Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Ninhydrin”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources
PubMed1980

Diet and medications giving positive ninhydrin reactions on TLC in a newborn urinary screening program.

During amino acid analysis of over 520,000 urine samples (provided by a urinary screening program), we often noticed different dietary compounds or medications giving positive ninhydrin reactions which could interfere with the interpretation of the thin layer chromatograms. Consequently, we have done an in vitro study of the chromatographic behaviour of the most frequently encountered artifacts in urine. We believe that the results of this work should make it easier for other laboratories doing similar analyses to recognize the presence of such compounds, thus facilitating the evaluation of their chromatograms.

Amino Acids↗
PubMed2001

Spectrophotometric method for the determination of amlodipine besylate with ninhydrin in drug formulations.

A spectrophotometric method has been developed for the determination of amlodipine besylate in pure form and in pharmaceutical preparations. The method is based on the reaction of the primary amino group of the drug with ninhydrin in N,N'-dimethylformamide (DMF) medium producing a coloured complex which absorbs maximally at 595 nm. Beer's law is obeyed in the concentration range of 10-60 microg ml(-1) with RSD of 0.66% and molar absorptivity of 6.52 x 10(3) l mol(-1) cm(-1). All variables were studied in order to optimize the reaction conditions. The proposed method has been applied successfully to the analysis of the bulk drug and its dosage forms. No interference was observed from common pharmaceutical adjuvants. Statistical comparison of the results with the reference method shows excellent agreement and indicates no significant difference in accuracy and precision.

Amlodipine↗
PubMed2003

Application of ninhydrin to spectrophotometric determination of famotidine in drug formulations.

A simple and fast spectrophotometric procedure has been developed for the determination of famotidine. The method is based on the interaction of ninhydrin with primary amines present in the famotidine. This reaction produces a blue coloured product which absorbed maximally at 590 nm. The effects of variables such as reagent concentration and reaction time were investigated to optimize the procedure. Beer's law was obeyed in the concentration range of 5-30 microg ml(-1) with molar absorptivity of 6.99 x 10(3) l M(-1) cm(-1). The results were validated statistically. The proposed method has been applied to the determination of famotidine in tablets with satisfactory results.

Chemistry, Pharmaceutical↗
PubMed1981

Identification of basic drugs by the thin-layer chromatographic profiles of their ninhydrin complexes.

Fifty-two common basic drugs produce various colours when spotted with ninhydrin on plastic thin-layer plates and heated. When the plate is then developed in a suitable solvent each of the coloured spots separates into a variety of additional coloured spots and patches, the number of which depends on the temperature of heating. The relative intensity and spatial arrangement form a profile that is highly characteristic of the compounds. The formation of such profiles was investigated at 100 and 160 degrees C.

Chromatography, Thin Layer↗
PubMed1975

Automated single-column analysis of amino acids using ascorbic acid as reductant for air-stable ninhydrin.

The procedure for operation of a constant-temperature, single-column automated amino acid analyser in the sub-nanomole range is described. The cycle time for a complete analysis is 90 min including equilibration for next cycle. Eluting buffers can be made in the laboratory or commercially available concentrates (Pico-Buffers) can be used. A novel reducing agent, ascorbic acid, incorporated into the column buffers was used to reduce air-stable ninhydrin.

Amino Acids↗
PubMed1985

High-performance liquid chromatographic analysis of guanidino compounds using ninhydrin reagent. II. Guanidino compounds in blood of patients on haemodialysis therapy.

An automated high-performance liquid chromatographic method using alkali-ninhydrin reagent for the post-column derivatization of guanidines has been developed. This procedure was applied to measurements made before and after haemodialysis. Among the guanidino compounds found in human blood, methylguanidine showed the lowest removal rate. The removal rate of guanidinosuccinic acid correlated with the plasma alpha 1-globulin fraction. The removal rate of each guanidino compound decreased with the period of dialysis.

Chromatography, High Pressure Liquid↗
PubMed1962

Contribution of E-amino groups to ninhydrin color production in proteins.

The ninhydrin color given by model compounds and by characterized proteins shows a consistent contribution from the epsilon-amino group of lysine of about 67 percent of that of an alpha-amino group, except in free lysine or in N-terminal lysine, where the epsilon-amino group makes a small contribution (7 to 10 percent) to the total color. This information can be applied to structure determination of N(epsilon) peptides of lysine.

Lysine↗
PubMedDate not supplied

Ninhydrin sweat test in leprosy.

Loss of sensation is an important feature of leprosy. Loss of sweating over the affected site due to loss of autonomic function occurs in leprosy. We have studied a simple, non-invasive, rapid method, using 1% ninhydrin in acetone, to detect loss of sweat function. The test was effective in detecting and grading the sweat function in 84 cases of different types of leprosy. We were able to detect normal sweating in 16 patients with hypopigmented lesion due to causes other than Hansen's disease.

Autonomic Nervous System Diseases↗
PubMedDate not supplied

[Allergic contact eczema to ninhydrin].

Use of a surgical marking pen to indicate test areas on the skin during epicutaneous evaluation caused eczema in three female patients undergoing patch testing. Close scrutiny of the individual components of this surgical marking pen revealed contact dermatitis to ninhydrine, a substance whose allergenic potential has hardly been noted in the relevant literature.

Adult↗
PubMed1987

[Comparison of 2 technics (ninhydrin vs. TNSB) for estimating circulating amino acid nitrogen, applied to the study of the intestinal absorption of solutions of free amino acids or small peptides].

The intestinal absorption of nitrogen from amino acids present in a solution of small peptides or of free amino acids with the same pattern, perfused intraduodenally, has been studied using two analytical techniques [2, 4, 6 trinitrobenzene-1-sulfonic acid (TNBS) after dialysis of the blood vs ninhydrine after chromatography] to determine post-perfusion porto arterial differences and to measure blood flow rate in the portal vein. The results obtained on blood nitrogen level with the chromatographic method were always higher than those obtained using the TNBS method. The differences in the values varied from 8 to 24% according to post-perfusion time and to blood sample origin (arterial or portal). On the contrary, the absorbed amounts of nitrogen measured by either analytical technique were not very much different: no significant and systematic deviation was found between the two. The TNBS method is thus useful as a preliminary approach to very elaborate studies on intestinal absorption. In these conditions, the nitrogen of amino acids from duodenally-perfused small peptides was absorbed earlier and more rapidly than that from a perfusion of a solution of free amino acids. The amount of nitrogen appearing in the portal vein five hours after perfusion exceeded the perfused amount owing to considerable recycling of endogenous nitrogen.

Amino Acids↗
PubMed1986

Sensitivity enhancement of ninhydrin-treated latent fingerprints by enzymes and metal salts.

Lyophilized Sigma Type III trypsin has been applied to latent prints two weeks to two months old. This trypsin preparation eliminates the background problems that had been encountered with old prints in a previous study. Zinc chloride treatment of latent prints previously exposed to ninhydrin enhances their detectability upon laser examination. However, it has been reported that the zinc chloride reaction occasionally fails to occur. Accordingly, we have investigated the optimization of this reaction. We find that high humidity and elevated temperature, particularly the former, are needed. Cadmium nitrate, although it produces weaker fluorescence than zinc chloride, may at times be useful. Reaction conditions are much the same as those for zinc chloride.

Cadmium↗
PubMed1983

Spectrophotometric determination of hydralazine hydrochloride tablets using ninhydrin.

A method is described for the assay of hydralazine HCl in tablets, based on the colored product formed by the reaction between hydralazine and ninhydrin. The reaction is conducted at room temperature in a pH 3 buffer solution and the colored product is measured spectrophotometrically at the absorption maximum at 442 nm. Under the stipulated conditions, this reaction is highly specific for hydralazine and is not affected by other drugs which may be used in combination with hydralazine. Results of infrared and mass spectrometric studies suggested that the colored product is a hydrazone. Ultraviolet spectrophotometry also showed that dilute solutions of hydralazine degrade rapidly in the presence of alcohols.

Hydralazine↗
PubMed1980

[GABA fluophore formation due to ninhydrin reaction in the octanolic milieu. Spectrofluorometric investigation. 1. (author's transl)].

As a result of the reaction of ninhydrin with gamma-aminobutyric acid and glutamic acid in the octanolic milieu, a fluorescent product, presumably a copper-II-chelat-complex, was formed. This appears analogous to the fluorescence histochemical procedure. the reaction product displays the following spectrofluorometric properties: excitation peak at lambda = 375 nm and emission plaximum at lambda = 445 nm. Spectrofluorometric estimations during performing various steps of the reaction were indicative of possibilities of the improvement of the fluorescence histochemical GABA demonstration.

Glutamates↗
PubMed1981

[GABA fluophore formation due to ninhydrin reaction in the octanolic milieu. Fluorescence histochemical investigation. 3. Information (author's transl)].

Various steps of the ninhydrin-reaction in the octanolic milieu (Wolman 1971; Pfister and Görne 1978) were tested on the cerebellum of adult rats. The results of the fluorescence histochemical procedure was found to be in comparison with the results ascertained to spectrofluorometric method. The findings were further indicative for a GABA-specificity of the reaction.

Animals↗
PubMed2002

Quantitative reaction cascades of ninhydrin in the solid state.

Crystalline ninhydrin (1) undergoes waste-free solid-state cascade reactions with dimedone, L-proline, three o-phenylenediamines, o-mercaptoaniline, two ureas, three thioureas, and methyl 3-aminocrotonate. The yields are quantitative and give pure crystalline products without workup just by milling stoichiometric mixtures of the crystalline reagents. The structures of the new and the previously obtained products with lower yields from solutions are established or confirmed by spectroscopic data and density functional calculations at the B3LYP/6-31G* level. The success of 3- and 4-cascade reactions in the crystal without melting is unusual and of unmatched atom economy. They are mechanistically investigated with atomic force microscopy techniques (AFM) on six different faces of 1 when o-phenylenediamine was the reagent (substitution, elimination, cyclization, elimination) and interpreted on the basis of known crystal structure data. Strict correlations to the crystal packings are observed. The characteristic surface features grow to microm heights in some cases at distances of 0.5 mm from the contact edge of the reacting crystals. The waste-free and easy syntheses of highly functionalized (C=O; O-H; C=N) heterocycles or of a tetraketone are also of interest for synthetic use.

Journal Article↗
PubMed1999

Effect of Cationic Micelles on the Kinetics of Interaction of Ninhydrin with l-Leucine and l-Phenylalanine.

The effect of cationic micelles of cetyltrimethylammonium bromide (CTAB) and N-cetylpyridinium bromide (CPB) on the interaction of l-leucine and l-phenylalanine with ninhydrin have been studied at 70 degrees C. Both surfactants strongly catalyze the reactions. The reaction rates are higher in CTAB micelles than in CPB micelles. Quantitative kinetic analysis has been performed on the basis of a pseudo-phase model. The influence of different salts on the reaction rates has also been seen and it is found that tightly bound/incorporated counterions are the most effective. Copyright 1999 Academic Press.

Journal Article↗