Amino acids compound production

Simple amino acid degradation products aldehydes, sulphur compounds (e.g. hydrogen sulphide, methanethiol), nitrogen compounds (e.g. ammonia, amines)... 

Whelan, J.K., and Emeis, K. (1992) Sedimentation and preservation of amino acid compounds and carbohydrates in marine sediments. In Productivity, Accumulation, and Preservation of Organic Matter Recent and Ancient Sediments (Whelan, J.K., and Farrington, J.W., eds.), pp. 176-200, Columbia University Press, New York. 

Anal3Ttical and Synthetical Study of Proteins.—Fischer attacked the problem of the constitution of proteins from the synthetic side. Assuming that proteins consist of units of amino acids, as indicated by the analytical study of their hydrolytic products, he attempted to synthesize, from amino acids, compounds of similar complexity to the proteins. As already stated (p. 386), he found that the double anhydrides, resulting from the esters of amino acids by the loss of two molecules of alcohol from two molecules of the ester, took up one molecule of water when treated with dilute alkali and a single anhydride was obtained. The reactions may be represented as follows ... 

Prior to its banning by the Food and Drug Administration (FDA) in 2004, ephedra was found in many food supplements, used by bodybuilders. Generally, it was compounded with other ingredients such as vitamins, minerals, and amino acids in products, which are said to increase muscle mass and enhance endurance (16). Performance improvement secondary to ephedrine ingestion has been established in a controlled clinical trials (17,18,19), and use of ephedrine has been prohibited by the International Olympic Committee. 

The synthesis of model compounds to verify the structures of xenobiotic amino acid adducts (products of nonenzymatic reactions of electrophilic xenobiotics with amino acids In proteins) are Included. Methods for synthesis of some rarely observed conjugate types will be briefly Introduced. The major organic methods for synthesis are exemplified and xenobiotic conjugates prepared via these reactions are tabulated with references to the original publications. 

Natural product extracts are generally complex and comprise mixtures of neutral, acidic, basic, lipophilic, hydrophilic, and amphiphilic (e.g., amino acids) compounds and, as a consequence, there is rarely one method that will serve for all eventualities. It is sometimes worthwhile to carry out H or NMR spectroscopy of the extract or fraction to determine the class of compound(s) to be separated (1)—deuterated NMR solvents are cheap ( 1.00 for CDCI3) and 1 D NMR experiments are quicker to run than the extensive... 

Table lV.B-4 lists several polynuclear (V-heterocyclic amines that exhibit extremely high mutagenicity levels in the Ames bioassay, are amino acid pyrolysis products, and have been identihed in various broiled, fried, or roasted foodstuffs as well as in CSC [Sugimura (3828c)]. On a per microgram basis, B[fl]P in the Ames bioassay with Salmonella typhimu-rium (Strain TA 98) shows about 200 revertants/pg. Several of the amino acid-derived compounds in Table lV.B-4 exceed the B[fl]P effect with the TA 98 strain by factors ranging from about 10 to over 2100. 

The best-estabhshed method for the enzymatic production of L-amino acids is the separation of racemates of iV-acetyl-DL-amino acids by aminoacylase. JV-Acetyl-L-amino acid is cleaved and yields L-amino acids whereas the D-amino acid compound does not react (Eq. 4-18). 

Immobilized enzymes are used in the industrial production of many compounds. They are used in the manufacture of amino acids, sugar products such as glucose and high fructose com syrup, and many types of pharmaceutical compounds including antibiotics such as penicillin (1-4). The enzyme is used in these cases for enantioselective synthesis, to produce the desired enantiomer or isomer. Enzymes are currently being explored for their use in the manufacture of biofuels (5). Enzymes are used in analysis in both free and immobilized states. In both states, they are able to determine, with great sensitivity, the concentration of substrates in complex matrices. Immobilized enzymes can be deployed in several different form factors, such as reactor tubes, microwell plates, and as enzyme electrodes in biosensor devices. 

The metabolic pathway responsible for biosynthesis of aromatic amino acids and for vitamin-like derivatives such as folic acid and ubiquinones is a major enzyme network in nature. In higher plants this pathway plays an even larger role since it is the source of precursors for numerous phenylpropanoid compounds, lignins, auxins, tannins, cyano-genic glycosides and an enormous variety of other secondary metabolites. Such secondary metabolites may originate from the amino acid end products or from intermediates in the pathway (Fig. 1). The aromatic pathway interfaces with carbohydrate metabolism at the reaction catalyzed by 3-deoxy-D-arabino-heptulosonate 7-phosphate (DAHP) synthase, the condensation of erythrose-4-phosphate and PEP to form... 

The requirement of coenzyme A for hippuric acid synthesis may be taken as evidence for a benzoyl-coenzyme A complex, similar to the acetyl-coenzyme A compound for which good evidence has been obtained. It is possible that coenzyme A-amino acid addition products are the real intermediates in protein synthesis, rather than the acyl phosphates shown in equation 37. 

The formation of amino acids as degradation products from the reaction of D-glucose and o-xylose with primary amines was investigated by Severin and co-workers [34]. They showed that the initially formed Amadori products either undergo oxidative degradation or give various amino acid compounds, such as N-propylalanine 26,2 -acetyl-N -(l-carboxyethyl)-L-lysine 27, N-(carboxyme-thyl)- 28, and N-(l-carboxyethyl)-alanine 29, respectively, as well as N-substi-tuted 4,5,6-trihydroxy-a-aminohexanoic acids 30 (Scheme 7). 

If pyrrole formation occurs with an amino acid, this product can react further (Formula 4.63) to yield a bicychc lactone (V in Formula 4.59). Other secondary products of 3-deoxyosone are compounds with a pyranone structure. In fact, P-pyranone (VI in Formula 4.59) is under discussion as the most important intermediate. It can be formed from the pyranose hemiacetal form of 3-deoxyosone (Formula 4.64). This compound has been identified only in the full acetal form (e. g., with carbohydrates on drying) because only this structure makes a relatively stable end product possible. The compounds mentioned have acidic hydrogen atoms in position 4, easily allowing condensation reactions with aldehydes and polymerization or the formation of brown dyes. 

Let us consider the first question. Since it has been shown that amino acid-RNA compounds can be formed by highly purified amino acid activating enzymes, and the properties of this reaction and of the reaction product correspond closely to those observed in crude systems or in vivo, it seems to be established beyond reasonable doubt that the mechanism of this reaction is as outlined in Section III, B, 3, d. Furthermore, the demonstration that the amino acid bound to transfer RNA can be transferred to the microsomes and be bound there in the interior of a peptide chain, seems to show that the RNA-amino acid compound can serve as a donor of amino acid for the incorporation reaction however, since not only GTP, but also ATP and soluble fraction (which mi t contribute a large number of other factors besides the transferring enzyme) are required for the transfer, the role of sRNA-amino acid is less clear-cut than it might be. A reversal of the reaction back to the adenylates, however, and incorporation by some other route seems to be excluded by the fact that even a hundredfold excess of nonisotopic amino acid does not interfere with the efficiency of the transfer, which under the right conditions, approaches 100% (14S). The evidence to date, then, indicates that the adenylate-sRNA pathway is a pathway of amino acid incorporation in the microsomal system of mammalian origin. 

The industrial process for preparing the reagent usually permits a little hydrolysis to occur, and the product may contain a little free calcium hydroxide or basic chloride. It cannot therefore be employed for drying acids or acidic liquids. Calcium chloride combines with alcohols, phenols, amines, amino-acids, amides, ketones, and some aldehydes and esters, and thus cannot be used with these classes of compounds. 

The amino add analysis of all peptide chains on the resins indicated a ratio of Pro Val 6.6 6.0 (calcd. 6 6). The peptides were then cleaved from the resin with 30% HBr in acetic acid and chromatogra phed on sephadex LH-20 in 0.001 M HCl. 335 mg dodecapeptide was isolated. Hydrolysis followed by quantitative amino acid analysis gave a ratio of Pro Val - 6.0 5.6 (calcd. 6 6). Cycll2ation in DMF with Woodward s reagent K (see scheme below) yielded after purification 138 mg of needles of the desired cyc-lododecapeptide with one equiv of acetic add. The compound yielded a yellow adduct with potassium picrate, and here an analytically more acceptable ratio Pro Val of 1.03 1.00 (calcd. 1 1) was found. The mass spectrum contained a molecular ion peak. No other spectral measurements (lack of ORD, NMR) have been reported. For a thirty-six step synthesis in which each step may cause side-reaaions the characterization of the final product should, of course, be more elaborate. 

Miscellaneous Reactions. Sodium bisulfite adds to acetaldehyde to form a white crystalline addition compound, insoluble in ethyl alcohol and ether. This bisulfite addition compound is frequendy used to isolate and purify acetaldehyde, which may be regenerated with dilute acid. Hydrocyanic acid adds to acetaldehyde in the presence of an alkaU catalyst to form cyanohydrin the cyanohydrin may also be prepared from sodium cyanide and the bisulfite addition compound. Acrylonittile [107-13-1] (qv) can be made from acetaldehyde and hydrocyanic acid by heating the cyanohydrin that is formed to 600—700°C (77). Alanine [302-72-7] can be prepared by the reaction of an ammonium salt and an alkaU metal cyanide with acetaldehyde this is a general method for the preparation of a-amino acids called the Strecker amino acids synthesis. Grignard reagents add readily to acetaldehyde, the final product being a secondary alcohol. Thioacetaldehyde [2765-04-0] is formed by reaction of acetaldehyde with hydrogen sulfide thioacetaldehyde polymerizes readily to the trimer. 

Naturally Occurring Compounds. Many derivatives of iadole are found ia plants and animals where they are derived from the amino acid tryptophan. Several of these have important biological function or activity. Serotonin [50-67-9] (12) functions as a neurotransmitter and vasoconstrictor (35). Melatonin [73-31-4] (13) production is controlled daily by the circadian cycle and its physiological level iafluences, and seasonal rhythms ia humans and other species (36). Indole-3-acetic acid [87-51-4] (14) is a plant growth stimulant used ia several horticultural appHcations (37). 

Also, Michael addition reactions occur between Ai-acylaminomalonic acid esters and unsaturated compounds, ie, acrolein [107-02-8] acrylonitrile [107-13-1y, acryhc acid esters, and amino acids result from hydrolysis of the addition products. 

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