Amino-acid related compounds

Urea has been reported as an excretion product of protein, purine and pyrimidine metabolism of microorganisms and zooplankton and may be 

Creatine, reported as being an excretion product specific to fish and not to zooplankton was determined in seawater by Whitledge and Dugdale (1972) using an automated procedure. The method was based on the reaction of creatine with alkaline ninhydrin solution after chelation of the alkaline earth elements with a complexing agent and fluorimetric detection of the reaction products. The method does not appear to have been widely adopted and the detection limit above the fluorimetric blank (around 0.10 pmole creatine 1 ) and the dubious stability of creatine in aqueous solution probably renders the method useful only in the laboratory. 

Despite the great interest in this class of compound and the numerous reports concerning the determination of total carbohydrates in seawater, surprisingly few determinations of individual monosaccharides have been made. Unlike the determination of free amino acids in seawater, no method for direct determination of free monosaccharides exists at present. Analogous to the developments in the detection of DFAA, the introduction of direct analysis techniques may change our concepts of the pattern of free sugars in seawater at a future date. 

A number of colorimetric procedures, relying on the formation of furfural derivatives of carbohydrates in concentrated sulphuric acid, employing 

In general, all the above-mentioned methods, employing concentrated sulphuric acid, have common drawbacks which may lead both to under- and over-estimation of carbohydrate content. During dehydration of individual sugars, non-detectable by-products such as 7-pyrones or benzene derivatives may be formed. No distinction is made between mono- and polysaccharides and since the different methods have different responses towards the various sugars, comparison of results obtained by the different authors is difficult. 

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H. Uchino, Y. Kanai, K. Kim do, M. F. Wempe, A. Chairoungdua, E. Morimoto, M. W. Anders, and H. Endou. Transport of amino acid-related compounds mediated by L-type amino acid transporter 1 (LAT1) Insights into the mechanisms of substrate recognition. Mol. Pharmacol. 61 729-737 (2002). 

Lacosamide is an amino acid-related compound that has been studied in both pain syndromes and partial seizures. The drug was approved in Europe and the USA in 2008 for the treatment of partial seizures. 

Robins, M. J. Uznanski, B. Nucleic Acids Related Compounds. 33. Conversions of Adenosine and Guanosine to 2,6 Dichloro, 2-Amino-6-chloro, and Derived Purine Nucleosides. Can. J. Chem. 1981, 59, 2601-2607. 

The presence in cigarette MSS of numerous free amino acids and amino acid-derived compounds was demonstrated in the mid-1950s. This occurred soon after the publication of the results of several cigarette smoke-related epidemiological... 

M. J. Robins and S. D. Hawrelak, Nucleic-acid related compounds. 28. 2 -Amino-araA 9-(2-amino-2-deoxy-P-D-arabinofuranosyl)adenine.-synthesis via nucleoside-aziridine or azido intermediates and biological effects. Tetrahedron Lett., 19 (1978) 3653-3656. 

Although it is possible to describe the clinicopatho-logical manifestations of pyridoxine deficiency and the metabolic role of pyridoxal phosphate, each pathological alteration cannot be explained by a specific metabolic alteration. Deficiency of a vitamin involved in several steps of the intermediary metabolism of amino acids is bound to be associated with severe clinicopath-ological changes, but the specific metabolic alterations responsible for the anemia and convulsions in pyridoxine deficiency have not been identified. y-Amino butyric acid, cystathione, sphingosine, and 5-hydroxy-tryptamine are compounds abundant in the brain. Pyridoxal phosphate is involved in their metabolic formation. Is there any correlation between the role of pyridoxal phosphate in the metabolism of these compounds and the development of convulsions and ataxia in pyridoxine deficiency Is the role of pyridoxine phosphate in the intermediary metabolism of sulfur amino acid related to the development of seborrheic dermatitis ... 

Synthesis from OC-Amino Acids and Related Compounds. Addition of cyanates, isocyanates, and uiea derivatives to a-amino acids yields hydantoin piecuisois. This method is called the Read synthesis (2), and can be considered as the reverse of hydantoin hydrolysis. Thus the reaction of a-amino acids with alkaline cyanates affords hydantoic acids, which cyclize to hydantoins in an acidic medium. 

The close electrochemical relationship of the simple quinones, (2) and (3), with hydroquinone (1,4-benzenediol) (4) and catechol (1,2-benzenediol) (5), respectively, has proven useful in ways extending beyond their offering an attractive synthetic route. Photographic developers and dye syntheses often involve (4) or its derivatives (10). Biochemists have found much interest in the interaction of mercaptans and amino acids with various compounds related to (3). The reversible redox couple formed in many such examples and the frequendy observed quinonoid chemistry make it difficult to avoid a discussion of the aromatic reduction products of quinones (see Hydroquinone, resorcinol, and catechol). 

The original commercial source of E was extraction from bovine adrenal glands (5). This was replaced by a synthetic route for E and NE (Eig. 1) similar to the original pubHshed route of synthesis (6). Eriedel-Crafts acylation of catechol [120-80-9] with chloroacetyl chloride yields chloroacetocatechol [99-40-1]. Displacement of the chlorine by methylamine yields the methylamine derivative, adrenalone [99-45-6] which on catalytic reduction yields (+)-epinephrine [329-65-7]. Substitution of ammonia for methylamine in the sequence yields the amino derivative noradrenalone [499-61-6] which on reduction yields (+)-norepinephrine [138-65-8]. The racemic compounds were resolved with (+)-tartaric acid to give the physiologically active (—)-enantiomers. The commercial synthesis of E and related compounds has been reviewed (27). The synthetic route for L-3,4-dihydroxyphenylalanine [59-92-7] (l-DOPA) has been described (28). 

The azlactones of a-benzoylaminocinnamic acids have traditionally been prepared by the action of hippuric acid (1, Ri = Ph) and acetic anhydride upon aromatic aldehydes, usually in the presence of sodium acetate. The formation of the oxazolone (2) in Erlenmeyer-Plochl synthesis is supported by good evidence. The method is a way to important intermediate products used in the synthesis of a-amino acids, peptides and related compounds. The aldol condensation reaction of azlactones (2) with carbonyl compounds is often followed by hydrolysis to provide unsaturated a-acylamino acid (4). Reduction yields the corresponding amino acid (6), while drastic hydrolysis gives the a-0X0 acid (5). ... 

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