scholarly journals The borohydride-reducible compounds of human aortic elastin. Demonstration of a new cyclic amino acid in alkali hydrolysate, and changes with age and in patients with annulo-aortic ectasia including one with Marfan syndrome

1985 ◽  
Vol 232 (1) ◽  
pp. 169-175 ◽  
Author(s):  
T Halme ◽  
M Jutila ◽  
T Vihersaari ◽  
P Oksman ◽  
N D Light ◽  
...  
Keyword(s):  
Acid Hydrolysis ◽  
Marfan Syndrome ◽  
Aldol Condensation ◽  
Condensation Product ◽  
Hydrolysis Product ◽  
Exchange Chromatography ◽  
Spectrometric Analysis ◽  
Cross Link ◽  
Aortic Ectasia ◽  
And Control

Human aortic elastin reduced with [3H]borohydride was analysed by ion-exchange chromatography after alkali or acid hydrolysis. Alkali hydrolysates of elastins contained a radioactive peak that was eluted between proline and leucine. This peak was not present in foetal elastin, but its proportion increased steadily during aging. Aortic samples from patients with annulo-aortic ectasia (aneurysm of the ascending aorta), including one with classical Marfan syndrome, contained less elastin (CNBr-insoluble material) than did the age-matched controls. The proportion of radioactivity in the new peak of all these aortas was low when compared with age-matched controls. Gas-chromatographic/mass-spectrometric analysis suggested that it contained a cyclic derivative of a hydrated aldol-condensation product. The concentration of the cross-link precursors, lysine aldehyde and aldol-condensation product (estimated from the acid-hydrolysis product 6-chloronorleucine and the acid-degradation product of reduced aldol-condensation product) was high in very young aortas but remained quite stable after childhood. No differences were observed in cross-link profiles of acid hydrolysates between pathological and control aortas. A low proportion of radioactivity in the new peak may indicate the presence of young or immature elastin in the pathological aortas.

scholarly journals The chemistry of the collagen cross-links. The characterization of Fraction C, a possible artifact produced during the reduction of collagen fibres with borohydride

1973 ◽  
Vol 135 (4) ◽  
pp. 657-665 ◽  
Author(s):  
Simon P. Robins ◽  
Allen J. Bailey
Keyword(s):  
Aldol Condensation ◽  
Condensation Product ◽  
Reduced Form ◽  
Borohydride Reduction ◽  
Cross Link ◽  
Collagen Fibres ◽  
Isolation And Identification ◽  
Cross Links

The present paper describes the isolation and identification of a major radioactive component of borotritide-reduced collagen, previously designated Fraction C. The derived structure for the compound confirms that it is identical with the ‘post-histidine’ component described by Tanzer et al. (1973) and given the trivial name histidino-hydroxymerodesmosine. Detailed studies of the effects of acid pH on the formation of Fraction C after borohydride reduction demonstrated the apparent lability of the non-reduced form, thus confirming our previous findings (Bailey & Lister, 1968). Inhibition of the formation of this component by the acid treatment appears to be due to protonation of the histidine imidazole group. Since the only new component formed on reduction of the acid-treated fibres was the reduced aldol condensation product, these results indicate that neither the histidine nor the hydroxylysine residues can be involved in covalent linkage with the aldol condensation product in the native fibre. It is suggested therefore that the proposed non-reduced aldimine form of Fraction C does not exist as an intermolecular cross-link in vivo. Thus the presence of histidino-hydroxymerodesmosine as a tetrafunctional cross-link in reduced collagen fibres is a result of a base-catalysed reaction promoted by the borohydride-reduction procedure and this component must therefore be considered as an artifact.

PHOSPHONOLIPIDS: XI. SYNTHESIS OF PHOSPHONOLIPID METABOLITES. L-α-GLYCERYL-(2-TRIMETHYLAMMONIUMETHYL)PHOSPHONATE

1967 ◽  
Vol 45 (11) ◽  
pp. 1747-1754 ◽  
Author(s):  
Erich Baer ◽  
Ranga Robinson
Keyword(s):  
Acid Hydrolysis ◽  
Phosphonic Acid ◽  
Cadmium Chloride ◽  
Condensation Product ◽  
Hydrolysis Product ◽  
Chloride Complex ◽  
Acid Analogue ◽  
Benzene Removal

The synthesis of a possible intermediate in phosphonolipid metabolism, viz. L-α-glyceryl-(2-trimethylammoniumethyl)phosphonate, a phosphonic acid analogue of L-α-glycerylphosphorylcholine, is described. The compound was obtained by condensation of D-acetone glycerol with (2-bromoethyl)metaphosphonate in boiling benzene, removal of the acetone group of the condensation product by acid hydrolysis, treatment of the hydrolysis product in dimethylformamide with trimethylamine at 60–62° for 3 days, isolation of L-α-glyceryl-(2-trimethylammoniumethyl)phosphate as cadmium chloride complex. Removal of the cadmium chloride was effected with a mixture of Amberlites IR-45 and IRC-50. A procedure for the preparation of (2-bromoethyl)metaphosphonate is reported.

Characterization of Chemical Impurities in Glutaraldehyde

1975 ◽  
Vol 33 ◽  
pp. 620-621
Author(s):  
B. J. Grenon ◽  
A. J. Tousimis
Keyword(s):  
Glutaric Acid ◽  
Spectroscopic Analysis ◽  
Aldol Condensation ◽  
Condensation Product ◽  
Amorphous Solid ◽  
Water Soluble ◽  
Impurity Component ◽  
Chemical Impurities ◽  
Soluble Liquid

Ever since the introduction of glutaraldehyde as a fixative in electron microscopy of biological specimens, the identification of impurities and consequently their effects on biologic ultrastructure have been under investigation. Several reports postulate that the impurities of glutaraldehyde, used as a fixative, are glutaric acid, glutaraldehyde polymer, acrolein and glutaraldoxime.Analysis of commercially available biological or technical grade glutaraldehyde revealed two major impurity components, none of which has been reported. The first compound is a colorless, water-soluble liquid with a boiling point of 42°C at 16 mm. Utilizing Nuclear Magnetic Resonance (NMR) spectroscopic analysis, this compound has been identified to be — dihydro-2-ethoxy 2H-pyran. This impurity component of the glutaraldehyde biological or technical grades has an UV absorption peak at 235nm. The second compound is a white amorphous solid which is insoluble in water and has a melting point of 80-82°C. Initial chemical analysis indicates that this compound is an aldol condensation product(s) of glutaraldehyde.

THE UPTAKE OF TRITIATED LYSINE VASOPRESSIN BY RAT AND PIG PITUITARY NEURAL LOBES IN VITRO

1971 ◽  
Vol 50 (4) ◽  
pp. 669-677 ◽  
Author(s):  
B. A. EDWARDS
Keyword(s):  
Tap Water ◽  
Exchange Chromatography ◽  
Control Group ◽  
Breakdown Product ◽  
Nacl Solution ◽  
Water Control ◽  
Neural Lobe ◽  
Lysine Vasopressin ◽  
And Control

SUMMARY Uptake of tritiated lysine vasopressin ([3H]LVP) was studied in halved neural lobes of rats (which had been given either tap water (control group) or 2% (w/v) NaCl solution as drinking water for 4 days) as well as in slices of pig neural lobe. Uptake of radioactivity into the neural lobes was shown but analysis of the extracts of incubated lobes of both species by ion exchange chromatography showed that very little of it remained in the tissue as hormone. In addition, some radioactivity was associated with trichloroacetic acid-insoluble proteins. After 90 min of incubation, and after correction for the breakdown, the uptake of unchanged [3H]LVP, expressed as a tissue: medium ratio, was 0·14 ± 0·04 and 0·09 ± 0·03 (mean ± s.e.m.) for the saline-treated and control rats respectively, while the tissue: medium ratios for the breakdown product(s) were 6·47 ± 0·45 and 5·50 ± 0·36. The results suggest uptake of [3H]LVP into the cell with almost complete intracellular breakdown of the hormone.

scholarly journals HbA1c levels in individuals heterozygous for hemoglobin variants

2017 ◽  
Vol 63 (4) ◽  
pp. 341-346
Author(s):  
Ricardo Silva Tavares ◽  
Fábio Oliveira de Souza ◽  
Isabel Cristina Carvalho Medeiros Francescantonio ◽  
Weslley Carvalho Soares ◽  
Mauro Meira Mesquita
Keyword(s):  
Test Group ◽  
Exchange Chromatography ◽  
Group Method ◽  
Control Group ◽  
Significant Difference ◽  
Hemoglobin Variants ◽  
Different Populations ◽  
And Control ◽  
Two Populations ◽  
Hba1c Levels

Summary Objective: To evaluate the levels of glycated hemoglobin (HbA1c) in patients heterozygous for hemoglobin variants and compare the results of this test with those of a control group. Method: This was an experimental study based on the comparison of HbA1c tests in two different populations, with a test group represented by individuals heterozygous for hemoglobin variants (AS and AC) and a control group consisting of people with electrophoretic profile AA. The two populations were required to meet the following inclusion criteria: Normal levels of fasting glucose, hemoglobin, urea and triglycerides, bilirubin > 20 mg/dL and non-use of acetylsalicylic acid. 50 heterozygous subjects and 50 controls were evaluated between August 2013 and May 2014. The comparison of HbA1c levels between heterozygous individuals and control subjects was performed based on standard deviation, mean and G-Test. Results: The study assessed a test group and a control group, both with 39 adults and 11 children. The mean among heterozygous adults for HbA1c was 5.0%, while the control group showed a rate of 5.74%. Heterozygous children presented mean HbA1c at 5.11%, while the controls were at 5.78%. G-Test yielded p=0.93 for children and p=0.89 for adults. Conclusion: Our study evaluated HbA1c using ion exchange chromatography resins, and the patients heterozygous for hemoglobin variants showed no significant difference from the control group.

Aniline hydroxylation and 7-ethoxycoumarin O-deethylation activities in solubilized and partially resolved liver cytochromes P-450 from ethanol-fed rats

1984 ◽  
Vol 62 (3) ◽  
pp. 266-271 ◽  
Author(s):  
V. Plourde ◽  
C. Hétu ◽  
J.-G. Joly
Keyword(s):  
Liver Microsomes ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Female Rats ◽  
Ethanol Administration ◽  
Molar Activity ◽  
Acidic Fraction ◽  
Chronic Ethanol Administration ◽  
And Control ◽  
Cytochrome P 450

Chronic ethanol administration in female rats enhances the apparent molar activity of liver microsomes for aniline hydroxylation and 7-ethoxycoumarin O-deethylation. Microsomal cytochromes P-450 from ethanol-fed and control rats have been solubilized and partially resolved in six fractions by anion-exchange chromatography. Induction of aniline hydroxylase activity by ethanol was associated with marked increases in the turnover numbers of the more basic cytochrome P-450 containing fractions in a reconstituted aniline hydroxylation system. Cytochrome P-450, exhibiting by far the highest 7-ethoxycoumarin O-deethylase activity, was eluted in a relatively acidic fraction; its turnover number with 7-ethoxycoumarin after ethanol consumption, however, did not differ significantly from that of the corresponding fraction from control microsomes. These observations suggest that induction of liver microsomal mixed function oxidases by ethanol may reflect the contribution of more than one cytochrome P-450 isozyme.

Structure Elucidation of 2-Amino-5-phenyl-2-oxazolin-4-one (Pemoline) and X-Ray Structure of its Hydrolysis Product 5-Phenyl-oxazolidine-2,4- dione

2005 ◽  
Vol 60 (8) ◽  
pp. 853-857 ◽  
Author(s):  
Piotr Kuś ◽  
Peter G. Jones ◽  
Rafał Celiński
Keyword(s):  
Acetic Acid ◽  
Hydrogen Bonds ◽  
Acid Hydrolysis ◽  
Single Crystals ◽  
Structure Elucidation ◽  
Hydrolysis Product ◽  
Spectroscopic Properties ◽  
Aqueous Acetic Acid ◽  
X Ray ◽  
Independent Molecules

In this study we compare spectroscopic properties of pemoline (2-amino-5-phenyl-2-oxazolin- 4-one) and its acid hydrolysis product 5-phenyl-oxazolidine-2,4-dione. Crystallization of pemoline from aqueous acetic acid gave single crystals of compound 2, the structure of which was determined by X-ray studies. All four crystallographically independent molecules form dimers linked by N-H···O = C hydrogen bonds.

scholarly journals The Effects of Microwave-Assisted Pretreatment and Cofermentation on Bioethanol Production from Elephant Grass

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Sefrinus Maria Dolfi Kolo ◽  
Deana Wahyuningrum ◽  
Rukman Hertadi
Keyword(s):  
Acid Hydrolysis ◽  
Hydrolysis Product ◽  
Pichia Stipitis ◽  
Pennisetum Purpureum ◽  
Bioethanol Production ◽  
Elephant Grass ◽  
Microwave Assisted ◽  
Liquid Chromatographic Analysis ◽  
High Concentrations ◽  
Liquid Chromatographic

The process of acid hydrolysis using conventional methods at high concentrations results in products having lower yields, and it needs a longer time of process; therefore, it becomes less effective. In this study, we analyzed the effects of microwave-assisted pretreatment and cofermentation on bioethanol production from elephant grass (Pennisetum purpureum). We used a combination of delignification techniques and acid hydrolysis by employing a microwave-assisted pretreatment method on elephant grass (Pennisetum purpureum) as a lignocellulosic material. This was followed by cofermentation with Saccharomyces cerevisiae ITB-R89 and Pichia stipitis ITB-R58 to produce bioethanol. The optimal sugar mixtures (fructose and xylose) of the hydrolysis product were subsequently converted into bioethanol by cofermentation with S. cerevisiae ITB-R89 and P. stipitis ITB-R58, carried out with varying concentrations of inoculum for 5 days (48 h) at 30°C and pH 4.5. The high-power liquid chromatographic analysis revealed that the optimal inoculum concentration capable of converting 76.15% of the sugar mixture substrate (glucose and xylose) to 10.79 g/L (34.74% yield) of bioethanol was 10% (v/v). The optimal rate of ethanol production was 0.45 g/L/d, corresponding to a fermentation efficiency of 69.48%.

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