monosodium glutamate | 32221-81-1

• 物质功能分类: 食品添加剂 - 增味剂
• 分子结构分类: 有机化合物 - 有机酸及其衍生物 - 羧酸及其衍生物
• 英文名称: monosodium glutamate
• 英文别名: sodium glutamate；MSG；Sodium;2-azaniumylpentanedioate
• CAS: 32221-81-1
• 化学式: C₅H₈NO₄*Na
• 分子量: 169.113
• InChiKey: LPUQAYUQRXPFSQ-UHFFFAOYSA-M

物化性质

• 溶解度：
  Soluble in water and alcohol, not in oils
• 物理描述：
  Monosodium glutamate appears as white or off-white crystalline powder with a slight peptone-like odor. pH (0.2% solution)7.0. (NTP, 1992)
• 颜色/状态：
  White free flowing crystals or crystalline powder
• 气味：
  Practically odorless
• 味道：
  Meaty taste comes from contaminants in crude glutamates; sweet-saline taste in large concn; no flavor in small quantity
• 沸点：
  225 °C (decomposes)
• 熔点：
  450 °F (Decomposes) (NTP, 1992)
• 密度：
  26.2 (saturated water solution at 20 °C)
• 旋光度：
  Specific optical rotation: +24.2 to +25.5 deg at 25 °C/D (concn = 8.0 g in 100 mL 1.0 N hydrochloric acid)
• 分解：
  When heated to decomposition it emits toxic fumes of oxides of /nitrogen and sodium oxide/.
• 稳定性/保质期：
  | 稳定性 | 不与强氧化剂兼容 | 注：这里的“|”用于分隔字段，实际使用时可以根据具体需求调整。

计算性质

• 辛醇/水分配系数(LogP)：
  -6.29
• 重原子数：
  11
• 可旋转键数：
  2
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.6
• 拓扑面积：
  106
• 氢给体数：
  2
• 氢受体数：
  5

ADMET

代谢

谷氨酸在组织中通过氧化脱氨代谢...或者通过与丙酮酸进行转氨作用产生草酸乙酸...然后通过α-酮戊二酸进入柠檬酸循环...。谷氨酸代谢的量虽然较少，但在生理上重要的途径包括脱羧生成γ-氨基丁酸（GABA）和酰胺化生成谷氨酰胺...。脱羧生成GABA依赖于吡哆醛磷酸，它是谷氨酸脱羧酶的辅酶...，谷氨酸转氨酶也是如此。维生素B6缺乏的大鼠血清谷氨酸水平升高，谷氨酸清除延迟...。/谷氨酸/

Glutamic acid is metabolized in the tissues by oxidative deamination ... or by transamination with pyruvate to yield oxaloacetic acid ... which, via alpha-ketoglutarate, enters the citric acid cycle ... .. Quantitatively minor but physiologically important pathways of glutamate metabolism involve decarboxylation to gamma-aminobutyrate (GABA) and amidation to glutamine ... . Decarboxylation to GABA is dependent on pyridoxal phosphate, a coenzyme of glutamic acid decarboxylase ..., as is glutamate transaminase. Vitamin B6-deficient rats have elevated serum glutamate levels and delayed glutamate clearance ... . /Glutamic acid/

来源:Hazardous Substances Data Bank (HSDB)

代谢

口服给大鼠1克/千克的谷氨酸钠后，仅观察到血浆焦谷氨酸水平的小幅上升。在这些条件下，没有观察到焦谷氨酸或谷氨酸在大脑水平上的增加。

Oral dose of 1 g/kg monosodium glutamate given to rats was followed by only a small rise in plasma pyroglutamate levels. No incr of pyroglutamate or glutamate brain levels was observed under these conditions.

来源:Hazardous Substances Data Bank (HSDB)

代谢

谷氨酸在组织中通过氧化脱氨代谢...或者通过丙酮酸的转氨作用产生草酸乙酸...后者通过α-酮戊二酸进入柠檬酸循环...。谷氨酸代谢的量虽然较少，但在生理上重要的途径包括脱羧生成γ-氨基丁酸（GABA）和酰胺化生成谷氨酰胺...。脱羧生成GABA依赖于吡哆醛磷酸，它是谷氨酸脱羧酶的辅酶...，谷氨酸转氨酶也是如此。维生素B6缺乏的大鼠血清谷氨酸水平升高，谷氨酸清除延迟...。/谷氨酸/

Glutamic acid is metabolized in the tissues by oxidative deamination ... or by transamination with pyruvate to yield oxaloacetic acid ... which, via alpha-ketoglutarate, enters the citric acid cycle ... .. Quantitatively minor but physiologically important pathways of glutamate metabolism involve decarboxylation to gamma-aminobutyrate (GABA) and amidation to glutamine ... . Decarboxylation to GABA is dependent on pyridoxal phosphate, a coenzyme of glutamic acid decarboxylase ..., as is glutamate transaminase. Vitamin B6-deficient rats have elevated serum glutamate levels and delayed glutamate clearance ... . /Glutamic acid/

来源:Hazardous Substances Data Bank (HSDB)

代谢

口服给大鼠1克/千克的谷氨酸钠仅导致血浆焦谷氨酸水平的小幅上升。在这些条件下，没有观察到焦谷氨酸或谷氨酸在大脑水平上的增加。

Oral dose of 1 g/kg monosodium glutamate given to rats was followed by only a small rise in plasma pyroglutamate levels. No incr of pyroglutamate or glutamate brain levels was observed under these conditions.

来源:Hazardous Substances Data Bank (HSDB)

毒理性

• 相互作用

在腹腔内注射10天的味精（MSG）剂量为4毫克/克体重，在大鼠的肝脏、肾脏和大脑中显著增加了丙二醛（MDA）的形成。同时给予维生素C、维生素E和槲皮素给MSG处理的大鼠，显著减少了由MSG引起的MDA增加。维生素E主要在肝脏减少脂质过氧化，其次是维生素C，然后是槲皮素，而维生素C和槲皮素在保护大脑免受膜损伤方面比维生素E表现出更大的能力。MSG在三个器官中引起的谷胱甘肽（GSH）水平下降与谷胱甘肽-S-转移酶（GST）活性的显著增加相对应。虽然MSG在肝脏中增加了超氧化物歧化酶和过氧化氢酶的活性（p < 0.001），但在肾脏和大脑中显著降低了这些酶的活性。这三种抗氧化剂有效地改善了MSG对三个器官中GSH水平和酶的影响。虽然MSG在大鼠的肝脏和肾脏中增加了葡萄糖-6-磷酸酶的活性（p < 0.001），但大脑中的酶活性极低。在用MSG处理的大鼠中，丙氨酸转氨酶、天冬氨酸转氨酶和γ-谷氨酰转移酶的活性显著增加。测试的抗氧化剂显著保护了免受MSG诱导的肝脏毒性。剂量为4毫克/克的MSG显著（p < 0.01）诱导了微核多色红细胞（MNPCEs）的形成。同时给予维生素C和槲皮素的大鼠，抑制了MSG诱导的MNPCEs的形成（p < 0.001）...

Monosodium glutamate (MSG) administered intraperitoneally /for 10 days/ at a dose of 4 mg/g bw markedly increase malondialdehyde (MDA) formation in the liver, the kidney and brain of rats. Simultaneous administration of VIT C, VIT E and quercetin to MSG-treated rats significantly reduced this increase in MDA induced by MSG. VIT E reduced lipid peroxidation mostly in the liver followed by VIT C and then quercetin, while VIT C and quercetin showed a greater ability to protect the brain from membrane damage than VIT E. The decreased glutathione (GSH) level elicited by MSG in the three organs corresponded with marked increase in the activity of glutathione-S-transferase (GST). While MSG increased (p < 0.001) the activities of superoxide dismutase and catalase in the liver, it decreased significantly the activities of these enzymes in the kidney and the brain. The three antioxidants were effective at ameliorating the effects of MSG on GSH levels and the enzymes in the three organs examined. While MSG increased the activity of glucose-6-phosphatase in the liver and kidneys of rats (p < 0.001), the activity of the enzyme was abysmally low in the brain. There were marked increases in the activities of alanine aminotransferase, aspartate aminotransferase and gamma-glutamyl transferase in rats treated with MSG. The antioxidants tested protected against MSG-induced liver toxicity significantly. MSG at a dose of 4 mg/g significantly (p < 0.01) induced the formation of micronucleated polychromatic erythrocytes (MNPCEs). Co-treatment of rats with VIT C and quercetin inhibited the induction of MNPCEs by MSG (p < 0.001) ...

来源:Hazardous Substances Data Bank (HSDB)

毒理性

• 毒性总结

谷氨酸及其铵盐、钙盐、单钠盐和钾盐在1988年由联合粮农组织/世界卫生组织食品添加剂专家委员会（JECFA）进行了评估。委员会注意到，只有在通过灌胃给予极高剂量（>30mg/kg体重）后，肠道和肝脏的代谢才会导致系统性循环中水平的升高。摄入单钠谷氨酸（MSG）并未与母体乳汁中水平升高有关，谷氨酸也没有轻易通过胎盘屏障。人类婴儿对谷氨酸的代谢与成人相似。使用MSG通过饮食给药进行的常规毒性研究，在多个物种中并未揭示任何特定的毒性或致癌作用，也没有在生殖和畸胎学研究中发现任何不良结果。注意到在通过注射给药或作为灌胃给予极高剂量的结果，在几个物种中产生了中枢神经系统损伤。比较研究表明，新生小鼠对神经元损伤最为敏感；年长的动物和其他物种（包括灵长类）则较不敏感。即使在饮用水中一次性给予10克MSG的剂量，人类血液中的谷氨酸水平也未达到与新生小鼠下丘脑损伤相关的水平。由于人类研究未能证实MSG与“中国餐馆综合症”或其他特异不耐性有关，JECFA为谷氨酸及其盐类分配了“未指定可接受日摄入量（ADI）”。对婴儿没有表明额外的风险。欧洲委员会的科学委员会（SCF）在1991年得出了类似的评估。美国实验生物学联合会（FASEB）和联邦药品管理局（FDA）随后的审查结论并未排除敏感亚群体的存在，但其他方面则与JECFA和SCF的安全性评估一致。

L-Glutamic acid and its ammonium, calcium, monosodium and potassium salts were evaluated by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in 1988. The Committee noted that intestinal and hepatic metabolism results in elevation of levels in systemic circulation only after extremely high doses given by gavage (>30mg/kg body weight). Ingestion of monosodium glutamate (MSG) was not associated with elevated levels in maternal milk, and glutamate did not readily pass the placental barrier. Human infants metabolized glutamate similarly to adults. Conventional toxicity studies using dietary administration of MSG in several species did not reveal any specific toxic or carcinogenic effects nor were there any adverse outcomes in reproduction and teratology studies. Attention was paid to central nervous system lesions produced in several species after parenteral administration of MSG or as a consequence of very high doses by gavage. Comparative studies indicated that the neonatal mouse was most sensitive to neuronal injury; older animals and other species (including primates) were less so. Blood levels of glutamate associated with lesions of the hypothalamus in the neonatal mouse were not approached in humans even after bolus doses of 10 g MSG in drinking water. Because human studies failed to confirm an involvement of MSG in "Chinese Restaurant Syndrome" or other idiosyncratic intolerance, the JECFA allocated an "acceptable daily intake (ADI) not specified" to glutamic acid and its salts. No additional risk to infants was indicated. The Scientific Committee for Food (SCF) of the European Commission reached a similar evaluation in 1991. The conclusions of a subsequent review by the Federation of American Societies for Experimental Biology (FASEB) and the Federal Drug Administration (FDA) did not discount the existence of a sensitive subpopulation but otherwise concurred with the safety evaluation of JECFA and the SCF.

来源:Hazardous Substances Data Bank (HSDB)

毒理性

• 解毒与急救

/SRP 特异性反应/：没有报告去污措施。不存在解毒剂。支持性措施：如果胸痛持续，进行心电图和心脏评估。提醒患者避免食用含有MSG（味精）的食物。

/SRP Idiosyncratic reaction/: No decontamination measures have been reported. No antidotes exist. Supportive measures: Follow with ECG and cardiac evaluation if chest pain persists. Alert patient to avoid foods with MSG.

来源:Hazardous Substances Data Bank (HSDB)

毒理性

• 人类毒性摘录

人类暴露研究/ ... 在6名健康对照和30名哮喘患者（7名：过敏性哮喘；15名：阿司匹林不耐受的内在性哮喘；8名：阿司匹林不耐受、酒精或食物添加剂不耐受的内在性哮喘）中测试了2.5克的高剂量。两名患者在摄入后6至10小时出现轻度支气管痉挛。讨论了不同的机制。可能涉及胆碱能机制，要么是由于乙酰胆碱合成的刺激，要么是由于反流性食管炎引起的迷走神经反射。然而，似乎需要高迷走神经高反应性才能发生哮喘。结论是，如果摄入高剂量，极少数内在性哮喘患者可能会对单钠谷氨酸不耐受。

/HUMAN EXPOSURE STUDIES/ ... A high dose of 2.5 g was tested in 6 healthy controls and 30 asthmatics (7: allergic asthma; 15: intrinsic asthma with intolerance to aspirin; 8: intrinsic asthma with aspirin intolerance, intolerance to alcohol or to food additives). Two patients presented with a mild bronchospasm, occurring 6 to 10 hours after the ingestion. Different mechanisms are discussed. A cholinergic mechanism might be incriminated, either due to stimulation of the synthesis of acetylcholine, or due to a vagal reflex elicited by a reflux esophagitis. However, a high vagal hyperreactivity seems to be needed for the occurrence of asthma. It is concluded that a very small subset of patients with intrinsic asthma might present with an intolerance to monosodium glutamate if high doses are consumed.

来源:Hazardous Substances Data Bank (HSDB)

毒理性

• 人类毒性摘录

/人类暴露研究/ 被广泛认为是“中国餐馆综合症”的诱因，其中潮红被认为是反应的一部分。六名受试者通过激光多普勒流速仪监测了面部皮肤血流量的变化，挑战单钠谷氨酸及其环化产物焦谷氨酸。此外，还查阅了在实验室接受单钠谷氨酸挑战的患者的记录。在测试的二十四人中，没有引起潮红，其中十八人曾有过中国餐馆综合症潮红的历史。这些结果表明，如果单钠谷氨酸引起的潮红确实存在，也一定很罕见。单钠谷氨酸及其环化产物焦谷氨酸可能会引起水肿和相关的症状。

/HUMAN EXPOSURE STUDIES/ Monosodium glutamate is widely regarded as the provocative agent in the "Chinese restaurant syndrome," of which flushing is regarded as part of the reaction. Six subjects were monitored by laser Doppler velocimetry for changes in facial cutaneous blood flow during challenge with monosodium glutamate and its cyclization product, pyroglutamate. Additionally, records of patients challenged with monosodium glutamate in the laboratory were reviewed. No flushing was provoked among the twenty four people tested, eighteen of whom gave a positive history of Chinese restaurant syndrome flushing. These results indicate that monosodium glutamate provoked flushing, if it exists at all, must be rare. Monosodium glutamate and its cyclization product, pyroglutamate, may provoke edema and associated symptoms.

来源:Hazardous Substances Data Bank (HSDB)

吸收、分配和排泄

谷氨酸通过一种对氨基酸特异性的主动转运系统从肠道吸收。这一过程是可饱和的，可以被竞争性抑制，并且依赖于钠离子浓度...在肠道吸收过程中，大量谷氨酸发生转氨作用，因此门静脉血液中的丙氨酸水平升高。如果摄入大量的谷氨酸，门静脉谷氨酸水平会增加...这种升高导致肝脏对谷氨酸的代谢增加，从而释放出葡萄糖、乳酸、谷氨酰胺和其他氨基酸到系统循环中...谷氨酸的药代动力学取决于它是自由的还是结合在蛋白质中，以及是否存在其他食物成分。肠道腔内和刷状缘的蛋白质消化产生小肽和氨基酸的混合物；二肽和三肽可能进入吸收细胞，在细胞内发生水解，释放更多的氨基酸。已知氨基酸和肽的转运存在缺陷...饮食蛋白质中的谷氨酸，连同分泌到肠道中的内源蛋白质，被消化成自由的氨基酸和小肽，这些都被吸收到粘膜细胞中，其中肽被水解成自由的氨基酸，并且一些谷氨酸被代谢。过量的谷氨酸和其他氨基酸出现在门静脉血液中。由于肠道粘膜细胞和肝脏中谷氨酸的快速代谢，即使摄入大量的饮食蛋白质，系统血浆水平也保持低。/谷氨酸/

Glutamate is absorbed from the gut by an active transport system specific for amino acids. This process is saturable, can be competitively inhibited, and is dependent on sodium ion concentration... . During intestinal absorption, a large proportion of glutamic acid is transaminated and consequently alanine levels in portal blood are elevated. If large amounts of glutamate are ingested, portal glutamate levels increase ... . This elevation results in increased hepatic metabolism of glutamate, leading to release of glucose, lactate, glutamine, and other amino acids, into systemic circulation ... . The pharmacokinetics of glutamate depend on whether it is free or incorporated into protein, and on the presence of other food components. Digestion of protein in the intestinal lumen and at the brush border produces a mixture of small peptides and amino acids; di-and tri-peptides may enter the absorptive cells where intracellular hydrolysis may occur, liberating further amino acids. Defects are known in both amino acid and peptide transport ... .. Glutamic acid in dietary protein, together with endogenous protein secreted into the gut, is digested to free amino acids and small peptides, both of which are absorbed into mucosal cells where peptides are hydrolyzed to free amino acids and some of the glutamate is metabolized. Excess glutamate and other amino acids appear in portal blood. As a consequence of the rapid metabolism of glutamate in intestinal mucosal cells and in the liver, systemic plasma levels are low, even after ingestion of large amounts of dietary protein. /Glutamic acid/

来源:Hazardous Substances Data Bank (HSDB)

吸收、分配和排泄

肠道和肝脏代谢导致仅在通过灌胃给予极高剂量（>30mg/kg体重）后，系统循环中的水平才会升高。摄入单钠谷氨酸（MSG）与母体乳汁中水平升高无关，谷氨酸不易通过胎盘屏障。人类婴儿对谷氨酸的代谢方式与成人相似。

... Intestinal and hepatic metabolism results in elevation of levels in systemic circulation only after extremely high doses given by gavage (>30mg/kg body weight). Ingestion of monosodium glutamate (MSG) was not associated with elevated levels in maternal milk, and glutamate did not readily pass the placental barrier. Human infants metabolized glutamate similarly to adults.

来源:Hazardous Substances Data Bank (HSDB)

吸收、分配和排泄

口服药理上高剂量的谷氨酸会导致血浆水平升高。血浆中谷氨酸的峰值水平既取决于剂量也取决于浓度……当相同剂量（1克/千克体重）的谷氨酸钠（MSG）通过灌胃的方式以水溶液给予新生大鼠时，将浓度从2%增加到10%会导致血浆下曲线面积增加五倍；在 mice中也观察到了类似的结果……相反，当MSG（1.5克/千克体重）以2%至20% w/v的不同浓度通过灌胃给予43天大的小鼠时，无法建立血浆水平与浓度之间的相关性……

Oral administration of pharmacologically high doses of glutamate results in elevated plasma levels. The peak plasma glutamate levels are both dose and concentration dependent ... . When the same dose (1 g/kg b.w.) of monosodium glutamate (MSG) was administered by gavage in aqueous solution to neonatal rats, increasing the concentration from 2% to 10% caused a five-fold increase in the plasma area under curve; similar results were observed in mice ... . Conversely, when MSG (1.5 g/kg b.w.) was administered to 43-day-old mice by gavage at varying concentrations of 2 to 20% w/v, no correlation could be established between plasma levels and concentration ...

来源:Hazardous Substances Data Bank (HSDB)

吸收、分配和排泄

按照每千克体重1克的标准剂量，通过灌胃给予10% w/v的MSG溶液，导致所有研究物种的血浆谷氨酸水平显著升高。在大鼠中，血浆谷氨酸的峰值水平最低（为禁食水平的6倍），而在小鼠中最高（为禁食水平的12-35倍）。在新生动物和成年动物之间观察到了与年龄相关的差异；在小鼠和大鼠中，婴儿的血浆谷氨酸峰值水平和曲线下面积高于成年动物，而在豚鼠中则观察到相反的情况。

Administration of a standard dose of 1 g/kg b.w. MSG by gavage as a 10% w/v solution resulted in a marked increase of plasma glutamate in all species studied. Peak plasma glutamate levels were lowest in adult monkeys (6 times fasting levels) and highest in mice (12-35 times fasting levels). Age-related differences between neonates and adults were observed; in mice and rats, peak plasma levels and area under curve were higher in infants than in adults while in guinea pigs the converse was observed.

来源:Hazardous Substances Data Bank (HSDB)

吸收、分配和排泄

谷氨酸通过一种对氨基酸特异性的主动转运系统从肠道吸收。这一过程是可饱和的，可以被竞争性抑制，并且依赖于钠离子浓度……在肠道吸收过程中，大量谷氨酸发生转氨作用，因此门脉血液中的丙氨酸水平升高。如果摄入大量的谷氨酸，门脉血液中的谷氨酸水平会升高……这种升高导致肝脏对谷氨酸的代谢增加，进而释放葡萄糖、乳酸、谷氨酰胺和其他氨基酸进入系统循环……谷氨酸的药代动力学取决于它是自由的还是结合在蛋白质中，以及是否存在其他食物成分。肠道腔内和刷状缘的蛋白质消化产生小肽和氨基酸的混合物；二肽和三肽可能进入吸收细胞，在细胞内发生水解，释放更多的氨基酸。已知氨基酸和肽的运输存在缺陷……膳食蛋白质中的谷氨酸以及分泌到肠道中的内源性蛋白质被消化成自由的氨基酸和小肽，这些都被吸收进入粘膜细胞，其中肽被水解成自由的氨基酸，部分谷氨酸被代谢。过量的谷氨酸和其他氨基酸出现在门脉血液中。由于肠道粘膜细胞和肝脏中谷氨酸的快速代谢，即使摄入大量膳食蛋白质后，系统血浆水平仍然较低。/谷氨酸/

Glutamate is absorbed from the gut by an active transport system specific for amino acids. This process is saturable, can be competitively inhibited, and is dependent on sodium ion concentration... . During intestinal absorption, a large proportion of glutamic acid is transaminated and consequently alanine levels in portal blood are elevated. If large amounts of glutamate are ingested, portal glutamate levels increase ... . This elevation results in increased hepatic metabolism of glutamate, leading to release of glucose, lactate, glutamine, and other amino acids, into systemic circulation ... . The pharmacokinetics of glutamate depend on whether it is free or incorporated into protein, and on the presence of other food components. Digestion of protein in the intestinal lumen and at the brush border produces a mixture of small peptides and amino acids; di-and tri-peptides may enter the absorptive cells where intracellular hydrolysis may occur, liberating further amino acids. Defects are known in both amino acid and peptide transport ... .. Glutamic acid in dietary protein, together with endogenous protein secreted into the gut, is digested to free amino acids and small peptides, both of which are absorbed into mucosal cells where peptides are hydrolyzed to free amino acids and some of the glutamate is metabolized. Excess glutamate and other amino acids appear in portal blood. As a consequence of the rapid metabolism of glutamate in intestinal mucosal cells and in the liver, systemic plasma levels are low, even after ingestion of large amounts of dietary protein. /Glutamic acid/

来源:Hazardous Substances Data Bank (HSDB)

安全信息

• 海关编码：
  2103901000

制备方法与用途

化学性质

谷氨酸钠是一种白色棱柱形结晶或结晶性粉末，无特殊气味，但具有独特的肉类鲜味。其相对密度为1.635，熔点为195℃，填充比容为1.20。该物质易溶于水，5%的水溶液pH值在6.7-7.2之间，难溶于乙醇和乙醚。谷氨酸钠不吸潮，在120℃开始失去结晶水，当温度达到150-160℃时会分子内脱水生成焦谷氨酸钠，从而丧失鲜味；约270℃下分解成吡咯。

小白鼠口服的LD₅₀值为16.2g/kg，根据FAO/WHO（1994）的规定，其ADI无需特别规定。

用途

谷氨酸钠是国内外应用最广泛的鲜味剂之一。它与食盐共存时可增强其呈味作用，并且当与5’-肌苷酸钠或5’-鸟苷酸钠一起使用时，会产生更佳的效果。中国食品添加剂法规允许按生产需要适量在各类食品中添加。

用途

谷氨酸钠也可用作食品调味剂。

生产方法

目前国内外普遍采用以大米、淀粉或糖蜜为原料，通过糖化、发酵、提取和精制等工序制成谷氨酸钠。具体过程如下：

1. 淀粉的糖化：使用双酶法。将浸泡后的大米砂磨成相对密度1.11（14°Bé）的淀粉浆，在pH 4.5，90℃条件下加入α-淀粉酶液化15-20分钟，然后升温至100℃灭酶5分钟；滤渣可用作饲料。将滤液调整为pH 5.0，再加入β-淀粉酶于60℃糖化12小时后升温至100℃灭酶并冷却澄清。上层清液直接放入糖液贮槽，沉淀液加硅藻土助滤后压滤，淀粉糖转化率可达92%。

2. 谷氨酸发酵：以15%左右的葡萄糖为碳源，并加入适量无机盐和生物素作为发酵培养基。冷却至40℃后送入灭菌罐中接种经过二级扩大培养的谷氨酸产生菌，利用流加液氨作为氮源进行通风发酵30小时，糖酸转化率可达50%，产酸水平约7.0%-7.5%。发酵过程中pH控制在7.0-7.2之间，温度前期保持在32-34℃，后期升至34-37℃。

3. 谷氨酸的提取：通常采用冷冻等电-离子交换法。将发酵液在等电罐中一边用冷冻盐水缓慢搅拌并冷却降温至5℃，一边用硫酸调pH值至3.22（等电点）。沉淀8小时后离心分离得到粗谷氨酸；母液和上层清液混合后再上离子交换树脂交换，并用氨水脱洗。前流分汇入清液重新上柱，后流分与氨水一起作为洗脱液。高流分与发酵液一并回等电罐，提取率可达88%-90%。

4. 谷氨酸精制：在60-65℃底水的中和罐中加入粗谷氨酸，并搅拌。缓慢加入纯碱溶液直至pH值达到6.2-6.4之间，控制中和液浓度为相对密度1.17-1.18（21-22°Bé）。待中和液降温至50℃以下时添加适量硫化钠溶液去除铁离子。然后用粗谷氨酸回调pH值到6.2-6.4并升温至60℃，加入粉末活性炭搅拌0.5小时后送入压滤机过滤。再将滤液通过颗粒活性炭柱二次脱色得到清液。清液送入真空煮晶锅中在60-70℃下蒸发浓缩到相对密度1.28（31.5°Bé），加入0.36-0.542mm的晶种继续结晶过程，期间需用热水杀晶并补加一定量清液。放料后经育晶槽离心分离得结晶味精，母液或通过脱色后再蒸发结晶，最终收率可达理论值的92%。

反应信息

• 作为反应物：
  描述：

  monosodium glutamate 以94%的产率得到
  参考文献：
  名称：

  MIXAJLOV, VENTSEL GEORGIEV;ZAXARIEVA, ANI TSVETKOVA;ZAXARIEV, OGNYAN IVAN+

  摘要：

  DOI：
• 作为产物：
  描述：

  monosodium L-glutamate 在 吡哆醛 sodium hydroxide 、 borate buffer 、 copper(II) sulfate 作用下， 以 乙醇 、 水 为溶剂， 反应 188.0h， 以84%的产率得到monosodium glutamate
  参考文献：
  名称：

  CATALYTIC POTENCY OF FUNCTIONALIZED (2,5)PYRIDINOPHANES AS NEW PYRIDOXAL MODEL COMPOUNDS

  摘要：

  结果表明，新的模型化合物 1a-c、2 和 3 对 l-谷氨酸钠消旋化的催化活性比吡哆醛强约 1.5 倍，而且催化剂 1a 足够稳定，在整个反应过程中没有出现分解现象。

  DOI：

  10.1246/cl.1981.5
• 作为试剂：
  描述：

  ammonium perrhenate 、 四聚甘胺酸 在 盐酸 、 monosodium glutamate 、 tin(ll) chloride 作用下， 以 水 为溶剂， 反应 3.5h， 以73%的产率得到
  参考文献：
  名称：

  ^99mTc SPECT imaging agent based on cFLFLFK for the detection of FPR1 in inflammation

  摘要：

  FPR1拮抗剂cFLFLFK与四甘氨酸螯合物结合，并用^99mTc标记。体外结合实验表明，化合物^99mTc.cFLFLFK是一种用于无创白细胞招募成像的有用工具。

  DOI：

  10.1039/c4dt02980a

文献信息

• 一种氨基酸型螯合剂及其规模化制造方法和应用
  申请人：南京华狮新材料有限公司

  公开号：CN109912440A

  公开（公告）日：2019-06-21

  本发明提供了一种工业大规模生产可降解的氨基酸型螯合剂组合物及其制备的方法，水溶液中，氨基酸、卤代乙酸和碱在碘化物催化剂的作用下，调节pH值范围为8～13，在反应温度为40℃至120℃条件下反应，反应结束后得到氨基酸型螯合剂组合物。该方法具有安全、高效、杂质较少、无放大效应极易实现规模化大生产的特点；原材料易得，反应收率高；所得的产品，具有更好的应用性能。本发明还提供了该组合物作为螯合剂在日用化学品、食品、农业、林业、造纸、纺织、印染、水处理、煤炭等领域的应用。
• Catalytic transfer hydrogenation and anticancer activity of arene–ruthenium compounds incorporating bi-dentate precursors
  作者：Yu-Hsiang Chang、Wohn-Jenn Leu、Amitabha Datta、Hung-Chang Hsiao、Chia-Her Lin、Jih-Hwa Guh、Jui-Hsien Huang

  DOI：10.1039/c5dt01310k

  日期：——

  (η6-cymene)RuCl[C4H3N(2-CH2NHtBu)]} (3), (η6-cymene)RuCl[C4H3N(2-CHNCH2Ph)]} (4), (η6-cymene)RuClC4H3N[2-CHNCH2(C4H7O)]}} (5) and (η6-cymene)RuCl[C4H3N(2-CHnBuNHCH2(C4H7O))]} (7). To the best of our knowledge, the aforementioned Ru compounds are not only characterized by 1H and 13C NMR spectroscopy, but for the first time their structures have been established by single crystal X-ray diffractometry

  钌基有机金属化合物目前作为抗癌药物受到广泛关注，并且似乎在肿瘤细胞上表现良好。我们开发了一系列包含N，O和N，N二齿配体的单核芳烃-钌化合物，并研究了它们作为抗癌药物对人激素难治性转移性前列腺癌（HRMPCs）细胞系的活性。钌化合物在–C O–→–CH（OH）–体系的转移加氢中也起有效催化剂的作用。三种类型的配体，即，谷氨酸钠，C 4 H ^ 3 NH（2-CH 2 NH吨丁基），和C 4 H ^ 3 NH（2-CH NR）分别加上[（η 6-cymene）的RuCl 2 ] 2（1）（甲基异丙基苯= 4- isopropyltoluene）以合成5的Ru-衍生物：[（η 6 -cymene）的RuCl（κ 2 - Ñ，ö -OOCCHNH 2 CH 2 CH 2 COOH）]（2）（η 6 -cymene）的RuCl [C 4 H ^ 3 N（2-CH 2 NH吨丁基）]}（3），（η
• [EN] CRYSTALLINE PARTICLES OF SALTS OF GLUTAMIC ACID N,N-DIACETIC ACID<br/>[FR] PARTICULES CRISTALLINES DE SELS DE L'ACIDE GLUTAMIQUE-N,N-DIACÉTIQUE
  申请人：AKZO NOBEL CHEMICALS INT BV

  公开号：WO2014090943A1

  公开（公告）日：2014-06-19

  The invention relates to a salt of glutamic acid-N,N-diacetic acid (GLDA) of the formula GLDA-YmHn, wherein m is equal to or more than 0.5 and lower than or equal to 2.5, n +m = 4, and wherein Y is a monovalent cation that is not a proton, comprising L-GLDA-YmHn to D-GLDA-YmHn in a range between 100:0 and 50:50 (L:D), characterized in that the salt is crystalline, a process to make such crystalline salt, and to uses of such salt, such as, in particular, in detergent compositions.

  该发明涉及谷氨酸-N，N-二乙酸盐（GLDA）的盐GLDA-YmHn，其中m等于或大于0.5且小于或等于2.5，n + m = 4，Y是一个不是质子的一价阳离子，包括L-GLDA-YmHn到D-GLDA-YmHn在100:0到50:50（L:D）范围内，其特征在于盐是结晶的，制备这种结晶盐的过程，以及这种盐的用途，特别是在洗涤剂组合物中。
• Synthesis, Characterization and Antibacterial Activity of Binuclear Chromium(II) Complexes of New Schiff Base Ligand Derived from Amino Acids
  作者：Voguri Haranath Babu、Anna Venkateswara Rao、Ashok More

  DOI：10.14233/ajchem.2019.21586

  日期：——

  Eight chromium(II) complexes of type, [Cr(L)(H2O)x]·xH2O (where L= Schiff base ligand) have been synthesized and characterized on the basis of elemental analysis IR, 1H, 13C NMR, mass and electronic spectroscopy, magnetic and conductance measurements. The amino acid schiff base ligand behaved as a octadentate ligand. The probable structures of the chromium(II) complexes have been elucidated and also the chromium(II) complexes were screened for antibacterial activity, which showed a moderate to good activity against Gram-positive and Gram-negative bacteria.

  根据元素分析、红外光谱、1H、13C NMR、质谱和电子能谱、磁性和电导测量，合成了八种[Cr(L)(H2O)x]-xH2O（其中 L= 希夫碱配体）类型的铬（II）配合物，并对其进行了表征。氨基酸席夫碱配体表现为八齿配体。铬（II）配合物的可能结构已经阐明，铬（II）配合物的抗菌活性也进行了筛选，结果表明其对革兰氏阳性菌和革兰氏阴性菌具有中度到良好的活性。
• N-对氨基苯甲酰-L-谷氨酸的制备方法
  申请人：江苏尚莱特医药化工材料有限公司

  公开号：CN108147977B

  公开（公告）日：2020-09-25

  本发明公开了一种N‑对氨基苯甲酰‑L‑谷氨酸的制备方法，具有以下步骤：①以对硝基苯甲酸为起始原料，以草酰氯为酰氯化试剂，以四氢呋喃与DMF为混合溶剂，经酰氯化反应制得对硝基苯甲酰氯；②由步骤①制得的对硝基苯甲酰氯与谷氨酸钠经缩合反应制得N‑对硝基苯甲酰‑L‑谷氨酸；③以水合肼为还原剂，以六水合三氯化铁为催化剂，由步骤②制得的N‑对硝基苯甲酰‑L‑谷氨酸经还原反应制得N‑对氨基苯甲酰‑L‑谷氨酸。本发明的酰氯化反应选择在四氢呋喃和DMF混合溶剂中以草酰氯作为酰氯化试剂，还原反应选择水合肼为还原剂且以六水合三氯化铁为催化剂，最终能够得到纯度≥99.9%的N‑对氨基苯甲酰‑L‑谷氨酸。