凡能水解成多个单糖分子或其衍生物的糖为多糖。它是由二十个至数万个单糖分子缩合、脱水而成的大分子化合物。多糖可以由一种单糖组成,如淀粉、纤维素等称为同聚多糖;也可以由不同单糖或其衍生物缩合而成,例如半纤维素,则被称为杂聚多糖。
自然界中,植物、动物和微生物都含有丰富的多糖。除了以游离形式存在外,多糖也常与蛋白质结合形成复合物。植物多糖的共同特点是天然性、保健价值及独特的水溶性胶体特性,这赋予食品较高的营养价值、稳定的组织结构以及优良的外观和口感,并延长了其货架期。
天然植物多糖对人体更为安全,吸收率更高。例如魔芋中的葡甘聚糖,这是一种极好的水溶性膳食纤维,具有饱腹感、降血脂、降血糖及通便等保健功能。尽管植物多糖本身不提供热量,但它对高热量、高脂肪和高蛋白的饮食结构有平衡营养的作用。
因此,亲水性的植物多糖常被称为植物胶,它们能够为食品生产加工提供增稠剂、凝胶剂、成膜剂及乳化剂等多种稳定剂。有效开发和利用植物多糖将有助于提升人类的生活质量、改善健康水平,并丰富食物资源,从而创造更多的经济价值。
淀粉是储存在植物体内的多糖,由直链淀粉和支链淀粉两种成分构成。在淀粉颗粒中,直链淀粉占比20~28%,其余为支链淀粉。直链淀粉由约250至300个D-葡萄糖分子通过α 1,4糖苷键连接而成,并卷曲成螺旋结构,具有一个非还原性末端和一个还原性末端,其分子量差异很大,从数千到150,000不等。直链淀粉遇碘呈蓝色反应,这是由于螺旋内部为分子碘占据所致。
支链淀粉由24至30个D-葡萄糖分子通过α 1,4和α 1,6糖苷键连接而成,形成类似灌木丛的结构。动物消化道中的α淀粉酶(存在于唾液及胰液中)可以随机作用于α 1,4糖苷键,将直链淀粉水解成麦芽糖和葡萄糖;植物中的β淀粉酶则在直链淀粉非还原性末端起作用,生成麦芽糖。支链淀粉同样可被α和β淀粉酶作用,但靠近分枝点的α 1,4和α 1,6糖苷键不被这些酶水解,在α淀粉酶及1,6葡萄糖苷酶共同作用下,支链淀粉完全水解为葡萄糖和麦芽糖。
琼脂糖是琼脂的重要组成部分,由D-半乳糖与3,6脱水半乳糖构成的单位重复缩合而成。琼脂糖在沸水中大量溶解,但当温度降至40℃以下时则成不溶性凝胶。这种琼脂糖凝胶常用作层析的支持体,通过氢键将半乳多糖链交联形成,因此在过于酸碱环境中不稳定。
中文名称 | 英文名称 | CAS号 | 化学式 | 结构式图片 |
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醋酸丙酸纤维素酯 | Cellulose, acetate propanoate | 9004-39-1 | C76H114O49 |
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邻氯苯亚甲基丙二腈 | citrate synthase (unknown stereospecificity) | 9027-96-7 | —— | —— |
西佐喃 | Schizophyllan | 9050-67-3 | C24H42O21 |
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葡聚糖凝胶LH-20 | methyl 1-acetyl-1H-thieno[3,2-c]pyrazole-5-carboxylate | 9041-37-6 | C9H8N2O3S |
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葡聚糖凝胶G-100 | Sephadex G-100 | 9050-94-6 | C226H274N28O14S6 |
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葡聚糖凝胶 | sephadex G 75 | 37224-29-6 | C22H23FN4OS |
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葡聚糖凝胶 | 6'-Iodononivamide | 859171-97-4 | C17H26INO3 |
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菊粉 | Inulin (by Enzymatic synthesis) | 9005-80-5 | C228H382O191 |
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肝素锂 | Heparin lithium salt | 9045-22-1 | C14H25NO20S3 |
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羧甲基醚纤维素钠盐 | Carmellose sodium | 9004-32-4 | C8H16NaO8 |
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羧甲基纤维素 | 7H | 9000-11-7 | C8H16O8 |
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羟丙基脱乙酰壳多糖 | Hydroxypropyl chitosan | 84069-44-3 | C51H101N3O24 |
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糊精棕榈酸酯 | (3R,4S,5S,6R)-2-[(2R,3S,4R,5R)-4,5-dihydroxy-2-(hydroxymethyl)-6-[(2R,3S,4R,5R,6S)-4,5,6-trihydroxy-2-(hydroxymethyl)oxan-3-yl]oxyoxan-3-yl]oxy-6-(hydroxymethyl)oxane-3,4,5-triol;hexadecanoic acid | 83271-10-7 | C34H64O18 |
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糊精 | Dextrin | 9004-53-9 | C18H32O16 |
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硫酸类肝素 | azane;(3R,4R,5S,6R)-3-[(2S,3S,4R,5R)-5-[(2R,3S,4S,5R)-6-carboxylato-4-hydroxy-5-methoxy-3-sulfonatooxyoxan-2-yl]oxy-4-hydroxy-3-(sulfonatoamino)-6-(sulfonatooxymethyl)oxan-2-yl]oxy-4,5-dihydroxy-6-[(3S,4R,5S,6R)-6-methoxy-5-(sulfonatoamino)-4-sulfonatooxy-2-(sulfonatooxymethyl)oxan-3-yl]oxyoxane-2-carboxylate | 9050-30-0 | C26H39N3O39S6-8 |
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甲基羟乙基纤维素 | ethane-1,2-diol;(2S,3R,4R,5S,6R)-2-(hydroxymethyl)-6-[(2S,3R,4S,5S,6S)-4,5,6-trihydroxy-2-(hydroxymethyl)oxan-3-yl]oxyoxane-3,4,5-triol;(2S,3S,4R,5S,6S)-2,3,4-trimethoxy-6-(methoxymethyl)-5-[(2R,3S,4R,5S,6S)-3,4,5-trimethoxy-6-(methoxymethyl)oxan-2-yl]oxyoxane | 9032-42-2 | C34H66O24 |
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琼脂糖 | Agarose | 9012-36-6 | C24H38O19 |
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琼脂 | Agar | 9002-18-0 | C14H24O9 |
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果胶 | β-D-galactopyranosiduronic acid | 9000-69-5 | C6H10O7 |
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木聚糖 | (2R,3R,5S,6S)-tetrahydropyran-2,3,4,5,6-pentol | 9014-63-5 | C5H10O6 |
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支链淀粉 | 6<sup>2</sup>-α-maltosyl-maltotriose (α-re) | 9037-22-3 | C30H52O26 |
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小菌核(SCLEROTIUMROLFSSII)胶 | Scleroglucan | 39464-87-4 | C24H44O20P2 |
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壳聚糖 | Chitosan | 9012-76-4 | C56H103N9O39 |
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半乳甘露聚糖 | 6-O-α-D-galactopyranosyl-4-O-β-D-mannopyranosyl-D-mannopyranose | 11078-30-1 | C18H32O16 |
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全氨基倍他环糊精 | heptakis(6-amino-6-deoxy)-β-cyclodextrin | 30754-24-6 | C42H77N7O28 |
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乳糖-N-四糖 | lacto-N-tetraose | 14116-68-8 | C26H45NO21 |
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乙基纤维 | Ethyl cellulose | 9004-57-3 | C20H38O11 |
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三乙酸纤维素 | O-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl)-(1->4)-O-(2,3,6-tri-O-acetyl-β-D-glucopyranosyl)-(1->4)-1,2,3,6-tetra-O-acetyl-β-D-glucopyranose | 9012-09-3 | C40H54O27 |
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β-环糊精 | β-cyclodextrin | 7585-39-9 | C42H70O35 |
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Α-葡萄糖基橘皮苷 | 7-[3,4-Dihydroxy-5-[3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-6-[(3,4,5-trihydroxy-6-methyloxan-2-yl)oxymethyl]oxan-2-yl]oxy-5-hydroxy-2-(3-hydroxy-4-methoxyphenyl)-2,3-dihydrochromen-4-one | 161713-86-6 | C34H44O20 |
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O-[2-乙酰氨基-2-脱氧-3-O-(2-乙酰氨基-2-脱氧-β | GlcNAc beta(1-3)GalNAc-alpha-Thr | 286959-52-2 | C20H35N3O13 |
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BETA-1,3-葡聚糖 | (2S,3R,4S,5R,6R)-2-[(2R,3R,4R,5S)-3,5-dihydroxy-2-(hydroxymethyl)oxan-4-yl]oxy-4-[(2S,3R,5S,6R)-3,5-dihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-6-(hydroxymethyl)oxane-3,5-diol | 9012-72-0 | C18H32O14 |
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ALFHA-酸性蛋白糖 | Glycoprotein | 66455-27-4 | C28H47N5O18 |
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6A-叠氮基-6A-脱氧-β-环糊精 | mono(6-azido-6-deoxy)β-cyclodextrin | 98169-85-8 | C42H69N3O34 |
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3-[3,5-二羟基-6-(羟基甲基)-4-[3,4,5-三羟基-6-(羟基甲基)四氢吡喃-2-基]氧基-四氢吡喃-2-基]氧基-2,4,5,6-四羟基-己醛 | 3-[3,5-Dihydroxy-6-(hydroxymethyl)-4-[3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxyoxan-2-yl]oxy-2,4,5,6-tetrahydroxyhexanal | 3256-04-0 | C18H32O16 |
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2,3,4,5,6,7-六羟基庚醛 | D-glycero-L-gluco-heptose | 23102-92-3 | C7H14O7 |
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—— | L-Glc(a1-4)[L-Glc(a1-6)]L-Glc(a1-4)a-L-Glc | 9005-79-2 | C24H42O21 |
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—— | [(2R,3R,4R,5R,6S)-4,5-dihydroxy-6-[[(1R,3R,4R,5S,8S)-3-[(2R,3S,4R,5R,6S)-5-hydroxy-2-(hydroxymethyl)-6-[[(1R,3S,4R,5S,8S)-3-hydroxy-4-sulfonatooxy-2,6-dioxabicyclo[3.2.1]octan-8-yl]oxy]-3-sulfonatooxyoxan-4-yl]oxy-4-sulfonatooxy-2,6-dioxabicyclo[3.2.1]octan-8-yl]oxy]-2-(hydroxymethyl)oxan-3-yl] sulfate | 9062-07-1 | C24H34O31S4-4 |
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—— | (2S,4S,5S)-2-(4-aminoimidazo[4,5-c]pyridin-1-yl)-5-(hydroxymethyl)oxolane-3,4-diol | 9013-34-7 | C11H14N4O4 |
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—— | (3R,4R,6R)-2-(hydroxymethyl)-6-[(3S,4S,6S)-4,5,6-trihydroxy-2-(hydroxymethyl)oxan-3-yl]oxyoxane-3,4,5-triol | 9005-84-9 | C12H22O11 |
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—— | β-cyclomannin | 7585-39-9 | C42H70O35 |
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—— | β-cyclomannin | 7585-39-9 | C42H70O35 |
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—— | ZINC;1-(5-cyanopyridin-2-yl)-3-[2-(6-fluoro-2-hydroxy-3-propanoylphenyl)cyclopropyl]urea;diacetate | 9000-07-1 | C23H23FN4O7Zn |
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—— | (1S,3R,5R,6S,8R,10R,11S,13R,15R,16S,18R,20R,21S,23R,25R,26S,28R,30R,31S,33R,35R,36R,37R,38R,39R,40R,41R,42R,43R,45R,46R,47R,48R,49R)-5,10,15,20,25,30,35-heptakis(hydroxymethyl)-2,4,7,9,12,14,17,19,22,24,27,29,32,34-tetradecaoxaoctacyclo[31.2.2.23,6.28,11.213,16.218,21.223,26.228,31]nonatetracontane-36,37,38,39,40,41,42,43,44,45,46,47,48,49-tetradecol | 7585-39-9 | (C6H10O5)7 |
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—— | Cellulose triacetate | 9012-09-3 | C40H54O27 |
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—— | (1R,3R,6S,8R,11S,13R,16S,18R,21S,23R,26S,28S,30R,31R,33S,35R,40S,41S,42S,43S,44S,45S,46R,47S,48R,49S)-5,10,15,20,25,30,35-heptakis(2-hydroxypropoxymethyl)-2,4,7,9,12,14,17,19,22,24,27,29,32,34-tetradecaoxaoctacyclo[31.2.2.23,6.28,11.213,16.218,21.223,26.228,31]nonatetracontane-36,37,38,39,40,41,42,43,44,45,46,47,48,49-tetradecol | 128446-35-5 | C63H112O42 |
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—— | 2-[3,5-Dihydroxy-2-(hydroxymethyl)oxan-4-yl]oxy-4-[3,5-dihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-6-(hydroxymethyl)oxane-3,5-diol | 9012-72-0 | C18H32O14 |
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—— | (1S,3R,6S,8R,11S,13R,16S,18R,21S,23R,26S,28R,31S,33R,37S,39S,41S,43S,45S,47S,49S)-5,10,15,20,25,30,35-heptakis(hydroxymethyl)-2,4,7,9,12,14,17,19,22,24,27,29,32,34-tetradecaoxaoctacyclo[31.2.2.23,6.28,11.213,16.218,21.223,26.228,31]nonatetracontane-36,37,38,39,40,41,42,43,44,45,46,47,48,49-tetradecol | 7585-39-9 | C42H70O35 |
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—— | Heparitin sulfate | 9050-30-0 | C14H25NO21S3 |
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—— | Glc4Me(a1-4)a-Glc1Me | 9005-82-7 | C14H26O11 |
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