Metabolic product

Levy and McNutt (1962) have studied the utilization of the naturally occurring pteridine, xanthopterin (CVIII) by a bacterium isolated from soil, hoping to relate some of the intermediates produced to metabolites formed in the normal biogenesis of pteridines. They isolated from cultures of this organism, and identified by ultraviolet 

Iwahara et al. (1960) have prepared polysaccharide fractions of the endotoxin from nine strains of E. coli and six strains of S.flexneri, and have recorded the infrared spectra of the fractions. For E. coli the bands in the region from 1(XX) to 650cm differed considerably from strain to strain, whereas those of six strains of S. flexneri were very similar to each other. 

A water-soluble metabolite of indole-3-acetic acid is formed by certain strains of Pseudomonas savastanoi. The material has been isolated from culture filtrates of this organism and purified by adsorption on charcoal and by ion-exchange chromatography on sulfonic acid resins and quaternary ammonium resins (Hutzinger and Kosuge, 1968). The isolated metabolite was identified as indole-3-acetyl-e-L-lysine (CXII) by chemical means and by infrared and ultraviolet spectroscopy. 

Infrared spectroscopy was one of the tools used (Levy and Frost, 1966) for a definitive identification of 2,3-dihydroxyphenylpropionic add, the product from the reaction between the enzyme, melilotate hydroxylase (from extracts of the Arthrobac-ter species), and melilotic acid, NADH, and oxygen. 

Loos et al. (1967u, b) have used gas chromatography, and ultraviolet and infrared spectroscopy to identify products of 2,4-dichlorophenoxyacetate (2,4D) and 4-hydroxyphenoxyacetate degradation by a soil arthrobacter. These products were phenol and hydroquinone. The results indicated that the arthrobacter degraded 2,4D via 2,4-dichlorophenol. 

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An interesting set of central nervous system properties has also been discovered and studied (Table VI-10). The work devoted to piscaine must be emphasized besides finding hypnotic properties of 2-amino-4-phenyl-thiazole on fish, the authors studied the structure of the metabolite, as well as the localization of the (radio labeled) metabolic product in various organs. Recently, thiazol-4-yl methoxyamine was shown to inhibit the development of morphine tolerance (1607). 5-Aminothiazole derivatives such as 419a were proposed as cardiovascular agents (1608, 1610). Substitution of the 5-aminothiazole radical on the cephalophosphorin structure gives a series of antibacterial products (1609). 

An important application of these results lies in the analysis of food flavorings using a combination of gas-phase chromatography and mass spectrometry (121, 122). Similarly, metabolic products of chlo-methiazole have been characterized (123). 

Description of Method. Creatine is an organic acid found in muscle tissue that supplies energy for muscle contractions. One of its metabolic products is creatinine, which is excreted in urine. Because the concentration of creatinine in urine and serum is an important indication of renal function, rapid methods for its analysis are clinically important. In this method the rate of reaction between creatinine and picrate in an alkaline medium is used to determine the concentration of creatinine in urine. Under the conditions of the analysis, the reaction is first-order in picrate, creatinine, and hydroxide. 

J. W. HoUeman, Health Effects of Haloalky I Phosphate Flame Retardants and Potential Metabolic Products, Oak Ridge National Laboratory, Term., 1984, DOE/NBM-4006848 (DE84 006848),... 

Slime layers are a mixture of bacterial secretions called extracellular polymers, other metabolic products, bacteria, gases, detritus, and water. Commonly, 99% of the slime layer is water, although much silt and debris may also become entrapped in it. 

Antibiosis Inhibition or lysis of an organism mediated by metabolic products of the antagonist these products include lytic agents, enzymes, volatile compounds, and other toxic substances. 

Toxic reactions occur by several mechanisms activation of metabolism, production of reactive intermediates and subsequent reactions with cell macromolecules, changing receptor responses, or through abnormal defence reactions. Several compounds cause toxicity by mimicking the organism s own hormones or neurotransmitters, or activating the body s endogenous receptors in some non-physiological way. ... 

Extensive research is currently underway to use biological markers (biomarkers) in exposure and risk assessment. Biomarkers include the reaction products of chemicals or their metabolic products with biological macromolecules, especially with DNA. They also involve indicators of effect, such as chromosomal damage, and indicators of individual genetic susceptibility. 

Determinant A chemical metabolic product of the change in the body s chemistry caused by exposure to a pollutant. The level of determinant is measured in a biological sample collected from the exposed worker, and compared to the biological exposure index (BEI). Determination The analytical measurement of a pollutant. 

Umsatz, m. exchange change, transformation sale, business, -produkt, n. product of exchange, spscif. metabolism product. Umschaltbrett, n. switchboard, umschalten, v.t. (also Elec.) reverse Elec.) commutate. 

The major dasses of antibiotics are secondary metabolic products of micro-organisms. Many were discovered by empirically screening culture filtrates or cell extracts for antimicrobial activity. A range of techniques (examples are methods using, impregnated discs, porous cylinders, cut wells, see Figure 6.2) have been used to carry out such screening. 

May produce toxins and enzymes above, plus other metabolic products on growth in host gut and hemocoel... 

Antimetabolites compete with and possibly oust naturally occurring metabolites required for normal biochemical reactions and lead either to the synthesis of malfunctioning macromolecules and/or blockade of necessary intermediate or final metabolic products that are vital to cell survival. Both processes interfere with DNA synthesis and therefore antimetabolites can be used in cancer treatment, as they inhibit cell division and the growth of tumors. 

Studies in the Biochemistry of Micro-organisms. Part XXVI. The Metabolic Products of Penicil-liarn charlesii, G. Smith, P. W. Clutterbuck, W. N. Haworth, H. Raistrick, G. Smith, and M. Stacey,... 

Any substance present in great excess can inhibit growth or even cause death. Metabolic products are often toxic to the organism that produces them. Thus, a batch fermentation can be limited by accumulation of products as well as by depletion of the substrate. A simple model for growth in the presence of an inhibitor is... 

Figure 22-1. Role of carnitine in the transport of long-chain fatty acids through the inner mitochondrial membrane. Long-chain acyl-CoA cannot pass through the inner mitochondrial membrane, but its metabolic product, acylcarnitine, can. 

As an example, the low-density lipoprotein (LDL) molecule and its receptor (Chapter 25) are internalized by means of coated pits containing the LDL receptor. These endocytotic vesicles containing LDL and its receptor fuse to lysosomes in the cell. The receptor is released and recycled back to the cell surface membrane, but the apoprotein of LDL is degraded and the choles-teryl esters metabolized. Synthesis of the LDL receptor is regulated by secondary or tertiary consequences of pinocytosis, eg, by metabolic products—such as choles-... 

The most significant metabolic product of testosterone is DHT, since in many tissues, including prostate, external genitalia, and some areas of the skin, this is the active form of the hormone. The plasma content of DHT in the adult male is about one-tenth that of testosterone, and approximately 400 ig of DHT is produced daily as compared with about 5 mg of testosterone. About 50-100 ig of DHT are secreted by the testes. The rest is produced peripherally from testosterone in a reaction catalyzed by the NADPH-depen-dent 5oi-reductase (Figure 42-6). Testosterone can thus be considered a prohormone, since it is converted into a much more potent compound (dihydrotestosterone) and since most of this conversion occurs outside the testes. Some estradiol is formed from the peripheral aromatization of testosterone, particularly in males. 

Many are inhibited by various drugs or their metabolic products, providing another cause of drug interactions Some exhibit genetic polymorphisms, which can result in atypical drug metabolism... 

Figure 2.17 Application of the reverse DEPT pulse sequence to monitor C-labeled glucose by mouse liver-cell extract. (A) Normal FT spectrum. (B) Reverse DEPT spectrum showing the a- and )3-anomeric proton resonances. (C) Two different CH2 proton resonances, a and b, appear after 1.5 h of metabolism. (D) Edited H spectrum confirming that the CH2 resonances arise from metabolic products. (Reprinted from J. Magn. Resonance 56, Brooks et al., 521, copyright 1984, Academic Press.)...

The harvest is a very eomplex mixture of bacterial cells, metabolic products and exhausted medium. In the ease of a live attenuated vaccine it is innocuous and all that is necessary is for the baeteria to be separated and resuspended in an appropriate menstmum, possibly for freeze-drying. In a vaccine made Irom a pathogen the harvest may be intensely dangerous and great care is necessary in the following procedures. 

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