北大有机课件 第十五章-糖类化合物

Chapter15Saccharides糖类化合物Saccharides(orCarbohydrates):糖类;碳水化合物衣，食，住，行息息相关Starch(淀粉）：polysaccharides能量来源Paper:cellulose(纤维素）Sucrose(蔗糖）:disaccharides植物的光合作用：CO2+H2OSaccharideCarbohydrate?Glucose(CH2O)6Cn(H2O)mSaccharides结构与保护作用：纤维素、几丁质、果胶能量来源：葡萄糖、淀粉、糖原，ATP复杂的生物学功能——重要的生命物质——影响蛋白质的折叠、溶解、半衰期、抗原性、生物活性；——信息分子参与生命活动中的各种识别和信号转导；Carbohydratechemistry/ChemicalglycobiologyGlycobiologyGeomics、Proteomics、Glycomics糖类药物(CarbohydrateDrugs)Saccharides血型物质与血型决定簇A型:Y=NHAcB型:Y=OHAB性:Y=NHAcorY=OHO型ProteinOOOOOOHOHHOYOHOHOHHOOHH3CONHAcHOOHOXProteinOOOOHOHOHHOOHH3CONHAcHOOHOXHO血型？SaccharidesOOSO3-HOHO-O3SHNOOHO2CHOOHOOOSO3--O3SHN-O3SOOOHOCO2HOSO3-OOHOOSO3--O3SHNOMe肝素五糖(HeparinPentasaccharide)OHHOHOOHHNOH3CHOOHOOOHHOOHOOOHHOOHOH阿卡波糖(Acarbose)OOOOOOSO2NH2托吡酯(Topiremate)糖类药物(CarbohydrateDrugs)SaccharidesOR1R1NH2NH2OH2NHONHR2OOOHHOH2NOH卡那霉素(Kanamycin)R1=OH,R2=H敌拜卡霉素(Dibekacin)R1=H,R2=H阿拜卡霉素(Arbelkacin)R1=H,R2=COCH(OH)CH2CH2NH2OHOHOOHAcHNCO2HHNNH2NHRelenzaOOHHOHOOOMeHOHOOHOOHOOHAcHNOOHOOHOHOOHOOHHOOCeramideGloboH抗原OCO2HOHOAcHNHOHOOHHOOHOOHAcHNOOOHOHOOHOOHHOOCeramideGangliosideGM2糖类药物(CarbohydrateDrugs)Saccharides一、Definitions:1.Carbohydrates:多羟基的醛，多羟基的酮2.Monosaccharides:最小的糖分子,不能水解3.Disaccharides:水解成两个单糖分子5.Polysaccharides:水解成多个单糖分子(9)4.Oligosaccharides水解成多个单糖分子(2~9)二、Classification:根据功能基Aldose(醛糖):Ketose(酮糖):SaccharidesCH2OHCCHHOCOHHCOHHCH2OHOCHOCCHHOCOHHCOHHCH2OHHOHGlucoseFructose根据C数丙糖(triose)丁糖(tetrose)戊糖(pentose)D-ribose己糖(hexose)GlucoseFrucose根据氧化反应性质ReducingsugarNon-reducingsugar蔗糖SaccharidesSaccharides三、StructureofMonosaccharides:1.开链结构及构型(ChainStructuresandConfigurations)：具有多个手性中心，2n分子有旋光甘油醛：CHOCH2OHHOHCHOCH2OHHHOD-(+)-GlyceraldehydeL-(-)-Glyceraldehyde*CHOCOHHCH2OHCHOCCHHOCOHHCOHHCH2OHHOH****CH2OHCCHHOCOHHCOHHCH2OHO***GlucoseFructoseSaccharides开链结构式的表示——Fischer投影式上下（氧化态）高低CHOOHHHHOOHHCH2OHOHHCHOHOHHOHHOHCH2OHHOH213456一对对映体D-GlucoseL-GlucoseSaccharides非对映异构体Epimer差向异构体CHOOHHHHOOHHCH2OHOHH213456CHOOHHHHOHHOCH2OHOHH213456D-GlucoseD-MannoseCHOOHHHHOOHHCH2OHOHH213456CHOOHHOHHOHHCH2OHOHH213456D-GlucoseD-AlloseCHOOHHHHOOHHCH2OHOHH213456CHOHHOHHOOHHCH2OHOHH213456D-GlucoseD-Galactose甘油醛：CHOCH2OHHOHCHOCH2OHHHOD-(+)-GlyceraldehydeL-(-)-GlyceraldehydeSaccharides糖构型表示法：D/L-Fischer投影式；与甘油醛比较CHOOHHHHOOHHCH2OHOHHCHOHOHHOHHOHCH2OHHOH213456D-GlucoseL-GlucoseCHOOHHOOHCH2OHOHCHOCH2OH简化式SaccharidesHOHCHOCH2OHCH2OHOHHOHHCHOCH2OHHOHHOHCHOCH2OHOHHOHHHOHCHOCH2OHOHHOHHHOHCHOCH2OHOHHHHOHOHCHOCH2OHHOHOHHOHHHOHCHOCH2OHHOHOHHOHHHOHCHOCH2OHHOHOHHHHOHOHCHOCH2OHHOHOHHHHOHOHCHOCH2OHHOHHHOOHHHOHCHOCH2OHHOHHHOOHHHOHCHOCH2OHHOHHHOHHOHOHCHOCH2OHHOHHHOHHOHOHCHOCH2OHOHHHHOHOHCHOD-GlyceraldehydeD-Erythrose(D-赤藓糖)D-Threose(D-苏糖)D-Ribose(D-核糖)D-Arabinose(D-阿拉伯糖)D-Xylose(D-木糖)D-Lyxose(D-来苏糖)D-Allose(D-阿洛糖)D-Altrose(D-阿卓糖)D-Glucose(D-葡萄糖)D-Mannose(D-甘露糖)D-Gulose(D-古罗糖)D-Idose(D-艾杜糖)D-Galactose(D-半乳糖)D-Talose(D-塔洛糖)D-醛糖系列D-，L-型糖互为一对对映体自然界存在的糖大多数都是D-型D.L.只用在糖、-氨基酸、-羟基酸的构型表示SaccharidesSaccharides(1)Glucose+TollensGlucose+FehlingGlucose+NaHSO3×acetal实验现象RCHO+2CH3OHRCHOCH3OCH3dryHClC6H12O6+CH3OHdryHCl(C6H11O5)OCH3(2)(3)Mutarotation(变旋现象）[]+112°Glucose溶液+52.7°放置Saccharides[]+18.7°Glucose溶液(4)IR,C=O;1HNMR,COH异常现象？糖中的-CHO不是游离的，而是以半缩醛的形式存在。SaccharidesOHOHOOHOHOHOHOHOOHOHOHO-D-吡喃葡萄糖-D-吡喃葡萄糖123456123456OOHHOHOOHOHOOHOHOHHOHO-D-呋喃果糖-D-呋喃果糖O123456123456Haworth透视式糖环的编号-、-异构体的定义端基异构体(anomer)非对映异构体差向异构体2.CyclicStructuresandConformations:Saccharides如何解释Mutarotation(变旋现象）？CHOCH2OH开链D-GlucoseOHOHOOHOHOH-D-吡喃葡萄糖OHOHOOHOHOH-D-吡喃葡萄糖C4-C5OHCHOOHHOOHHHHHHOCH2Fischer向右横倒，弯曲CHOCH2OHOHHHOHOHHOHHD-GlucoseFischer123456OHOHOOHOHOHOHOHOOHOHOH--OHOHOHOHCH2OHOH123564Saccharides-D-(+)-Glu[]+112°m.p.146°C开链D-(+)-Glu-D-(+)-Glu[]+18.7°m.p.150°C36.4%0.5%63.6%(+112°)36.4%+(+18.7°)63.6%=52.7°OHOHOOHOHOHOHOHOOHOHOHCHOCH2OHOHHHOHOHHOHH如何实现Fischer投影式Haworth透视式？Fischer,左侧基团Haworth，环上；右侧基团环下SaccharidesOHOHOOHOHOHOHOHOOHOHOH-D-吡喃葡萄糖-D-吡喃葡萄糖CHOCH2OHOHHHOHOHHOHHD-GlucoseC4-C5FischerOHCHOOHHOOHHHHHHOCH2OHOHOHOHCH2OHOH12356向右横倒，弯曲Fischer1234564CHOCH2OHOHHOOHOHD-GlucoseOHOHOHOHCH2OHOH12356OHOOHOHCH2OHOHHemiacetal123456CH3OH/H+OHOOHOHCH2OHOCH3123456-or-甲基葡萄糖苷-,-isomersEpimers(端基差向异构体）互为非对映异构体Saccharides环状缩醛的形成：Saccharides吡喃己醛糖吡喃戊醛糖&吡喃己酮糖OHOHOOHOHOH2134521345D-OHOOHOHOHOHL-Haworth式中构型的判断OOH2134521345L-OOHCH2OHD-呋喃己醛糖CHOHHOHHOOHHCH2OHOHHCHOOHCHHHHOOHHCH2OHOH*OOHOHOH*R-D-呋喃半乳糖端基异构体的确定C5-CH2OHC4-OH/C5-OHC5-构型(R-,S-)SaccharidesOOHHOHOOHOHN式(I,4C1式），较稳定优势构象A式(II,1C4式），不稳定OOHOHHOHOOH-D-GlucoseOOHHOHOOHOH-D-GlucoseConformationsOHOHOOHOHOHOHOHOOHOHOHCHOCH2OHOHHHOHOHHOHH-,36.4%-,63.6%AnomericEffectOOR-OOR-形成糖苷？SaccharidesC2~C6羟基取代时：(端基效应)溶剂的作用：极性溶剂非极性溶剂CCH2OHOHOHHOOHOHD-Glucose....OHHOOHCCH2OHOHHO-D-(+)-GlucoseOCH2OHHOOHOHOHorOOHHOHOOHOHorOHHOOHCCH2OHHOHO-D-(+)-GlucoseorOCH2OHHOOHOHOHOOHHOHOOHOHorSaccharidesSaccharidesCH2OHHOHOHHHHOHOHCHOOCH2OHHOOHOHOHOOHHOHOOHOHCH2OHHOHHHOHHOHOHCHOOCH2OHHOOHOHOHOOHHOHOOHOHCH2OHHOHOHHHHOHOHCHOOCH2OHHOOHHOOHOOHHOHOOHOHD-GlucoseD-GalactoseD-MannoseSaccharidesCH2OHOHHOHHHOHCHOOHOOHOHOHCH2OHOHHOHHHHCHOOHOOHOHCH2OHHOHOHHHHOOCH2OHOHOOHHOOHOHOHOOHHOOH