Isolation of an alkaloid.ppt

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,Isolation of an alkaloid:Caffeine,Isolation,of an,alkaloid,:,Caffeine,Tea and coffee are popular beverages known from antiquity.Both are rich in caffeine,a,central nervous system(CNS,),respiratory,and cardiac stimulant.Caffeine is also a,diuretic,agent,(tending to increase,urine,production)and can produce nervousness,insomnia,and racing heartbeat(tachycardia).Heavy consumption can lead to a caffeine dependence such as headache and even nausea can be experienced without it.,自古以来，茶和咖啡就是人们熟知的饮料。它们都含有丰富的咖啡因，一种中枢神经系统、呼吸和心脏的刺激物（强心剂）。咖啡因也是一种利尿剂（使尿量增加），并且能产生焦虑、失眠和心跳加速（心动过速）。过量使用会导致咖啡因依赖，如产生咖啡因缺乏时的头痛、恶心等感觉。,Caffeine is one of the alkaloids,witch are basic,nitrogen,containing compound found in certain plant materials.,Structurally,it is 1,3,7-tri,methyl,xanthine.It is also a,derivative,of,purine,and is therefore related to the purine,base,s in,nuclear acids,and to,uric acid,.,Two closely related compound are the dimethylxanthines,theophylline,which occurs along with caffeine in tea,and theobromine,witch occurs instead of caffeine in cocoa.,咖啡因是一种生物碱，是从某些植物原料中发现的一种基本含氮化合物。结构上，它是,1,3,7-,三甲基嘌呤。它也是嘌呤衍生物，因此，与核酸和尿酸中的嘌呤碱有相似之处。,两种密切相关的化合物是茶叶中伴随着咖啡因一同出现的二甲基黄嘌呤，即茶碱，另一种是出现在可可中的可可碱。,The caffeine content of caffeine beans is about 1%-2%by weight and in tea leaves is about 2%-4%.Because of differences in methods of brewing,however,an average cup of coffee contains about twice as much as caffeine as a cup of tea(100mg versus 50 mg).Cola nuts are aslo a rich source of caffeine,and the caffeine content of cola beverages typically runs 40-50mg per 12oz container.Many commercial analgesic(pain-killing)medicine also contain caffeine to counteract the drowsiness often produced by the active,ingredient,s in such preparation.The most important commercial source of caffeine is as a,by-product,in the production of decaffeinated coffee.,咖啡豆中咖啡因的质量含量大约为,1%-2%,，茶叶中大约是,2%-4%,。但是由于制取方法的不同，一杯咖啡中咖啡因的含量是等质量一杯茶中的,2,倍。可乐果也是咖啡因的一种丰富的来源，最具典型代表性的是可乐饮料中的咖啡因含量可达到每,12,盎司含,40-50mg,。许多商业镇痛药中也含有咖啡因用来抵制其制备过程中的活性成分带来的睡意。咖啡因最重要的商业来源是作为生产脱咖啡因咖啡时的副产物。,Caffeine is easily,isolate,d and,separate,d from other substances present in the tea leaf or coffee bean by virtue of the fact that it is,soluble,in hot water,can be,extract,ed from cold water by,chlorinated hydrocarbons,such as,methylene chloride,and,sublime,s.In the first step,caffeine is extracted from the plant source with boiling water.This separates it from the,cellulose,plant,protein,s,fats,and other,insoluble,high-,molecular,weight substances present in the leaf or bean.Soluble sugars,peptide,s,plant,pigment,s,acids,and,tanning,s(pentadigalloyglucose derivatives)also,dissolve,in the hot water.The addition of,sodium,sulfate,increases the,ionic,strength witch helps prevent,emulsion,formation during the next step.The,aqueous,layer is then extracted with methylene chloride to separate the caffeine while the sugars,peptides,and,polar,pigments remain in the aquous phase.,Evaporation,of the methylene chloride then affords,crude,caffeine,which is conveniently,purified,by,sublimatio,n.Because pure caffeine is reported to be,characterize,d by,convert,ing it to a,salicylate,salt m.p.135137.,咖啡因极易与茶叶中所含的其他物质分离基于它能溶于热水，可以用诸如二氯甲烷之类的卤代烃萃取，并且易于升华的特性。第一步，用沸水将咖啡因从植物原料中萃取出来，这一步是将咖啡因与存在于茶叶或咖啡豆中的纤维素、植物蛋白、脂肪和其它不溶性高分子分离开来。可溶性的糖，缩氨酸，植物色素，酸类和单宁酸也溶解在热水中。加入硫酸钠增加离子强度以预防下一步中乳化现象的发生。然后水层用二氯甲烷萃取分离出咖啡因，而糖类、缩氨酸和极性的色素则保留在水相中。蒸发二氯甲烷得到咖啡因粗品，通过升华可以便利地将粗制咖啡因纯化。,依据文献报道，可以利用纯咖啡因的水杨酸盐熔点为,135-137,进行特征性鉴别。,1 Isolation of caffeine from tea,Place 5 tea bags(about 10g)and 200 ml of water into 400ml,beaker,and boil the mixture gently with a,burner,or,hot plate,for 1520min to produce a,concentrate,extract.Be careful not to break the tea bags.Cool the breaker in ice until it is at or slightly below room temperature and squeeze as much soluble as possible from the tea bags as you remove them by hand(the,volume,of liquid should be 100150ml).Dissolve about 10g of,anhydrous,sodium sulfate in the cold solution,and then add about 3g(or 15ml in a dry,graduated cylinder,)of,celite,(,filter aid,).,1,、从茶叶中分离咖啡因,在,400ml,的烧杯中放入,5,包茶叶（约,10g,）和,200ml,水，用火炉火加热板温和煮沸混合物,15-20,分钟制备浓缩的萃取物。小心不要破坏茶包。将烧杯放在冰块中冷却至室温或微低于室温，在移除茶包时用手尽可能多地挤出其中的溶液（溶液体积应为,100-150ml,）。在冷却液中溶解约,10g,无水硫酸钠，然后加入,3g,（或,15ml,）硅藻土（助滤剂）。,Fit a 5.5 cm dia.(or 4.5 cm dia.)Bucher,funnel,into a 125 ml,filter flask,connected through a,trap,to an,aspirator,add filter paper,wet it and turn on the aspirator for a shot time to ensure that the paper is snugly pressed against the porcelain plate of the funnel.Prepare a pad of celite(filter aid)by forming a slurry of about 2g of celite with 10ml of water in a small beaker.Turn on the aspirator again,swirl,the slurry,and quickly add it to the funnel.Allow it to form a,uniform,pad at least several mm in thickness.Discard the water that has accumulated in the filter flask.,With the aspirator,vacuum,on,carefully add the slurry of tea extract and celite to the celite pad already in the funnel.When this vacuum filtration is complete,let the pad suck dry for a minute.,在一个连有节气阀的吸滤器上放置一个直径,5.5cm(,或,4.5cm),的布氏漏斗，加上滤纸，润湿，抽滤一段时间以保证滤纸紧贴在漏斗的瓷盘底部。通过将,2g,硅藻土与,10ml,水搅拌成浆状用以准备一层硅藻土垫。重新开启抽气，搅拌浆状物成旋状，迅速倒入漏斗中。使其形成一层几毫米厚的均一垫层，然后将抽滤瓶中的水倒掉。,在真空抽滤的状态下，小心地将成浆状的茶叶萃取物和硅藻土倒入已有一层硅藻土垫的漏斗中。真空抽滤完成后，让垫层再抽干几分钟。,Transfer the extract to a 250ml or 500ml,separator funnel,add 25ml of methylene chloride,and gently shake the mixture for about 2 min to ensure good,equilibration,between the phases.Allow the funnel to stand for 10 min.Drain the lower layer(which will not be full separated)into a 125ml,erlenmeyer flask,.Extract the aqueous layer with three more 25ml portions of methylene chloride,each time shaking gently for about 2 min and then allow the mixture to stand for 10 min before draining the lower layer.Pour the combined methylene chloride extracts into a 125ml sepatatory funnel and allow a few minutes more for most of the residual aqueous layer to separate the top.Use the essentially clear lower layer for one of the two following isolation,procedure,s.,将萃取物转移到一个,250,或,500ml,的分液漏斗中，加入,25ml,二氯甲烷，将混合物轻轻振荡约,2,分钟确保相之间充分平衡。静置约,10,分钟。将下层液体（没有被完全分离的部分）排到一个,125ml,的锥形瓶中。用三份,25ml,量的二氯甲烷萃取水相部分三次，每次都轻微振荡约,2,分钟，静置,10,分钟。将含有二氯甲烷的萃取物倾倒至一个,125ml,的分液漏斗中，再放置几分钟使尽可能多的残留水分被分离到上相中。,使用下面两种分离步骤之一分离基本纯净的下相。,Procedure 1 Add a,boiling chip,to the combined methylene chloride extracts in a 125ml erlenmeyer flask,and carefully evaporate all but a few milliliters of the solvent in a hood with gentle heating(heat lamp,steam bath,or hot plate),Procedure 2 Evaporate all but a few milliliters of the methylene chloride layer in several portions with a,rotary evaporator,.,步骤,1,在,125ml,装有二氯甲烷萃取液的锥形瓶中加入一片沸石，温火（加热灯、蒸气浴或加热板）小心蒸发至溶剂只余几毫升。,步骤,2,将含有二氯甲烷的萃取物分成几份于旋转蒸发器中蒸发至只余几毫升。,Transfer the concentrated solution with a,filter pipet,to a small,sublimation apparatus,.With the top of the sublimator open and with an aspirator hose connected to the side arm,carefully evaporate the methylene chloride by gently heating the bottom of the sublimator with a heat lamp or,microburner,.Scrape any caffeine from the side of the sublimator into the center of the bottom with long spatula.,用移液管将浓缩的溶液转移到一个小升华器中，保持升华器顶部打开，一侧连接抽气管，用加热灯或微波加热器加热升华器的底部，小心蒸发二氯甲烷。用长刮刀从一侧到中心刮下升华器底部所有的咖啡因。,Clamp the sublimator in a vertical position with the cold finger in place and the aspirator connected to the side arm and turned on,fill the cold finger with ice water,and heat the caffeine with a small flame until it sublimes onto the cool surface.Continue until no more caffeine vapors are seen.Turn off the aspirator,allow the apparatus to cool for a few minutes,and carefully remove the cold finger so that very little of the sublimate falls back into the residue in the bottom of the,sublimator,.Scrape the sublimate onto some weighing paper and slide it into a small tared(weighed),vial,.Calculate the appropriate percent of caffeine recovered based on the assumed weight of the tea leaves(10g).,夹紧升华器垂直放入冷冻器，吸气器连接在一侧并保持打开状态。用冰水填满指形冷冻器，小火加热咖啡因直至其升华到冷的表面。继续加热至不再看到咖啡因蒸汽。关闭吸气器，让设备冷却几分钟，小心移除指型冷凝器以确保几乎没有升华物回落到升华器的底部残留物中。刮下升华物到称量纸上倒入已称重的小瓶内。以设定的茶叶质量（,10g,）为基础计算所回收咖啡因得大致百分比。,2 Caffeine salicylate,Mix about 75mg(0.543mmol)of calicyclic acid with 100mg(0.515mmol)of caffeine and 5ml of methylene chloride in a 10ml Erlenmeyer flask.Warm the flask on a steam bath until the solid dissolved,carefully add,petroleum ether,until the solution just becomes cloudy,heat it and add a few drops of methylene chloride to make it clear,then allow it to cool slowly.Needle crystals should form.Cool the ether mixture in ice and isolate the caffeine salicylate by suction filtration with a small Hirsch funnel.Allow the sample to dry and obtain a,melting point,(appropriate 137,.),2,、咖啡因水杨酸盐,于,10ml,锥形瓶中混合约,75g,水杨酸，,100g,咖啡因和,5ml,二氯甲烷。蒸气浴加热直至固体溶解，小心加入石油醚至溶液开始出现浑浊，加热加入几滴二氯甲烷使之澄清，然后缓慢冷却。即出现针状结晶。用冰冷却醚混合物并用赫氏漏斗吸滤分离咖啡因水杨酸盐。干燥样品测得熔点（约为,137,）。,3.,Detect,ing caffeine in,medication,s,Caffeine can be detected readily in medications such as Excedrin by,thin layer chromatography,.Crush and,power,a tablet and extract it with 23ml of,methanol,.Filter the solution and sue it to spot a TLC plate with a,micropipe,drawn from a melting point eapillary.Silica gel plates give a good separate with a mixture of,chloroform,/95%,ethanol,(10:1).The caffeine spot can be detected by UV light or by,iodine,vapor.Use a sample of the sublimed caffeine for a control comparison.,3,、检测药物中的咖啡因,药物，如止痛片中的咖啡因用薄层色谱法非常易于检测。将药片碾碎并呈粉末，用,23ml,甲醇萃取。过滤溶液，用熔点毛细管熔化得到的微管将溶液点到硅胶板上，使用氯仿,/95%,乙醇（,10:1,）为 展开剂，可以获得很好的分离效果。咖啡因点可以用紫外线或碘蒸气检测。使用升华的咖啡因样品作为控制比较。,Alkaloid,生物碱,Caffeine,咖啡因,central nervous system(CNS),中枢神经系统,diuretic agent,利尿剂,urine,尿,purine,嘌呤,nuclear acid,核酸,uric acid,尿酸,by-product,副产物,chlorinated hydrocarbon,卤代烃,methylene chloride,二氯甲烷,sublime v.,升华,sublimation n.,升华,sublimator,升华器,cellulose,纤维素,tanning,单宁,peptide,缩氨酸,pigment,色素,sodium sulfate,硫酸钠,ionic,离子的,emulsion,乳化,aqueous,水的,anhydrous,无水的,Evaporation,蒸发,Vapor,水蒸气，蒸发,Crude,粗的（产品）,Convert,转化,Salicylate,水杨酸盐,Beaker,烧杯,hot plate,加热板,burner,火炉,concentrate,浓缩,volume,体积,graduated cylinder,量筒,celite,硅藻土,filter aid,助滤剂,funnel,漏斗,filter flask,抽滤瓶,trap,节水阀,aspirator,吸气器,swirl,搅拌，打旋,uniform,均一的,vacuum,真空,separator funnel,分液漏斗,equilibration,平衡,procedure,步骤，程序,boiling chip,沸石,steam bath,蒸气浴,rotary evaporator,旋转蒸发,apparatus,设备，仪器,microburner,微波加热,petroleum ether,石油醚,melting point,熔点,thin layer chromatography TLC,薄层色谱,methanol,甲醇,chloroform,氯仿,ethanol,乙醇,iodine,碘,Conference(会议),Congress（代表大会）,Convention（大会）,Symposium(专业讨论会),Colloquium(学术讨论会),Seminar(研究讨论会),Workshop（专题讨论）,Impact factor IF影响因子,science citation index SCI 科学引文索引,Gene 基因,Genetic 遗传的,Cancer 肿瘤,Compass 指南,Royal 皇室的，王室的,Carbon 碳,Rubber 橡胶,Browse 浏览,Author affiliation 作者单位,Alkaloid 生物碱,Caffeine 咖啡因,central nervous system(CNS)中枢神经系统,diuretic agent 利尿剂,urine 尿,purine 嘌呤,nuclear acid 核酸,uric acid 尿酸,by-product 副产物,chlorinated hydrocarbon 卤代烃,methylene chloride 二氯甲烷,sublime v.升华,sublimation n.升华,sublimator 升华器,cellulose 纤维素,tanning 单宁,peptide 缩氨酸,pigment 色素,sodium sulfate 硫酸钠,ionic 离子的,emulsion 乳化,aqueous 水的,anhydrous 无水的,Evaporation 蒸发,Vapor 水蒸气，蒸发,Crude 粗的（产品）,Convert 转化,Salicylate 水杨酸盐,Beaker 烧杯,hot plate 加热板,burner 火炉,concentrate 浓缩,volume 体积,graduated cylinder 量筒,celite 硅藻土,filter aid 助滤剂,funnel 漏斗,filter flask 抽滤瓶,trap 节水阀,aspirator 吸气器,swirl 搅拌，打旋,uniform 均一的,vacuum 真空,separator funnel 分液漏斗,equilibration 平衡,procedure 步骤，程序,boiling chip 沸石,steam bath 蒸气浴,rotary evaporator 旋转蒸发,apparatus 设备，仪器,microburner 微波加热,petroleum ether 石油醚,melting point 熔点,thin layer chromatography TLC 薄层色谱,methanol 甲醇,chloroform 氯仿,ethanol 乙醇,iodine 碘,