Extraction,Purification,Biological Activities Of Polyphenol From Artocarpus Heterophyllus Lam Peel

Artocarpus heterophyllus Lam.,whichis one of typical tropical fruits.The quality of peel is about 40%of fruit.It is not edible,but can be used for cattle and fish feed.However,a large number of peel was discarded into agricultural waste,resulting in a large waste of resources and environmental pollution.It contains minerals,?-carotene and dietary fiber and other rich nutrients,but also contains polyphenols,flavonoids and alkaloids and other active substances.Polyphenols has antioxidant,anti-microbial,blood lipids and other biological effects,showing great value in medicine,health care products,cosmetics and other industries.In this paper,jackfruit peel was investigated to establish the extraction and separation method of polypheno ls,which provided basis for its reuse and development ofnew ingredient ofnatural polyphenol.The extraction processing and effects of macroporous resin and dextran gel column chromatography on purification of polyphenols from jackfruit peel were studied.The purified product's structure was identified by UV spectroscopy,UPLC-MS and NMR.The scavenging activity of DPPH free radicals and tyrosinase inhibitory activity of polyphenols from jackfruit peel were also studied.Results are as follows:?1?Polyphenols weree extracted fro m jackfruit peel by ultrasonic assisted solvent extraction.The effects of factors such as solvent concentration,liquid-solid ratio,extraction temperature,ultrasonic time and ultrasonic power on the yield of polyphenols were investigated and the extraction processing was optimized by Box-Behnken combination experiment design.The optimal extraction conditions were as follows:ethanol volume fraction 66%,extraction temperature 41?,liquid-solid ratio 27:1?mL/g?.Theyield of polyphenols from jackfruit peel was 2.24%,which was close to the theoretical prediction.?2?NKA-2was screened as a suitable resin for the purification of polyphenols from jackfruit peel.The effects of factors such as the concentration of polyphenols and the volume fraction of ethanol on the adsorption and resolution of NKA-2 resin were studied.The concentration of polyphenol was 0.4 mg/mL,the volume of sample was 145mL,the flow rate was 3 mL/min,the amount of distilled water was 250 mL,the volume fraction of ethanol was 70%,the amount of eluent was 145 mL,elution flow rate of 3 mL/min.The results showed that the recovery rate of polyphenols was 75.64%,total phenol content increased from 27.33 mg/g to 65.59 mg/g,which was 2.39 times higher than that before purification.The removal rate of DPPH free radicals was increased from 75.35%to89.53%.The results showed that NKA-2 resin has good effects on polyphenols from jackfruit peel.?3?Experimental results show that polyphenols contain procyanidins through the UV-visible spectroscopy analysis.3,4-dihydroxybenzoic acid?protocatechuic acid?and dibutyl phthalate was determined respectivelyfrom 70%and 100%ethanol eluant of NKA-2 macroporous resin by UPLC-MS and NMR.In addition,it is presumed that the polyphenols of jackfruit peel may also contain phenolic compounds such as type A procyanidin dimer,type B procyanidin dimer and chlorogenic acid from mass spectrum.The amount is not sufficient for the analysis of the nuclear magnetic spectrum,so that t he molecular structure can not be further explored to determine the above speculation.?4?The results showed that the IC₅₀ values against DPPH free radicals of polyphenols from jackfruit peel and vitamin Cwere 0.031 and 0.11 mg/mL,respectively.The DPPH free radical scavenging rate of each extract was:aqueous phase>n-butanol phase>ethyl acetate phase>crude extract>dichloromethane phase>petroleum ether phase,indicating that the antioxidant active substances were mainly concentrated in aqueous phase.There was a significant correlation between the concentration of polyphenols and the inhibition rate of tyrosinase activity?P<0.01?,and the correlation coefficient was 0.972.The IC ₅₀values againsttyrosinase activity of polyphenols from jackfruit peel and kojic acid were respectively 158.85?g/mL and 18.97?g/mL.The tyrosinase inhibition rates of aqueous phase,n-butanol phase and ethyl acetate phase were respectively 69.78%,59.52%,54.37%,which were higher than methylene chloride and petroleum ether phase.