Study On Chemical Constituents,Antioxidation And Tyrosinase Inhibition Activity Of Damask Rose Flower Residue

Damask rose is an excellent product for extracting rose essential oil.It has been introduced in many countries in the world.However,the flower residue left after the extraction of essential oil are treated more extensively,which wastes resources and pollutes the environment.This paper mainly studied the chemical constituents of damask rose flower residue extracted with essential oil,antioxidation and tyrosinase inhibition activity of different extracts.At last,the total phenolic content?TPC?and the indicator content determination were studied.The tissue crushing extraction method was used instead of the traditional extraction method,using water as the solvent,the extract was concentrated under reduced pressure to a specific gravity of about 1.1,and then extracted with a gradient of petroleum ether,ethyl acetate and ethanol.As a result,three extracts were obtained,DRFR-A,DRFR-B and DRFR-C,respectively.The various chromatogramphic techniques such as silica gel and ODS chromatography were used in this experiment and 11 compounds were identified from DRFR-A by spectroscopic analysis.They are Daucostero?1?,Quercetin?2?,Kaempferol?3?,Gallic acid?4?,protocatechuic acid?5?,Pyrogallic Acid?6?,2-Phenylethyl 3,4,5-trihydroxybenzoate?7?,Methyl gallate?8?,p-Hydroxybenzoic acid?9?,p-Hydroxyphenethyl alcohol?10?,Astragalin?11?.Among them,compounds 1,6,7,9,10 were obtained from the plant for the first time.To further develop and utilize rose residue,the free radical scavenging rate was used as the index to evaluate the effects of antioxidant activity.DPPH?2,2-diphenyl-1-picrylhydrazyl?and ABTS[2,2-azino-bis?3-ethylbenzothiazoline-6-sulphonic acid?]were employed to determine the antioxidant activity for the three extraction sites.The results showed that the half-maximal inhibitory concentration(IC₅₀)of DPPH radical scavenging of DRFR-A,DRFR-B and DRFR-C were0.002760 mg/mL,0.004091 mg/mL and 0.02214 mg/mL,respectively.The IC50 of ABTS radical scavenging of the three extraction sites were 0.002258 mg/mL,0.003970 mg/mL and 0.02031 mg/mL,respectively.The positive control was VC with IC50 of 0.001672 mg/mL and 0.002052 mg/mL,respectively.Antioxidant activity was observed in all the three sites,and the order of antioxidant activity was DRFR-A>DRFR-B>DRFR-C.The ethyl acetate site of Damask Rose Flower Residue?DRFR-A?has a strong tyrosinase inhibition capacity.Its IC₅₀ was calculated of 200?g/mL by Kinetic equation,while the positive control kojic acid IC₅₀ was calculated of 5.6?g/mL.The total phenolic content?TPC?of DRFR-A,DRFR-B,DRFR-C and total DRFR were measured by Folin-Ciocalteu method.The results showed that the TPC of the four sites were 637.3±14.6,422.5±9.3,124.6±2.5 and 386.4±6.5 mg GAE/g,respectively.As well as,The results of the antioxidant activity of the three parts is positively correlated to the TPC of them.Gallic acid is the indicator component of DRFR,and it was determined by HPLC.Methods:Chromatographic analysis consisted of a Innovation Explorer C₁₈ column?4.6 mm×250 mm,5?m?and a mobile phase of Acetonitrile-0.5%H3PO4?Gradient elution?.The detection wave length was 250 nm.The column temperature was 30?and the flow rate was 0.8mL/min.Results:A good linearity of Gallic acid was in the range of 0¹ mg/mL,the regression equation was C=0.8123S-0.0128,and r² was 0.9992.The average recovery was 100.006%and RSD was 2.17%.As a result,the content of Gallic acid in the rose residue was 5.12%.This RP-HPLC method is fast,simple,reliable and specific.In this dissertation,Damask rose has been deeply and systematically studied.The extraction and separation methods have the characteristics of saving,environmental protection and high efficiency.11 compounds were isolated and purified,of which 5 were firstly assigned,laying the foundation for the further study of rose scum.Antioxidant and anti-tyrosinase activity evaluation were simple and easy to operate,which provides theoretical guidance for the development of food antioxidants and whitening cosmetics.The method for determination of total phenols?TPC?and index components in rosettes is stable,reliable and specific,which has certain reference value for rapid determination of its total phenol content and its quality control.