日本落叶松新鲜松针的化学成分及其抗氧化活性研究(英文).docx

日本落叶松新鲜松针的化学成分及其抗氧化活性研究(英文)
ResearchonChemicalCompositionandAntioxidantActivityofFreshPineNeedlesofJapaneseLarch
Introduction
TheJapaneselarch(Larixkaempferi)isadeciduousconiferoustreespeciesthatiswidelydistributedinJapan,Korea,andChina.Itisanimportanttreespeciesinforestryandlandreclamationduetoitsadaptabilitytovarioussoilandclimateconditions.ThepineneedlesofJapaneselarcharerichinbioactivecompounds,includingphenolicacids,flavonoids,andterpenoids,whichhavebeenreportedtopossessvariouspharmacologicalactivities,suchasantioxidant,anti-inflammatory,andanti-cancereffects.Inthisstudy,weaimedtoinvestigatethechemicalcompositionandantioxidantactivityoffreshpineneedlesofJapaneselarch.
Methods
Materials
FreshpineneedlesofJapaneselarchwerecollectedfromaforestinHokkaido,Japan,inNovember2020.Theplantmaterialwasidentifiedbyaplanttaxonomistandavoucherspecimen(JL2020)wasdepositedintheherbariumofHokkaidoUniversity.
Chemicalanalysis
Thefreshpineneedleswerewashedwithwaterandair-driedatroomtemperaturefor1week.Thedriedneedlesweregroundintopowder,andthenextractedwith80%methanolbyultrasonication.Theextractwasfilteredandevaporatedtodrynessunderreducedpressure.Thechemicalcompositionoftheextractwasanalyzedbyhigh-performanceliquidchromatography(HPLC)withaC18columnandadiodearraydetector.Themobilephasewascomposedof0.1%formicacidinwater(A)andacetonitrile(B),andthegradientelutionwasasfollows:0-5min,10%B;5-20min,10-20%B;20-25min,20-30%B;25-30min,30-40%B;30-35min,40-50%B;35-40min,50-60%B;40-45min,60-70%B;45-50min,70-80%B;50-55min,80-90%B;55-60min,90-95%B;60-65min,95-10%B;65-70min,10%B.Theflowratewassetat0.8mL/min,andthewavelengthofthediodearraydetectorwassetat280nm.
Antioxidantactivityassay
Theantioxidantactivityoftheextractwasevaluatedbythe2,2-diphenyl-1-picrylhydrazyl(DPPH)radicalscavengingassay.Theassaywasperformedaspreviouslydescribed(Blois,1958).Briefly,1mLoftheextract(1mg/mLinmethanol)wasmixedwith1mLofa0.1mMDPPHsolutioninmethanol.Themixturewasincubatedinthedarkatroomtemperaturefor30min,andthenth