Separation and determination of D-malic acid enantiomer by reversed-phase liquid chromatography after derivatization with (R)-1-(1-naphthyl) ethylamine

Abstract L-Malic acid is the Active Pharmaceutical Ingredient of the latest generation of compound electrolyte injection (STEROFUNDIN ISO, Germany) and plays a very important role in the rescue of critically ill patients. The optical purity of L-malic acid is a Critical Quality Attributes. A new reversed-phase high performance liquid chromatography (RP-HPLC) method for pre-column derivatization of D-malic acid enantiomer impurity in L-malic acid bulk drug was established. The derivatization reaction was carried out using (R)-1-(1-naphthyl)ethylamine ((R)-NEA) as a chiral derivatization reagent. The Kromasil C18 column was used with a detection wavelength of 225 nm, a flow rate of 1.0 mL·min-1, and a column temperature of 30 °C. The mobile phase was acetonitrile-0.01 mol·L-1 potassium dihydrogen phosphate solution (containing 20 mmol·L-1 sodium heptanesulfonate, adjusted to pH 2.80 with phosphoric acid) (at a ratio of 45:55) and the resolution of D-malic acid and L-malic acid derivatization products reached 1.7. The proposed method possesses the advantages of simple operation, mild conditions, stable derivatization products and low cost. Also it gave better separation and was more accurate than previous methods

Suplemento de magnesio y ácido málico para fibromialgia / Magnesium and malic acid supplement for fibromyalgia

INTRODUCCIÓN La fibromialgia es una condición reumática no articular caracterizada por distintos síntomas, donde destacan principalmente el dolor, sensibilidad muscular, fatiga, insomnio, rigidez matinal, depresión y disminución de la funcionalidad cotidiana. Aún no existe claridad respecto de su etiología, pero se ha planteado que la deficiencia de elementos tales como el magnesio podría tener un rol tanto en la fisiopatología de la fibromialgia como también contribuir a sus síntomas clínicos. MÉTODOS Realizamos una búsqueda en Epistemonikos, la mayor base de datos de revisiones sistemáticas en salud, la cual es mantenida mediante el cribado de múltiples fuentes de información, incluyendo MEDLINE, EMBASE, Cochrane, entre otras. Extrajimos los datos desde las revisiones identificadas, analizamos los datos de los estudios primarios, realizamos un metanálisis y preparamos una tabla de resumen de los resultados utilizando el método GRADE. RESULTADOS Y CONCLUSIONES Identificamos siete revisiones sistemáticas que en conjunto incluyeron 11 estudios primarios, de los cuales solo uno corresponde a un ensayo aleatorizado. Concluimos que el uso de magnesio y ácido málico en pacientes con fibromialgia tiene poco o nulo impacto en dolor y en los síntomas depresivos.

INTRODUCTION Fibromyalgia is characterized by myalgia and a combination of different symptoms including pain, fatigue, insomnia, morning rigidity, depression and a reduction in every-day functioning. Its aetiology is not clear, but it has been suggested that deficiency in certain minerals such as magnesium may play a role both in the physiopathology and in contributing to the symptoms. METHODS We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. RESULTS AND CONCLUSIONS We identified seven systematic reviews which included 11 primary studies of which one was a randomized trial. Our conclusion is that the use of magnesium and malic acid in patients with fibromyalgia makes little or no difference on pain and on depressive symptoms.

Effects of overexpression of carboxylation pathway genes and inactivation of malic enzymes on malic acid production in Escherichia coli / 生物工程学报

Malic acid is a dicarboxylic acid that is widely used in food, pharmaceutical and chemical industries. We studied the effects of overexpression of carboxylation pathway genes and inactivation of malic enzymes on the aerobic production of malic acid. Over expression of phosphoenolpyruvate (PEP) carboxylase (ppc) generated strain E21, which increased malic acid production from 0.57 g/L to 3.83 g/L. Then pyc gene from Coryenbacterium glutamicus and pck gene from Actinobacillus succinogenes were overexpressed in E21 separately. The resulting strains E21 (pTrcpyc) and E21 (pTrc-A-pck) produced 6.04 and 5.01 g/L malate with a yield of 0.79 and 0.65 mol/mol glucose, respectively. Deleting two malic enzymes (encoded by maeA and maeB) also led to an increase of 36% in malic acid production with a production of 5.21 g/L. However, the combination of malic enzymes deletion and pyc overexpression could not further increase the yield of malic acid. After optimization of fermentation conditions, strain E21 (pTrcpyc) produced 12.45 g/L malic acid with a yield of 0.84 mol/mol which is 63.2% of the theoretical yield.

Initial pH of medium affects organic acids production but do not affect phosphate solubilization

The pH of the culture medium directly influences the growth of microorganisms and the chemical processes that they perform. The aim of this study was to assess the influence of the initial pH of the culture medium on the production of 11 low-molecular-weight organic acids and on the solubilization of calcium phosphate by bacteria in growth medium (NBRIP). The following strains isolated from cowpea nodules were studied: UFLA03-08 (Rhizobium tropici), UFLA03-09 (Acinetobacter sp.), UFLA03-10 (Paenibacillus kribbensis), UFLA03-106 (Paenibacillus kribbensis) and UFLA03-116 (Paenibacillus sp.). The strains UFLA03-08, UFLA03-09, UFLA03-10 and UFLA03-106 solubilized Ca3(PO4)2 in liquid medium regardless of the initial pH, although without a significant difference between the treatments. The production of organic acids by these strains was assessed for all of the initial pH values investigated, and differences between the treatments were observed. Strains UFLA03-09 and UFLA03-10 produced the same acids at different initial pH values in the culture medium. There was no correlation between phosphorus solubilized from Ca3(PO4)2 in NBRIP liquid medium and the concentration of total organic acids at the different initial pH values. Therefore, the initial pH of the culture medium influences the production of organic acids by the strains UFLA03-08, UFLA03-09, UFLA03-10 and UFLA03-106 but it does not affect calcium phosphate solubilization.

Caffeic acids from roots of Arctium lappa and their neuroprotective activity / 中草药

Objective: To investigate the caffeic acid compounds from the roots of Arctium lappa and their neuroprotective activity. Methods: The compounds were isolated by column chromatography over silica gel, octadecylsilane (ODS) chemically bonded silica gel, Sephadex LH-20, and AB-8 macroporous resin coupled with preparative HPLC. Their structures were elucidated by spectroscopic analysis and their neuroprotective activity against glutamate-induced neurotoxicity was evaluated in SH-SY5Y cells by MTT assay. Results: Eight caffeic acid compounds were isolated from the roots of A. lappa, which were identified as 1,5-O-dicaffeoyl-3-O-(4-malic acid methyl ester)-quinicacid (1), 3,5-O-dicaffeoyl-quinic acid methyl ester (2), 3,4-O-dicaffeoyl-quinic acid methylester (3), 4,5-O-dicaffeoyl-quinic acid methyl ester (4), (2E)-1,4-dimethyl-2- [(4-hydroxyphenyl)methyl]-2-butenedioicacid (5), chlorogenic acid methyl ester (6), caffeic acid mtheyl ester (7), and 3,4,3',4'-tetrahydroxy-δ-truxinate (8). In vitro, these compounds showed the neuroprotective activity against glutamate-induced neurotoxicity on different levels. Conclusion: The neuroprotective activity of the roots in A. lappa against glutamate-induced neurotoxicity is related to the caffeic acid compounds. Compound 1 is a new compound; Compound 5 is a new natural compound; Compounds 2-4 and 6-7 are isolated from A. lappa for the first time; Compound 8 is isolated from the plants of Arctium L. for the first time.

Quality evaluation of Moutan Cortex at different growth stages / 中草药

Objective: To evaluate the quality of Moutan Cortex at different growth stages. Methods: Metabonomics based on high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC/Q-TOF-MS) was applied to find the variation of different growth stages. Results: Forty-six metabolites were identified by MS molecular ions and major fragments in conjugation with literature data. The results of principal component analysis showed that the constituent of Moutan Cortex at three growth stages were obviously different. The levels of 13 metabolites were related to the growth time of Moutan Cortex. One-year-old Moutan Cortex contained higher levels of malic acid and gallic acid, suggesting the requirement of sufficient materials for growth and synthesis of complicated secondary metabolites at the first stage. However, in two- and three-years-old Moutan Cortex the levels of some important active compounds such as paeonol and monoterpene glucosides increased. It could be deduced that within three years grouth, good quality of Moutan Cortex was associated with the longer growth time. Conclusion: These results provide the evidence for the quality evaluation of Moutan Cortex at different growth stages, and demonstrate that metabonomics is a powerful approach for the quality evaluation of traditional Chinese malera medica.

Chemical constituents in leaves of Ilex ficoidea / 中草药

Objective: To investigate the chemical constituents in leaves of Ilex ficoidea. Methods: The various chromatographic techniques were used to isolate and purify the compounds and their structures were identified by the spectral data and physicochemical properties. Results: Sixteen compounds were isolated from 95% ethanol extract and identified as friedelan-3-one (1), 4-epifriedelin (2), lupeol (3), oleanolic acid (4), 3-acetoxy-oleanoic acid (5), 3β-acetoxy-6α, 13β-dihydroxyolean-7-one (6), 2-(4-hydroxybenzyl) malic acid (7), quercetin-3-O-α-L-arabinopyranoside (8), hyperoside (9), cis-syringin (10), ethyl-O-β-L-arabinopyranoside (11), emodin (12), chrysophanol (13), physcion (14), α-spinasterol (15), and β-sitosterol (16). Conclusion: All the compounds are isolated from the species for the first time, among which compounds 1, 2, 6-8, 12, and 13 are isolated from the plants in genus Ilex L. for the first time.

RESEARCH ON BATCH QUANTITIVE DETERMINATION OF L-MALIC ACID IN FERMENTATION LIQUOR / 微生物学通报

A simple and rapid method was established for the determination of the content of L-malic acid in fermentation liquor. This procedure includes six steps: (1) Use a microi- njector to inject the fermentation liquor quantitively on the filter paper, then use the chromatography solution (n-butanol: formic acid: water=8:1.5:1) for paper chromatography. (2) Atomize the display reagent (10ml 0.02?10~(-2) bromocresol green: 0.2ml 10?10~(-2) sodium hydroxide) on the chromatography paper. (3) Scissor off L-malic acid spots from the paper and put in into 5 ml distilled water for three hours. (4) In 1ml eluent, add 6 ml 96?10~(-2) sulphuric acid and 0.1ml 1.0?10~(-2) ?-naphthol.(5) Heat the reaction system in 100℃ water for sixty minutes. (6) After cooling determine the optical density at the wavelength 476 am in the colorimeter.

The Study of Enzymatic Activity of Mutant Strain Rhizopus oryzae with L-Malic Acid Accumulation / 微生物学通报

A stable and efficient L-Malic acid accumulation mutant strain Rhizopus oryzae ME-M15 was discovered occasionally in the mutation breading for fumaric acid producers. Rhizopus oryzae ME-M15 gave a L-Malic acid output of 16.3 g/L on average after fermentation for 96 hours, more than 3 times than that of the parent strain ME-F10. In addition, other metabolites such as ethanol and fumaric acid were re-markably decreased in accordance with the depressed activity of the cytosolic isoenzyme of fumarase and alcohol dehydrogenase in strain ME-M15, while the activity of the pyruvate carboxylase had no significant difference.