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 109 records · Page 6Linked to original sources
PubMed1999

The Micelle-Induced Interaction between Ninhydrin and Tryptophan.

The effects of micelles of cetyltrimethylammonium bromide (CTAB) and cetylpyridinium bromide (CPB) on the observed pseudo-first-order rate constants for the interaction of ninhydrin with tryptophan were studied. The influence of different parameters was considered, i.e., reactant concentration, surfactant concentration, temperature, and effect of added salts. The data are explained in terms of the pseudo-phase model of the micelles. Copyright 1999 Academic Press.

Journal Article↗
PubMed1978

Screening of safrole, eugenol, their ninhydrin positive metabolites and selected secondary amines for potential mutagenicity.

The mutagenicity of safrole, eugenol, the secondary amines, with which they combine during metabolism, and the ninhydrin positive urinary metabolites of safrole and eugenol was tested. The panel of tests included the direct bacterial assay, a microsomal mutagenesis assay and a host-mediated assay. With the direct bacterial assay employing four mutant strains of Salmonella typhimurium (TA1530, TA1531, TA1532, TA1964), all the compounds gave negative results. In the microsomal mutagenesis assay, employing the same four mutant strains, safrole and safrole metabolite II were mutagenic with strains TA1530 and TA1532. Dimethylamine was also found to be a weak mutagen in the microsomal mutagenesis assay with strain TA1530. Safrole and safrole metabolite II were also mutagenic in the host-mediated assay with strains TA1950 and TA1952. Negative results were observed for safrole metabolites I and III, eugenol, eugenol metabolites I and II, piperidine, pipecolic acid, proline, and pyrrolidine in all three assay systems.

Animals↗
PubMed1973

Effect of high tyrosine content on the determination of tryptophan in protein by the acidic ninhydrin method. Application to chicken ovoinhibitor.

Colorimetric determination of tryptophan in intact proteins by the acidic ninhydrin method of Gaitonde & Dovey (1970) gives high apparent tryptophan contents for proteins having high tyrosine/tryptophan ratios. Correction for this interference by tyrosine can be achieved by plotting the ratio of observed to expected tryptophan content as a function of tyrosine/tryptophan ratio for proteins of known composition. The equation of the line is: [Formula: see text] Application of this correction to chicken ovoinhibitor, which contains 17 tyrosine residues per molecule, gave results that agree with tryptophan content determined by other methods.

Animals↗
PubMed1987

Are ninhydrin-positive substances volume-regulatory osmolytes in rat renal papillary cells?

1. A study has been made of the concentrations and contents of ninhydrin-positive substances (n.p.s.), presumed to be predominantly but not exclusively amino acids, in the cells of rat renal papillary slices incubated in variously modified Krebs phosphate-bicarbonate Ringer solution. 2. When the medium osmolality was increased from 710 (control) to 2000 mosmol/kg H2O by additional NaCl and urea, the steady-state cellular n.p.s. concentration rose from 42.3 +/- 0.6 (mean +/- S.E. of mean; n = 36) to 105 +/- 2 (n = 68) mmol/l (glycine equivalent). Cell fluid content fell from 5.11 +/- 0.09 (n = 36) to 4.16 +/- 0.11 (n = 68) microliter/mg solute-free dry weight. Hence cell n.p.s. content increased from 211 +/- 4 (n = 36) to 421 +/- 10 (n = 68) nmol/mg solute-free dry weight. 3. A comparable loss of cell fluid was observed when urea was replaced by sucrose or sorbitol. No increase in cell n.p.s. occurred, and there was a marked cell Na+-for-K+ exchange. 4. The extent of the increase in cell n.p.s. in the presence of 2000 mosmol/kg H2O (NaCl + urea) was sensitive to the presence of external anions in the sequence acetate less than Cl- less than NO3- less than or equal to SCN-. 5. Cell n.p.s. concentration increased progressively as the medium osmolality was increased by the addition of urea, but Na+ at a concentration above 330 mmol/l had an inhibitory effect. The increase in n.p.s. concentration was also significantly reduced in hyperosmotic media in which Na+ was replaced by choline. 6. The increase in cell n.p.s. content due to hyperosmotic NaCl + urea was completely inhibited by pre-incubation in control medium containing trimethylamine N-oxide. 7. On transference of slices from control to hyperosmotic media (NaCl + urea) the steady-state increase in cell n.p.s. concentration was complete within 20 min and followed a time course similar to that for cell fluid loss. The n.p.s. concentration and cell fluid content returned to control levels, with similar time courses, following re-immersion in control medium. 8. Efflux of alpha-amino[1-14C]isobutyric acid (AIB) from slices pre-loaded in control medium containing 1 mmol AIB/l was slightly but significantly slower into AIB-free hyperosmotic NaCl + urea than into AIB-free control medium. The rate of efflux was greatly increased by the presence of hyperosmotic sucrose or very high Na+ (935 mmol/l).(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acids↗
PubMed1979

Free amino acids and ninhydrin-reacting compounds of median and lateral lobes in human benign prostatic hypertrophy.

The levels of free amino acids and ninhydrin-reacting substances were determined in median and lateral lobes of human benign prostatic hypertrophy. Student's paired t test showed only a statistical difference for the hypotaurine concentration. This compound is present at higher levels in the lateral lobes. The different hypotheses formulated in the literature about the presence and possible metabolic role of hypotaurine in the male reproductive tract are examined.

Amino Acids↗