Nelly Blumenkrantz

New method for quantitative determination of uronic acids

Abstract A new method for determination of uronic acids with meta-hydroxydiphenyl is introduced. It is simpler, quicker, more sensitive, and more specific than other methods, and it needs lesser amounts of fluid. It is recommended for determination of acid mucopolysaccharides in biological materials.

An assay for hydroxyproline and proline on one sample and a simplified method for hydroxyproline.

Abstract A critical study of the different steps involved in previous procedures for hydroxyproline determination allows the omission of some of them without losing the advantages of the methods. Studies on the first toluene extract, usually discarded, shows that (1) at room temperature, the oxidation product of proline with chloramine T dose not interfere with the color reaction of the hydroxyproline oxidation product, and (2) it allows the detection of both imino acids on the same sample provided the first toluene extract is further oxidized with periodate. The modified hydroxyproline assay presented gives similar results with a simpler procedure.

An assay for total hexosamine and a differential assay for glucosamine and galactosamine.

Two new procedures are presented for quantitative determination of glucosamine and galactosamine. One, which is proposed for total hexosamine, yields chromogens of equal intensity with equal concentration of glucosamine and galactosamine. There is addition of the correspondent chromogens when they are present in mixtures. The procedure is presented as a manual as well as an automated assay. The other procedure is a differential assay which allows the detection of galactosamine without interference by glucosamine. By the two procedures, the hexosamines present in acid mucopolysaccharides and/or glycoproteins can be determined.

A quick and specific assay for hydroxyproline

Abstract Hydroxyproline is oxidized by periodic acid and various periodates in strong acid medium, while proline is oxidized only in neutral medium (1). This phenomenon led us to elaborating an assay method for quantitative determination of hydroxyproline in the presence of proline. The procedure and its application for quantitative assay of hydroxyproline in isolated collagen and in skin and urine are reported below.

An automated procedure for quantitative determination of hydroxyproline

1. An automated procedure for quantitative assay of hydroxyproline in urine including a comparison with manual assays in common use is described. The procedure is based on the oxidation of hydroxyproline by chloramine T in aqueous solution. The oxidation product reacts with Ehrlichs reagent, and the chromogen obtained is registered in a recorder connected to the colorimeter. 2. The assay can be used to determine hydroxyproline in other biological materials as well. It includes other reagents and a simpler flow diagram than a previously reported method for determination of hydroxyproline in collagen and elastin. The method is simple, sensitive, reproducible, and specific. It is proposed for studies of collagen metabolism and recommended for routine medical chemistry laboratories.

An improved method for the assay of hydroxylysine.

Abstract An improved method for specific detection of hydroxylysine is presented. The procedure is based on the capability of 0.0015 m periodic acid and periodates to oxidize hydroxylysine without interference of proline. Glycosylated hydroxylysine can be detected in collagen by oxidation of unglycosylated residues before hydrolysis.

Simple procedures for determination of [14C]hydroxyproline

Two improved and simplified procedures are presented for determination of [14C]hydroxyproline. Simplification is achieved by boiling samples without previous toluene extractions and, after boiling, passing the toluene extracts through a silicic acid column. Procedure I avoids incomplete toluene extraction of [14C]proline derivatives and uses instead a specific adsorption to a silicic acid column. Procedure IIA introduces inter alia the silicic acid column to reduce the interference of incompletely extracted [14C]proline. Procedure IIB simplifies procedure IIA by replacing extraction of [14C]proline derivatives with a silicic acid column. The new procedures are simple, handy, specific and reproducible methods for determination of [14C]hydroxyproline and are preferable to any other method known today. Procedure IIB is specially recommended for routine use.

EFFECT OF DIPHENYLHYDANTOIN ON CONNECTIVE TISSUE

Decreased collagen biosynthesis by 10‐day‐old chick embryo tibiae was observed under the influence of sodium diphenylhydantoinate. A complex was formed by the drug and ferrous or ferric ions. An inhibition of the hydroxylation of 14C‐proline and 14C‐lysine may be a consequence of the binding of ferrous ions to the drug. In addition, a decreased incorporation of 14C‐glucosamine was observed. A hampered collagen biosynthesis has also been observed to be effected by other drugs capable of producing a lupus‐like syndrome.

Effect of amino acids on collagen biosynthesis

SummaryThe effect of various amino acids on collagen biosynthesis was studied in organ cultures of chicken embryo tibiae.Competitive interrelationship between selected amino acids influences independently the uptake of proline and lysine, precursors of hydroxyproline and hydroxylysine, respectively, which are the two amino acids characteristics of collagen.On the basis of these influences, the possibility of biosynthesis of anomalous collagens is stressed. Parallel studies of biosynthesis of hydroxyproline and hydroxylysine are necessary.

Automated quantitative assay for hydroxylysine in biological materials

The adaption to the Auto-Analyzer of a highly sensitive, specific, reproducible quick assay for hydroxylysine is represented. No interference of proline or hydroxyproline are observed.