Comprehensive Evaluation Of The Main Phenolic Components And Biological Activities Of Goji Leaves And Study On Their High-efficient Extraction And Enrichment Technology

In this study,we selected three important forest resources,“Ningqi No.1”,“Lycium ruthenicum Murr.”,and“Ningqi Cai No.1”.The young leaves at the tip and the old leaves at the base were selected to establish a rapid detection method for goji leaves.The method of 5 phenolic compounds compared the chemical composition content and the in vitro activity of different varieties of goji leaves in different parts,analyzed the correlation between the activity and the composition,and finally established a green,efficient and simple extraction method to extract 5 kinds of phenolic compounds in goji leaves.The main research results of this paper are as follows:(1)Established a high performance liquid chromatography method that can simultaneously detect the five phenolic compounds of neochlorogenic acid,chlorogenic acid,cryptochlorogenic acid,rutin,and kaempferol-3-O-rutinoside in goji leaves:Column:Phenomenex Luna PFP(4.6 mm×250mm,5μm)column,column temperature 40℃;mobile phase:A(0.1%formic acid water)-B(acetonitrile);gradient elution:0-10 min,10-10%B;10-15 min,10-16%B;15-30 min,16-18%B;30-40 min,18-18%B;40-45 min,18-30%B.The detection wavelength is 350nm,the flow rate is 1.0 m L/min,and the injection volume is 20μL.This method presents a good linear relationship(R~2>0.99),and has high reproducibility,precision,stability and sample recovery.(2)The total content of total phenols,total flavonoids and 5 kinds of phenolic compounds in goji leaves and the antioxidant capacity of DPPH,all have the condition that the top leaves are larger than the base leaves,and they are all of the top leaves of"Ningqicai No.1"The most content(the highest antioxidant capacity).Through the in vitro antibacterial test,it was found that the goji leaf extract had significant antibacterial ability against E.coli and Staphylococcus aureus,and the top leaves of"Ningqicai No.1"had the strongest antibacterial ability.Through correlation analysis,it is inferred that the antioxidant capacity of goji leaves may be affected by rutin,and its antibacterial capacity may be affected by chlorogenic acid,cryptochlorogenic acid,and rutin.(3)Using the top leaves of“Ningqicai No.1”as raw materials,the optimal extraction process conditions for the extraction of five phenolic compounds from goji leaves with green supramolecular solvents were studied.Through single factor test combined with response surface analysis,the best extraction process was determined as:extraction solvent:100%supramolecular solvent synthesized from 5%caprylic acid-24%ethanol-71%hydrate,solid-liquid ratio:22 mg/m L,vortex time:6 minutes,vortex rotation speed:100%.The extraction rate under this parameter condition:neochlorogenic acid,0.381 mg/m L;chlorogenic acid,7.939 mg/m L;cryptochlorogenic acid,6.734 mg/m L;rutin,8.944mg/m L;kaempferol-3-O-rutin,6.734 mg/m L.The high performance liquid chromatography detection method established in this paper and the comparative data of the chemical composition and biological activity of different goji leaves provide a usable method for the follow-up study of the chemical composition of goji leaves,as well as provide a new options for the utilization and planting of goji leaves and the management plan of goji resources.The supramolecular solvent used for extraction is natural and green,with low consumption,and the extraction technology is efficient and simple.It lays the foundation for the technical development of the supramolecular solvent for the effective chemical components of plants,and also provides a new reference way for the processing and utilization of goji leaves.