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Toxicity amino acids

Factors that can predispose patients to developing metabolic bone disease include deficiencies of phosphorus, calcium, and vitamin D vitamin D and/or aluminum toxicity amino acids and hypertonic dextrose infusions chronic metabolic acidosis corticosteroid therapy and lack of mobility.35,39 Calcium deficiency (due to decreased intake or increased urinary excretion) is one of the major causes of metabolic bone disease in patients receiving PN. Provide adequate calcium and phosphate with PN to improve bone mineralization and help to prevent metabolic bone disease. Administration of amino acids and chronic metabolic acidosis also appear to play an important role. Provide adequate amounts of acetate in PN admixtures to maintain acid-base balance. [Pg.1507]

Hegarty, M.P. (1978). Toxic amino acids of plant origin, in Keeler, R.F., VanKampen, K.R. and James, L.F., Eds. Ejfects of poisonous plants on livestock. Academic Press, New York, pp. 575-585. [Pg.67]

Wheat, rye, and barley have a common ancestral origin in the grass family. Oats are more distantly related to the analogous proteins in wheat, rye, and barley and the oat prolamins (avenin) have substantially lower proline content. Avenin accounts for 5-15% of the total protein in oats, whereas in wheat, barley, and rye, prolamins constitute 40-50% of the total protein (Kilmartin et al., 2006). Some investigators believe that there are similarities between the protein structure of oats and some wheat-like sequences, which may indicate that large amounts of oats could potentially be toxic to patients with celiac disease. However, the putative toxic amino acid sequences are less frequent in avenin than in other prolamins, which explains the less toxic nature of oats (Arentz-Hansen et al., 2004 Ellis and Ciclitira, 2001, 2008 Shan et al., 2005 Vader et al., 2002, 2003). [Pg.260]

Insecticidal analogs of arginine. The toxic amino acid L-canavanine is synthesized by more than 1500 species of legumes including alfalfa and clover.192... [Pg.1379]

Homocysteine, HSCH2CH2CH(NH2)C02H, is a toxic amino acid that is thought to acylate lysine residues on proteins via its corresponding thiolactone (72) (Scheme 19). Now, for the first time, the kinetics have been studied of the aminolysis of (72) and of two model compounds, y-thiobutyrolactone (72 H instead of NH2) and N-trimethylamino homocysteine thiolactone (72 Me3N+ instead of NH2). A Brpnsted plot for homocysteine thiolactone (72) gave ft = 0.66. This and other data supported... [Pg.73]

The engineering of bacterial metabolic pathways to improve commercial fermentative production of amino acids has traditionally involved the use of relatively crude, nonspecific mutagenesis methods coupled to repeated rounds of arduous screening for resistance to toxic amino acid... [Pg.42]

Primary structure of proteins can be chemically modified in order to improve their functional properties. This approach has been used with success to study the structure-function relationships (enzymatic function, biological function, physico-chemical and functional properties). Deliberate chemical modification of food proteins can result in alteration of the nutritive value, formation of potentially toxic amino acid derivatives, and contamination by toxic chemicals. [Pg.2]

There has been some concern about the effect of alkaline conditions on the formation of toxic amino acids in corn, particularly lysinoalanine (13). However, since lysinoalanine was found in very small amounts in foods prepared under more rigorous conditions than those applied traditionally, and since the lime treatment of corn has been a processing... [Pg.257]

The seeds of the Costa Rican plant Aieleia Herbert smith ii are avoided by all seed eaters (except a weevil that adapts them for its defence) because they contain two toxic amino acids (IR spectra like other amino acids). Neither compound is chiral. What is the structure of these compounds They can easily be separated because one (A) is soluble in aqueous base but the other (B) is not. [Pg.850]

The intramolecular [2 + 2] photocycloaddition of an a-carboxy enamide with an olefin has been elegantly exploited independently by Pirrung and by Clardy and coworkers in the synthesis of the toxic amino acid 2,4-methanoproline via irradiation of 32 (equation 9)15. [Pg.646]

Raised concentrations of lithocholate, portal bacteremia, and/or endotoxemia have all been suggested as contributing to hepatic triaditis in patients with inflammatory bowel disease receiving parenteral nutrition. Toxic amino acids or their metabolic products, excessive calorie administration and a disturbed carbohydrate/protein... [Pg.2710]

After compound P (or K), the heterolytic cleavage of the oxygen-oxygen bond occurs and the two electrons leave together with the formed water. This results in another symmetric oxygen-iron compound, Q, which is probably an iron-bound oxene (31, 63,147). The compound Q has two fewer electrons than the diferric state. Since a perferryl state is not expected to occur as a stable form in a biological compound, Q needs two iron ions. Besides, a mononuclear iron without a second redox partner would probably lead to formation of toxic amino acid... [Pg.389]

In moderate doses, alfalfa is beneficial because of the large quantities of iron and vitamins it contains. However, the seeds contain relatively high levels of the toxic amino acid canavanine, which may promote pancytopenia with routine ingestion of large quantities of seeds. [Pg.294]

Lundhohn, N., et al. Domoic acid, the toxic amino acid responsible for amnesic shellfish poisoning, now in Pseuodonitzschia seriata (Bacillariophyceae) in Europe. Phycologia, 33, 475 78 (1994). [Pg.395]

C7H,5N30j, Mr 173.22, monohydrate of the monohydrochloride, mp. 131-134 °C, [a]p +18° (5 M HCl). A toxic amino acid from the creeping indigo plant (7n-digofera spicata) and related species (Fabaceae)It is hepatotoxic and teratogenic, potently inhibits the ami-noacylation of arginine, and is a competitive inhibitor of arginase. It also prevents the incorporation of thymidine in the DNA in cultured human red blood cells. For synthesis, see Lit.. ... [Pg.316]

Fowden, L., D. Lewis, and H. Tristram Toxic amino acids. Their action as antimetabolites. Advan. Enzymol. 29, 89 (1967). [Pg.269]

Various legumes (seeds of plants of the Fabaceae family) are rich sources of free aliphatic hydroxyamino acids. Common amino acids such as 4-hydroxyleucine, 4-hydroxynorvahne and 5-hydroxynorleucine are hydroxyderivatives of branched chain amino acids, L-leucine (2-4), L-isoleucine (2-4), L-norvahne (2-24) and L-norleucine (2-25). Another common amino acidinlegumes is L-homoserine (2-26), which is derived from 2-aminobutyric acid, the intermediate in the biosynthesis of threonine from aspartic acid. Frequently O-acyl- and O-amino derivatives of homoserine are seen. An example of an O-aminoderivative of homoserine is a toxic amino acid known as canaUne (see Section 2.2.1.2.4). The most common source of this amino acid is the jack bean Canavalia ensiformis). [Pg.26]


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