Optimization Of Extraction Of Cinnamaldehyde And Cinnamic Acid From Cinnamomum Cassia Twig And Preparation And Antibacterial Activity Of Composite Silver Nano-preparation

Cinnamon is a plant homologous to medicine and food,in which cinnamaldehyde and cinnamic acid with high content are two insoluble active components,which have obvious antioxidant and antibacterial activity.In this paper,through the method of ultrasonic-assisted microwave extraction,making use of the advantages of microwave extraction in the extraction of polar components,the response surface optimization design experiment was carried out on the basis of single factor experiments to determine the best extraction conditions.On this basis,using the reducibility of cinnamaldehyde and cinnamic acid as reductants and stabilizers for green preparation of metal and oxide nanocomposites,The AgNPs were prepared by hydrothermal synthesis using cinnamaldehyde and cinnamic acid as reducing agents,respectively.The methods of preparing cinnamaldehyde-AgNPs preparation and cinnamic acid-AgNPs preparation were explored.The AgNPs were collected and characterized by ultraviolet-visible absorption spectrum(UV-Vis),infrared absorption spectrum(FTIR),transmission electron microscope(TEM),X-ray diffractometer(XRD),X-ray photoelectron spectroscopy(XPS),atomic force microscope(AFM)and thermogravimetric analyzer(TGA).The preliminary application of antibacterial activity of nanocomposites was studied.1.Cinnamaldehyde and cinnamic acid were extracted from Cinnamomum cassia twig by ultrasonic-assisted microwave extraction and hydrothermal synthesis.Based on the single factor experiment of four factors and five levels,the response surface optimization experiment was designed to determine the best extraction conditions.At the same time,compared with the traditional Cmurl 8 column,pentafluorophenyl column has better ability to separate structural similar or isomers.The AgNPs were prepared from the crude extract extracted by ultrasonic-assisted microwave extraction,and the size and particle size distribution of the AgNPs were uniform.UV-Vis and XPS proved that the The AgNPs existed in the prepared materials and had long antibacterial aging.2.Cinnamaldehyde-AgNPs and cinnamic acid-AgNPs were prepared by one-step hydrothermal method because the main components of cinnamon twig extract were cinnamaldehyde and cinnamic acid.The optimized preparation conditions were obtained.The synthesized silver nanocomposites were observed by UV-Vis and TEM.The results show that the AgNPs are mainly spherical particles with uniform particle size.The results of XRD measurements show that the AgNPs have highly crystalline structure.The results of bacteriostatic experiment showed that the two composite nano-preparations had strong inhibitory effect on E.coli and C.albicans.The inhibition rate experiment showed that cinnamaldehyde-silver composite nano-preparation had obvious sustained release effect and prolonged the bacteriostatic time.