Hydrolysis of the amino groups in condensed 2,4-diaminopyrimidine systems (1) has been used as a common method for the synthesis of oxo-substituted pyrimidines. In particular, the treatment with 6 M HCl usually yields exclusively the 2-amino-4-oxopyrimidine isomer (2). During our work, we found that the hydrolysis of the amino groups ...

The structural complexity of the nitrogen sources strongly affects biomass production and secretion of hydrolytic enzymes in filamentous fungi. Fusarium oxysporum and Aspergillus nidulans were grown in media containing glucose or starch, and supplemented with a nitrogen source varying from a single ammonium salt (ammonium sulfate) to free amino acids ...

Cycling of soluble non-protein N compounds is thought to be indicative of the N-nutritional status of trees. We determined the major N forms in bark, wood and foliage and estimated the dependence of prevalent N forms on N availability in Pinus sylvestris L. trees from northern Sweden. Trees subjected to ...

A global assessment of the impact of the anthropogenic perturbation of the nitrogen and sulfur cycles on forest ecosystems is carried out for both the present-day [1980-1990] and for a projection into the future [2040-2050] under a scenario of economic development which represents a medium path of development according to ...

Poly(hydroxybutyric acid) (PHB) and other biodegradable polyesters are promising candidates for the development of environment-friendly, totally biodegradable plastics. The use of cane molasses and corn steep liquor, two of the cheapest substrates available in Egypt, may help to reduce the cost of producing such biopolyesters. In this work, the effect ...

Pseudomonas syringae pv. tabaci, the causal agent of the wildfire of tobacco, produces the phytotoxin tabtoxin. The effects of carbon, nitrogen sources and amino acids on growth and tabtoxin production by pv. tabaci, were examined by varying the components of a defined basal medium, which contained the following nutrients per ...

Dissolved combined amino acids (DCAA) are important constituents of the dissolved organic nitrogen (DON) pool in marine environments, although little is known about their sources, dynamics and sinks. The DCAA pool consists of various compounds including proteins and peptides, proteins linked to sugars and amino acids adsorbed to humic and ...

L-Canavanine, L-2-amino-4-(guanidinooxy)butyric acid, is a potentially toxic nonprotein amino acid of certain leguminous plants. Many species are prolific canavanine producers; they divert enormous nitrogen resource to the storage of this single natural product. Canavanine, a highly effective protective allelochemical, provides a formidable chemical barrier to predation and disease. The accumulated ...

The influence of the consumed carbon to nitrogen (C/N) ratio on arachidonic acid (AA) production and mycelial morphology was investigated in cultures of Mortierella alpina using shake flasks and a fermentor. The consumed C/N ratio was varied from 5 to 32 under the condition that the total initial amount of ...

A simple and reliable method for the determination of NH4+, K+, Na+, aspartic acid, asparagine, glutamine, and alanine by ion chromatography has been developed. It is suitable for monitoring changes of nitrogen metabolism in soybean because it can accurately measure concentrations o asparagine and NH4+, two key substances for nitrogen ...

We studied the effect of an acute 4-h period of hyperinsulinemia (H) on net utilization rates (AAUR(net)) of 21 amino acids (AA) in 17 studies performed in 13 late-gestation fetal sheep by use of a novel fetal hyperinsulinemic-euglycemic-euaminoacidemic clamp. During H [84 +/- 12 (SE) microU/ml H, 15 +/- 2 ...

BACKGROUND/AIMS: Glucocorticoids upregulate hepatic urea synthesis and cause protein breakdown to prevail over synthesis, releasing amino acids into the blood stream and increasing the substrate supply for hepatic urea synthesis. Budesonide is a new generation glucocorticoid that may be used for treatment of inflammatory diseases, e.g. Crohn's disease and autoimmune ...

BACKGROUND: Sucrose exerts a sparing effect on whole-body protein metabolism, mainly during the absorptive phase. OBJECTIVE: We aimed to characterize the acute postprandial effect of addition of sucrose on deamination of dietary and endogenous nitrogen, with particular consideration being given to the effects of bioavailability. DESIGN: Twenty-one subjects equipped with ...

The distribution of nitrogen metabolism end-products and the associated enzyme activities, free amino acids and purine base catabolites were investigated in all the body compartments (circulating fluids and tissues) of the hydrothermal vent tubeworm Riftia pachyptila to acquire a general overview of nitrogen metabolism in this symbiotic organism. There were ...

A combination of electrospray ionization, high-field asymmetric waveform ion mobility spectrometry, and mass spectrometry (ESI-FAIMS-MS) was used for the analysis of a solution containing a mixture of the nine chlorinated and brominated haloacetic acids. For a carrier gas of nitrogen in the FAIMS analyzer, haloacetate anions of the mono- and ...

A freshwater cat fish was exposed to sublethal concentrations of two pesticides--carbaryl, a carbamate and phorate, an organophosphorus pesticide for 24, 72, 120 and 168 hr. The alterations in the serum profile of non protein nitrogen compounds demonstrated an increase in urea, uric acid and creatinine throughout the experimental period.

The objective of the study was to determine the influence of either oral or intramuscular administration of stanozolol on nitrogen retention in dogs by using a non-invasive 15N-amino acid tracer technique. Ten healthy, intact, adult male sled dogs received either stanozolol tablets, 2 mg/dog PO, q12h, for 25 days (Group ...

The thermal cis-to-trans isomerization of 1,3-diphenyltriazene (DPT) has been investigated in buffered aqueous solutions by means of laser-flash photolysis techniques. The cis-to-trans isomerization process is found to be catalyzed by general acids and general bases as a result of acid/base-promoted 1,3-prototropic rearrangements. Acid catalysis is attributed to rate-limiting proton transfer ...

A study was carried out on the changes occurring in the amino acid fraction of a hybrid ryegrass during ensilage in laboratory-scale silos to help to establish the relative roles of plant and microbial proteases on protein degradation in the silo. Herbage treatments included (i) normal grass without treatment (ii) ...

Model smear soft cheeses, prepared with Debaryomyces hansenii and Brevibacterium linens as ripening starters, were ripened under aseptic conditions. Results of the cheese-making trials, in triplicate, were similar and showed similar patterns of protein degradation. In all of the trials, the acid-soluble nitrogen and nonprotein nitrogen (NPN) indexes and NH3 ...

To examine what causes increased viscosity in culture broth in Streptomyces fradiae culture, various natural nitrogen sources were investigated. Extracellular protease activity increased with culture time and decomposed the natural nitrogen source into amino acids. In the case of gluten meal, after a culture time of 5 d, concentrations of ...

The hydrothermal vent tubeworm Riftia pachyptila lacks a mouth and gut and lives in association with intracellular, sulfide-oxidizing chemoautotrophic bacteria. Growth of this tubeworm requires an exogenous source of nitrogen for biosynthesis, and, as determined in previous studies, environmental ammonia and free amino acids appear to be unlikely sources of ...

Pseudomonas stutzeri strain 1317 was found to grow on various fatty acids, alcohols, diols, as well as glucose and gluconate for the synthesis of polyhydroxyalkanoates (PHA) with various monomer units. The PHA monomer structures were dependent on the type of fatty acids and alcohols, as well as the diols in ...

The South Pennines, an area of acid-sensitive geology at the centre of a major industrial region, have undergone perhaps the most severe historic exposure to sulphur and nitrogen deposition in the UK. This study addresses a lack of existing research on the region by presenting the findings of a survey ...

Candida guilliermondii UFMG-Y65, isolated from a gold mine, was able to utilize different nitriles and the corresponding amides as sole source of nitrogen, at concentrations up to 2 M. Resting cells cultivated on YCB-acetonitrile medium showed nitrile hydrolyzing enzyme activities against acrylonitrile and benzonitrile. These enzymes were inducible and intracellular; ...

The nitrogen composition of wines aged with yeast for a long period of time, as in the case of sparkling wines, depends on the composition of the base wine and on the compounds released by the yeast. In this paper, the release of the different classes of nitrogen compounds during ...

1. The effect of caecectomy on nitrogen utilisation and excretion was examined in growing chicks fed on a commercial diet. 2. Caecectomy had no significant effect on food intake or body weight gain. 3. Caecectomy caused significantly higher moisture content in excreta (P<0.01). 4. Gastrointestinal passage time of digesta was ...

Surface reaction layers grown on bioactive glass (Bioglass), by immersion in either simulated body fluid (SBF) or minimal essential medium (alpha-MEM) for 2, 5, 32 and 72 h, were analyzed by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Layers grown in alpha-MEM exhibited delamination when observed in SEM. ...

The yeast Cryptococcus sp. UFMG-Y28 can utilize benzonitrile as a nitrogen and possible additional carbon source. The kinetics of growth on Yeast Carbon Base (YCB) added of benzonitrile as sole nitrogen source showed that benzonitrile was metabolized to benzoic acid and ammonia. Liquid chromatography analysis indicated that Cryptococcus sp. UFMG-Y28 ...

Streptomycetes are Gram-positive bacteria with a unique capacity for the production of a multitude of varied and complex secondary metabolites. They also have a complex life cycle including differentiation into at least three distinct cell types. Whilst much attention has been paid to the pathways and regulation of secondary metabolism, ...

The optimum conditions for the production of (-)-mitorubrinic acid by mutant strain of Penicillium funiculosum CCM F-8080 were examined in shaken flask cultures. The highest production of this metabolite was achieved in a medium with glucose as the sole carbon source and (NH4)2HPO4 as the nitrogen source. The most suitable ...

BACKGROUND: The efficiency of dialysis membranes is generally evaluated by assessing their capacity to remove small, water-soluble and non-protein-bound reference markers such as urea or creatinine. However, recent data suggest that protein-bound and/or lipophilic substances might be responsible for biochemical alterations characterizing the uraemic syndrome. METHODS: In the present study, ...

Tryptophan hydroxylase is a pterin-dependent amino acid hydroxylase that catalyzes the incorporation of one atom of molecular oxygen into tryptophan to form 5-hydroxytryptophan. The substrate specificity and hydroxylation regiospecificity of tryptophan hydroxylase have been investigated using tryptophan analogues that have methyl substituents or nitrogens incorporated into the indole ring. The ...

Amino acid infusion during general anesthesia induces thermogenesis and prevents postoperative hypothermia and shivering. We propose that amino acid prevention of hypothermia during anesthesia shortens the hospital stay. Core temperatures and pulmonary oxygen uptake were measured in 45 patients, receiving an IV amino acid mixture, 126 mL/h, before and/or during ...

Ammonium is an important intermediate of protein metabolism and is a key component of acid-base balance. Investigations of the metabolism of NH(4)(+) in vivo using isotopic techniques are difficult because of the low concentration of NH(4)(+) in biological fluids and because of frequent artifactual isotopic dilution of the enrichment of ...

We studied the effects of the new amino acid solution MRX-III on the nutritional status and nitrogen metabolism of rats with chronic renal failure (CRF) in comparison with those of a general amino acid solution (MPR-F). The essential amino acids/non-essential amino acids ratio was 3.21 for MRX-III and 1.09 for ...

OBJECTIVE: To evaluate the influence of 1.1% amino acid dialysis solution (AADS) on parameters of nutrition in continuous ambulatory peritoneal dialysis (CAPD) patients. STUDY DESIGN: Studies were performed in 8 men, using AADS for the overnight exchange. Before starting AADS, food intake, nutritional status, and laboratory indices were evaluated and ...

A porous cellulose tape containing a silica gel that was previously impregnated with a processing solution containing p-toluenesulfonic acid, sulfanilic acid, N-1-naphthyl ethylene diamine dihydrochloride, ethylene glycol and methanol has been developed to provide a highly sensitive detection of nitrogen dioxide in air. When the sample including nitrogen dioxide was ...

BACKGROUND/AIMS: Hypoglycemia has well-described effects on glucose metabolism, whereas the possible effects on hepatic amino nitrogen conversion in relation to muscle amino nitrogen flux are more uncertain. METHODS: We studied six healthy young male subjects three times, i.e. for 6 h in the basal state, during a 6-h euglycemic hyperinsulinemic ...

OBJECTIVE: To compare the biochemical and nutritional effects of amino acid dialysis with dextrose dialysis in children receiving continuous cycling peritoneal dialysis (CCPD). DESIGN: A prospective randomized cross-over study. SETTING: Nonhospitalized patients. PATIENTS: Seven children aged 1.8 to 16.0 years (mean 8.1 years) with end-stage renal disease who were receiving ...

Twenty-four cecectomized and 24 intact White Pekin ducks were used in two experiments to assess the influence of cecectomy on ME and amino acid digestibility of several feed ingredients for ducks. Corn and soybean meal (SBM) were evaluated in Experiment 1, and bakery meal (BM), red dog (RD), and wheat ...

The formation of HEMF [2 (or 5)-ethyl-5 (or 2)-methyl-4-hydroxy-3 (2H)-furanone] by yeast was examined in an attempt to investigate its mechanism and involved factors. HEMF formation was promoted by yeast cultivation in a heat-sterilized medium which included glucose, ribose, and a nitrogenous compound such as an extract of shoyu koji, ...

There are only a few examples of microbial conversion of picric acid (2,4,6-trinitrophenol). None of the organisms that have been described previously is able to use this compound as a sole source of carbon, nitrogen, and energy at high rates. In this study we isolated and characterized a strain, strain ...

A novel strategy for the maximum production of a biodegradable copolymer, poly(3-hydroxybutyric-co-hydroxyvaleric) acid, P(HB-co-HV), was developed, based on the kinetic parameters obtained from fed-batch culture experiments of Alcaligenes eutrophus. The effects of various culture conditions such as mole ratio of carbon:nitrogen in feed medium (C/N); total fatty acids concentrations; and ...

OBJECTIVE: The objective of the study was to determine whether a prolonged maternal infusion of amino acids would increase the umbilical uptake of amino acids and uteroplacental ammonia production. STUDY DESIGN: Six pregnant sheep (134.5 2.3 days after conception) were infused for 12 hours overnight with an amino acid solution. ...

A sensitive method for very-long-chain fatty acid analysis was developed by gas chromatography-nitrogen-phosphorus detection by using cyanomethyl derivatization. Bromoacetonitrile as alkylating reagent was used to improve nitrogen phosphorus detection detectability of compounds containing non-nitrogen. The carboxyl group of very-long-chain fatty acid was alkylated to cyanomethyl esters. Reaction conditions were 40 ...

Provision of nutrients through the peritoneum is as old as peritoneal dialysis (PD) itself. Studies with a shelf-stable amino acid-based dialysis solution have shown that the amino acids absorbed during one exchange quantitatively exceed the daily losses of proteins and amino acids. The supplementary amino acids are well tolerated and ...

The phototrophic bacterium Rhodobacter capsulatus utilizes the aromatic amino acids L-phenylalanine and L-tyrosine as nitrogen source. L-Phenylalanine is hydroxylated to L-tyrosine, which is further converted into p-hydroxyphenyl pyruvate (pHPP) by a transamination reaction. The bacterium is unable to grow at the expense of these amino acids as the sole carbon ...

The complexes of general formula [(LMS)2Pd(amino acid)]Cl with LMS = levamisole, and amino acid = L-alanine, L-phenylglycine, L-phenylalanine, L-valine, L-methionine, and L-proline, were synthesized by the interaction of [(LMS)2PdCl2] with the sodium salts of L-amino acids. The newly synthesized complexes are characterized by elemental analysis, conductivity, magnetic susceptibility, optical rotation ...

Reactive nitrogen species derived from nitric oxide are potent oxidants formed during inflammation that can oxidize membrane and lipoprotein lipids in vivo. Herein, it is demonstrated that several of these species react with unsaturated fatty acid to yield nitrated oxidation products. Using HPLC coupled with both UV detection and electrospray ...