Urinary metabolites of cis-9,10-methylene octadecanoic acid. cis-3,4-Methylene hexanedioic acid and related compounds

cis-3,4-Methylene hexanedioic acid has been discovered in human urine. It has been isolated and identified by mass spectrometry and synthesis. The daily excretion in nine subjects on a free diet was 88 mumol/day (range, 32 to 144 mumol/day). cis-3,4-Methylene hexanedioic acid was given orally to a rat. About 90% of the dose was recovered unchanged in the urine within 24 h. Intragastric administration of cis-9,10-methylene [9,10-3H2]octadecanoic acid to rats gave four labeled urinary metabolites. The major one was cis-3,4-methylene hexanedioic acid, the others were 2,3-methylene pentanedioic acid and isomers of methylene heptanedioic acid and methylene octanedioic acid. Within 72 h, about 40% of the administered radioactivity could be recovered from the urine and another 40% from the carcass. About 20% of the recovered radioactivity was found to be water. Of the radioactivity administered to rats orally as cis-9,10-methylene [9,10-3H2]octadecanoic acid methyl ester, about 50% could be recovered from the lymph of the thoracic duct within 9 h. Intraperitoneal administration of cis-9,10-methylene octodecanoic acid methyl ester to rats gave the same metabolites. Of the given amount, 50 mol % could be recovered from the urine as cis-3,4-methylene hexanedioic acid and 19 mol % as homologues within 38 days.

Gas chromatographic mass spectrometric identification of N-dicarboxylmonoglycines

A number of N-dicarboxylmonoglycines of biological interest have been synthesized. They were characterized by means of mass spectrometry. Gas chromatography of the methyl esters of methylmalonyl-, succinyl-, glutaryl-, adipyl-, suberyl- and sebacylglycines showed a single sharp peak for each compound on Dexsil 300 and OV-17 columns. Methylene unit values and mass spectra of the six methyl esters are reported.

Microdetermination of methylmalonic acid and other short chain dicarboxylic acids by gas chromatography: use in prenatal diagnosis of methylmalonic acidemia and in studies of isovaleric acidemia

We have developed a sensitive gas-chromatographic method for the determination of methylmalonic acid and other short chain dircarboxylic acids in biological samples. The method is based on the isolation of the short chain dicarboxylic acid fraction by Dowex 3 X 4 column chromatography followed by gas-chromatography analysis of these acids as methyl esters. 2-n-Pentyl-malonic acid is used as an internal standard. With this method, methylmalonic, succinic and methylsuccinic acids were consistently detected and accurately measured in urine and serum from normal subjects; the identity of these acids being verified by mass spectroscopy. The method's sensitivity permitted its used in the prenatal diagnosis of methylmalonic acidemia by measuring methylmalonic acid in urine and amniotic fluid from three pregnant heterozygous women at risk. One affected (vitamin B-12 responsive type) and two unaffected fetuses were correctly diagnosed prenatally as judged by postnatal investigations. The amount of methylmalonic acid in urine and amniotic fluid was distinctly increased (2 to 14 times normal) in the former and consistently normal in the latter two cases during the third trimester of pregnancy. Effect of prenatal therapy with large doses of vitamin B-12 was closely followed in the first case using analyses of multiple maternal urine specimens. Urinary methylsuccinic acid excretion was studied in two cases with isovaleric acidemia. It was normal in a sample from a patient in remission but was increased seven fold over control during an episode of ketoacidosis.

Liquid chromatographic separation and detection of nanogram quantities of biologically important dicarboxylic acids

Phenacyl and benzyl derivatives of some biologically significant dicarboxylic acids have been prepared in a quantitative manner using a crown ether catalyst. They were separated using reversed-phase chromatography. The column used was packed with Corasil II to which a C9 phase (nonyl) was bonded. Water-methanol (68:32) was used as the mobile phase. Detection limits in the range of 5--15 ng have been obtained for a non-optimized system. The ease of preparation of these derivatives, coupled with their excellent chromatographic properties, makes this a very attractive procedure for the investigation of mixtures containing biologically significant acids. The implications and future of this technique are discussed.

[Change in Bacillus anthracoides spores and their content of dipicolinic acid during germination]

The content of dipicolinic acid (DPA) was assayed in the spores of Bacillus anthracoides 96 during various stages of its growth. The content of DPA was ca. 10.7 per cent of the dry biomass weight in the seven-day-old culture containing 96 to 99 per cent of the spores in a "starvation" medium. The morphology of the culture was modified, and the content of DPA in the spores fell to 3.6 per cent half an hour after the inoculation into the medium favourable for the growth (MPA). During the following one to four hours of the germination, the refraction index of the spores and the content of DPA in them decreased (the content of DPA to 2 per cent).

Quantitative method for the gas chromatographic analysis of short-chain monocarboxylic and dicarboxylic acids in fermentation media

A method for the preparation and gas chromatographic analysis of the butyl esters of volatile (C-1-C-7) and nonvolatile (lactic, succinic, and fumaric) acids in microbial fermentation media is presented. Butyl esters were prepared from the dry salts of the acids. The esters were separated by temperature programming on a column of Chromosorb W coated with Dexsil 300 GC liquid phase and analyzed with a flame ionization detector. Apparent recoveries with butanol-HCl or butanol-H2SO4 as butylating agents were 80 to 90% for most acids. Chromatographic profiles of the butyl esters demonstrated that both volatile and nonvolatile acids can be detected and separated in 24 min on a single column. Standard calibration curves (peak area versus concentration) of the butyl esters were linear in the range of 5 to 40 mumol of acid per ml. The advantages of using an internal standard (heptanoic acid) for quantitating fatty acids in a mixture are given. Chromatograms of butylated fermentation media in which rumen anaerobic bacteria were grown illustrated that this method is useful for determining short-chain volatile and nonvolatile acids of toxonomic significance.

Dipicolinic acid location in intact spores of Bacillus megaterium

Beta-attenuation analysis of intact spores of Bacillus megaterium containing tritium-labeled dipicolinic acid has shown that dipicolinic acid is located in the spore protoplast and not in the cortex.

Effect of carbon source on size and associated properties of Bacillus megaterium spores

The size of the spores produced by Bacillus megaterium ATCC 19213 depended upon the nature of the carbon source present in the defined medium in which they were produced. Homogeneous preparations of small (0.38 mum(3)), nearly spherical spores were produced after batch culture in the presence of 2.8 mm citrate, and large (1.17 mum(3)), oblong spores were produced by replacement culture in the presence of 7.35 mm acetate. Large and small spores had approximately the same deoxyribonucleic acid content, density, and heat resistance. Large spores contained about 2.5 times the dipicolinic acid, glucosamine, ribonucleic acid, Mn(2+), and lipid and about 1.5 times the Mg(2+), Fe(2+), Ca(2+), and dry weight of small spores. Large spores were especially enriched in Zn(2+) (4.5-fold). More protein (1.5-fold) was extracted from small spores with 1 n NaOH than from large spores, possibly indicating a difference in the spore coats, but large spores contained about twice the Kjeldahl nitrogen of small spores. A difference in the coats may account for the fact that, unlike small spores, large spores showed improved germination with increased times and temperature of heat shocking. The possibility of determining the location of some of these substances within the spore by comparing the compositional ratios with estimated volumes of specific spore layers is discussed.

Preparation of methyl derivatives of some organic acids for analysis by gas-liquid chromatography

One microgram to 1 mg of organic acid was completely converted to its methyl derivative when it was dissolved in methanol and treated with an excess of ethereal diazomethane. Single products were obtained from α-ketoglutaric acid, oxaloacetic acid, pyruvic acid, glyoxylic acid, or hydroxypyruvic acid on reaction with thionyl chloride – methanol. The separation of 24 organic acids by gas–liquid chromatography on a Reoplex 400 column is presented.

The metabolism of p-fluorophenylacetic acid by a Pseudomonas sp. I. Isolation and identification of intermediates in degradation

A Pseudomonas sp. capable of growing on p-fluorophenylacetic acid as sole carbon source has been isolated using the enrichment culture technique. All the organic fluorine is released into the culture medium as fluoride ion during growth. A number of fluorinated intermediates have been isolated from the culture medium when resting cells were incubated with the substrate. Using infrared, nuclear magnetic resonance, and mass spectroscopic techniques together with chemical degradative procedures, these have been identified as D(+)-monofluorosuccinic acid, trans-3-fluoro-3-hexenedioic acid, (−)-4-carboxymethyl-4-fluorobutanolide, 4-fluoro-2-hydroxyphenylacetic acid, and 4-fluoro-3-hydroxyphenylacetic acid.

Analysis of the organic acids of Bryophyllum calycinum

Major and minor acids present in dried leaf tissue of Bryophyllum calycinum were identified or characterized using the combined methods of ion exchange chromatography, paper and thin-layer chromatography, gas chromatography, and infrared spectroscopy. After esterification of the acids in methanol containing H+ form cation exchange resin, their amounts were determined by gas chromatography. The acids identified and their approximate percentage amounts of the total acid content were: malic 32.5%, citric 10.1%, isocitric 46.5%, succinic 1.0%, fumaric 0.9%, pyruvic 1.0%, oxalacetic 0.4%, α-ketoglutaric 0.5%, glyoxylic 0.1%, lactic 0.2%, oxalic 0.2%, and cis-aconitic 1.6%. Tentative characteristics were proposed for previously undetermined acids present mainly in amounts from 0.05% to 0.6%. These were apparently mono-, di-, and tricarboxylic acids containing from three to seven carbons in the carbon chain. Most of these evidently had additional functional groups, including methyl, keto, and hydroxyl groups. The boiling points of the methyl esters of these acids ranged from 140° to 300°.

Murine amyloid fibril protein: isolation, purification and characterization

Murine amyloid has been produced by four different induction methods ( Mycobacterium butyricum, casein, casein plus Freund's adjuvant and endotoxin-induced mouse amyloidosis) in several strains and obtained from mice with "spontaneous" amyloidosis. The amyloid fibrils have been concentrated from spleen and liver. Electron microscopy of all of these preparations reveals the amyloid fibril to be 100 Å in width and composed of two parallel filaments, each measuring 35-40 Å in width and having the appearance of a twisted ribbon. X-ray diffraction of all preparations reveals a "backbone" spacing at 4.75 Å and a "side chain" spacing at 11 Å indicating a "β-pleated sheet" structure. Identification of the major protein component of amyloid fibril concentrates was made by combined use of sodium dodecyl sulfate polyacrylamide disc electrophoresis, labeling of the protein with 3H-tryptophan and Sepharose 4B gel filtration. Purification of the amyloid protein from spontaneous amyloidosis liver was accomplished by sequential gel filtration with 5 M guanidine in 1 N acetic acid on Sepharose 4B and Sephadex G-100 or G-75 columns. The material is a unique glycoprotein with a molecular weight of 7200, a high content of dicarboxylic and short chain amino acids, a significant amount of tryptophan and an unreactive NH2-terminal amino acid, tentatively identified as pyrrolid-2-one-5-carboxylic acid. There are no methionine, half-cystine, hydroxylysine or hydroxyproline residues. Murine amyloid protein, therefore, has striking similarities to many human amyloid protein preparations. It differs from the human proteins in the similarity of molecular weights of different preparations.

Human amyloid protein: chemical variability and homogeneity

The morphology of the fibril of amyloid derived from different individuals is similar, but occasionally significant differences are noted. All human amyloid filaments have a "β-pleated sheet" conformation as revealed by x-ray diffraction, and those examined after orientation show a "cross-β" pattern. All amyloid fibril concentrates studied so far can be fractionated to obtain the major amyloid protein component(s) by sequential gel filtration with 5 M guanidine-HCl in 1 N acetic acid on Sepharose 4B and Sephadex G-100 or G-75 columns with the removal of over 28% of proteins representing minor constituents. The major amyloid protein(s) obtained from the spleen and/or liver of six patients is found to contain tryptophan, to be deficient in hydroxylysine and hydroxyproline and usually at least one commonly occurring amino acid and to have a high content of dicarboxylic acid and short chain amino acids and unreactive (blocked) NH2-terminal groups or aspartic acid-asparagine (Asx). However, the amyloid protein(s) from each individual differs from that of the others in molecular weight, in amino acid composition and in the presence or absence of specific tryptic peptides. Amyloid protein(s) from the liver and spleen of the same individual is identical. No chemical characteristics distinguish amyloid proteins derived from cases classified clinically as "primary" from those classified as "secondary." There is a striking chemical similarity between amyloid proteins and the NH2-terminal variable fragment of the light and heavy chain of immumoglobulin proteins.

Distribution of enzymes in mesophyll and parenchyma-sheath chloroplasts of maize leaves in relation to the C4-dicarboxylic acid pathway of photosynthesis

1. Mesophyll and parenchyma-sheath chloroplasts of maize leaves were separated by density fractionation in non-aqueous media. 2. An investigation of the distribution of photosynthetic enzymes indicated that the mesophyll chloroplasts probably contain the entire leaf complement of pyruvate,P(i) dikinase, NADP-specific malate dehydrogenase, glycerate kinase and nitrite reductase and most of the adenylate kinase and pyrophosphatase. The fractionation pattern of phosphopyruvate carboxylase suggested that this enzyme may be associated with the bounding membrane of mesophyll chloroplasts. 3. Ribulose diphosphate carboxylase, ribose phosphate isomerase, phosphoribulokinase, fructose diphosphate aldolase, alkaline fructose diphosphatase and NADP-specific ;malic' enzyme appear to be wholly localized in the parenchyma-sheath chloroplasts. Phosphoglycerate kinase and NADP-specific glyceraldehyde phosphate dehydrogenase, on the other hand, are distributed approximately equally between the two types of chloroplast. 4. After exposure of illuminated leaves to (14)CO(2) for 25sec., labelled malate, aspartate and 3-phosphoglycerate had similar fractionation patterns, and a large proportion of each was isolated with mesophyll chloroplasts. Labelled fructose phosphates and ribulose phosphates were mainly isolated in fractions containing parenchyma-sheath chloroplasts, and dihydroxyacetone phosphate had a fractionation pattern intermediate between those of C(4) dicarboxylic acids and sugar phosphates. 6. These results indicate that the mesophyll and parenchyma-sheath chloroplasts have a co-operative function in the operation of the C(4)-dicarboxylic acid pathway. Possible routes for the transfer of carbon from C(4) dicarboxylic acids to sugars are discussed.

Differential responses to fasting and subsequent feeding by microsomal systems of rat liver: 6- and 9-desaturation of fatty acids

Hepatic microsomal preparations from nonfasted, fasted, and fasted-fed rats were employed, together with cofactors, in studies of 9-desaturation of stearate-1-(14)C and 6-desaturation of linolenate-1-(14)C. Prior fasting sharply reduced 9-desaturation but did not affect 6-desaturation; feeding restored 9-desaturation. Position of desaturation was determined by permanganate-periodate oxidation and separation of the dicarboxylic acids. Feeding after fasting stimulated both desaturase systems but either dl-ethionine or actinomycin D prevented this. Dietary carbohydrate or saturated fat increased 9-desaturation and dietary protein increased 6-desaturation. Insulin treatment of nonfasted rats increased 9-desaturation but not 6-desaturation. High dietary unsaturated fat (20% safflower oil) stimulated 6-desaturation but inhibited the 9-desaturation response to feeding. The results indicate that the two desaturases are distinct and are inducible in response to different substances.