scholarly journals The isolation and characterization of bilirubin diglucuronide, the major bilirubin conjugate in dog and human bile

1976 ◽  
Vol 155 (3) ◽  
pp. 477-486 ◽  
Author(s):  
E R Gordon ◽  
C A Goresky ◽  
T H Chang ◽  
A S Perlin

The chemical structure of the major conjugate of bilirubin was unequivocally elucidated by structural analysis. The conjugated bilirubins were first separated from the lipid components of human duodenal aspirates or dog gall-bladder bile, and then resolved by t.l.c. into a series of tetrapyrroles. The major tetrapyrrole was then converted into its more stable dipyrrolic azo derivative for further analysis. The conjugated moiety of the azopigment was characterized after methanolysis with sodium methoxide. This reaction yields two types of product, those soluble in water and those soluble in organic solvents. The organic-soluble fraction was shown by t.l.c. and mass spectrometry to contain the methyl esters of the dipyrrolic azo derivatives of bilirubin. The water-soluble materials were analysed by enzymic procedures, t.l.c., n.m.r. spectrometry and combined g.l.c. and mass spectrometry. This analysis showed that the only water-soluble product resulting from the methanolysis was glucuronic acid. The structure was identical with that of pure standards, on both mass spectrometry and n.m.r. spectroscopy. No contaminating moieties were found. Quantitative measurement indicated that the glucuronic acid had been released in a 1:1 molar ratio with the resulting methyl esters of the dipyrrolic azo derivatives of bilirubin. This unequivocally establishes bilirubin diglucuronide as the major pigment present in bile. Past problems with identification of bilirubin diglucuronide were shown to originate from procedures which resulted in incomplete separation and isolation of the azopigments of the conjugated bilirubins, owing to contamination by biliary lipids.

1977 ◽  
Vol 167 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Ellen R. Gordon ◽  
Tak-Hang Chan ◽  
Karen Samodai ◽  
Carl A. Goresky

Bilirubin and its conjugates were extracted from either dog gall-bladder bile or bile-containing human duodenal juice into chloroform containing 10mm-tetraheptylammonium chloride. The intact bilirubin tetrapyrroles were then separated by t.l.c. Structural elucidation was made after coupling of the individual pigments with diazonium salts. Four azopigments were detected: azopigment αo or dipyrrolic azobilirubin; azopigment δ or dipyrrolic azobilirubin monoglucuronide; azopigment α3 or dipyrrolic azobilirubin monoglucoside; and, from dog gall-bladder bile, azopigment α2. The last conjugate required further verification of its structure. After methanolysis, it was shown by combined g.l.c.–mass spectrometry to contain xylose in a 1:1 molar ratio with the azopigments of bilirubin. Human bile contained 86% bilirubin diglucuronide, 7% bilirubin monoglucuronide monoglucoside diester, 4% bilirubin monoglucuronide and 3% bilirubin. Dog gall-bladder bile had a considerably different composition; it contained 47% bilirubin diglucuronide, 40% bilirubin monoglucuronide monoglucoside diester, 8% bilirubin monoglucuronide, 4% bilirubin diglucoside, 1–2% bilirubin and traces of conjugates containing xylose. The total bilirubin content and proportions of the conjugates did not change in bile that was frozen and stored at −20°C under N2, whereas in the chloroform/tetraheptylammonium chloride extract, similarly stored, total pigment was slowly lost and the diglucuronide conjugate converted into the monoglucuronide.


2017 ◽  
Author(s):  
Stefan Jenkins ◽  
Tami L Swenson ◽  
Rebecca Lau ◽  
Andrea Rocha ◽  
Alex Aaring ◽  
...  

Exometabolomics enables analysis of metabolite utilization of low molecular weight organic substances by soil isolates. Environmentally-based defined media are needed to examine ecologically relevant patterns of substrate utilization. Here, we describe an approach for the construction of defined media using untargeted characterization of water soluble soil metabolites. To broadly characterize soil metabolites, both liquid chromatography mass spectrometry (LC/MS) and gas chromatography mass spectrometry (GC/MS) were used. With this approach, 96 metabolites were identified, including amino acids, amino acid derivatives, sugars, sugar alcohols, mono- and di-carboxylic acids, osmolytes, nucleobases, and nucleosides. From this pool of metabolites, 25 were quantified. Water soluble organic carbon was fractionated by molecular weight and measured to determine the fraction of carbon accounted for by the quantified metabolites. This revealed that, much like soil microbial community structures, these soil metabolites have an uneven quantitative distribution, with a single metabolite, trehalose accounting for 9.9 percent of the (< 1 kDa) water extractable organic carbon. This quantitative information was used to formulate two soil defined media (SDM), one containing 23 metabolites (SDM1) and one containing 46 (SDM2). To evaluate SDM for supporting the growth of bacteria found at this field site, we examined the growth of 30 phylogenetically diverse soil isolates obtained using standard R2A medium. The simpler SDM1 supported the growth of up to 13 isolates while the more complex SDM2 supported up to 25 isolates. One isolate, Pseudomonas corrugata strain FW300-N2E2 was selected for a time-series exometabolomics analysis to investigate SDM1 substrate preferences. Interestingly, it was found that this organism preferred lower-abundance substrates such as guanine, glycine, proline and arginine and glucose and did not utilize the more abundant substrates maltose, mannitol, trehalose and uridine. These results demonstrate the viability and utility of using exometabolomics to construct a tractable environmentally relevant media. We anticipate that this approach can be expanded to other environments to enhance isolation and characterization of diverse microbial communities.


1981 ◽  
Vol 27 (6) ◽  
pp. 599-603 ◽  
Author(s):  
Svein Valla ◽  
Johs. Kjosbakken

An extracellular, acidic polysaccharide has been isolated from the culture medium of a spontaneous cellulose-negative strain of Acetobacter xylinum. Chemical analysis shows that the polymer is composed of glucose, mannose, rhamnose, and glucuronic acid in a molar ratio approximating 3:1:1:1. No evidence for the presence of cellobiose units as structural parts in the polysaccharide has been found.


1990 ◽  
Vol 111 (4) ◽  
pp. 1639-1643 ◽  
Author(s):  
S C Ho ◽  
M Schindler ◽  
J L Wang

Extracts of Bradyrhizobium japonicum were fractionated on Sepharose columns covalently derivatized with lactose. Elution of the material that was specifically bound to the affinity column with lactose yielded a protein of Mr approximately 38,000. Isoelectric focusing of this sample yielded two spots with pI values of 6.4 and 6.8. This protein specifically bound to galactose-containing glycoconjugates, but did not bind either to glucose or mannose. Derivatives of galactose at the C-2 position showed much weaker binding; there was an 18-fold difference in the relative binding affinities of galactose versus N-acetyl-D-galactosamine. These results indicate that we have purified a newly identified carbohydrate-binding protein from Bradyrhizobium japonicum, that can exquisitely distinguish galactose from its derivatives at the C-2 position.


Proceedings ◽  
2019 ◽  
Vol 29 (1) ◽  
pp. 125 ◽  
Author(s):  
Uţoiu ◽  
Iosăgeanu ◽  
Toma ◽  
Mănoiu ◽  
Uţoiu ◽  
...  

Kefiran is the water-soluble branched glucogalactan from kefir grains and it contains Dgalactoseand D-glucose units in approximately equal quantities [...]


1972 ◽  
Vol 128 (5) ◽  
pp. 1319-1328 ◽  
Author(s):  
S. J. Quirk ◽  
G. B. Robinson

1. Brush borders were isolated from rabbit kidney-cortex homogenates by rate-zonal centrifugation through a sucrose density gradient in a B-XIV zonal rotor, followed by differential centrifugation. 2. The method of preparation gave brush borders of high purity with a reasonable yield. The morphological appearance supported the evidence from enzymic and chemical investigations, that the brush borders were only slightly contaminated with endoplasmic reticulum, mitochondria, lysosomes and nuclei. 3. The molar ratio of cholesterol to phospholipid lay within the range found in other plasma membranes, but the carbohydrate content was double that found in liver plasma membranes. 4. Alkaline phosphatase, maltase, trehalase and aminopeptidase were major enzymic constituents of the brush borders, and had an approximately equal yield and enrichment, but none of these enzymes fulfilled the criteria for marker enzymes. 5. Mg2+-dependent and Na+,K+-dependent adenosine triphosphatases, although found in brush borders, had low yields and low enrichments.


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