上游充通大兽 1.Monosaccharides Are Aldehydes or SHANGHAI JIAO TONG UNIVERSITY Ketones with Multiple Hydroxyl Groups Glyceraldehyde(甘油醛)hasa single asymmetric(非对称的) carbon atom. HO 甘油醛具有一个非对称碳原子。 D-Glyceraldehyde L-Glyceraldehyde (an aldose) (an aldose) Thus,there are two stereoisomers of this sugar:D- glyceraldehyde and L- glyceraldehyde. COH HO- C一H 因此它具有两种立体构型。 CH>OH CH>OH These two forms are D-Glyceraldehyde L-Glyceraldehyde enantiomers(对映体)，or mirror images of each other. The prefixes D-and L-designate the absolute configuration
Glyceraldehyde (甘油醛) has a single asymmetric (非对称的) carbon atom. 甘油醛具有一个非对称碳原子。 Thus, there are two stereoisomers of this sugar: Dglyceraldehyde and Lglyceraldehyde. 因此它具有两种立体构型。 These two forms are enantiomers (对映体), or mirror images of each other. 1. Monosaccharides Are Aldehydes or Ketones with Multiple Hydroxyl Groups The prefixes D- and L-designate the absolute configuration
上游充通大兽 1.Monosaccharides Are Aldehydes or SHANGHAI JIAO TONG UNIVERSITY Ketones with Multiple Hydroxyl Groups Monosaccharides and other sugars are often be represented by Fischer projections..费舍尔投影式 CHO In a Fischer projection of a molecule,atoms joined to an asymmetric(非对称的)carbon atom by horizontal bonds are H-C-0H in front of the plane of the page,and those joined by vertical CH2OH bonds are behind the page H CH2OH Fischer投影式能清晰地 一C一OH 描述各个不对称碳原子 CH2OH CH>OH CH>OH 的立体结构。 D-Glyceraldehyde L-Glyceraldehyde Dihydroxyacetone Figure 11.1 Fischer projections of trioses.The top structure reveals the stereochemical relations assumed for Fischer projections
Figure 11.1 Fischer projections of trioses. The top structure reveals the stereochemical relations assumed for Fischer projections. 1. Monosaccharides Are Aldehydes or Ketones with Multiple Hydroxyl Groups Monosaccharides and other sugars are often be represented by Fischer projections. 费舍尔投影式 In a Fischer projection of a molecule, atoms joined to an asymmetric (非对称的) carbon atom by horizontal bonds are in front of the plane of the page, and those joined by vertical bonds are behind the page Fischer投影式能清晰地 描述各个不对称碳原子 的立体结构
上游充通大兽 1.Monosaccharides Are Aldehydes or SHANGHAI JIAO TONG UNIVERSITY Ketones with Multiple Hydroxyl Groups Most naturally occurring sugars belong to the D series CHO OH CHOH D-Glyceraldehyde CHO 甘油醛 CHO OH HO- 有四个、五个、六个 OH H OH 和七个碳原子的单糖分别 CH2OH 赤藓糖 CH2OH -Erythrose D-Threose 苏糖 叫四碳糖(tetroses), CHO CHO CHO CHO 五碳糖(pentoses),六 HO- H OH HO- OH -OH HO H HO 碳糖(hexoses),和七 OH OH 阿拉 OH OH 碳糖(heptoses)。 CH>OH 核糖 CH2OH 伯糖 CH2OH 木糖 CH2OH o-Ribose D-Arabinose D-Xylose D-ly黑ose CHO CHO CHO CHO CHO CHO CHO CHO OH HO- OH HO OH HO- H OH HO- OH OH HO OH OH HO- -H OH OH OH HO HO HO H OH OH OH OH OH CH2OH CH2OH CH2OH CH2OH CH2OH CH2OH D-Allose D-Altrose D-Glucose D-Mannose D-Gulose D-ldose D-Galactose p-Talose 葡萄糖甘露糖 半乳糖 Figure 11.2 D-Aldoses containing 3,4,5,and 6 carbon atoms
Figure 11.2 D-Aldoses containing 3, 4, 5, and 6 carbon atoms.. 1. Monosaccharides Are Aldehydes or Ketones with Multiple Hydroxyl Groups Most naturally occurring sugars belong to the D series 甘油醛 赤藓糖 苏糖 核糖 葡萄糖 甘露糖 半乳糖 木糖 阿拉 伯糖 有四个、五个、六个 和七个碳原子的单糖分别 叫四碳糖（tetroses）， 五碳糖（pentoses），六 碳糖（hexoses），和七 碳糖（heptoses）
上游充通大兽 1.Monosaccharides Are Aldehydes or SHANGHAI JIAO TONG UNIVERSITY Ketones with Multiple Hydroxyl Groups 糖的D-和L-构型只表示离羰基或醛基最远的那个不对称碳原 子的构型。 CHO CHO 2 H-COH HO-CI H—C—OH H- CH>OH CH>OH D-Erythrose D-Threose 赤藓糖 苏糖 The four-carbon aldoses D-erythrose(赤藓糖)andD-threose(苏糖) have the same configuration at C-3(because they are D-sugars)but opposite configurations at C-2.They are diastereoisomers(非对映体)，not enantiomers,because they are not mirror images of each other. Sugars differing in configuration at a single asymmetric center are called epimers(差向异构体) 仅有一个立体中心构型不同的糖被称为差向异构体
The four-carbon aldoses D-erythrose (赤藓糖 ) and D-threose (苏糖) have the same configuration at C-3 (because they are D-sugars) but opposite configurations at C-2. They are diastereoisomers (非对映体), not enantiomers, because they are not mirror images of each other. Sugars differing in configuration at a single asymmetric center are called epimers（差向异构体）. 仅有一个立体中心构型不同的糖被称为差向异构体。 1. Monosaccharides Are Aldehydes or Ketones with Multiple Hydroxyl Groups 赤藓糖 苏糖 糖的D-和L-构型只表示离羰基或醛基最远的那个不对称碳原 子的构型
上游充通大兽 1.Monosaccharides Are Aldehydes or SHANGHAI JIAO TONG UNIVERSITY Ketones with Multiple Hydroxyl Groups D-Ribose(核糖)，the carbohydrate component of RNA,is a five-carbon aldose.5碳醛糖 D-Glucose(葡萄糖)，D-mannose(甘露糖)，andD-galactose(半乳 糖)are abundant six-carbon aldoses.6碳醛糖 Note that D-glucose and D-mannose differ in configuration only at C-2. Thus,D-glucose and D-mannose are epimeric at C-2;D-glucose and D- galactose are epimeric(差向异构)atC-4. CHO CHO CHO CHO CHO H OH OH OH HO OH HO HO -H HO OH HO-C—H H -OH H一 -OH H OH OH H C OH H OH H —OH OH 5 CH2OH CH2OH D-Ribose CH2OH CH2OH CH2OH D-Galactose D-Glucose D-Glucose D-Mannose 核糖 半乳糖 葡萄糖 葡萄糖 甘露糖
D-Ribose (核糖), the carbohydrate component of RNA, is a five-carbon aldose. 5碳醛糖 D-Glucose（葡萄糖）, D-mannose（甘露糖）, and D-galactose（半乳 糖） are abundant six-carbon aldoses. 6碳醛糖 Note that D-glucose and D-mannose differ in configuration only at C-2. Thus, D-glucose and D-mannose are epimeric at C-2; D-glucose and Dgalactose are epimeric （差向异构）at C-4. 1. Monosaccharides Are Aldehydes or Ketones with Multiple Hydroxyl Groups 核糖 半乳糖 葡萄糖 葡萄糖 甘露糖