FREE SULFHYDRYL GROUPS IN HAPTOGLOBIN

1967 ◽  
Vol 45 (4) ◽  
pp. 551-556 ◽  
Author(s):  
Brenda L. Tattrie ◽  
G. E. Connell
Keyword(s):  
Acid Hydrolysis ◽  
Guanidine Hydrochloride ◽  
Spectrophotometric Titration ◽  
Sulfhydryl Groups

Human haptoglobin of types 1-1 and 2-2 has been examined for its content of free sulfhydryl groups by two methods: (i) treatment of haptoglobin in the presence of 7.2 M guanidine hydrochloride with 14C-iodoacetate followed by acid hydrolysis and determination of 14C-carboxymethylcysteine content, and (ii) spectrophotometric titration of haptoglobin in the presence of 7.2 M guanidine hydrochloride with p-chloromercuribenzoate. By both methods, the content of free sulfhydryl was less than 1 equiv/105 g of protein.

DETERMINATION OF MICRO-AMOUNTS OF 5β-PREGNAN-3α-OL-20-ONE IN URINE USING INFRARED-SPECTROMETRY

1962 ◽  
Vol 41 (2) ◽  
pp. 234-246 ◽  
Author(s):  
H. J. van der Molen
Keyword(s):  
Infrared Spectrum ◽  
Quantitative Determination ◽  
Acid Hydrolysis ◽  
Chromatographic Separation ◽  
Pure Form ◽  
Infrared Spectrometry ◽  
Hydrolysis Of

ABSTRACT A procedure for the quantitative determination of 5β-pregnan-3α-ol-20-one in urine is described. After acid hydrolysis of the pregnanolone-conjugates in urine, the free steroids are extracted with toluene. Pregnanolone is isolated in a pure form as its acetate; after chromatographic separation of the free steroids on alumina, the fraction containing pregnanolone is acetylated and rechromatographed on alumina. Quantitative determination of the isolated pregnanolone-acetate is carried out with the aid of the infrared spectrum recorded by a micro KBr-wafermethod. The reliability of the method under various conditions is discussed under the headings, specificity, accuracy, precision and sensitivity. It is possible to determine 30–40 μg pregnanolone in a 24-hours urine portion with a precision of 25%.

The impact of acid hydrolysis conditions on carbohydrate determination in lignocellulosic materials: a case study with Eucalyptus globulus bark

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ricardo Jorge Oliveira ◽  
Bruna Santos ◽  
Maria J. Mota ◽  
Susana R. Pereira ◽  
Pedro C. Branco ◽  
...  
Keyword(s):  
Acid Hydrolysis ◽  
Eucalyptus Globulus ◽  
Industrial Processes ◽  
Lignocellulosic Materials ◽  
Optimal Conditions ◽  
Hydrolysis Conditions ◽  
The Impact ◽  
Eucalyptus Bark

Abstract Lignocellulosic biomass represents a suitable feedstock for production of biofuels and bioproducts. Its chemical composition depends on many aspects (e.g. plant source, pre-processing) and it has impact on productivity of industrial bioprocesses. Numerous methodologies can be applied for biomass characterisation, with acid hydrolysis being a particularly relevant step. This study intended to assess the most suitable procedures for acid hydrolysis, taking Eucalyptus globulus bark as a case study. For that purpose, variation of temperature (90–120 °C) was evaluated over time (0–5 h), through monosaccharides and oligosaccharides contents and degradation. For glucose, the optimal conditions were 100 °C for 2.5 h, reaching a content of 48.6 wt.%. For xylose, the highest content (15.2 wt.%) was achieved at 90 °C for 2 h, or 120 °C for 0.5 h. Maximum concentrations of mannose and galactose (1.0 and 1.7 wt.%, respectively) were achieved at 90 and 100 °C (2–3.5 h) or at 120 °C (0.5–1 h). These results revealed that different hydrolysis conditions should be applied for different sugars. Using this approach, total sugar quantification in eucalyptus bark was increased by 4.3%, which would represent a 5% increase in the ethanol volume produced, considering a hypothetical bioethanol production yield. This reflects the importance of feedstock characterization on determination of economic viability of industrial processes.

Optimisation of microwave-assisted acid hydrolysis for the determination of seleno-amino acids bound to proteins in powdered milk, lyophilized milk and infant formula

2019 ◽  
Vol 79 ◽  
pp. 128-133
Author(s):  
Romina Lopez ◽  
Luis Escudero ◽  
Roberto D’Amato ◽  
Daniela Businelli ◽  
Massimo Trabalza-Marinucci ◽  
...  
Keyword(s):  
Amino Acids ◽  
Acid Hydrolysis ◽  
Infant Formula ◽  
Powdered Milk ◽  
Microwave Assisted

Determination of Unconjugated and Total N-Acetyl-p-aminophenol (NAPA) in Urine and Serum

1967 ◽  
Vol 13 (3) ◽  
pp. 215-219 ◽  
Author(s):  
Karel P M Heirwegh ◽  
Johan Fevery
Keyword(s):  
Liver Disease ◽  
Acid Hydrolysis ◽  
Azo Dye ◽  
Acidic Medium ◽  
Diazonium Salt ◽  
Accurate Method ◽  
Total N ◽  
Hydrolysis Of ◽  
Urine And Serum

Abstract A sensitive and accurate method is described for the determination of N-acetyl-p-aminophenol (NAPA) and its metabolites in urine and serum. In strongly acidic medium, p-aminophenol (PAP) resulting from differential extraction and acid hydrolysis of total NAPA and unconjugated NAPA, is diazotized and the diazonium salt coupled with N-(1-naphthyl)ethylenediamine (NED) in the presence of ethanol. The blue azo dye formed is determined spectrophotometrically. Application to liver disease is briefly reported.

scholarly journals Determination of Exposed Sulfhydryl Groups in Heated β-Lactoglobulin A Using IAEDANS and Mass Spectrometry

2007 ◽  
Vol 55 (17) ◽  
pp. 7107-7113 ◽  
Author(s):  
Joseph J. Kehoe ◽  
André Brodkorb ◽  
Daniel Mollé ◽  
Emilie Yokoyama ◽  
Marie-Héléne Famelart ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Sulfhydryl Groups ◽  
Β Lactoglobulin

scholarly journals Determination of Sulfhydryl Groups in Milk Using Ellman's Procedure and Clarifying Reagent®

1993 ◽  
Vol 76 (8) ◽  
pp. 2152-2155 ◽  
Author(s):  
Marie-France Guingamp ◽  
Gerard Humbert ◽  
Guy Linden
Keyword(s):  
Sulfhydryl Groups
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