单糖是由3~7个碳原子与氢及氧原子结合形成的多羟基醛或酮,其中最简单的单糖为含3个碳原子的丙糖。随着碳原子数目的增加,依次有丁糖、戊糖和己糖等。在人体内,重要的戊糖包括核糖和脱氧核糖,它们分别组成核糖核酸与脱氧核糖核酸。生物学上最重要的三种单糖是葡萄糖、果糖和半乳糖,其共同化学式为C6H12O6。
这些单糖具有特定的结构特征:含有醛基或酮基,其中葡萄糖和半乳糖含有醛基,而果糖则含酮基。由于它们具有还原性,可用于检查尿液或血液中的糖分含量。此外,单糖还具备多个羟基,能够参与典型的酯化、成苷、脱氧、脱水及氨基化的反应。
作为许多糖类的基本单位,食物中的复杂糖类在消化后会被分解为单糖,并主要在小肠上部被吸收。不同类型的单糖吸收速度各异:葡萄糖的吸收率为100%,半乳糖为110%,果糖为43%,甘露糖为19%,木酮糖为15%,而阿拉伯糖仅为9%。
单糖不仅是构成海洋生物、海水和海洋沉积物中糖类物质的基本组分,还广泛存在于其中。在海洋浮游生物中,常见的单糖按丰度顺序包括半乳糖、葡萄糖、甘露糖、核糖、木糖、岩藻糖、鼠李糖和阿拉伯糖。多数情况下,这些单糖以多聚糖或结合形式存在于生物体内,并且也普遍存在于海水中。
在海洋环境中,果糖的来源有限,但在海水中能够通过差向异构化从葡萄糖转化而来。海水中的单糖浓度一般为0—20微克/升,通常以10微克碳/升代表总游离单糖的浓度。海水中单糖含量可通过METH法测定;对于葡萄糖,则常用酶促或生物鉴定法直接测量。在进行所有个别单糖的测定时,通常采用色谱分离方法。
由于单糖是非挥发性化合物,在使用气相色谱法检测时需要经衍生化处理。常用的液相色谱技术包括乙醇/水分配色谱和硼酸络合物离子交换色谱等。
中文名称 | 英文名称 | CAS号 | 化学式 | 结构式图片 |
---|---|---|---|---|
1-硫代-b-D-吡喃葡萄糖苷对甲苯酯 | (2R,3S,4S,5R,6S)-2-Hydroxymethyl-6-phenylsulfanyl-tetrahydro-pyran-3,4,5-triol | 2936-70-1 | C12H16O5S |
|
1-甲氧基-5-O-(叔丁基二苯基硅烷)-2-脱氧-beta-D-赤式戊呋喃糖苷 | (2R,3R,5R)-2-tert-butyldiphenylsilyloxymethyl-3-hydroxy-5-methoxy-tetrahydrofuran | 130144-86-4 | C22H30O4Si |
|
1-甲氧基-2,3-O-异亚丙基-5-苄氧基-beta-D-呋喃核糖苷 | (2R,3R,4R,5R)-2-benzyloxymethyl-3,4-isopropylidenedioxy-5-methoxytetrahydrofuran | 33019-63-5 | C16H22O5 |
|
1-甲氧基-2,3-O-异亚丙基-5-O-对甲苯磺酰基-beta-D-呋喃核糖苷 | methyl 2,3-O-isopropylidene-5-O-p-tolylsulfonyl-β-D-ribofuranoside | 4137-56-8 | C16H22O7S |
|
1-甲氧基-2,3,5-三苄氧基-beta-D-呋喃核糖 | methyl 2,3,5-tri-O-benzyl-β-D-ribofuranoside | 64363-77-5 | C27H30O5 |
|
1-甲氧基-2,3,5-三乙酰氧基-D-呋喃核糖苷 | 2,3,5-tri-O-acetyl-1-O-methylglycoside | 52554-28-6 | C12H18O8 |
|
1-甲氧基-2,3,5-三(4-氯苯甲酰)氧基-beta-D-呋喃核糖 | Methyl 2,3,5-tri-O-(4-chlorobenzoyl)-beta-D-ribofuranoside | 29755-00-8 | C27H21Cl3O8 |
|
1-甲基-3-吲哚基-beta-D-吡喃半乳糖苷 | (2R,3R,4S,5R,6S)-2-(Hydroxymethyl)-6-((1-methyl-1H-indol-3-yl)oxy)tetrahydro-2H-pyran-3,4,5-triol | 207598-26-3 | C15H19NO6 |
|
1-氯-3,5-二对氯苯甲酰氧基-2-脱氧-D-核糖 | 5-chloro-2-(((4-chlorobenzoyl)oxy)methyl)tetrahydrofuran-3-yl 4-chlorobenzoate | 3601-90-9 | C19H15Cl3O5 |
|
1-氯-3,5-二-O-对甲苯甲酰基-2-脱氧-D-呋喃核糖 | [5-chloro-3-[(4-methylbenzoyl)oxy]oxolan-2-yl]methyl 4-methylbenzoate | 4330-21-6 | C21H21ClO5 |
|
1-氯-2-脱氧-3,5-二-O-对甲苯甲酰基-L-呋喃核糖 | 2-deoxy-3,5-di-O-(p-toluoyl)-α-L-erythro-pentofuranosyl chloride | 141846-57-3 | C21H21ClO5 |
|
1-氨基-1-脱氧-beta-D-半乳糖 | galactopyranosylamine | 74867-91-7 | C6H13NO5 |
|
1-氨基-1-脱氧-D-半乳糖醇 | 1-Amino-1-desoxy-D-talit | 488-42-6 | C6H15NO5 |
|
1-氧代十二烷基-Α-D-葡萄糖苷 | 1-O-lauroyl-α-D-glucopyranose | 64395-91-1 | C18H34O7 |
|
1-叠氮-1-脱氧-β-D-吡喃葡萄糖苷 | 4-azido-4-deoxy-D-glucose | 20379-59-3 | C6H11N3O5 |
|
1-叠氮-1-脱氧-β-D-吡喃半乳糖苷四乙酸酯 | (2R,3S,4S,5R,6R)-2-(acetoxymethyl)-6-azidotetrahydro-2H-pyran-3,4,5-triyl triacetate | 13992-26-2 | C14H19N3O9 |
|
1-叠氮-1-脱氧-β-D-吡喃半乳糖苷 | 1-amido-1-deoxygalactopyranose | 35899-89-9 | C6H11N3O5 |
|
1-乙酰氧基-2,3,5-三苯甲酰氧基-1-beta-D-呋喃核糖 | 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose | 6974-32-9 | C28H24O9 |
|
1-乙酰氧基-2,3,5-三苄氧基-D-呋喃核糖 | acetyl 2,3,5-tri-O-benzyl-α-D-ribofuranoside | 58381-23-0 | C28H30O6 |
|
1-乙酰氧基-2,3,5-三(4-氯苯甲酰)氧基-beta-D-呋喃核糖 | 1-O-acetyl-2,3,5-tris-O-(p-chlorobenzoyl)-β-D-ribofuranose | 144084-01-5 | C28H21Cl3O9 |
|
1-β-D-阿拉伯呋喃糖苷胸腺嘧啶 | thymine arabinoside | 605-23-2 | C10H14N2O6 |
|
1-Α-氯-3,5-二-O-对甲苯甲酰基-2-脱氧-D-呋喃核糖 | 2-deoxy-3,5-di-O-p-toluoyl-α-D-erythro-pentofuranosyl chloride | 4330-21-6 | C21H21ClO5 |
|
1-O-甲基-3,5-二-O-[(2,4-二氯苯基)甲基]-alpha-D-赤式戊呋喃糖苷-2-酮 | 3,5-bis-O-(2,4-dichlorophenylmethyl)-1-O-methyl-α-D-erythro-pentafuranos-2-ulose | 443642-30-6 | C20H18Cl4O5 |
|
1-O-甲基-3,5-二-O-(2,4-二氯苯甲基)-2-甲基-alpha-D-呋喃核糖苷 | (2S,3R,4R,5R)-4-((2,4-dichlorobenzyl)oxy)-5-(((2,4-dichlorobenzyl)oxy)methyl)-2-methoxy-3-methyltetrahydrofuran-3-ol | 443642-31-7 | C21H22Cl4O5 |
|
1-O-Alpha-D-吡喃葡萄糖-D-甘露糖醇二水合物 | isomalt | 20942-99-8 | C12H24O11 |
|
1-(2-脱氧-2-氟-beta-D-阿拉伯呋喃基)尿嘧啶 | 1-(2'-deoxy-2'-fluoro-β-D-arabinofuranosyl)uracil | 69123-94-0 | C9H11FN2O5 |
|
1,6-脱水-β-D-葡萄糖-2,3,4-三邻醋酸 | 2,3,4-tri-O-acetyllevoglucosan | 13242-55-2 | C12H16O8 |
|
1,6-脱水-β-D-葡萄糖 | levoglucosan | 498-07-7 | C6H10O5 |
|
1,6-脱水-beta-d-吡喃甘露糖 | 1,6-anhydro-β-D-glucose | 14168-65-1 | C6H10O5 |
|
1,6-内醚-D-半乳糖 | 1,6-anhydro-β-D-galactopyranose | 644-76-8 | C6H10O5 |
|
1,5-脱水-DL-半乳糖醇 | (3R,4R,5S)-2-(hydroxymethyl)oxane-3,4,5-triol | 154-58-5 | C6H12O5 |
|
1,5-无水葡萄糖醇 | 1,5-anhydro-D-glucitol | 154-58-5 | C6H12O5 |
|
1,4-脱水-L-半乳糖醇 | 2,5-anhydro-DL-altritol | 27826-73-9 | C6H12O5 |
|
1,4-脱水-D-山梨醇 | 1,4-anhydro-D-glucitol | 12441-09-7 | C6H12O5 |
|
1,4-甲苯磺酰基-2,3-异亚丙基苏糖醇 | 1,4-di-o-tosyl-2,3-isopropylidene-D-threitol | 51064-65-4 | C21H26O8S2 |
|
1,3,5-三苯甲酰基-D-呋喃核糖 | 1,3,5-tri-O-benzoyl-α-D-ribofuranoside | 22224-41-5 | C26H22O8 |
|
1,3,5-三乙酰基-2-脱氧-D-赤式戊呋喃糖 | (3,5-Diacetyloxyoxolan-2-yl)methyl acetate | 4594-52-9 | C11H16O7 |
|
1,3,4,6-四-O-乙酰基-2-氨基-2-脱氧-Β-D-葡萄糖盐酸盐 | 1,3,4,6-tetra-O-acetyl-D-glucosamine hydrochloride | 10034-20-5 | C14H22NO9*Cl |
|
1,3,4,6-四-O-乙酰基-2-叠氮-2-脱氧-Β-D-吡喃葡萄糖 | 1,3,4,6-Tetra-O-acetyl-2-azido-2-deoxy-β-D-glucopyranose | 80321-89-7 | C14H19N3O9 |
|
1,3,4,6-O-四乙酰基-2-脱氧-D-吡喃葡萄糖 | 1,3,4,6-tetra-O-acetyl-2-deoxy-D-glucopyranose | 69515-91-9 | C14H20O9 |
|
1,3,4,6-O-四乙酰基-2-叠氮-2-脱氧-alpha-D-吡喃半乳糖苷 | 1,3,4,6-tetra-O-acetyl-2-azido-2-deoxy-α-D-galactopyranose | 67817-30-5 | C14H19N3O9 |
|
1,2:5,6-二异亚丙基-alpha-D-异呋喃糖 | Diacetone D-glucose | 2595-05-3 | C12H20O6 |
|
1,2:5,6-二异亚丙基-3-O-(甲磺酰基)-alpha-D-呋喃葡萄糖 | 1,2,5,6-di-O-isopropylidene-3-O-methylsulfonyl-α-D-glucofuranose | 5450-26-0 | C13H22O8S |
|
1,2:5,6-二-O-环己亚基-alpha-D-呋喃葡萄糖 | 1,2:5,6-di-O-cyclohexylidene-α-D-glucofuranose | 23397-76-4 | C18H28O6 |
|
1,2:5,6-O-双异丙叉-Alpha-D-己呋喃核糖-3-酮水合物 | 1,2:5,6-Di-O-isopropylidene-a-D-ribo-hexofuranose-3-ulose monohydrate | 10578-85-5 | C12H20O7 |
|
1,2:3,5-双-O-异亚丙基-alpha-D-呋喃木糖 | 1,2:3,5-di-O-isopropylidene-D-xylofuranose | 20881-04-3 | C11H18O5 |
|
1,2-O-异亚丙基-alpha-D-呋喃木糖 | 1,2-O-isopropylidene-α-D-xylose | 20031-21-4 | C8H14O5 |
|
1,2-O-异亚丙基-D-呋喃葡萄糖 | 1,2-O-isopropylidene-α-D-glucofuranose | 18549-40-1 | C9H16O6 |
|
1,2-O-(1-乙氧基亚乙基)-β-D-甘露吡喃糖三乙酸 | 1,2-O-(1-Ethoxyethylidene)-beta-D-mannopyranose triacetate | 28140-37-6 | C16H24O10 |
|
1,2,4,6-O-四乙酰基-3-脱氧-D-吡喃葡萄糖 | 1,2,4,6-tetra-O-acetyl-3-deoxy-D-glucopyranose | 5040-09-5 | C14H20O9 |
|