药学专业英语视听说教程 课件 上篇Lecture 9 Natural Products

Lecture9NaturalProductsphytochemistryrecrystallizationtaxolrotaryevaporationalkaloidartemisininderivativeprecipitatefiltrationopioidDescribethefollowingprocesses.1.Recrystallization2.Rotaryevaporation3.Filtration4.Chemicalprecipitationallchemicaltransformationsthatoccurinthecellofanyorganismbreakdownlargemoleculesintosmalleronesassembleformedinonereactionandthemconsumedintheotherreactionfinalproductsofreactionsthesmallermoleculestobuildlargeunitsorlargerpartsmoleculesgeneratedthroughthesechemicalreactionsareabsolutelynecessaryforthelifeofaplantgrowth,developmentandreproductionprotection,competitionandspeciesinteractionfightsomediseasesterpenesmedicinalbenefitsormedicinalvaluesalkaloidscoumarinsphenoliccompoundstanninsmetabolitesfungibioactivitiesantimicrobialsynthesizingecosystemsdefensehitsTTFFFFT1.HowdidTuYouyoubeginheranti-malariadrugdiscoveryjourney?Tu’squestdidn’tbegininChinabutinthejunglesofVietnamwherethousandsofsoldierswereleftincapacitatedafterbeingbittenbythemalaria-carryingmosquitoes.TuparticipatedinProject523tosearchforacure.2.TuYouyouhadtestedtheplantartemisiabeforewithoutsuccess.Whatwasthereasonforthepreviousfailure?Andhowdidshesolvetheproblem?Heatingtheplanttoextractthecompoundmightdamagethedrugintheprocess.Shetriedtomimictheextractmethodofancientway,extractingthemixtureatlowtemperature.AHandbookofPrescriptionsforEmergenciesbyGeHong(284–346CE)recorded“Ahandfulofqinghaoimmersedwith2litersofwater,wringoutthejuiceanddrinkitall(青蒿一握，以水二升渍，绞取汁，尽服之)”.1.HowdidEhrlichandhisteamdevelopSalversanintoasuccessfultreatmentforsyphilis?----Firstly,theycollaboratedwithaJapanesescientist,SahachiroHata,whoprovidedausableanimalmodelbysuccessfullyinfectingrabbitswiththerabbitversionofsyphilis.Thisanimalmodelallowedtheteamtotestvariouscompoundsandobservetheireffectsonthedisease.----Secondly,theyscreenedoldarseniccompounds,includingCompound606,andfoundthatitwaseffectiveintreatingsyphilisintherabbitmodel.Afterconductingfurthersafetytestsinanimalmodels,theymovedontolargerclinicaltrialsinhumans.ByApril1910,theyobservedpromisinginitialresultsfromthesetrials.----Finally,aftermoreresearchandverification,theyreleasedthedrugtothepublicunderthenameSalversan,whichbecameastandardofcareforsyphilisfordecadesduetoitseffectivenessandsafetyinhumans.2.Whatisthefurtherdevelopmentofarsenic-basedtreatments?----Thefurtherdevelopmentofarsenic-basedtreatmentssawinitialrefinementsandadvancementswiththereleaseofNeosalvarsanandMapharseninthe1930sbyEhrlichandhisteam.However,thesetreatmentswereeventuallyreplacedbymoreeffectiveantibioticssuchaspenicillinstartinginthe1930s.----Despitethis,therewasaresurgenceofinterestinarsenic-basedtreatments,specificallyarsenictrioxide,inthe1990sforcancertreatment.ThiscompoundwasapprovedbytheFDAin2000andanupdatedsolutionwasapprovedin2018,specificallyforthetreatmentofacutepromyelocyticleukemia(APL),atypeofcancerthataffectswhitebloodcells.3.Whatcanyoulearnfromthestoryofturningtoxicarsenictousefulmedicine?----InnovationandCreativity:Theabilitytorepurposeandtransformpotentiallyharmfulsubstancesintovaluablemedicaltreatmentsdemonstratesthepowerofinnovationandcreativityinscienceandmedicine.Ehrlichandhisteamwereabletoseebeyondthetoxicityofarsenicanddevelopitintoausefultreatmentforsyphilis.----PersistenceandRefinement:Thedevelopmentofarsenic-basedtreatmentsdidn'thappenovernight.Thereweredrawbacksandadversereactionsreported,buttheteamkeptmakingrefinementsandimprovements.Thisshowstheimportanceofpersistenceandcontinuousimprovementinthedevelopmentofmedicaltreatments.----PotentialforRediscovery:Evensubstancesthathavefallenoutoffavorduetotheadventofmoremoderntreatmentscanstillhavepotentialapplications.Theresurgenceofinterestinarsenictrioxideasacancertreatmentinthe1990sshowsthatevenoldsubstancescanberediscoveredandrepurposedfornewuses.----BalancingRiskandBenefit:Thedevelopmentanduseofarsenic-basedtreatmentsalsohighlighttheneedtocarefullybalancetherisksandbenefitsofmedicaltreatments.Whilearsenic-b