Structure Analysis And Biological Activity Of Condensed Tannins From Laguncularia Racemose And Bruguiera Gymnorrhiza

Laguncularia racemose is a common plant in the mangrove reserve of dongzhai port,hainan province.Bruguiera gymnorrhiza is a mangrove plant in the yunxiao wetland park of zhangzhou city,fujian province.In this article,the structural analysis and bioactivity of CTs from them were discussed.Our have already completed the determination of total phenol content(TPC)and condensed tannins(CTs)content.The results showed that TPC and CTs content of L.racemosa were 353.74 ± 0.36 mgGAE/g DW,105.74±2.50 mg/g DW,while TPC of B.gymnorhiza were 251.48 ± 0.27 mgGAE/g DW and CTs content were 133.75±0.0.04 mg/g DW.The structural elucidation were identified by 13C NMR,RP-HPLC techniques.Theirs CTs were mainly composed of procyanidins(PC)without esterified,a small amount of prodelphinidins(PD),and propelargonidin(PP).C2 and C3 positions of flavane-3-ols have cis form and trans form,mainly 2,3-cis stereo-chemical structures.In addition,the mean degree of polymerization(mDP)of CTs from L.racemosa was estimated to be 17.3 and mDP of CTs from B.gymnorhiza was 4.85.According to enzyme kinetic experiments,the results showed that CTs inhibited tyrosinase activity prominently(IC50=7.57±0.138 ?g mL-1 for L.racemosa and 123.86 ± 0.14 ?g mL-1 for B.gymnorhiza,respectively)in a reversible and mixed-type manner.They interacted with enzyme as well as substrates to reduce enzyme activity.Furthermore,The present study was to investigate that CTs inhibited proliferation effectively on tyrosinase activity as mediated by suppressing MITF and melanogenic proteins(TYR,Tyrp-1,Tyrp-2)possibly through regulating MC1R/?-MSH melanin synthesis pathway,leading to inhibit melanin content and cellular tyrosinase activity of B16F10 cells.Fresh-cut lotus root were treated with 250 ?g mL-1,1000 ?g mL-1 CTs from L.racemosa and 500?g mL-1,1000?g mL-1 CTs from B.gymnorhiza,then stored at 4? for 17 days or 18 days to discussed the effects on preventing it from browning.The results showed that CTs treatment inhibited cut surface browning and lightened membrane lipid peroxidation as reflected by low polyphenol oxidase(PPO),peroxidase(POD)activity,malondialdehyde(MDA)content,and prevention of total phenolics oxidation,thereby delay the browning of fresh-cut lotus roots.Besides,Our finding showed that CTs were provided with a growing anti oxidation capacity,antibacterial activity.Therefore,CTs from L.racemosa and B.gymnorhiza have feasible applications in food,medicine,and the cosmetics uses.