Study On Extraction,Nanomodification And Activity Of Quercetin In Sophora

Quercetin,one of the most well-known flavonoids,has been included in human diet for a long history.The use of quercetin has been widely associated with a great number of health benefits,including antioxidant,anti-inflammatory,anbacteria and anticancer as well as the function to ease some cardiovascular diseases(i.e.,heart disease,hypertension,and high blood cholesterol).However,poor water solubility,chemical instability and low bioavailability of quercetin greatly limit its application.The use of a drug delivery system can improve its water solubility,increasing its stability,efficacy and bioavailability.Fluorescent group Ⅱ-Ⅵ nanocrystals(CdSe),also known as quantum dots,have received great attention due to their stable fluorescent properties.Shell-core protection at quantum dots can significantly improve its stability.ZnS can be used as a shell material.Therefore,quantum dots(CdSe/ZnS)with fluorescent properties can provide real-time monitoring and observation in medicine.The synthesized quantum dot CdSe/ZnS is used as a core;the negatively charged quercetin can be conjugated to CdSe/ZnS by an ionic bond.The newly synthesized quantum dot nanomaterial QCZ NPs is applied to the inhibition activity of drug-resistant bacteria and tumors.The main findings are as follows:1.Optimization of Extraction Technology of Quercetin in SophoraQuercetin was extracted from glutinous rice by ethanol ultrasonic extraction and supercritical CO2 extraction.The results of orthogonal test showed that the optimal process of ethanol ultrasonic extraction was 70%ethanol,the ratio of material to liquid was 1:15,the extraction time was 50 min,and the maximum extraction rate was 6.43%.In the supercritical CO2 extraction test,the orthogonal test results show that the optimal process of supercritical CO2 extraction method is the entrainer flow rate is 1.0 mL/min,the temperature is 50 ℃,the extraction time is 2.0 h,the pressure is 30 MPa,and the maximum The extraction rate can reach 7.26%.In comparison,the supercritical CO2 extraction method has a higher extraction rate.In this experiment,the extract was separated and purified,and separated by column chromatography on silica gel column.The crude extract was successfully purified.The purity of the sample was found to be 96.2%by HPLC.2.Study on the inhibition activity of Quercetin modified ZnS wrapped CdSe quantum dots against drug-resistant bacteriaThe quercetin was successfully synthesized on CdSe to form CdSe-Qe nanoparticles,and then ZnS was used as the outer shell to coat the surface of the nanoparticles.The QCZ NPs were successfully synthesized.The characterization results show that the QCZ NPs have a particle size of about 10 nm,uniform size and uniform dispersion in aqueous solution,and their water solubility and fluorescence intensity are significantly increased after ZnS coating.In the in vitro antibacterial experiments,drug-resistant Escherichia coli(E.coli)and Bacillus subtilis(B.subtilis)which are more sensitive to the inhibit action of QCZ NPs were screened.Studies on the antibacterial mechanism of QCZ NPs have shown that QCZ NPs destroy the bacterial cell integrity,destroy the bacterial cell wall,inhibit protein synthesis,and the destruction of bacterial structure is the main cause of bacterial death.In the animal bacteraemia model,the animal bacteraemia model was established by injection of E.coli into the tail vein.QCZ NPs were used to treat infected mice.The results showed that QCZ NPs can significantly inhibit E.coli in vivo and significantly improve the survival rate of nude mice.The results of in vitro and in vivo experiments show that QCZ NPs have significant inhibitory effects on drug-resistant E.coli and B.subtilis,and can be used as potential nano-level antibacterial drugs.3.Study on anti-tumor activity of quercetin modified ZnS coated CdSe quantum dotsNanoparticle QCZ NPs exhibits anticancer activity,further enhances the anti-tumor activity of quercetin alone,and applies the fluorescence characteristics of quantum dots to the anti-tumor activity of quercetin.Through MTT assay,it was found that QCZ NPs have a broad spectrum of anti-tumor activity,especially for BGC-823 cells.According to RTCA analysis,QCZ NPs can significantly inhibit the proliferation and migration of BGC-823 cells.For the fluorescence characteristics of quantum dots,we performed a time-gradient quantum dot fluorescence intensity test.The results showed that after 4 hours of incubation of QCZ NPs,the fluorescence intensity of the cells reached a maximum.The anti-tumor activity of QCZ NPs was studied by establishing a tumor-bearing mouse model.The results showed that QCZ NPs can significantly inhibit tumor tissue in mice,induce tumor cell apoptosis in tumor tissues,and achieve the effect of treating tumors in mice.The biotoxicity of QCZ NPs was studied.The results show that the quantum dot nanomaterials do not produce toxic side effects on the main organs of mice.In summary,this paper optimizes the CO2 upercritical fluid extraction,improves the extraction rate of quercetin extracted from glutinous rice,and purifies quercetin with higher purity.The novel water-soluble quantum dot material QCZ NPs was obtained by nano-modification of quercetin.The in vitro and in vivo experiments proved that the nano-material has superior anti-tumor and antibacterial activity.