《有机化学》课件 碳水化合物

1、? ?有机化学有机化学? ?课件第课件第1818章章 碳水化合物碳水化合物2糖的分类单糖(Monosaccharide)不能水解成更简单多羟基醛酮的碳水化合物(葡萄糖，果糖)低聚糖(寡糖，Oligosaccharide)水解时能生成210个单糖的碳水化合物(蔗糖，麦芽糖)多糖(Polysaccharide)水解时能生成10个以上单糖的碳水化合物(淀粉，纤维素)5单糖的结构与名称(2)CHOCH2OHHOHCHOOHHOHCH2OHHD-()-赤藓糖D-()-ErythroseCHOHOHOHCH2OHHD-()-苏阿糖D-()-Threose丁醛糖(Aldotetrose)D-(+)-甘油醛6

2、单糖的结构与名称(3)CHOOHHOHCH2OHHCHOHOHOHCH2OHHCHOOHHOHOHHCH2HOHCHOHOHOHOHHCH2HOHCHOOHHHOHOHCH2HOHCHOHOHHOHOHCH2HOHD-()-核糖D-()-RiboseD-()-阿拉伯糖D-()-ArabinoseD-(+)-木糖D-(+)-XyloseD-()-来苏糖D-()-Lyxose戊醛糖(Aldopentose)D-()-赤藓糖D-()-苏阿糖7单糖的结构与名称(4-1)CHOOHHOHOHHCH2HOHCHOHOHOHOHHCH2HOHCHOOHHOHOHHHOHCH2OHHCHOHOHOHOHHHO

3、HCH2OHHCHOOHHHOHOHHOHCH2OHHCHOHOHHOHOHHOHCH2OHHD-(+)-阿洛糖D-(+)-AlloseD-(+)-阿卓糖D-(+)-AltroseD-(+)-葡萄糖D-(+)-GlucoseD-(+)-甘露糖D-(+)-Mannose己醛糖(Aldohexose)D-()-核糖D-()-阿拉伯糖8单糖的结构与名称(4-2)CHOOHHHOHOHCH2HOHCHOHOHHOHOHCH2HOH己醛糖(Aldohexose)CHOOHHOHHHOHOHCH2OHHCHOHOHOHHHOHOHCH2OHHD-()-古罗糖D-()-GluloseD-()-艾杜糖D-()

4、-IdoseD-(+)-半乳糖D-(+)-GalactoseD-(+)-太罗糖D-(+)-TaloseCHOOHHHHOHOHOHCH2OHHCHOHOHHHOHOHOHCH2OHHD-(+)-木糖D-()-来苏糖9单糖的结构与名称(5)CH2CH2OOHOH二羟基丙酮 DihydroxyacetoneCH2OHOHOHHOHCH2OHHOHD-()-果糖D-()-Fructose10缩醛与半缩醛(缩醛)(半缩醛)11葡萄糖的开链和氧环式结构哈沃斯投影式(Haworth projection)-D-葡萄糖-D-葡萄糖正位异构体(Anomer,异头体)12葡萄糖的开链结构和性质CHOOHHHOH

5、OHHOHCH2OHHD-(+)-葡萄糖D-(+)-Glucose碳骨架用钠汞齐还原生成己六醇；用HI进一步还原生成正己烷。醛基可以与羟胺、苯肼等羰基试剂作用。用溴水氧化，得到己酸。五个羟基与乙酸酐作用生成五酰基衍生物。13葡萄糖的氧环式结构和性质变旋光现象-D-葡萄糖(36%)D=+m.p.=146C-D-葡萄糖(64%)D=+m.p.=150C变旋光现象任何纯洁的葡萄糖水溶液的比旋光最终都变为D的现象14果糖的开链和氧环式结构-D-果糖-D-果糖INTRINSIC CHEMISTRY OF FRUCTOSERobert S. ShallenbergerNew York State Agri

6、cultural Experiment Station, Cornell University, Geneva,New York 14456, USAPure & Appi. Chem. Vol. 50, pp.l409-1420.15吡喃糖与呋喃糖O吡喃(Pyran)OOHCH2OHOHOHOH-D-吡喃葡萄糖吡喃糖(Pyranose)O呋喃(Furan)CH2OOHOHOHOHHOH2C-D-呋喃果糖呋喃糖(Furanose)16所有的CH键都处于交叉式的位置所有化学键的夹角环己烷的构象17直立键(a键)与平伏键(e键)18吡喃葡萄糖的构象(-D-吡喃葡萄糖)(-D-吡喃葡萄糖)1

7、9单糖的反响生成糖苷OOHCH2OHOHOHOHCHOOHHHOHOHHOHCH2OHHOCH2OHOHOHOHOHCH3OH, HClCH3OH, HClOOCH2OHOHOHOHCH3OCH2OHOHOHOHOCH3甲基-D-吡喃葡萄糖苷甲基-D-吡喃葡萄糖苷糖苷Glycoside20单糖的反响被硝酸氧化CHOOHHHOHOHHOHCH2OHHCOOHOHHHOHOHHOHCOOHHOCHOHOHOHCH2OHOHHNO3D-吡喃葡萄糖D-葡萄糖D-葡萄糖二酸21单糖的反响被溴水氧化CHOOHHHOHOHHOHCH2OHHCOOHOHHHOHOHHOHCH2OHHBr2H2OD-葡萄糖酸D

8、-葡萄糖22费林试剂、托伦斯试剂和本尼迪特试剂斐林试剂(Fehlings reagent)：硫酸酮和碱性酒石酸钾钠托伦斯试剂(Tollens reagent)：硝酸银的氨水溶液本尼迪特试剂(Benedicts reagent)：柠檬酸、硫酸铜、碳酸钠COOHCHCHCOOHOHOHCH2CCH2(OH)COOHCOOHCOOH酒石酸(Tartaric acid)柠檬酸(Citric acid)复原糖(Reducing sugar)能被费林试剂、托伦斯试剂或本尼迪特试剂氧化的糖23单糖的反响和托伦斯试剂的作用CHOOHHHOHOHHOHCH2OHHCOOHOHHHOHOHHOHCH2OHH+Ag

9、+ (银镜)托伦斯试剂D-葡萄糖D-葡萄糖酸24单糖的反响和费林(本尼迪特)试剂的作用Some diabetes self-test kits sold in drugstores for home use employ Benedicts test.Fundamentals of Organic Chemistry John McMurryCHOOHHHOHOHHOHCH2OHHCOOHOHHHOHOHHOHCH2OHH+Cu2O(红色)本尼迪特试剂(或托伦斯试剂)25单糖的反响被高碘酸氧化CHOOHHHOHOHHOHCH2OHH+HCHOHCOOHHCOOHHCOOHHCOOHHCOOH5

10、IO4反应定量进行26单糖的反响催化加氢CHOOHHHOHOHHOHCH2OHHCH2OHOHHHOHOHHOHCH2OHHH2NiD-葡萄糖D-葡萄糖醇27单糖的反响被硼氢化钠复原CHOOHHHOHOHHOHCH2OHHCH2OHOHHHOHOHHOHCH2OHH1. NaBH42. H2OD-葡萄糖D-葡萄糖醇28单糖的反响生成脎CHOOHHHOHOHHOHCH2OHHCHOHOHHOHOHHOHCH2OHHCHCNNHC6H5HOHOHHOHCH2OHHNNHC6H52C6H5NHNH22C6H5NHNH2D-葡萄糖D-葡萄糖脎D-甘露糖差向异构体(Epimer)只有一个碳原子构型不同的

11、非对映体29单糖的反响生成醚OCHOHOHOHCH2OHOHOCHOOCH2OCH3CH3CH3OCH3OCH3(CH3)2SO4NaOHD-葡萄糖五甲基-D-葡萄糖30单糖的反响生成酯(五乙酰基-D-葡萄糖)OOHOHCH2OHOHOPO3H2OCHOHOHOHCH2OHOPO3H21-磷酸-D-葡萄糖酯6-磷酸-D-葡萄糖酯31二糖蔗糖(Sucrose)OOHOHCH2OHOHOOCH2OHOHCH2OHOH-D-呋喃果糖基-D-吡喃葡萄糖苷(-D-吡喃葡萄糖基-D-呋喃果糖苷)C12H22O11非复原糖无变旋光现象不能生成脎分子中无苷羟基32蔗糖的水解D-葡萄糖 D=+D-果糖D= 92

12、蔗糖D=+(转化糖)C12H22O11+ H2OC6H12O6C6H12O6+H+转化反应(1:1混合物D= 22)Sucrose, or ordinary table sugar, is probably the most abundant pure organic chemical in the world. Whether from sugar cane (20% by weight) or from sugar beets (15% by weight), and whether raw or refined, all table sugar is sucrsoe.Fundamenta

13、ls of Organic Chemistry John McMurry33SucroseJohn McMurrySucrose is a disaccharide that yields 1 equivalent of glucose and 1 equivalent of fructose on hydrolysis. This 1:1 mixture of glucose and fructose is often referred to as invert sugar because the sign of optical rotation changes (inverts) duri

14、ng the hydrolysis from sucrose, D=+, to a glucose/fructose mixture, D=22. Insects such as honeybees have enzymes called invertases that catalyze the hydrolysis of sucrose to glucose + fructose. Honey, in fact, is primarily a mixture of glucose, fructose, and sucrose.Fundamentals of Organic Chemistry

15、 John McMurry34二糖麦芽糖(Maltose)OOHOHCH2OHOHOOOHCH2OHOHOH4-O-(-D-吡喃葡萄糖基)-D-吡喃葡萄糖苷C12H22O11还原糖有变旋光现象能生成脎分子中有苷羟基苷羟基35二糖纤维二糖(Cellobiose)还原糖有变旋光现象能生成脎分子中有苷羟基4-O-(-D-吡喃葡萄糖基)-D-吡喃葡萄糖苷苷羟基OOHOHCH2OHOHOOOHCH2OHOHOH36多糖直链淀粉(Amylose)OOHCH2OHOHOOOHCH2OHOHOOOHCH2OHOHO1,4-O-(-D-glucopyranoside)polymer直链淀粉约占淀粉总含量的201

16、,4-苷键1,4-苷键1437OOHCH2OHOHOOOHCH2OHOOOHCH2OHOHOOOOHCH2OHOH支链淀粉约占淀粉总含量的80。平均每25个葡萄糖基就有一个支链-1,4-苷键-1,6-苷键多糖支链淀粉(Amylopectin)38StarchJohn McMurryNature uses starch as the medium by which plants store energy for later use; potatoes, corn, and cereal grains all contain large amounts of starch. When eaten,

17、 starch is digested in the mouth and stomach by enzymes called glycosidases(消化酶), which catalyze the hydrolysis of glycoside bonds and release individual molecules of glucose. Like most enzymes, glycosidases are highly selective in their action. They hydrolyze only the -glycoside links in starch and

18、 leave the -glycoside links in cellulose untouched. Thus, humans can eat potatoes and grains but not grass.Fundamentals of Organic Chemistry John McMurry39多糖糖原(Glycogen)Glycogen is a polysaccharide that serves the same energy-storage function in animals that starch serves in plants. Dietary carbohyd

19、rate not needed for immediate energy is converted by the body to glycogen for long-term storage. Fundamentals of Organic Chemistry John McMurry401,4-O-(-D-glucopyranoside) polymer多糖纤维素(Cellulose)Nature uses cellulose primarily as a structural material to impart strength and rigidity to plants. Wood,

20、 leaves, and cotton are primarily cellulose. Cellulose also serves as a raw material for the manufacture of cellulose acetate, known commercially as acetate rayon. Fundamentals of Organic Chemistry John McMurryOOHCH2OHOHOOOHCH2OHOHOOOHCH2OHOHO14-1,4-苷键41脱氧糖(Deoxy Sugar)D-Ribose-D-Ribofuranose-D-Ribo

21、furanose2-Deoxy-D-ribose2-Deoxy-D-ribofuranose 2-Deoxy-D-ribofuranose42氨基糖(Amino sugar)Another structural variation is the replacement of a hydroxyl group in a carbohydrate by an amino group to give an amino sugar. The most abundant amino sugar is one of the oldest and most abundant organic compound

22、s on earth. N-Acetyl-D-glucosamine is the main component of the polysaccharide in chitin, the substance that makes up the tough outer skeleton of arthropods and insects. Chitin has been isolated from a 25-million-year old beetle fossil, and more than 1011 tons of chitin is produced in the biosphere

23、each year. Lobster shells, for example, are mainly chitin. More than 60 amino sugars are known, many of them having been isolated and identified only recently as components of antibiotics. The anticancer drug doxorubicin hydrochloride (Adriamycin), for example, contains the amino sugar L-daunosamine

24、 as one of its structural units.43Sweetness(1)John McMurrySay the word sugar and most people immediately think of sweet-tasting candies, desserts, and such. In fact most of the simple carbohydrates do taste sweet, but the degree of sweetness varies greatly from one sugar to another. With sucrose (table sugar) as a reference point, fructose is nearly twice as sweet, but lactose is only about one-sixth as sweet. Comparisons are difficult, though, because sweetness is a matter of taste, and the ranking of sugars is a matte