D-果糖 | 470-23-5

• 分子结构分类: 有机化合物 - 有机氧化合物
• 中文名称: D-果糖
• 中文别名: B-D-呋喃果糖；哌非尼酮；d-呋喃果糖
• 英文名称: D-fructose
• 英文别名: fructose；β-D-fructofuranose；beta-D-fructofuranose；(2R,3S,4S,5R)-2,5-bis(hydroxymethyl)oxolane-2,3,4-triol
• CAS: 470-23-5；53188-23-1
• 化学式: C₆H₁₂O₆
• 分子量: 180.158
• InChiKey: RFSUNEUAIZKAJO-ARQDHWQXSA-N

物化性质

• 沸点：
  440.1±45.0 °C(Predicted)
• 密度：
  1.694±0.06 g/cm3(Predicted)
• 物理描述：
  Solid
• 熔点：
  119-122°C
• 溶解度：
  778 mg/mL at 20 °C

计算性质

• 辛醇/水分配系数(LogP)：
  -2.3
• 重原子数：
  12
• 可旋转键数：
  2
• 环数：
  1.0
• sp3杂化的碳原子比例：
  1.0
• 拓扑面积：
  110
• 氢给体数：
  5
• 氢受体数：
  6

ADMET

代谢

自由果糖直接被小肠吸收。当果糖以蔗糖的形式摄入时，它被消化（分解）然后以自由果糖的形式被吸收。果糖的吸收发生在粘膜膜上，通过涉及GLUT5和GLUT2运输蛋白的促进运输进行。果糖在肝脏中被果糖激酶（Km=0.5 mM）磷酸化。果糖激酶最初产生果糖1-磷酸，后者被醛缩酶B分解产生三糖二羟基醋酸磷酸（DHAP）和甘油醛。DHAP然后转化为甘油-3-磷酸，刺激三酸甘油酯的生成。几乎所有（45%）摄入的纯果糖在3-6小时内被身体用于能量。如果果糖与葡萄糖一起摄入（通常在自然界中是这样），那么在同一时间框架内有高达66%的果糖被用于能量。大约三分之一（29%）到一半（54%）的摄入果糖转化为葡萄糖。不到1%的果糖似乎直接转化为三酸甘油酯。

Free fructose is absorbed directly by the intestine. When fructose is consumed in the form of sucrose, it is digested (broken down) and then absorbed as free fructose. Fructose absorption occurs on the mucosal membrane via facilitated transport involving GLUT5 and GLUT2 transport proteins. Fructose is phosphorylated in the liver by fructokinase (Km= 0.5 mM). Fructokinase initially produces fructose 1-phosphate, which is split by aldolase B to produce the trioses dihydroxyacetone phosphate (DHAP) and glyceraldehyde. DHAP is then converted to glycerol-3-phophate which stimulates production of triglycerides. Nearly half (45%) of all pure fructose consumed is used up within 3-6 hours by the body for energy. If fructose is consumed with glucose (as it typically is in nature), up to 66% of it is used for energy within the same time frame. Roughly a third (29%) to a half (54%) of all fructose consumed is converted to glucose. Less than 1% of fructose appears to be directly converted to triglycerides.

来源:Toxin and Toxin Target Database (T3DB)

毒理性

• 毒性总结

果糖与其他糖类不同，它能够导致细胞内ATP（三磷酸腺苷）的耗竭、核苷酸转换以及尿酸的产生。由于果糖在肝脏中迅速被磷酸化（转变为果糖-1-磷酸），导致自由磷酸和ATP迅速下降。ATP的下降刺激了腺苷单磷酸（AMP）脱氨酶，该酶将AMP脱氨生成次黄嘌呤核苷酸（IMP），随后IMP被转化为尿酸。尿酸通常是一种抗氧化剂，但在血浆中没有足够的抗坏血酸（维生素C）存在时，它就会作为促氧化剂。由于许多使用高果糖玉米糖浆增甜的软饮料和食品中不含维生素C，因此产生的尿酸可能导致包括痛风、慢性炎症、高血压、体重增加、脂肪肝疾病和肥胖等多种有害影响。许多研究已经表明，高尿酸血症与多种代谢和心血管疾病有关，包括糖尿病和冠心病。升高的血清尿酸水平也被证明是高血压和肾疾病发生的最可靠的预测因子，以及脂肪肝疾病。果糖诱导的尿酸生成还会导致线粒体氧化应激，刺激脂肪积累，这与过量的热量摄入无关。几项研究表明，氧化应激是血管、肾、肝细胞和暴露于尿酸的脂肪细胞中最早期观察到的现象之一。高果糖摄入也与肝脏ATP更严重的耗竭有关，这可能会损害肝脏的“能量平衡”。高果糖饮料也被证明会导致循环中的胰岛素和瘦素水平降低，以及胃饥饿素水平升高。由于瘦素和胰岛素可以减少食欲，而胃饥饿素可以增加食欲，一些研究者怀疑大量摄入果糖可能会增加体重增加的可能性。

Fructose is distinct from other sugars in its ability to cause intracellular ATP depletion, nucleotide turnover, and the generation of uric acid. Uric acid is generated via fructose due to its rapid phosphorylation (to fructose-1-phosphate) in the liver, leading to a rapid drop in free phosphate and ATP. This drop in ATP leads to the stimulation of adenosine monophosphate (AMP) deaminase which deaminates AMP to produce IMP, which is subsequently converted to uric acid (A15346). Uric acid is normally an anti-oxidant but without sufficient amounts of ascorbic acid (vitamin C) present in the plasma, it functions as a pro-oxidant. Because many soft drinks and foods that are sweetened with high fructose corn syrup do not contain vitamin C, the resulting uric acid can lead to a number of harmful effects, including gout, chronic inflammation, hypertension, increased adiposity, fatty liver disease and obesity (A15346). Many studies have shown that elevated uric acid levels are associated with several metabolic and cardiovascular conditions, including diabetes and coronary artery disease (A15346). Elevated serum uric acid has also been shown to be the most reliable predictor for the development of hypertension and incident renal disease (A15347) as well as fatty liver disease (A15348). Fructose-induced uric acid generation also causes mitochondrial oxidative stress that stimulates fat accumulation independent of excessive caloric intake (A15349). Several studies have demonstrated that oxidative stress is one of the earliest phenomena observed in vascular, renal, liver cells and adipocytes exposed to uric acid (A15347). High fructose consumption is also associated with more severe depletion of liver ATP, which may impair liver "energy balance”. High-fructose beverages have also been shown to lead to lower circulating insulin and leptin levels, and higher ghrelin levels. Since leptin and insulin decrease appetite and ghrelin increases appetite, some researchers suspect that eating large amounts of fructose increases the likelihood of weight gain.

来源:Toxin and Toxin Target Database (T3DB)

毒理性

• 致癌物分类

对人类不具有致癌性（未被国际癌症研究机构IARC列名）。

No indication of carcinogenicity to humans (not listed by IARC).

来源:Toxin and Toxin Target Database (T3DB)

毒理性

• 健康影响

果糖或高果糖玉米糖浆的急性摄入基本上是无毒的。长期的过量果糖摄入已被证明是痛风、胰岛素抵抗、高血压、肥胖、脂肪肝疾病、LDL胆固醇升高和甘油三酯升高的原因（或间接原因），从而导致代谢综合征。在Wistar大鼠（一种糖尿病的实验室模型）中，与10%葡萄糖喂养相比，10%果糖喂养被发现可以使血液甘油三酯水平增加86%，而相同量的葡萄糖对甘油三酯没有影响。2008年的一项研究发现，摄入果糖或富含果糖的食物与痛风发作有显著的相关风险。人们怀疑软饮料（例如碳酸饮料）和其他加糖饮料中发现的果糖是这种增加发病率的主要原因。

Acute consumption of fructose or high fructose corn syrup is essentially non-toxic. Chronic, excess fructose consumption has been shown to be a cause (or indirect cause) of gout, insulin resistance, hypertension, obesity, fatty liver disease, elevated LDL cholesterol and elevated triglycerides, leading to metabolic syndrome. In Wistar rats, a laboratory model of diabetes, 10% fructose feeding as opposed to 10% glucose feeding was found to increase blood triglyceride levels by 86%, whereas the same amount of glucose had no effect on triglycerides. A 2008 study found a substantial risk of incident gout associated with the consumption of fructose or fructose-rich foods. It is suspected that the fructose found in soft drinks (e.g., carbonated beverages) and other sweetened drinks is the primary reason for this increased incidence.

来源:Toxin and Toxin Target Database (T3DB)

毒理性

• 暴露途径

摄取

Ingestion

来源:Toxin and Toxin Target Database (T3DB)

毒理性

• 毒性数据

每天摄入超过100克纯果糖可能会导致体重每周适度但统计学上显著地增加0.44公斤。每天摄入100克或更多的果糖还会显著提高空腹血清甘油三酯水平。 LD50：15000毫克/千克（静脉注射，兔）

Consuming more than 100 g a day of pure fructose may lead to a modest but statistically significant rise in body weight of 0.44 kg a week. Consuming 100 g or more of fructose a day also significantly increases fasting levels of serum triglycerides. LD50: 15000 mg/kg (intravenous, rabbit)

来源:Toxin and Toxin Target Database (T3DB)