Biochemical Contributions

Miscellaneous Biochemical Contributions.—The enzymatic bromination of the thiazole ring has been described. 2-Acetamidothiazole or 2-aceto- 

The structure of aeruginoic acid, which is isolated from the culture medium of Pseudomonas aeruginosa, has been recognized as 2-u-hydroxy-phenylthiazole-4-carboxylic acid, and confirmed by an unequivocal synthesis of the Hantzsch type.  

Thiazol-4-ylmethoxyamine hydrochloride acts as a histidine decarboxylase inhibitor, lowering brain histamine levels in rats.  

2-(6 -Hydroxybenzothiazol-2 -yl)-4-hydroxythiazole (141) and some of its derivatives, which appear to be concerned in the bioluminescence of the firefly, have been prepared and their spectral properties examined.  

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Comparative studies on the primary structures of homologous P. from different species (e.g. hemoglobin from vertebrates, see Homologous proteins) or analogous P. (e. g. subtilisin from Bacillus subtilis and mammalian trypsin) have made a valuable biochemical contribution to questions of divergent and convergent evolution. However, for an explanation of P. function and behavior, especially the mechanism of enzyme action, the primary structure alone is insufficient, and a knowledge of secondary and tertiary structure is needed. 

Dodds, C. 1957. Biochemical Contributions to Endocrinology. Stanford Univ. Press, Stanford, California. 

The biochemical basis for the toxicity of mercury and mercury compounds results from its ability to form covalent bonds readily with sulfur. Prior to reaction with sulfur, however, the mercury must be metabolized to the divalent cation. When the sulfur is in the form of a sulfhydryl (— SH) group, divalent mercury replaces the hydrogen atom to form mercaptides, X—Hg— SR and Hg(SR)2, where X is an electronegative radical and R is protein (36). Sulfhydryl compounds are called mercaptans because of their ability to capture mercury. Even in low concentrations divalent mercury is capable of inactivating sulfhydryl enzymes and thus causes interference with cellular metaboHsm and function (31—34). Mercury also combines with other ligands of physiological importance such as phosphoryl, carboxyl, amide, and amine groups. It is unclear whether these latter interactions contribute to its toxicity (31,36). 

Most studies concerning pyrimidines originate from biochemical questions. Since these systems are dominated by hydrogen-bonding and/or dispersion contributions, methods beyond the Hartree-Fock level are mandatory. The success of quantum chemical studies in this field is impressive and many effects could be explained on the basis of these theoretical investigations. 

The fireflies, railroad worms, and click beetles use the same luciferin in their luminescence reactions. Recent studies on the railroad worms and the click beetles have greatly contributed to the biochemical understanding of the firefly bioluminescence (see Section 1.2). Concerning luminous Diptera, significant progress has been made only recently. 

Contribution to Biochemical Research Foundation Seminar on the Chemistry of Nucleic Acids ," M. Stacey,/ Franklin Inst., 253 (1952) 89. 

Stafford K, Gomes AB, Shen J, et al p-Opioid receptor downregularion contributes to opioid tolerance in vivo. Pharmacol Biochem Behav 69 233—237, 2001... 

The pentagon stabilization has been found in a biochemical phenomenon [80], The hydrogen on the thiazolium ring 9 (Scheme 7) is easily ionized to afford the corresponding carbene 10, a key catalyst in enzymatic reactions for which thiamine (vitamin B-1,11) pyrophosphate is the cofactor. The pentagon stability is expected to contribute to this unusual deprotonation. A lone pair generated on the carbon atom in 10 can similarly delocalize through the vicinal C-N and C-S a bonds in a cyclic manner. 

Chambers JE, Carr RE. 1995. Biochemical mechanisms contributing to species differences in insecticidal toxicity. Toxicology 105 291-304. 

The prominent role played by Japanese investigators in carbohydrate science is underscored by the two substantial chapters by Japanese authors in the current volume. This volume also pays tribute to one of the greatest Japanese carbohydrate scientists, Hamao Umezawa, in the obituary article contributed by Tsuchiya, Maeda, and Horton. Hamao Umezawa dedicated his entire, extraordinarily productive career to the development of antibiotics his innovative contributions are exemplified by his chapter in Volume 30 of this series on the biochemical mechanism of inactivation of aminoglycoside antibiotics. 

We believe that most if not all diseases are manifestations of abnormalities of molecules, chemical reactions, or biochemical processes. The major factors responsible for causing diseases in animals and humans are hsted in Table 1-2. All of them affect one or more critical chemical reactions or molecules in the body. Numerous examples of the biochemical bases of diseases will be encountered in this text the majority of them are due to causes 5, 7, and 8. In most of these conditions, biochemical smdies contribute to both the diagnosis and treatment. Some major uses of biochemical investigations and of laboratory tests in relation to diseases are summarized in Table 1-3. 

Gil, A., Ghersa, G M. and Perebnan, S. 2002. Root thiophenes in Tagetes minuta L. accessions from Argentina genetic and environmental contribution to changes in concentration and composition. Biochem. Syst. Ecol. 30 1-13. 

Nakajima T, Wang RS, Elovaara E, et al. 1992a. A comparative study on the contribution of cytochrome P-450 isozymes to metabolism of benzene, toluene and trichloroethylene in rat liver. Biochem Pharmacol 43 251-257. 

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