2-Methylcitric acid
(Synonyms: 2-甲基柠檬酸,Methylcitric acid) 目录号 : GC60479
An endogenous tricarboxylic acid
Cas No.:6061-96-7
Sample solution is provided at 25 µL, 10mM.
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Quality Control & SDS
- View current batch:
- Purity: >97.00%
- COA (Certificate Of Analysis)
- SDS (Safety Data Sheet)
- Datasheet
2-Methylcitric acid is an endogenous tricarboxylic acid formed by the condensation of propionyl-CoA with oxaloacetic acid by citrate synthase under conditions of propionyl-CoA accumulation.1 Accumulation of 2-methylcitric acid is associated with cobalamin deficiencies, propionic acidemia, and methylmalonic acidurias.1,2
1.Allen, R.H., Stabler, S.P., Savage, D.G., et al.Elevation of 2-methylcitric acid I and II levels in serum, urine, and cerebrospinal fluid of patients with cobalamin deficiencyMetabolism42(8)978-988(1993) 2.Al-Dirbashi, O.Y., McIntosh, N., and Chakraborty, P.Quantification of 2-methylcitric acid in dried blood spots improves newborn screening for propionic and methylmalonic acidemiasJ. Med. Screen.24(2)58-61(2017)
| Cas No. | 6061-96-7 | SDF | |
| 别名 | 2-甲基柠檬酸,Methylcitric acid | ||
| Canonical SMILES | CC(C(O)=O)C(C(O)=O)(O)CC(O)=O | ||
| 分子式 | C7H10O7 | 分子量 | 206.15 |
| 溶解度 | DMF: 25 mg/ml,DMSO: 30 mg/ml,Ethanol: 10 mg/ml,PBS (pH 7.2): 10 mg/ml | 储存条件 | Store at 2-8°C |
| General tips | 请根据产品在不同溶剂中的溶解度选择合适的溶剂配制储备液；一旦配成溶液，请分装保存，避免反复冻融造成的产品失效。 储备液的保存方式和期限：-80°C 储存时，请在 6 个月内使用，-20°C 储存时，请在 1 个月内使用。 为了提高溶解度，请将管子加热至37℃，然后在超声波浴中震荡一段时间。 |
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| Shipping Condition | 评估样品解决方案：配备蓝冰进行发货。所有其他可用尺寸：配备RT，或根据请求配备蓝冰。 | ||
| 制备储备液 | |||
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1 mg | 5 mg | 10 mg |
| 1 mM | 4.8508 mL | 24.2542 mL | 48.5084 mL |
| 5 mM | 0.9702 mL | 4.8508 mL | 9.7017 mL |
| 10 mM | 0.4851 mL | 2.4254 mL | 4.8508 mL |
| 第一步：请输入基本实验信息（考虑到实验过程中的损耗，建议多配一只动物的药量） | ||||||||||
| 给药剂量 | mg/kg |  |
动物平均体重 | g | |
每只动物给药体积 | ul | |
动物数量 | 只 |
| 第二步：请输入动物体内配方组成（配方适用于不溶于水的药物；不同批次药物配方比例不同，请联系GLPBIO为您提供正确的澄清溶液配方） | ||||||||||
| % DMSO % % Tween 80 % saline | ||||||||||
| 计算重置 | ||||||||||
计算结果:
工作液浓度： mg/ml；
DMSO母液配制方法： mg 药物溶于 μL DMSO溶液（母液浓度 mg/mL，
体内配方配制方法：取 μL DMSO母液，加入 μL PEG300，混匀澄清后加入μL Tween 80，混匀澄清后加入 μL saline，混匀澄清。
1. 首先保证母液是澄清的；
2.
一定要按照顺序依次将溶剂加入，进行下一步操作之前必须保证上一步操作得到的是澄清的溶液，可采用涡旋、超声或水浴加热等物理方法助溶。
3. 以上所有助溶剂都可在 GlpBio 网站选购。
Determination of methylmalonic acid, 2-Methylcitric acid, and total homocysteine in dried blood spots by liquid chromatography-tandem mass spectrometry: A reliable follow-up method for propionylcarnitine-related disorders in newborn screening
J Med Screen 2021 Jun;28(2):93-99.PMID:32615850DOI:10.1177/0969141320937725.
Objectives: Determination of methylmalonic acid, 2-Methylcitric acid, and total homocysteine in dried blood spots by liquid chromatography-tandem mass spectrometry has usually been used as a second-tier test to improve performance of newborn screening for propionylcarnitine-related disorders. However, factors that potentially affect its detection results have not been investigated, and we aimed to evaluate these influencing factors and explore their potential utility in newborn screening and initial follow-up for propionylcarnitine-related disorders. Methods: This study comprised a prospective group (1998 healthy infants, to establish cutoff values and investigate the influencing factors) and a retrospective group (804 suspected positive cases screened from 381, 399 newborns for propionylcarnitine-related disorders by tandem mass spectrometry, to evaluate the performance of newborn screening and initial follow-up). Results: Cutoff values for methylmalonic acid, 2-Methylcitric acid, and total homocysteine were 2.12, 0.70, and 10.05 µmol/l, respectively. Concentration of methylmalonic acid, 2-Methylcitric acid, and total homocysteine in dried blood spots is not impacted by sex, age, birth weight, gestational age, or dried blood spot storage time. A total of 75 of 804 cases were screened positive by combined tandem mass spectrometry and liquid chromatography-tandem mass spectrometry, thus eliminating 90% of the false positives without compromising sensitivity. Eighteen propionylcarnitine-related disorders were successfully identified, including one CblX case missed in the initial follow-up by tandem mass spectrometry. Conclusions: Methylmalonic acid, 2-Methylcitric acid, and total homocysteine detected in dried blood spots by liquid chromatography-tandem mass spectrometry is a reliable, specific, and sensitive approach for identifying propionylcarnitine-related disorders. We recommend this assay should be performed rather than tandem mass spectrometry in follow-up for propionylcarnitine-related disorders besides second-tier tests in newborn screening.
Analysis of 2-Methylcitric acid, methylmalonic acid, and total homocysteine in dried blood spots by LC-MS/MS for application in the newborn screening laboratory: A dual derivatization approach
J Mass Spectrom Adv Clin Lab 2021 Mar 17;20:1-10.PMID:34820666DOI:10.1016/j.jmsacl.2021.03.001.
Inborn errors of propionate, cobalamin and methionine metabolism are targets for Newborn Screening (NBS) in most programs world-wide, and are primarily screened by analyzing for propionyl carnitine (C3) and methionine in dried blood spot (DBS) cards using tandem mass spectrometry (MS/MS). Single-tier NBS approaches using C3 and methionine alone lack specificity, which can lead to an increased false-positive rate if conservative cut-offs are applied to minimize the risk of missing cases. Implementation of liquid chromatography tandem mass spectrometry (LC-MS/MS) second-tier testing for 2-Methylcitric acid (MCA), methylmalonic acid (MMA), and homocysteine (HCY) from the same DBS card can improve disease screening performance by reducing the false-positive rate and eliminating the need for repeat specimen collection. However, DBS analysis of MCA, MMA, and HCY by LC-MS/MS is challenging due to limited specimen size and analyte characteristics leading to a combination of low MS/MS sensitivity and poor reverse-phase chromatographic retention. Sufficient MS response and analytical performance can be achieved for MCA by amidation using DAABD-AE and by butylation for MMA and HCY. Herein we describe the validation of a second-tier dual derivatization LC-MS/MS approach to detect elevated MCA, MMA, and HCY in DBS cards for NBS. Clinical utility was demonstrated by retrospective analysis of specimens, an interlaboratory method comparison, and assessment of external proficiency samples. Imprecision was <10.8% CV, with analyte recoveries between 90.2 and 109.4%. Workflows and analytical performance characteristics of this second-tier LC-MS/MS approach are amenable to implementation in the NBS laboratory.
2-Methylcitric acid impairs glutamate metabolism and induces permeability transition in brain mitochondria
J Neurochem 2016 Apr;137(1):62-75.PMID:26800654DOI:10.1111/jnc.13544.
Accumulation of 2-Methylcitric acid (2MCA) is observed in methylmalonic and propionic acidemias, which are clinically characterized by severe neurological symptoms. The exact pathogenetic mechanisms of brain abnormalities in these diseases are poorly established and very little has been reported on the role of 2MCA. In the present work we found that 2MCA markedly inhibited ADP-stimulated and uncoupled respiration in mitochondria supported by glutamate, with a less significant inhibition in pyruvate plus malate respiring mitochondria. However, no alterations occurred when α-ketoglutarate or succinate was used as respiratory substrates, suggesting a defect on glutamate oxidative metabolism. It was also observed that 2MCA decreased ATP formation in glutamate plus malate or pyruvate plus malate-supported mitochondria. Furthermore, 2MCA inhibited glutamate dehydrogenase activity at concentrations as low as 0.5 mM. Kinetic studies revealed that this inhibitory effect was competitive in relation to glutamate. In contrast, assays of osmotic swelling in non-respiring mitochondria suggested that 2MCA did not significantly impair mitochondrial glutamate transport. Finally, 2MCA provoked a significant decrease in mitochondrial membrane potential and induced swelling in Ca(2+)-loaded mitochondria supported by different substrates. These effects were totally prevented by cyclosporine A plus ADP or ruthenium red, indicating induction of mitochondrial permeability transition. Taken together, our data strongly indicate that 2MCA behaves as a potent inhibitor of glutamate oxidation by inhibiting glutamate dehydrogenase activity and as a permeability transition inducer, disturbing mitochondrial energy homeostasis. We presume that 2MCA-induced mitochondrial deleterious effects may contribute to the pathogenesis of brain damage in patients affected by methylmalonic and propionic acidemias. We propose that brain glutamate oxidation is disturbed by 2-Methylcitric acid (2MCA), which accumulates in tissues from patients with propionic and methylmalonic acidemias because of a competitive inhibition of glutamate dehydrogenase (GDH) activity. 2MCA also induced mitochondrial permeability transition (PT) and decreased ATP generation in brain mitochondria. We believe that these pathomechanisms may be involved in the neurological dysfunction of these diseases.
Quantification of 2-Methylcitric acid in dried blood spots improves newborn screening for propionic and methylmalonic acidemias
J Med Screen 2017 Jun;24(2):58-61.PMID:27216769DOI:10.1177/0969141316645824.
Background Newborn screening for propionic acidemia and methylmalonic acidurias using the marker propionylcarnitine (C3) is neither sensitive nor specific. Using C3 to acetylcarnitine (C3/C2) ratio, together with conservative C3 cut-offs, can improve screening sensitivity, but the false positive rate remains high. Incorporating the marker 2-Methylcitric acid has been suggested, to improve the positive predictive value for these disorders without compromising the sensitivity. Methods Between July 2011 and December 2012 at the Newborn Screening Ontario laboratory, all neonatal dried blood spot samples that were reported as screen positive for propionic acidemia or methylmalonic acidurias based on elevated C3 and C3/C2 ratio were analyzed for 2-Methylcitric acid, using liquid chromatography tandem mass spectrometry. Results Of 222,420 samples screened, 103 were positive for methylmalonic acidurias or propionic acidemia using C3 and C3/C2 ratio as markers. There were nine true positives: propionic acidemia (n = 3), Cobalamin (Cbl) A (n=1), and Cbl C (n = 5). Among false positives there were 72 neonates not affected, 20 with maternal B12 deficiency, and two incidental finding (transcobalamin II and unclassified Cbl defect). 2-Methylcitric acid was analyzed in all 103 samples and ranged between 0.1 and 89.4 µmol/l (reference range 0.04-0.36). Only 14 samples exceeded the set 2-Methylcitric acid cut-off of 1.0 µmol/l, including the samples from all nine true positives. Conclusion By including 2-Methylcitric acid in the screening algorithm, the positive predictive value of our primary and secondary screening targets improved from 8.7 to 64.3%. This would have eliminated 89 unnecessary referrals while maintaining 100% sensitivity.
Elevation of 2-Methylcitric acid I and II levels in serum, urine, and cerebrospinal fluid of patients with cobalamin deficiency
Metabolism 1993 Aug;42(8):978-88.PMID:8345822DOI:10.1016/0026-0495(93)90010-l.
Citrate synthase catalyzes the condensation of acetyl-coenzyme A (CoA) and oxaloacetic acid to form citric acid. The enzyme also catalyzes the condensation of propionyl-CoA and oxaloacetic acid with a maximal reaction velocity (Vmax) approximately 10(-4) times that of acetyl-CoA to form 2-Methylcitric acid, which contains two asymmetric carbon atoms and exists as two pairs of related enantiomers designated as 2-Methylcitric acid I and II. Cobalamin (Cbl) deficiency can lead to increases in intracellular levels of propionyl-CoA. To assess the magnitude of increased synthesis of 2-Methylcitric acid in Cbl deficiency, we developed a new capillary gas chromatographic-mass spectrometric assay and measured 2-Methylcitric acid levels in serum and cerebrospinal fluid (CSF) of normal subjects and patients with clinically confirmed Cbl deficiency. The normal range for 2-Methylcitric acid level was 60 to 228 nmol/L for serum in 50 normal blood donors and 323 to 1,070 nmol/L for CSF in 19 normal subjects. In 50 patients with clinically confirmed Cbl deficiency, values for 2-Methylcitric acid in serum ranged from 93 to 13,500 nmol/L; 44 (88%) had values above the normal range. In five patients with clinically confirmed Cbl deficiency, levels of the sum of 2-Methylcitric acid I and II ranged from 1,370 to 16,300 nmol/L in CSF, and all five (100%) patients had levels above the normal range. We conclude that levels of 2-Methylcitric acid are elevated in serum and CSF of most patients with Cbl deficiency.