Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “SUCCINIC ACID”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,027 records · Page 57Linked to original sources
PubMedDate not supplied

Synthesis, structure, and properties of rac-2,3-dimercaptosuccinic acid, a potentially useful chelating agent for toxic metals.

rac-2,3-Dimercaptosuccinic acid (rac-DMSA) may be a more effective antidote for the treatment of heavy metal poisoning than meso-2,3-dimercaptosuccinic acid (meso-DMSA), which is used at present. A comparative study of these two chelating agents has been undertaken in order to investigate this possibility. The structures of rac-DMSA and the precursor in its synthesis, rac-2,3-bis(acetylthio)succinic acid, have been determined by single-crystal X-ray analysis and compared with the structures of the corresponding meso compounds. The concentration distributions of the various ionic and molecular species of rac-DMSA that are present in aqueous solutions in the pH range 1.8-12.8 have been calculated from the four acid dissociation constants that have been determined potentiometrically at an ionic strength of 0.10. The conformations of these species in aqueous solutions have been determined by 1H NMR spectroscopy as a function of pH. The rac-DMSA exists in the crystal lattice as a double-stranded structure in which each molecule is in a gauche configuration. The meso-DMSA, however, exists in a single strand in which each molecule has adopted an anti configuration and the individual molecules are joined together at each end by hydrogen bonds. These differences in the conformations of rac- and meso-DMSA may account for the significant difference in the solubilities of the two compounds in aqueous solutions. In acidic solutions at elevated temperatures of about 95 degrees C, rac-DMSA is slowly but irreversibly converted to meso-DMSA. This conversion does not occur at ambient temperatures.

Crystallography, X-Ray↗
PubMed2003

Role of organic acids in enhancing the desorption and uptake of weathered p,p'-DDE by Cucurbita pepo.

Experiments were conducted to assess the effect of seven organic acids [succinic, tartaric, malic, malonic, oxalic, citric, ethylene-diaminetetraacetic (EDTA)] over a concentration range of two orders of magnitude (0.001-0.10 M) on the abiotic desorption of weathered p,p'-DDE and the extraction of polyvalent inorganic ions from soil. At 0.05 M all organic acids significantly increased contaminant desorption by 19-80%. Organic acids also increased the aqueous concentration of eight inorganic constituents extracted from soil, with at least a six-fold increase in the release of Al, Fe, Mn, and P at 0.001 M. Zucchini seedlings grown for 28 d in soil containing weathered p,p'-DDE (300 ng/g, dry weight) were periodically amended with distilled water, citric or oxalic acids (0.01 M). Plants receiving water removed 1.7% of the p,p'-DDE from the soil. Seedlings amended with citric or oxalic acids removed 2.1 and 1.9% of the contaminant, respectively, and contained up to 66% more contaminant in the shoot system than unamended vegetation. A second crop of untreated (distilled water) zucchini in the same soil removed more contaminant than the first crop (2.5%), although the addition of organic acids did not further enhance contaminant uptake. The data indicate that the addition of low molecular weight organic acids causes the partial dissolution of the soil structure through the chelation of inorganic structural ions, potentially enhancing bioavailability and having implications for the phytoremediation of persistent organic pollutants in soil.

Acids↗
PubMed1989

Ca2+ binding cyclic octapeptides having an alternating Sar and a hydrophobic amino acid in the sequence.

Cyclic octapeptides having alternating Sar and hydrophobic amino acid sequences, such as cyclo[Lys(Z)-Sar-Leu-Sar-Leu-Sar-Leu-Sar] (C8KL), cyclo[Glu(OMe)-Sar-Lys(Z)-Sar-Leu-Sar-Leu-Sar] (C8KE, and cyclo[Lys(Suc)-Sar-Leu-Sar-Leu-Sar-Leu-Sar] [C8K(Suc)L, Suc represents succinic acid], were synthesized. These cyclic octapeptides formed a complex selectively with Ca2+. Upon complexation, trans peptide bonds of Sar residues were isomerized to cis peptide bonds. C8KL and C8KE showed very similar characteristics of Ca2+ binding, extraction of Ca2+ from an aqueous solution to a chloroform solution, and Ca2+ transport through a liquid chloroform membrane. C8KL transported Ca2+ across the lipid bilayer membrane above the phase-transition temperature, while C8KE and C8K(Suc)L did not. Therefore, the transport of Ca2+ through the lipid bilayer membrane is very sensitive to the hydrophobicity of the carrier molecule.

Amino Acid Sequence↗
PubMed2002

In vivo and in vitro (27)Al NMR studies of aluminum(III) chelates of triazacyclononane polycarboxylate ligands.

The metallic radioisotope of a known radiopharmaceutical chelate, (67)Ga(NOTA) (NOTA=1,4,7-triazacyclonane-1,4,7-triacetic acid), used for tumor detection, was substituted by the chemically similar but non radioactive aluminum ion. Our aim was to detect and evaluate the in vivo behavior of the chelate. For this purpose, Al(NOTA) and the related chelate Al(NODASA) (NODASA=1,4,7-triazacyclononane-1-succinic acid-4,7-diacetic acid) were studied using in vitro and in vivo (27)Al NMR spectroscopy in rats. Both chelates showed high stability towards acid catalyzed dissociation and their (27)Al NMR resonances are characteristic of highly symmetrical species, with chemical shifts within the range for octahedral or pseudo-octahedral geometries. The thermodynamic stability constant of the novel chelate Al(NODASA) was estimated using (27)Al NMR. The value obtained suggested that the chelate does not undergo in vivo demetalation by transferrin. The in vivo spectroscopic studies and the analysis of blood and urine samples for Al(III) concentrations indicated that the chelates remain intact under physiological conditions and that they are mainly eliminated from the body through the kidneys.

Aluminum↗
PubMed1977

Effect of acute uremia on arginine metabolism and urea and guanidino acid production by perfused rat liver.

Since arginine is a precursor of urea and other guanidino derivatives, we have evaluated its metabolism in acute uremia using the isolated perfused rat liver. Female Sprague-Dawley rats underwent bilateral nephrectomy (n = 5) or sham operation (n = 5) 48 h prior to liver perfusion. Fifty microCi of L-[guanidino 14C] arginine and unlabelled arginine and aspartic acid were added to the recycling perfusate 15 min prior to liver perfusion. Perfusate concentrations of urea and other guanidino derivatives were measured with high-pressure liquid chromatography. After the initial 30 min of perfusion, net uptake of arginine was lower, and net release of guanidino-succinic acid (GSA) was higher in the livers of acutely uremic rats. Net release of urea was also higher in uremia but the results did not achieve statistical significance. In uremia, the percent conversion of 14C arginine to 14C urea was significantly higher (79 +/- 5 [SE]%) than in controls (58 +/- 7%). These results demonstrate increased GSA production by livers of acutely uremic rats and suggest that acute uremia may be associated with increased arginine utilization and increased production of urea.

Acute Kidney Injury↗
PubMed1995

Palmitate-induced beta-cell insensitivity to glucose is coupled to decreased pyruvate dehydrogenase activity and enhanced kinase activity in rat pancreatic islets.

We previously found that long-term exposure to fatty acids impairs glucose-induced insulin release. In the present study, we investigated whether impairment is related to decreased pyruvate dehydrogenase (PDH) and increased PDH kinase activity. Rat pancreatic islets were cultured for 48 h in RPMI-1640 medium with or without 0.125 mmol/l palmitate. Potentiation of insulin responses to succinic acid monomethylester (SAM) by 10 mmol/l acetate and pyruvate were subsequently compared in order to assess whether generation of acetyl-coenzyme A (CoA) from pyruvate was deficient in the intact beta-cell. Potentiation by acetate was similar in control and palmitate-preexposed islets. In contrast, pyruvate potentiated SAM-induced response by 122% in control but by only 39% in palmitate-exposed islets (P < 0.001). In extracts of palmitate-exposed islets, the active (unphosphorylated) form of PDH was decreased by 50% and total PDH activity (assessed after phosphatase treatment) by 25%. The proportion of active form to total PDH activity was also reduced (42.7 +/- 2.6% after palmitate vs. 66.6 +/- 4.3% in control islets, P < 0.01). In the same preparations, PDH kinase activity was enhanced 1.7-fold by palmitate in terms of the rate constant of ATP-dependent inactivation of PDH (P < 0.05). To test for a role of free (not PDH-bound) kinase, a PDH-free mitochondrial fraction was prepared, and its kinase activity was tested against a pig heart PDH preparation. Free kinase activity was increased 1.9-fold in palmitate-treated islets (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Acetates↗
PubMedDate not supplied

[Effect of nitroglycerin and sodium nitrite on myocardial mitochondrial respiration and oxidative phosphorylation normally and in coronarogenic ischemia].

The effect of nitroglycerin and sodium nitrite (2.10(-6), 2.10(-5) and 2.10(-4) g/ml) on respiration and oxidative phosphorylation of mitochondria of the normal and ischemized dog myocardium has been investigated in the presence of glutamate, succinate and alfaketoglutarate. The drugs inhibited ADP-activated oxygen consumption and ADP phosphorylation rate upon oxidation of succinic acid formed in mitochondria from exogenic glutamate, without changes in the phosphorylation coefficient and free oxidation rate (i. e. in the absence of ADP) in mitochondria of the healthy and ischemic heart. In the ischemic area one can also observe an inhibition of ADP-activated oxidation of endogenic succinate formed from exogenic glutamate.

Animals↗
PubMed1977

Diagnosis of anaerobic infections by gas-liquid chromatography.

Anaerobic bacteriology of clinical specimens is an expensive and time-consuming operation. In the present investigation it was shown that fatty acids produced by anaerobic bacteria may serve as bacterial markers in clinical material. Ten specimens of pus were analyzed by gas liquid chromatography and the results were compared with the bacteriological findings. Good correlations were found for the recovery of Bacteroides fragilis and the presence of isobutyric, butyric and succinic acids. It is concluded that direct gas-liquid chromatography of clinical specimens provides a rapid presumptive test for the presence of B. fragilis in anaerobic infections.

Bacteria↗
PubMed2006

Reactivity of dimethyl fumarate and methylhydrogen fumarate towards glutathione and N-acetyl-L-cysteine--preparation of S-substituted thiosuccinic acid esters.

Dimethyl fumarate (DMF) is used successfully to treat psoriasis. In spite of its proven clinical efficacy, the mode of metabolism and the pharmacodynamics of DMF are still not completely understood. Some previous studies have indicated that orally applied DMF for a considerable part is quickly hydrolysed to methylhydrogen fumarate (MHF) at basic pH conditions as present in the upper intestine, especially in the presence of biological fluids containing esterases. On the other hand it was shown that DMF due to its high lipophilicity rapidly penetrates into cells and may thus at least in part be absorbed after po application without being hydrolysed. On the other hand, no detectable amounts of DMF were hitherto found in plasma samples after po administration. In order to shed light on possible further routes of presystemic metabolism of DMF, studies on the reactivity towards glutathione (GSH) were carried out. GSH is present in millimolar concentrations in almost all cells. DMF due to its nature as an alpha,beta-unsaturated carboxylic acid ester can react spontaneously with thiols via a Michael-type addition. It could be shown that DMF reacts at high rates under near-physiological conditions. Studies on the reaction kinetics at pH 7.4 show that GSH addition proceeds rapidly to yield a 1:1 mixture of both diastereomeric 2-(S-glutathionyl)-succinic acid dimethyl esters. MHF under identical conditions was shown to react with GSH as well leading to a mixture of four products (2 diastereomeric pairs). However, MHF reacted at a much lower rate. The structures of all thiol conjugates were confirmed unambiguously by extensive NMR measurements. GSH conjugates and the corresponding mercapturic acids on grounds of the high spontaneous reactivity observed may be expected to be major metabolites of unhydrolysed DMF which makes its way into enterocytes. On the other hand, MHF, due to its slow reaction with GSH, may have higher chances than DMF to react with more essential thiol groups in macromolecules.

Acetylcysteine↗
PubMed1976

Rapid diagnosis of anaerobic infections by direct gas-liquid chromatography of clinical speciments.

Current methods to isolate and identify anaerobic bacteria are laborious and time consuming. It was postulated that the short-chain fatty acids (SCFA) produced by these organisms might serve as microbial markers in clinical material. 98 specimens of pus or serous fluid were analyzed by gas-liquid chromatography, and findings were compared with culture results. Good correlations were found for the recovery of anaerobic Gram-negative bacilli and the presence of isobutyric, butyric, and succinic acids. 19 of 20 specimens with significant amounts of these acids (greater than 0.01 mumol/ml) yielded bacteroides or fusobacteria. Culture of the single "false-positive" specimen failed to grow anaerobic Gram-negative bacilli, although clinical data and Gram-stain suggested their presence. 77 of 78 specimens which has insignificant concentrations of the marker acids failed to yield anaerobic, Gram-negative bacilli in culture. The single "false-negative" specimen yielded Bacteroides pneumosintes, an organism which does not ferment carbohydrates. It is concluded that direct gas-liquid chromatographic analysis of clinical specimens provides a rapid presumptive test for the presence of anaerobic, Gram-negative bacilli.

Bacterial Infections↗
PubMed1994

L-malic acid production by entrapped Saccharomyces cerevisiae into polyacrylamide gel beads.

The yeast Saccharomyces cerevisiae was entrapped within polyacrylamide gel beads by employing a procedure that uses sodium dodecylsulfate as a detergent to improve the spherical configuration of the beads. The resulting preparation showed a rate of fumarate bio-conversion to L-malic acid about 60 times higher than that found for the free cells. Almost all fumarate was converted in 30 min of incubation. The thermal stability of the immobilized cells did not significantly differ from the free cells. An optimal pH of 5.7 was found for the immobilized preparation and no succinic acid was detected as a byproduct in the incubation mixture.

Acrylic Resins↗
PubMed1986

Effect of guanidino-propionic acid on lymphocyte proliferation.

The 'uremic toxin', guanidino propionic acid (GPA), which was detected in uremic serum in correlation with BUN level, modified the mitogenic response of normal lymphocytes to phytohemagglutinin (PHA). Mild modifications can be detected in the concentrations which are found in uremic patients. Other guanidino compounds which have been detected in uremic sera, such as guanidino succinic acid (GSA), guanidino butyric acid (GBA) and guanidino acetic acid (GAA), show similar inhibitory pathways. It is suggested that guanidino compounds contribute to the immunological disturbances in uremia. The complexity of their action on lymphocyte mitogenic response is probably the cause of the conflicting results which have been reported in the literature.

Cell Division↗
PubMed1997

Effect of alpha-tocopherol succinate on free radical and lipid peroxidation levels in BL6 melanoma cells.

Numerous studies have proposed a radical or oxidant involvement in a number of degenerative diseases such as cancer. This has led to suggestions that the supplementation of antioxidants such as alpha-tocopherol (vitamin E) may function to reduce the growth of cancer. In this study, a nonmalignant Monkey kidney (LLCMK) and a malignant Murine melanoma (BL6-F10) cell line were supplemented with varying levels of alpha-Tocopherol acid succinate (vitamin E succinate) ranging from 1 to 10 microg/ml. BL6-F10 cells supplemented with 5, 7, and 10 microg/ml vitamin E succinate, showed significant decreases in cell proliferation, and this decrease was accompanied by a concomitant increase rather than a decrease in the levels of free radicals and lipid peroxidation. LLCMK cells supplemented with 1-10 microg/ml vitamin E succinate showed no significant increase or decrease in growth, while the levels of lipid peroxidation were shown to be insignificantly elevated at 5, 7, and 10 microg/ml vitamin E succinate. Free radical levels in LLCMK cells were significantly decreased at 1 microg/ml vitamin E succinate, while at 3, 5, 7, and 10 microg/ml supplementary vitamin E succinate, free radical levels increased compared to the 1 microg/ml group, but not compared to control cultures. These results suggest that the inhibitory effects of vitamin E succinate on BL6-F10 cell growth in vitro is not a consequence of its antioxidant properties, but may, in fact, be due to one or more of its other potential roles within the cells, such as the regulation of cellular enzyme activities involved in growth.

Animals↗
PubMed2004

A pH-stating mechanism in isolated wheat (Triticum aestivum) aleurone layers involves malic acid transport.

Acidification of the starchy endosperm by the aleurone layer following germination has been established; however, the physiological and metabolic responses of this tissue to external pH have been incompletely investigated. In this investigation, isolated wheat (Triticum aestivum) aleurone layers were incubated in different solutions at initial pH values of 3, 4 and 6 in the absence of phytohormones. After 24 h of incubation, the initial pH of all malate and succinate buffers shifted towards a value close to 4.2. These results suggest the existence of a pH-stating mechanism, instead of the simple acidification process reported previously. The rise of initial pH 3 by aleurone layers was accompanied by a high net uptake of external malic- or succinic acid. In contrast, incubation in glycyl-glycine buffer (a supposedly non-permeating cation at pH 3) partially prevented that pH rise in a pH-3 solution. The 14C-malate taken up from media at pH 3 was mostly broken down to CO2, indicating that an effective metabolic control of the intracellular malate level was operating. At pH 6, an uptake of 14C-malate and 14CO2 production occurred as well, but at slower rates than at pH 3. When buffer concentration was increased, at initial pH values of 3 or 6, a higher uptake or secretion of malic acid, respectively, was carried out by the aleurone layers. The pH of these buffers varied less than that of dilute ones, but always showed a tendency toward a pH near 4. These results suggest that a balance between secretion and uptake of malic acid, accompanied by the corresponding biosynthesis or degradation, is the basis of this pH-stating mechanism.

Acid-Base Equilibrium↗
PubMed1988

Responses of the L5178Y tk+/tk- mouse lymphoma cell forward mutation assay: III. 72 coded chemicals.

Seventy-two chemicals were tested for their mutagenic potential in the L5178Y tk+/- mouse lymphoma cell forward mutation assay, using procedures based upon those described by Clive and Spector (Mutat Res 44:269-278, 1975) and Clive et al. (Mutat Res 59:61-108, 1979). Cultures were exposed to the chemicals for 4 hr, then cultured for 2 days before plating in soft agar with or without trifluorothymidine (TFT), 3 micrograms/ml. The chemicals were tested at least twice. Significant responses were obtained with allyl isothiocyanate, p-benzoquinone dioxime, benzyl acetate, 2-biphenylamine HCl, bis(2-chloro-1-methylethyl)ether, cadmium chloride, chlordane, chlorobenzene, chlorobenzilate, 2-chloroethanol, chlorothalonil, cytarabine.HCl, p,p'-DDE, diazinon, 2,6-dichloro-p-phenylenediamine, N,N-diethylthiourea, diglycidylresorcinol ether, 2,4-dimethoxy aniline.HCl, disperse yellow 3, endosulfan, 1,2-epoxyhexadecane, ethyl acrylate, ethyl benzene, ethylene thiourea, F D and C yellow Number 6, furan, heptachlor, isophorone, mercuric chloride, 4,4'-methylenedianiline.2 HCl, methyl viologen, nickel sulfate.6H2O, 4,4'-oxydianiline, pentachloroethane, piperonyl butoxide, propyl gallate, quinoline, rotenone, 2,4,5,6-tetrachloro-4-nitro-anisole, 1,1,1,2-tetrachloroethane, trichlorfon, 2,4,6-trichlorophenol, 2,4,5-trimethoxybenzaldehyde, 1,1,3-trimethyl-2-thiourea, 1-vinyl-3-cyclopetene dioxide, vinyl toluene, and ziram. Apart from 2-biphenylamine.HCl, 2-chloroethanol, disperse yellow 3, ethylene thiourea, FD and C yellow number 6, phenol, and 1,1,2-tetrachloroethane, rat liver S9 mix was not a requirement for these compounds. Chemicals not identified as mutagens were acid red, 11-aminoudecanoic acid, boric acid, 5-chloro-o-toluidine, coumaphos, cyclohexanone, decabromodiphenyl oxide, di(2-ethylhexyl)adipate, ferric chloride, fluometuron, melamine, monuron, phenesterin, phthalimide, reserpine, sodium dodecyl sulfate, 4,4-sulfonyldianiline, tetrachloroethylene, and zearalenone. The assay was incapable of providing a clear indication of whether some chemicals were mutagens; these were benzyl alcohol, 1,4-dichlorobenzene, phenol, succinic acid-2,2-dimethyl hydrazide, and toluene.

Animals↗
PubMed1985

Effects of replacement of the hydroxyl group of cholesterol and tocopherol on the thermotropic behavior of phospholipid membranes.

The role of the hydroxyl groups of cholesterol and tocopherol in mediating their interaction with phospholipid bilayers has been a subject of considerable interest. We have examined this question by using derivatives of cholesterol and tocopherol in which the hydroxyl group is esterified to succinate. The hemisuccinate esters of cholesterol and alpha-tocopherol can be readily incorporated into phospholipid membranes and in fact can by themselves form closed membrane vesicles as demonstrated by the encapsulation of [3H]sucrose. The thermotropic behavior of mixtures containing each succinate ester and phospholipid was studied by differential scanning calorimetry. The effect of cholesteryl hemisuccinate on the thermotropic properties of dipalmitoylphosphatidylcholine and dimyristoylphosphatidylethanolamine is very similar to that of cholesterol. This indicates that the 3 beta-OH is not required for the formation of a cholesterol-phospholipid complex. In mixtures of tocopherol acid succinate and phospholipids the peak transition temperature is progressively shifted to lower temperatures as the mole fraction of alpha-tocopherol succinate is increased, while the enthalpy of the transition is only slightly affected. At a tocopherol succinate/phospholipid molar ratio of 9/1 a phase transition is still detectable. A comparison between tocopherol succinate and tocopherol indicates that the substitution of the hydroxyl group reduces the interaction of tocopherol with phospholipids to a small but measurable extent. Thus, the hydroxyl group of tocopherol is more important than the hydroxyl group of cholesterol in influencing their interactions with phospholipids.

Chemical Phenomena↗
PubMedDate not supplied

Plasma clearance and oxidation of dodecanedioic acid in humans.

BACKGROUND: Dicarboxylic acids are water-soluble, contrary to monocarboxylic acids, and have a metabolic pathway intermediate between those of lipids and carbohydrates. Our goal was to investigate the plasma turnover and oxidation rate of dodecanedioic acid (C12) in eight healthy male volunteers. METHODS: A simultaneous infusion of both cold (0.24 mmol/min corresponding to 0.396 kcal/min) and radiolabeled (1.62 microCi/min) C12 free acid was performed. Blood specimens were sampled over a period of 360 minutes, and 24-hour urine samples were collected to measure the levels of C12 by high-performance liquid chromatography and liquid scintillation. Indirect calorimetry was continuously performed, and expired 14CO2 was collected. Binding of C12 in human plasma was determined in separate experiments using equilibrium dialysis. RESULTS: A linear one-compartment model was used to describe the kinetics of labeled C12. Its volume of distribution was 139.02 +/- 10.84 mL/kgbw (mean +/- SE), and its plasma elimination constant was 0.01 +/- 0.004 min-1. The 24-hour urinary excretion of C12 was 3.14 +/- 0.96 mmol, corresponding to about 7% of the administered dose. The amount of C12 oxidized, expressed as percent oxidation, was equal to 35.44 +/- 1.64%. The mean basal value of npRQ (0.80 +/- 0.006) significantly (p < .02) decreased during the infusion to 0.78 +/- 0.01, which is a value close to that theoretically calculated (0.77). The oxidation of free fatty acids was significantly increased at the end of the C12 infusion, whereas the glucose oxidation was reduced to about 50%. CONCLUSIONS: The experimental data suggest that C12 might represent a fuel substrate immediately available for tissue energy requirements, because a relevant amount of C12 is promptly oxidized. Its prompt oxidation and its conversion to succinic acid support the use of dodecanedioic acid in parenteral nutrition, especially in insulin-resistance conditions in which glucose uptake and oxidation is impaired.

Binding Sites↗
PubMed2000

Methylmalonic acid measured in plasma and urine by stable-isotope dilution and electrospray tandem mass spectrometry.

BACKGROUND: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) with electrospray ionization is robust and allows accurate measurement of both low- and high-molecular weight components of complex mixtures. We developed a LC-MS/MS method for the analysis of methylmalonic acid (MMA), a biochemical marker for inherited disorders of propionate metabolism and acquired vitamin B(12) deficiency. METHODS: We added 1 nmol of the internal standard MMA-d(3) to 500 microL of plasma or 100 microL of urine before solid-phase extraction. After elution with 18 mol/L formic acid, the eluate was evaporated, and butyl ester derivatives were prepared with 3 mol/L HCl in n-butanol at 65 degrees C for 15 min. For separation, we used a Supelcosil LC-18, 33 x 4.6 mm column with 60:40 (by volume) acetonitrile:aqueous formic acid (1 g/L) as mobile phase. The transitions m/z 231 to m/z 119 and m/z 234 to m/z 122 were used in the selected reaction monitoring mode for MMA and MMA-d(3,) respectively. The retention time of MMA was 2.2 min in a 3.0-min analysis, without interference of a physiologically more abundant isomer, succinic acid. RESULTS: Daily calibrations between 0.25 and 8.33 nmol in 0.5 mL exhibited consistent linearity and reproducibility. At a plasma concentration of 0.12 micromol/L, the signal-to-noise ratio for MMA was 40:1. The regression equation for our previous gas chromatography-mass spectrometry (GC-MS) method (y) and the LC-MS/MS method (x) was: y = 1.030 x -0.032 (S(y|x) = 1.03 micromol/L; n = 106; r = 0.994). Inter- and intraassay CVs were 3. 8-8.5% and 1.3-3.4%, respectively, at mean concentrations of 0.13, 0.25, 0.60, and 2.02 micromol/L. Mean recoveries of MMA added to plasma were 96.9% (0.25 micromol/L), 96.0% (0.60 micromol/L), and 94.8% (2.02 micromol/L). One MS/MS system used only overnight (7.5 h) replaced two GC-MS systems (30 instrument-hours/day) to run 100-150 samples per day, with reductions of total cost (supplies plus equipment), personnel, and instrument time of 59%, 14%, and 75%, respectively. CONCLUSIONS: This method is well suited for large-scale MMA testing (> or =100 samples per day) where a shorter analytical time is highly desirable. Reagents are less expensive than the anion-exchange/cyclohexanol-HCl method, and sample preparation of batches up to 100 specimens is completed in less than 8 h and is automated.

Chromatography, Liquid↗