the detection of different Chinese herbal medicine lignans.The main contents are as follows:(1)A simple and efficient acetonitrile/salt aqueous two-phase system combined with HPLC-MS was developed for the determination of lignans in Schisandra chinensis(Turez)baill,including schizandrin,schisandrol,schisantherin,deoxyschizardrin and schisandrin b.In this study,the sample was mixed with acetonitrile,distilled water and inorganic salt together.The acetonitrile/salt aqueous two-phase system is formed and the target analytes were enriched in the upper phase solution(acetonitrile-rich phase).The target compounds were separated and determined by HPLC-MS.The experimental results showed that good linear relationship(r>0.9999)in the detection concentration range were obtained.The limit of detection(LOD)and limit of quantitation(LOQ)were 0.01?0.05 ?g mL-1 and 0.04?0.17 ?g mL-1,respectively.The inter-day precision RSD was less than 1.61%and the intra-day precision RSD was less than 2.89%.The spiked recovery was between 89.25%and 95.00%.Compared with other methods,the filtration,centrifugation and concentration were avoided.This present method has the characteristics of simple experimental operation,high extraction yield,short extraction time,low sample and organic solvent consumption.It is a simple,efficient and green extraction method.(2)Microwave-assisted ionic liquid-based in situ dispersive liquid-liquid microextraction combined with HPLC-MS was developed and applied to the extraction of magnolol and honokiol from Magnolia officinalis Rehd et Wils.In this study,ionic liquid was used as the extraction solvent.After microwave extraction,the ion-pairing reagent was added to the obtained sample extract,and the target analytes were separated and enriched by in-situ dispersive liquid-liquid microextraction.Finally,qualitative and quantitative analysis was performed by HPLC-MS.The experimental results showed that good linear relationship(r>0.9999)in the detection concentration range was obtained.The limit of detection(LOD)and limit of quantitation(LOQ)were 17.2?23.9 ng mL-1 and 57.4?79.6 ng mL-1,respectively.The spiked recovery was between 89.25%and 95.00%.Compared with the traditional ultrasonic extraction and reflux extraction,the present method has some advantages in solvent consumption and extraction time.It can be used for the extraction of magnolol and honokiol in Chinese herbal medicine and related medical products. |
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