生物化学上册双语

1、1I. Introduction21. ExistenceuThe most abundant class of organic molecules found in natureuWidely distributed in plants and animalsuOriginated from photosynthesisuBasic composition: C, H, O (N, P, S)uEmpirical formula: (CH2O)nuConstituting a versatile class of moleculesMono-/oligo-/polysaccharides (

2、单糖/寡糖/多糖)Derivatives (衍生物)Glycoconjugates (复合糖)I. IntroductionP.132. FunctionI. IntroductionP.143. Definition葡萄糖果糖甘油醛二羟基丙酮Carbohydrates are polyhydroxy aldehydes or ketones (多羟基醛/多羟基酮) or substances that yield such compounds on hydrolysis.5Three major classes of carbohydratesI. Introduction65. Chara

3、cteristic chemical features (化学通性)I. IntroductionP.271.Two families: aldoses & ketoses (醛糖和酮糖)2.Stereochemistry (立体化学)3.Structures: linear & cyclic (线状和环状结构)4.Properties: physical & chemical (物理和化学性质)*optical activity and chirality (光活性和手性)5.Important monosaccharides and their derivative

4、s (重要的单糖及其衍生物)II. Monosaccharides81. Two families: Aldoses & ketosesAldoses(醛糖)Ketoses(酮糖)II. Monosaccharides甘油醛二羟丙酮丙糖己糖92. StereochemistryII. Monosaccharides10(1) Plane-polarized light (平面偏振光 )Plane-polarized light (平面偏振光) a light with its electric vector vibrating on a specific plane called th

5、e plane of polarization (偏振面)Polarimeter (偏振器偏振器) an instrument used to measure optical activity.Polarimeter(偏光计)Light source(non-polarized light)非偏振光Polarizer(偏光器)Plane-polarized light(平面偏振光 )Sample tube棱镜Plane of polarization rotated(偏振面发生了旋转)11(2) Optical activity (旋光性)A material which can rotate

6、 the plane of the plane-polarized light is called to have optical activity, and this material is an optically active substance. (能使平面偏振光的偏振面发生旋转的物质被称为具有旋光性)t = t c lRotation(旋光度)Specific rotation (比旋)Concentration (浓度, g/ml)Length (dm)Wavelength (波长, nm)TemperatureRotation 12(3) Chirality (手性) Compo

7、unds without chiral centers do not normally show optical acitivity. (没有) Compounds with one chiral center will show optical activity. (有一个) Compounds with more than one chiral center may or may not show optical activity depending on whether or not they are non-superimposable on their mirror image (c

8、hiral) or superimposable (achiral). (有一个以上)Optically active molecule Chiral molecule(旋光性分子 手性分子)Optical activity (旋光性) Chirality (手性)Chiral centers(手性中心)?HHHHOHHHOHHHHH*13tn chiral centers 2n maximum stereoisomersTrue or false:vChiral molecules are always optically active.( )vOptically active molecu

9、les always have chiral centers.( )vChiral molecules have always chiral centers.( )vMolecules with chiral centers are always chiral.( )II. MonosaccharidesP.3CHOC*OHHC*HHOC*OHHC*OHHCH2OHn = 4 24 = 16 isomers14(4) Fischer projections (Fischer投影式)投影式甘油醛(+)()RSDL透视式II. MonosaccharidesP.415Fischer project

10、ionsHaworth projectionsCHOOHHHHOOHHOHHCH2OHCHOHHOOHHHHOHHOCH2OHOHOHOHHHOHHOHCH2OHHOOHHHOHHHOHHOOHHHOHOHHOHHHCH2OHCH2OHOHD-(+)-GlucoseL-(-)-Glucose-D-Glucose-L-GlucoseFlipping4 C* 24 = 16 isomers8 D-forms8 L-formsD or L refers to the configuration of the C* farthest from the carbonyl C.16Aldoses (醛糖)

11、17Ketoses (酮糖)II. Monosaccharides18Two systems of specifying the absolute configurations(绝对构型的两种表达体系)Group 4 with the lowest priorityD/L referring to the configuration of the molecule (对整个分子而言)R/S referring to the configuration of a specific C* (对单个C*原子而言)D-glucose2R,3S,4R,5R-aldohexose (己醛糖) R/S co

12、nvention priority rulesCHOCOHHCHHOCOHHCOHHCH2OH123456+/ referring to the optical activity of the chiral molecule(指分子的旋光性，与分子或原子的构型无直接关系)19qD-forms of monosaccharides predominate in nature.qL-Monosaccharides also exist in nature.qD-glucose is the enantiomer of L-glucose. But D-aldohexoses (己醛糖) are n

13、ot necessarily enantiomers of all of their L-isomers.II. MonosaccharidesThe above four are stereoisomers.CHOCOHHCHHOCOHHCOHHCH2OH123456CHOCHHOCOHHCHHOCHHOCH2OH123456CHOCHHOCHHOCOHHCOHHCH2OH123456D-GlucoseL-GlucoseD-MannoseCHOCOHHCOHHCHHOCHHOCH2OH123456L-MannoseEnantiomerEnantiomerDiastereomerDiaster

14、eomer203. StructureII. Monosaccharides21Epimers two sugars that differ only in the configuration around one carbon atom.Epimers are usually diastereomers. (差向异构体多是非对映异构体)差向异构体是仅有一个手性碳原子的构型不同的Anomers Two monosaccharides that differ only in their configuration about the hemiacetal or hemiketal carbon

15、atom.Anomers are epimers. (异头物是差向异构体)差向异构体.差向异构体异头物甘露糖 半乳糖 22Hemiacetals (半缩醛) and hemiketals (半缩酮)醛酮半缩醛半缩酮缩醛缩酮Addition(加成反应)Substitution(取代反应)23Cyclic structure (1): FormationII. MonosaccharidesP.9异头物-Anomer-Anomer-D-吡喃葡糖-D-吡喃葡糖Anomeric C (异头碳)24Cyclic structure (2): Haworth projections (Haworth透射式

16、)When lining up clockwisely:-CH2OH above the ring - D-configuration-CH2OH below the ring -L-configuration-OH at the anomeric C and -CH2OH:On the opposite side On the same side D or L? or ?CHOCOHHCHHOCOHHCOHHCH2OHOHOHHOHHOHHOHCH2OHHOHOHOHHHOHHOHCH2OHH123456123456123456Fischer projection formulasHawor

17、th projection formulasP.10TopBottom25-D-glucoseD-glucose(Linear)-D-glucose36%0.024%64%20D = +112.2o20D = +18.7oCyclic structure (3): , anomersMutarotation (变旋变旋)：在水溶液中糖的-和-异头物之间互相转化导致其旋光度发生变化的现象146oC m.p.148-155oC m.p.II. Monosaccharides+52.6oP.8-9-D-glucose and -D-glucose are not enantiomers to eac

18、h other; they are epimers and anomers with different properties.(-D-glucose和-D-glucose不是互为对映异构体，是差向异构体和异头物，具有不同的物理/化学性质。)26Mutarotation (变旋)36%20D = +112.2o146oC m.p.64%20D = +18.7o148-155oC m.p.(0.024%)At equilibrium, 20D = +52.6o27Cyclic structure (4): Pyranoses & furanosesPyranoses（吡喃糖）Furano

19、ses（呋喃糖）II. MonosaccharidesP.1028CHOCOHHCHHOCOHHCOHHCH2OHOHOHHOHHOHHOHCH2OHHOHOHOHHHOHHOHCH2OHH123456123456123456CH2OHCOCHHOCOHHCOHHCH2OH123456OOHOHOHCHOHCH2OHOOHOHOHCHOHCH2OHOHOHCH2OHOHOHOHHHOHOHOHCH2OHOHOHHH123456123456OOHOHCH2OHOHCH2OHOOHOHOHCH2OHCH2OH123456123456123456123456-D-吡喃葡糖-D-吡喃葡糖-D-呋喃葡糖

20、-D-呋喃葡糖-D-吡喃果糖-D-吡喃果糖-D-呋喃果糖-D-呋喃果糖D-glucoseD-fructose29Cyclic structure (5): ConformationFor D-glucose, -form is more stable than -form.For other aldohexoses, -form is more stable than -form.OHOHHHOHHHOHOH2CHOHOOHHOHHOHOHHHCH2OHHTwo possible chair conformations of -D-glucoseII. MonosaccharidesP.133

21、04. PropertiesPhysical properties (物理性质):vOptical activity & mutarotation (旋光性和变旋): See Table 1-1, P.14vSweetness (甜度): See Table 1-2, P.15vSolubility (溶解度): P.15All soluble in H2O except glyceraldehyde (除甘油醛外均为水溶性)insoluble in nonpolar organic solvents (不溶于非极性有机溶剂)Chemical properties (化学性质)II.

22、Monosaccharides31Chemical properties1. Isomerization (异构化)2. Oxidation (氧化)3. Reduction (还原)4. Formation of osazone (糖脎)5. Formation of sugar ester (糖酯) and sugar ether (糖醚)6. Formation of glycoside (糖苷)7. Dehydration (脱水)8. Elongation and shortening of monosaccharide chain (单糖链的延长和缩短)II. Monosaccha

23、ridesP.15CHOCOHHCHHOCOHHCOHHCH2OH1234563221%2.5%II. Monosaccharides63.5%CCOHHCHHOCOHHCOHHCH2OHOHCCOHCHHOCOHHCOHHCH2OHOHHD-GlucoseD-Ba(OH)2CH2OHCCHHOCOHHCOHHCH2OHOD-FructoseD-CCHHOCHHOCOHHCOHHCH2OHOHD-MannoseD-P.15-1633Chemical Properties (2): OxidationCH=OCH2OHOHOHOHHOCOOHCH2OHOHOHOHHOCH=OCOOHOHOHOH

24、HOCOOHCOOHOHOHOHHOCu2+OH-Dehydrogenase(脱氢酶)HNO3Aldonic acid醛糖酸Uronic acid糖醛酸Aldaric acid醛糖二酸Sugar acids(糖酸)Br2/H2O34Oxidizing agents (氧化剂): H2O2, Ag+, Fe3+, Cu2+Fehling reagents: tartrate (酒石酸钾钠)，NaOH, CuSO4Benedict reagents: citric acid (柠檬酸), Na2CO3, CuSO4Reducing sugar (还原糖):Capable of reducing o

25、xidizing agents (可以还原以上的氧化剂)All aldoses and many ketoses are reducing sugars (所有醛糖和多数酮糖)Fructose is a reducing sugar (果糖是还原糖)CHOOHHHHOOHHOHHCH2OH+ 2Cu2+ + 4OH-COOHOHHHHOOHHOHHCH2OH+ 2CuOH + H2OAldoseAldonic acidCu2OA qualitative test for reducing sugars (还原糖还原糖)P.16(Red precipitate)还原糖的定性检测35Chemica

26、l Properties (2): Oxidation (continued)CHOOHHHHOOHHOHHCH2OHCOOHOHHHHOOHHOHHCH2OHBr2/H2OpH 6.0CH=OCH2OHOHOHOHHOHHHHHCOOH4 HCOOHHCHO+IO4-This reaction is specific for aldoses.(此反应只适用于醛糖)This reaction is useful in providing structural information (此反应可帮助分析糖的结构)II. Monosaccharides361,2-linkage1,4-linkag

27、e1,6-linkageOxidation by IO4-OOHOOCH2OHOHO=HCO=HCOOOCH2OHIO4-H2CH2COOOCH2OHHOHONaBH4H2CH2COOHOHCH2OHHOHOH2CH2CCH=OOHOHCH2OHHOHOCH2OHHCCH2OHOHCHOHCCH2OHOH+H+OOOOHOHCH2OHIO4-NaBH4CH2OHHOHCCHOHCHOCH2OH+H+CHOOHCOOOCH2OHCH2H2COOOCH2OHOHOHCH2H2COOHOHCH2OHOHOHCH2H2CCHOOHOHCH2OHOHOHCH2OHOOHOOHOHCH2IO4-NaBH4

28、CH2OHHCCHOCH2OH+CH2OHOOHCOHCOOCH2O+ HCOOHCH2H2COOCH2+ HCOOHOHHOOOCH2H2COOHCH2OH+ HCOOHOHHOCH2H2CCHOOHCH2OH+ HCOOHOHHOOH+ HCOOHH+P.7237Chemical Properties (3): ReductionCH=OCH2OHOHOHOHHOCH2OHCH2OHOHOHOHHOCH2OHCH2OHOHHOCH=OCH2OHOHHOHOHONaBH4NaBH4180oRotationD-葡萄糖D-葡萄醇L-古洛糖L-古洛醇C=OCH2OHHOOHOHCH2OHC=OCH

29、2OHHOOHCH2OHHOHOHOD-果糖L-山梨糖NaBH4NaBH4Sugar alcohols(糖醇)38Sugar alcohols (糖醇)CH2OHCH2OHOHOHOHHOD-Glucitol(D-葡萄醇)Sorbitol (山梨醇）CH2OHCH2OHOHOHHOD-Mannitol(D-甘露醇)HOCH2OHCH2OHOHOHHOD-Xylitol(D-木糖醇)CH2OHCH2OHOHGlycerol(甘油醇)HHHHHHHHHHHHII. Monosaccharides39Chemical Properties (4): Formation of osazone（糖脎）C

30、HOOHHHHOOHHOHHCH2OH3 C6H5-NH-NH2+CHN=NHC6H5HHOOHHOHHCH2OHN-NHC6H5+ C6H5-NH2 + NH3 + 2H2OHAcpH4-6苯肼苯脎 (黄色晶体)This reaction is useful in characterizing reducing sugars (此反应用于鉴定还原糖).Yellow crystals withv Different crystal shapesv Different melting pointsII. Monosaccharides40Chemical Properties (5): Suga

31、r Esters & Sugar Ethers(糖酯和糖醚)OHHOHHOHHOHHOHOHOHH3COCOHH3COCOHHOCOCH3HOCOCH3OCOCH3(CH3CO)2OPyridine, 0oCOHHOHHOHOHOHHHOHOHH3COHH3COHOCH3OCH3HHOCH31). CH3SOCH2Na2). CH3IAcetylation(乙酰化)Methylation(甲基化)Phosphorylation(磷酸化)OHHOHHOHOHOHHHOHOHHOHHOHOHOHHHOPO3-+ ATP+ ADPP.1941OHOHHOCH2OHHHHOHHOOHOHHOC

32、H2OHHHHO-CH3HOHemiacetal(半缩醛)Acetal(缩醛)Glycone (糖基)Aglycone(配基)Glycosidic bond(糖苷键)Chemical Properties (6): Glycoside (糖苷)Glycoside (糖苷)Monosaccharide (单糖)II. MonosaccharidesGlycosidic bond is unstable under acidic conditions.(糖苷键在酸性条件下不稳定)P.19H+Reducing sugarNon-reducing sugar42Chemical Properties

33、(7): Dehydration5-Hydroxymethyl furfural5-羟甲糠醛CHOCOHHCHHOCOHHCOHHCH2OHCHOCOHCHCOHHCOHHCH2OHCHOCOCHCOHHCOHHCH2OHCHCHOCOCCHCOHHCH2OHCHOOCHOHOH2CHOHCHOHOH2C-H2O-H2ODifferent furfurals react with polyphenols to generate different specific colors, therefore this reaction is useful in characterizing the m

34、onosaccharides.(用于单糖的定性检测)II. MonosaccharidesP.2043OCHOHOH2COHOH-H2O(Seliwanoff test)糠醛-萘酚蒽酚红紫色缩合物 (Molish test)糠醛蓝绿色复合物 (蒽酚反应)5-羟甲糠醛-H2OOCHOOHOHHOCH3OHHO (Bial test)鉴定酮糖鉴定戊糖鉴定糖类测定总糖量糠醛445. Important monosaccharides and their derivativesMonosaccharidesSugar phosphate esters (单糖磷酸酯)Sugar alcohols (糖醇

35、)Sugar acids (糖酸)Sugar esters (糖酯)Sugar ethers (糖醚)Deoxy sugars (脱氧糖)Amino sugars (氨基糖)Glycosides (糖苷)II. MonosaccharidesP.22NNNNNH2OOHOHHHHHOPOO-OPOO-OP-OO-OAdenosine triphosphate (ATP)45III. Oligosaccharides (寡糖)461.Glycosidic bonds (糖苷键)vFormation: 由一个单糖的异头碳上的羟基和另一个单糖的任一个C上的羟基缩合而成by condensation

36、of-OH group at the anomeric C (异头碳上的羟基) from one sugar-OH group from another sugarvReducing end (还原端): - with a free anomeric CvNonreducing end (非还原端)：- without a free anomeric CvAn oligosaccharide with a reducing end is a reducing sugar (有还原端的寡糖是还原糖).vStability of glycosidic bonds(糖苷键的稳定性):oHydroly

37、zed by acid (被酸水解)oStable in alkaline solution (对碱稳定)麦芽糖III. OligosaccharidesP.34Reducing end()Nonreducing end()47Maltose （麦芽糖）Glucose-1,4-glucoseCellobiose（纤维二糖）glucose-1,4-glucoseIsomaltose（异麦芽糖)Glucose- -1,6-glucoseOOHOOHOHCH2OHCHOHOOHOHOHCH2OOHOHOHCH2OHCHOOHOHCH2OHOOHOOHOHOHCH2OHOOHOHCH2OHOCHOHO

38、-D-glucopyranosyl-(14)-D-glucopyranoseO-D-吡喃葡糖基-(14)-D-吡喃葡糖Glc (14) Glc(14) (16) (14)482. Nomenclature (命名)-乳糖半乳糖-葡萄糖Gal (14) Glc蔗糖葡萄糖-果糖Glc (12) FruFru (21) Glc海藻糖葡萄糖-葡萄糖Glc (1 1) GlcNonreducing sugarsReducing sugarsO-D-吡喃半乳糖基-(14)-D-吡喃葡糖P.35单糖的缩写见P.31，表1-4493. Some oligosaccharide examplesIII. Oli

39、gosaccharidesP.36-4050Cyclodextrins (环糊精)-OH at C-6-OH at C-2, C-3HydrophobicInside(内部疏水)HydrophilicOutside(外部亲水)readily dissolve in wateradsorb hydrophobic moleculesto to form water-soluble inclusion complex so that their chemical/physical properties can be changed, e.g.,increased solubilityhigher

40、stability against light, heat and oxygenwidely used as stabilizer, anti-oxidant, emulsifier, solubility enhancer, etc.51IV. Polysaccharides (多糖)521. ExistencevMost carbohydrates found in nature occur as polysaccharides.vConsisting of more than 20 monosaccharides.vMolecular weight (分子量) of 30000 4x10

41、8 vThe most common constituent is D-glucosevPolysaccharides differ from each other in:Nature of the component monosaccharides (单糖)Length of the chains (链长)Types of the bonds linking the units (糖苷键)Degree of chain branching (支链程度)vNonreducing sugars (非还原糖)vNo mutarotation (没有变旋现象)vNo sweetness (无甜味)I

42、V. PolysaccharidesP.40532. ClassificationpBiological sources (生物来源)Plant, animal, microorganismpBiological functions (生物功能)Storage polysaccharides (贮存多糖)e.g. starch (淀粉)Structural polysaccharides (结构多糖)e.g. cellulose (纤维素)Information carrierspCompositions (组成)Homopolysaccharides (同多糖)Heteropolysacch

43、arides (杂多糖)IV. Polysaccharides543. Homopolysaccharides (同多糖)55Starch: Amylose & amylopectin（直链淀粉 & 支链淀粉）P.41 14A short segment of amylose (直链淀粉)( 16)( 14)A segment of amylopectin (支链淀粉)56Amylose （直链淀粉）57A cluster of amylose and amylopectin58Amylose & amylopectin (直链和支链淀粉)vBoth have coil

44、ed helical structures due to 14 linkages (都是螺旋结构) vBoth are characterized by reaction with I2 (都与I2发生特征反应)Amylose (直链淀粉) dark blue (深蓝色)Amylopectin (支链淀粉) purple (紫色)vBoth have a reducing end (都有一个还原端)vEasily hydrated because of OH groups ready to form H-bonds with water (都易于水合，因为易与水形成氢键)vIngested b

45、y hydrolysis with amylases (淀粉酶水解而被吸收)Amylases are capable of cleaving starch and glycogen:P.42Fig.1-2459Cellulose（纤维素）IV. PolysaccharidesP.4560CelluloseIV. PolysaccharidesP.46Fig.1-27614. Hetereopolysaccharides（杂多糖）IV. Polysaccharides62OOHHHHHOHHHOH2COOHOHOOHHH2CH11342563nD-galactose3,6-anhydro-L-g

46、alactoseAgarose (琼脂糖)Agar (琼脂)Agarose (琼脂糖)Agaropectin (琼脂胶)IV. PolysaccharidesSepharose (琼脂糖凝胶)P.49Three-dimensional structure: a double helix with a three-fold screw axis.Can take up 99.5% H2OYield Sepharose as a support used in gel filtration chromatography.63Peptidoglycan (肽聚糖) major component i

47、n the bacterial cell wallsIV. Polysaccharides金黄色葡萄球菌(a gram-positive bacterium)P.51-53P.53图1-31Muropeptide(胞壁肽)14Lysozyme hydrolyzes the 14 glycosidic bondPenicillin prevents the synthesis of cross-links64Glycosaminoglycan()OHHHOSO3-HOHCOO-HOOHHHNHSO3-HOHCH2OSO3-HOD-Glucuronate-2-sulfateN-Sulfo-D-gl

48、ucosamine-6-sulfateHeparin (肝素)己糖醛酸己糖胺nP.66-6965V. Glycoconjugates（复合糖）Glycobiology (糖生物学)66VI. Analysis of CarbohydratesGlycoconjugateOligosaccharide mixtureSeparated oligosaccharidesMonosaccharidesFully methylatedcarbohydrateSmalleroligosaccharidesCompositionof mixtureTypes and amountsof monosacch

49、arideunitsPositions ofGlycosidic bondsSequence ofMonosaccharides,Position &Configuration ofGlycosidic bondsSequence ofMonosaccharides,Position &Configuration ofGlycosidic bondsEndoglycosidase (内切糖苷酶)Chromatography, filtration, etc. (层析分离)HPLC, GCH+/H2OMixture resolutionMethylation orEnzymati

50、c analysisNMR, MSHydrolysis(水解)Methylation(甲基化)Exoglycosidases(外切糖苷酶)P.71671.Two families: aldoses & ketoses (醛糖和酮糖)2.Stereochemistry (立体化学)3.Structures: linear & cyclic (线状和环状结构)4.Properties: physical & chemical (物理和化学性质)*optical activity and chirality (光活性和手性)5.Important monosaccharides and their derivatives (重要的单糖及其衍生物)II. Monosaccharides68(1) Plane-polarized light (平面