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 505 records · Page 28Linked to original sources
PubMed1964

EVALUATION OF THE EXTRACT-RELEASE VOLUME PHENOMENON AS A RAPID TEST FOR DETECTING SPOILAGE IN BEEF.

Ground beef of several grades, obtained fresh and held refrigerated until spoiled, was presented to a test panel for scoring on color, odor, and tactile response (tackiness) as to degree of acceptance. Panel scores were correlated with total bacterial counts, ninhydrin-reactive substances, and ERV (extract-release volume) on the same meat. ERV correlated highest with bacterial counts the largest number of times; tackiness, odor, ninhydrin, and color followed in that order. Correlation between bacterial numbers and organoleptic qualities was best, with tackiness followed closely by odor, and then by color. Correlation between tackiness and odor was high. The degree of correlation between bacterial numbers, tackiness, and ERV was high enough to warrant the use of the ERV phenomenon as a rapid test of microbial quality of beef. An ERV value of 25 under the conditions of the test was supported as a divider between acceptable and unacceptable ground beef.

Animals↗
PubMed1966

Growth of lactic acid bacteria in waste waters of vegetable-processing plants.

Waters used in washing, blanching, cooling, and conveying vegetables during processing for freezing were filtered, sterilized, and inoculated with Streptococcus faecalis, S. lactis, or Lactobacillus plantarum. The contents of total nitrogen and total solids were determined, and ninhydrin tests and Benedict's tests for reducing sugars were performed. Substances positive to the ninyhydrin tests and also capable of supporting the growth of the bacteria to high levels of population were found in waters used to blanch cut green beans, but not in the cooling or conveying waters. They were found only in waters following slicing of blanched whole beans. They were also present in waters used in processing purple hull peas at all stages, but only in the waters used to blanch and cool lima beans. The substances were present in waters used to wash and blanch squash, but only in the waters used to blanch greens; they were not found in the cooling waters during the handling of either vegetable. No waters used in the processing of okra yielded a positive ninhydrin test, nor did they support the growth of the lactic acid bacteria.

Enterococcus faecalis↗
PubMed1974

Collagenolytic activity of dental plaque associated with periodontal pathology.

Certain dental plaques, removed from sites of gingival and periodontal pathology in mentally retarded, institutionalized individuals, when incubated in phosphate buffer with Achilles tendon collagen, gave rise to an increase in ninhydrin-positive material. These plaques, while showing great variability, released significantly more ninhydrin-positive material per milligram of plaque (wet weight) than did either the endogenous or heat-treated controls. Certain plaques could also break down soluble, tritiated, labeled collagen isolated from the calvaria of chicken embryos. Bacteroides melaninogenicus and Clostridia histolyticum were found in plaques by either fluorescent antibody or cultural methods. C. histolyticum, when detected, accounted for about 0.01 to 0.1% of the bacteria in plaque. A conspicuous isolate from some plaques was a Bacillus species which rapidly liquefied gelatin. Cell-free supernatants of this organism were able to degrade about 50 to 70% of the soluble collagen when incubated at 36 C. C. histolyticum ATCC 8034 caused an 80% degradation of the collagen under the same conditions of incubation. The Bacillus strains were facultative, could ferment glucose, reduced nitrate to nitrite, and were catalase, indole, and urease negative. The limited taxonomic information for the isolates is compatible with the description given for Bacillus cereus.

Animals↗
PubMed1970

Isolation and Characterization of a Galactosamine Wall from Spores and Spherules of Physarum polycephalum.

The myxomycete, Physarum polycephalum, can be induced under laboratory conditions to form two different hard-walled forms, spores and spherules. Characterization of both types of walls revealed only a single sugar, galactosamine. It was identified after acid hydrolysis of the isolated walls by chromatography in three solvent systems, by its positive reaction with ammoniacal silver nitrate, ninhydrin, Galactostat, and the Elson-Morgan test, and by ninhydrin degradation to lyxose. Galactosamine was present as a polymer with solubility characteristics the same as the beta1-4-linked glucosamine polymer (chitosan). The walls were also found to contain about 2% protein. Spherule walls revealed a single glycoprotein on gel electrophoresis. Spore walls contained a similar protein component. The phosphate content of isolated spherule walls was 9.8%, and that of spore walls was 1.4%. Spore walls also contained about 15% melanin which was shown to be similar to fungal melanin. A novel method was used to measure the rate of mature spherule formation based on the loss of extractability of P. polycephalum natural pigment. The presence of a rare galactosamine polymer in P. polycephalum spore and spherule walls as the only carbohydrate suggests that the myxomycetes are not closely related to the fungi or the protozoa.

Journal Article↗
PubMed1971

Comparison of the phospholipid composition of Bifidobacterium and Lactobacillus strains.

Phospholipid composition of 10 Bifidobacterium strains of human intestinal origin and of 9 Lactobacillus strains was determined by quantitative two-dimensional thin-layer chromatography. Phospholipids of three Bifidobacterium strains from honey bees and of two strains from bovine rumen liquor were qualitatively investigated. Diphosphatidylglycerol and phosphatidylglycerol were present in strains of both genera. All Bifidobacterium strains contained as specific phospholipids a new polyglycerolphospholipid, compound 15, and its lyso derivatives, earlier detected in B. bifidum var. pennsylvanicus. Also, lyso compounds of diphosphatidylglycerol and alanyl phosphatidylglycerol were only present in this genus in variable amounts. Lysyl phosphatidylglycerol was the only ninhydrin-positive phospholipid in seven Lactobacillus strains. In L. delbrückii and L. helveticus it was absent and partially replaced by an unidentified ninhydrin-negative phospholipid. The differences in phospholipid composition between bifidobacteria and lactobacilli may be another argument to differentiate these two genera.

Animals↗
PubMed1963

NATURE OF THE LIPIDS OF SOME LACTIC ACID BACTERIA.

Ikawa, Miyoshi (University of California, Berkeley). Nature of the lipids of some lactic acid bacteria. J. Bacteriol. 85:772-781. 1963.-Lactobacillus casei, L. plantarum, Leuconostoc mesenteroides, Pediococcus cerevisiae, and Streptococcus faecalis were grown on a lipid-free medium, and the amounts of acetone-soluble lipids, acetone-insoluble phospholipids, and unextracted or bound lipid in the cells were estimated. Neutral glycerides appeared to be absent, or present only in traces, in L. casei and S. faecalis. L. plantarum, L. mesenteroides, and P. cerevisiae, in addition to containing glycerides, appeared to contain glycolipids of glucose and galactose. Glycerol was present in the phospholipid fraction of all the organisms, and, in addition, galactose was present in L. mesenteroides. Paper chromatography of hydrolysates of the phospholipid fractions showed the absence of the usual phospholipid nitrogen bases, serine, ethanolamine, and choline, in these organisms. Microbiological assays of lyophilized unextracted cells for myo-inositol and choline also showed that lipids containing these components occurred in very small amounts at most. The principal ninhydrin-reacting substance in the phospholipid fraction of L. casei, L. plantarum, P. cerevisiae, and S. faecalis was lysine, which seemed to be exclusively of the l configuration. The principal ninhydrin-reacting substance in the L. mesenteroides phospholipid fraction was d-alanine. These amino acids appeared to be bound in components of the phospholipid fraction and not free.

Enterococcus faecalis↗
PubMed1997

Degradation of protein and utilization of the hydrolytic products by a predominant ruminal bacterium, Prevotella ruminicola B1(4).

Degradation and utilization of protein by Prevotella ruminicola B1(4), a proteolytic bacterium that is prominent in the rumen, was examined. In preliminary experiments, proteinaceous N sources produced faster growth rates than did NH4Cl, based on changes in optical density over time. However, ammonium chloride produced a greater maximum cell density than did proteinaceous N sources. Of the proteinaceous N sources, an enzymatic hydrolysate of soybean protein with a relative peptide size of 3 AA residues produced a greater growth rate and maximum cell density compared with the other proteinaceous N sources. Further experiments revealed that P. ruminicola B1(4) grew faster and to a greater final dry weight with soybean protein than with casein. Degradation of both proteins was low as was indicated by the slow disappearance of soluble protein, low concentrations of free AA and peptides, and the decrease in ammonia concentrations over time. Patterns of degradation did differ between the two proteins, however. Accumulation of peptides and free AA from soybean protein peaked 2 h earlier than those from casein, and concentrations of free AA and peptides from soybean protein were lower on average than those from casein. Prevotella ruminicola B1(4) preferentially utilized Asp, Ile, Leu, Lys, and Arg from soybean protein compared with casein. The relative size of peptides that accumulated from both proteins, as determined by the ratio of ninhydrin reaction after HCl hydrolysis to ninhydrin reaction before HCl hydrolysis, suggested that part of the proteolytic activity of P. ruminicola B1(4) is a dipeptidase. Our findings suggest that P. ruminicola may have a greater impact on peptide degradation than on protein degradation in the rumen.

Amino Acids↗
PubMed2000

Fingerprint enhancement revisited and the effects of blood enhancement chemicals on subsequent profiler Plus fluorescent short tandem repeat DNA analysis of fresh and aged bloody fingerprints.

This study was aimed at determining the effect of seven blood enhancement reagents on the subsequent Profiler Plus fluorescent STR DNA analysis of fresh or aged bloody fingerprints deposited on various porous and nonporous surfaces. Amido Black, Crowle's Double Stain. 1,8-diazafluoren-9-one (DFO), Hungarian Red, leucomalachite green, luminol and ninhydrin were tested on linoleum, glass, metal, wood (pine, painted white), clothing (85% polyester/15% cotton, 65% polyester/35% cotton, and blue denim) and paper (Scott 2-ply and Xerox-grade). Preliminary experiments were designed to determine the optimal blood dilutions to use to ensure a DNA typing result following chemical enhancement. A 1:200 blood dilution deposited on linoleum and enhanced with Crowle's Double Stain generated enough DNA for one to two rounds of Profiler Plus PCR amplification. A comparative study of the DNA yields before and after treatment indicated that the quantity of DNA recovered from bloody fingerprints following enhancement was reduced by a factor of 2 to 12. Such a reduction in the DNA yields could potentially compromise DNA typing analysis in the case of small stains. The blood enhancement chemicals selected were also evaluated for their capability to reveal bloodmarks on the various porous and nonporous surfaces chosen in this study. Luminol. Amido Black and Crowle's Double Stain showed the highest sensitivity of all seven chemicals tested and revealed highly diluted (1:200) bloody fingerprints. Both luminol and Amido Black produced excellent results on both porous and nonporous surfaces, but Crowle's Double Stain failed to produce any results on porous substrates. Hungarian Red, DFO, leucomalachite green and ninhydrin showed lower sensitivities. Enhancement of bloodmarks using any of the chemicals selected, and short-term exposure to these same chemicals (i.e., less than 54 days), had no adverse effects on the PCR amplification of the nine STR systems surveyed (D3S 1358, HumvWA, HumFGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820) or of the gender determination marker Amelogenin. The intensity of the fluorescent signals was very similar and the allele size measurements remained constant and identical to those of untreated bloody fingerprints. No additional background fluorescence was noted. Continuous exposure (for 54 days) to two of the seven enhancement chemicals selected (i.e., Crowle's Double Stain and Hungarian Red) slightly reduced the amplification efficiency of the longer STR loci in profiles of fresh and 7 to 14-day-old bloodprints. This suggests that long-term exposure to these chemicals possibly affects the integrity of the DNA molecules. This study indicates that significant evidence can be obtained from fresh or aged bloody fingerprints applied to a variety of absorbent and nonabsorbent surfaces which are exposed to different enhancement chemicals for short or long periods of time. It also reaffirms that PCR STR DNA typing procedures are robust and provide excellent results when used in concert with fluorescence-based detection assays after fingerprint identification has taken place.

Blood Chemical Analysis↗
PubMed1975

Binding of 63Ni (II) to ultrafiltrable constituents of rabbit serum in vivo and in vitro.

Binding of 63Ni(ll) to ultrafiltrable constituents of rabbit serum was studied (a) after in vitro incubation (2 h, 37 degrees C) of rabbit serum with 63NiCl2 (10-100 mumol/liter), and (b) at intervals (0.25-2 h) after in vivo administration of 63NiCl2(40-160 mumol/kg body wt,i.v.). Serum ultrafiltrates were fractionated by thin-layer chromatography, and the separated compounds made visible by autoradiography and by ninhydrin staining. Severel (congruent to 5) ultrafilitrable 63Ni-complexes were demonstrable as distinct radiodense 63Ni-bands with chromatographic mobilities corresponding to those of ninhydrin-positive bands. Unbound 63Ni(ll) was not detected in serum ultraviltrates in either the in vitro or in vivo experiments. In sera (n equals 10) incubated in vitro with 63Ni(ll) (10 mumol/liter), the mean percentage of ultrafiltrable 63Ni was 36% (range equals 33-38) of total serum 63Ni. In contrast, in sera (n equals 10) obtained 2 h after i.v. injection of 63Ni(ii) (40 mumol/kg), the mean concentration of total serum 63Ni was 10.8 mumol/kg), the mean concentration of total serum 63Ni was 10.8 mumol/liter (ranger equals 6-14), and the mean percentage of ultrafiltrable 63Ni was 15% (range equals 9-21) of total serum 63Ni. The disparity between the percentages of ultrafiltrable 63Ni obtained in vitro and in vivo was obviated when the in vivo experiments were performed in rabbits bilaterally nephrectomized, with ligated common bile ducts. This investigation confirms the existence of several nickel receptors in serum ultrafilitrates and substantiates the role of ultrafiltrable complexes in the excretion of nickel.

Amino Acids↗
PubMed2002

Effect of exogenous histidine and Garcinia cambogia on histamine formation in skipjack (Katsuwonus pelamis) homogenates.

Histamine consumed with food gives rise to allergic reactions. Dark muscle fish, for example skipjack (Katsuwonus pelamis) has been shown to contain histamine. Studies using TLC (acetone: NH4OH, 80:20.5) on silica gel G60 plates and densitometry after spraying with ninhydrin, using a computerized densitometer, showed that freshly harvested skipjack has no detectable histamine (detection limit, 50 micrograms.g-1 fish). However, with time histamine (Rf 0.84) is formed > 1.5 mg.g-1 probably through microbial action. Skipjack contains high levels of free histidine at levels of > 10 mg.g-1 (Rf 0.41) but fish like seer (Scomberamous spp.), which are not reported to be allergenic, contain < 4 mg.g-1 histidine. Addition of exogenous histidine (50 mg.g-1) results in histamine formation in seer 2.2-fold that of skipjack under the same conditions. A type of herring (Amblygaster spp., sinhala-hurulla) is not a histamine former, but had been shown to cause allergenic reactions, resulting in a ninhydrin positive spot (Rf 0.79) on incubating for 24 hours. Addition of arginine and lysine to blended skipjack results in their loss probably by decarboxylation. Addition of the spice Garcinia cambogia (extracts 0.2 g ml-1) known as 'goraka' in Sri Lanka (sinhala) and 'kukum' in India (hindhi), to fresh skipjack incubates prevents histamine formation as a results of lowering pH to 3.2-3.6 whereas Avverhoea bilimbi (bilin) and Tamarindus indica (tamarind) extracts did not prevent histamine formation.

Animals↗
PubMed1991

Solid-phase synthesis of neurokinin A antagonists. Comparison of the Boc and Fmoc methods.

During the preparation of the NK-2 selective tachykinin antagonist MEN 10208 (Thr-Asp-Tyr-D-Trp-Val-D-Trp-D-Trp-Arg-NH2) and its analogs by the solid-phase method employing the Boc strategy routinely used in our laboratory, we encountered difficulties in the coupling of hydrophobic amino acids D-Trp and Val. To study the coupling problems several syntheses of MEN 10208 and analogs were carried out with different activation strategies. These syntheses yielded considerable amounts of deletion sequences even though a negative Kaiser test was obtained after each coupling. Inaccessibility of the free amino group of the growing peptide due to steric hindrance of the hydrophobic residues during coupling, and for the ninhydrin complex during the Kaiser test, may account, at least in part, for the unsatisfactory synthetics results and for the false-negative ninhydrin tests. Repetition of each synthesis with the Fmoc strategy on a newly developed DOD resin for peptide amides using the DCC/HOBt chemistry gave superior results in terms of the yield and purity of the crude peptides. Therefore, the Fmoc strategy appears to offer advantages over the Boc method for the preparation of these peptides containing hydrophobic amino acids.

Amino Acid Sequence↗
PubMed1990

[Changes in protein fractions of milk obtained from cows with mastitis caused by Staphylococcus aureus. Preliminary studies].

The effect was studied of cow udder infection with S. aureus on changes of milk proteins. The tested milk was derived from two cows of the black-white lowland breed aged 5 years in the second stage of lactation. Proteins soluble and insoluble at pH 4.6 were characterized by means of starch-urea and polyacrylamide gel electrophoresis. The solution of nitrogen compound reacting with ninhydrin and soluble at pH 4.6 was separated by gel filtration, thin-layer chromatography and high-voltage paper electrophoresis, thin-layer chromatography and high-voltage paper electrophoresis. In the milk of the infected cow degradation of alpha s, beta and kappa casein, and increased content of gamma immunoglobulin. In whey proteins a rise was observed of serum albumin content and a decrease of beta-lactoglobulin and alpha lactoalbumin. In the solution after precipitation of casein at pH 4.6 in the milk of the infected cow a greater number of fractions reacting with ninhydrin was found. The observed range of degradation changes in milk protein in the infected cow (S. aureus) suggests that it has a negative effect on the technological, nutritional and hygienic value of milk.

Albumins↗
PubMedDate not supplied

An evaluation of the advantages and effectiveness of picric acid monitoring during solid phase peptide synthesis.

The effectiveness of picric acid for the monitoring of coupling completion during solid phase peptide synthesis was evaluated. Each coupling step was monitored during the synthesis of 124 peptides by the method of simultaneous multiple peptide synthesis. Of the peptides tested (1622 picrate determinations), approximately 10% underwent a single low yield step, another 10% had 2 or 3 consecutive low yield steps and about 20% contained "humps" 4 to 8 steps long. In virtually all instances, the low yield steps occurred only at or after coupling step 7. High picrate values obtained after incorporation of methionine appear to be caused by a sulfonium salt in the side chain of methionine. Differences in average reactivities of amino acids correlated with structural elements of their side chains. Picric acid, which is currently seldom used for monitoring of coupling completion during solid phase peptide synthesis, was found to be straightforward and nondestructive. While picric acid monitoring is not as sensitive as the more commonly used ninhydrin method, it yields information which is not detectable with the use of ninhydrin and is clearly superior for certain applications and investigations.

Amino Acid Sequence↗
PubMedDate not supplied

Determination of taurine in infant formulas using ultrafiltration and cation-exchange chromatography.

A fast and simple method for determination of taurine in infant formulas has been developed. The sample preparation uses disposable ultrafiltration cartridges to remove protein and clarify the sample. Hydrolysis is avoided, simplifying the procedure and increasing efficiency. One mL sample is centrifuged in a cartridge for 45 min. The filtrate is diluted with pH 2.2 citrate buffer and injected into a high performance amino acid analyzer. A cation-exchange column (sodium phase) is used with a single buffer eluant and an isocratic chromatographic program. Colorimetric detection is performed following post-column ninhydrin reaction. Chromatographic resolution from other ninhydrin-positive compounds is excellent. Average recoveries for 3 levels of spike for various products were 100-102%. Precision is 1-3% RSD, depending on product. Linearity, specificity, and ruggedness are excellent. The method is applicable to quality control testing of milk-based, soy-based, and prehydrolyzed protein-based infant formulas in the ready-to-use, concentrate, and powder forms. A variety of commercially available infant formulas from different manufacturers were analyzed and all were found to contain taurine levels comparable to human milk. Some human milk and cow's milk samples were also analyzed and results compare well with literature values.

Amino Acids↗
PubMed1988

[Identification of 5-aminovaleric acid as a characteristic product of metabolism of various Clostridium species].

An unusual ninhydrin-positive compound has been isolated from feces of accidentally contaminated Sprague-Dawley autbred rats and identified by mass spectrometry and 1H-NMR spectroscopy techniques as 5-aminovaleric acid. The described procedure of isolation, purification and structure determination can be recommended as a general method of identification of unusual ninhydrin-positive compounds in complex mixtures of biological origin. The 5-aminovaleric acid was found to be produced by an anaerobic bacterium Clostridium bifermentans. It is shown that not all Clostridium spp. excrete his amino acid and that the majority of microorganisms, normally inhabiting intestine of rats, simians and man, do not possess this ability. On the basis of data obtained, the test for 5-aminovaleric acid is proposed to be included into the taxonomy of bacteria.

Amino Acids↗
PubMedDate not supplied

Restoration of plantar sweat secretion in the feet of leprosy patients.

As part of the studies on nerve damage and its consequences in leprosy, the status of sweat gland function in the anaesthetic sole of the feet of leprosy patients was investigated qualitatively and semi-quantitatively, before and after surgical decompression of the posterior tibial neurovascular bundle. Sweat prints of the feet of the patients were obtained pre-operatively and postoperatively on Whatman's No. 1 filter paper. The paper was treated with one percent Ninhydrin and the intensities of the Ninhydrin positive areas were quantitated. Forty one feet of thirty six patients have been studied in this manner. Sweat print analysis of twenty normal people have also been done, and included for comparison. This operative procedure has been found to effect an improvement in the sweat gland function in the feet of more than fifty percent of leprosy patients studied so far.

Foot↗
PubMed1965

The measurement of bilharziasis prevalence and schistosomal egg output. Aims and techniques, with an account of a field method.

For bilharziasis prevalence surveys based on excretal examination the two primary requirements are precision and reproducibility. For a reproducible prevalence survey a subsample of stool or urine must be exhaustively examined for eggs. This requirement is identical with that for egg-counting. Adequate methods for both purposes are therefore the same. For urine studies methods involving concentration and further subsampling involve more possible sources of error than do recent methods using filtration, followed by staining of eggs with ninhydrin. A method is described for use in the field whereby the urine is sucked into a plastic filter-holder by hypodermic syringe. For stool samples concentration techniques involve a variable extraction fraction. Stoll-counting uses a very small sample for bilharziasis work and possibly new methods, again using filtration and ninhydrin staining, will prove of greater value. Field testing of methods has not yet reached the position where any one technique can be said to be ideal.

Filtration↗
PubMed1981

Prostaglandin-generating factor of anaphylaxis. Identification and isolation.

Anaphylaxis of human lung in vitro is accompanied by prostaglandin (PG) formation. To search for factors capable of generating PG, supernatants prepared by reversed anaphylaxis of human lung tissue were added to guinea pig lung and PG formation examined. The PG-generating activity fractionated between Mr = 500 and 5000 by ultramembrane filtration and was designated prostaglandin-generating factor of anaphylaxis or PGF-A. Partially purified PGF-A was soluble in 80% ethanol and insoluble in chloroform or ethyl acetate. Paper chromatography of anti-IgE-treated human lung preparations revealed a ninhydrin-positive spot at RF 0.27 to 0.41 with PG-generating activity. When subjected to gel filtration on Sephadex G-50 or G-25, PGF-A demonstrated peak PG-generating capacity at Mr = 1200 to 1800. Peak fractions were pooled and chromatographed on CM52 cellulose with PGF-A activity eluting at 0.16 to 0.3 M NH4COOH. The pooled peak of PGF-A activity from Sephadex G-25 filtration and CM52 chromatography eluted as a single peak at 0.024 M NH4HCO3 on DE52. Application of the peak off DE52 to a paper chromatogram revealed a single ninhydrin-positive spot with an RF 0.27 to 0.41 with the capacity to generate PGs. Amino acid analysis of three purifications revealed the following: Glu/Asp/Gly/Ser/Thr (6:3:2:1:1). Based on these analyses, a Mr = 1450 was calculated for the PGF-A. Therefore, PGF-A represents a novel mediator of lung anaphylaxis which may be partly responsible for PG generation accompanying allergic reactions.

Amino Acids↗