Coenzyme factor

Cobalt, cyclopentadienyl complexes with thioformaldehyde, 55, 14 Cocaine analogs, isoxazolines, 60, 297 Coenzyme factor 420, synthesis, 55, 192 Colloidal media, iodination of pyrazoles in. 57, 344... 

Deazaflavines and pyrido[2,3-d 6,5-d ]dipyrimidines, which possess an ability to oxidize an alcohol, are obtained from 6-chloro-5-formyl-3-methyluracil and anilines or 6-aminopyrimidines [76CC203 78CPB3208 81JA5943 84TL(25) 1741 86JHC241]. This method is applied to the total synthesis of coenzyme factor 420 [90JCS(P1)253] (Scheme 100). 

Reduction of 7/, A °-methylene-H4MPT to A( -methyl-H4MPT is catalyzed by methylene-H4MPT reductase (Reaction 5, Table 2). Reduced coenzyme factor F420 is the physiological electron donor. The enzyme appears to be soluble and not to contain a prosthetic group [67-69a]. The subsequent methyl-group transfer from... 

Another milestone in flavin research was the characterization of the flavo-semiquinones, the first example of a stable flavin radical. In addition to riboflavin, FMN, and FAD, a number of flavin analogs with biological activities have been found in micro-organisms and plants. Among these, the coenzyme factor F420 isolated from methanogenic bacteria should be mentioned, which has 5-deazaflavin as its chromophore. 

Amino-Alditols. - Aldose oximes, e.p... of mannose and arabinose, can be reduced electrochemically to 1-aminoalditols glucose oxime reacted differently, because, it is proposed, of its strong tendency to cyclize to an N-glucosyl hydroxylamine derivative. l-Amino-2-acetamido-1,2-dideoxy-D-alditols have been prepared by sodium cyano-borohydride reduction of 2-acetamido-2-deoxy-glycosylamines (D-Glc, D-Man, and D- lc-D-Glc).6-(5-deoxy-D-ribit-5-yl)amino-uracil has been condensed with 2-chloro-4-hydroxybenzaldehyde to give a flavin derivative which was further elaborated to Redox Coenzyme Factor 420. ... 

Although choline can be synthesized in the body from serine and methionine with the aid of vitamin B-12 and fola-cin as coenzyme factors, it is not made fast enough and in sufficient quantity for many animal species—especially the young besides, adequate building materials—serine, methionine, vitamin B-12, and folacin—must be present. 

HISTORY. The continuing study of thiamin as a coenzyme in carbohydrate metabolism revealed that this metabolic system required other coenzyme factors in addition to thiamin. In work with lactic acid bacteria, Reed discovered in 1951, that one of these factors is a fat-soluble acid which he named lipoic acid (after the Greek liposior fat). 

Clinical Effects of Thiamin Deficiency. If a deficiency of thiamin is not corrected (if thiamin is not present in sufficient amounts to provide the key energizing coenzyme factor in the cells), the clinical effects will be reflected in the gastrointestinal system, the nervous system, and the cardiovascular system. Severe thiamin deficiency of long duration will culminate in beriberi, the symptoms of which are polyneuritis (inflammation of the nerves), emaciation and/or edema, and disturbances of heart function. 

Anhydrotetracycline oxygenase from Streptomjces aureofaciens which cataly2es the conversion of anhydrotetracycline to dehydrotetracycline, has been isolated and characterized as a flavin-dependent oxygenase (83). It consists of two subunits of mol wt = 57, 500 based on SDS/polyacrylamide—gel electrophoresis. The cosynthetic factor 1 of Streptomjces aureofaciens involved in the reduction of 5a,lla-dehydrochlortetracycline to chlortetracycline, has been identified as 7,8-didemethyl-8-hydroxy-5-deazariboflavin. This work was aided by comparison of spectral data with that of an authentic sample obtained from the hydrolysis of coenzyme F-420 (84). 

Flavins — Riboflavin is first of all essential as a vitamin for humans and animals. FAD and FMN are coenzymes for more than 150 enzymes. Most of them catalyze redox processes involving transfers of one or two electrons. In addition to these well known and documented functions, FAD is a co-factor of photolyases, enzymes that repair UV-induced lesions of DNA, acting as photoreactivating enzymes that use the blue light as an energy source to initiate the reaction. The active form of FAD in photolyases is their two-electron reduced form, and it is essential for binding to DNA and for catalysis. Photolyases contain a second co-factor, either 8-hydroxy-7,8-didemethyl-5-deazariboflavin or methenyltetrahydrofolate. ... 

BaddUey J. Thain, E.M. (1953) Coenzyme A. Part VIII. The Synthesis of Pantetheine 4 -Phosphate (Acetobacter Stimulatory Factor), a Degradation Product of the Coenzyme. Journal of the Chemical Society, 1610-1615. 

A handbook on inorganic and coordination chemistry of porphyrins has been published.1765 Factor F430 is the nickel-hydrocorphinoid group of the enzyme methyl coenzyme M reductase.47,48 The mystery of this particular metalloprotein is one of the major reasons for the development of Ni11-porhyrin coordination chemistry, although not the only one. 

Each catalytic center of methyl coenzyme M reductase, (MCR), contains a yellow chromophore factor F430.4 The structure of Ni-F430 determined by the crystallographic analysis and the proposed mechanism of MCR is shown in Scheme 10.47... 

As part of a study into the activation of metal catalysts in thiol or thiolate-rich environments, X-substituted coenzyme M and thioglycolate derivatives were investigated in a Ni-catalyzed crosscoupling reaction with a zinc co-factor the role of zinc was shown to be in a transmetallation process.571... 

Following the elucidation of the structure of the biologically active forms of Vitamin B12 in 1961, a number of enzymes have been well characterized which require B 12-coenzymes. A survey of the properties of these enzymes in terms of molecular weight, subunits and other co-factor requirements has already been published in excellent reviews by Hogenkamp (29) and Stadtman (30). 

Haem, Fe Chlorophyll, Mg Coenzyme B12, Co Factor F-430, Ni Electron transfer in membranes and elsewhere Light capture and transduction in membranes Transfer of methyl, rearrangements of substrates Activation of carbon monoxide... 

Biotin is a growth factor for many bacteria, protozoa, plants, and probably all higher animals. In the absence of biotin, oxalacetate decarboxylation, oxalosuccinate carboxylation, a-ketoglutarate decarboxylation, malate decarboxylation, acetoacetate synthesis, citrulline synthesis, and purine and pyrimidine syntheses, are greatly depressed or absent in cells (Mil, Tl). All of these reactions require either the removal or fixation of carbon dioxide. Together with coenzyme A, biotin participates in carboxylations such as those in fatty acid and sterol syntheses. Active C02 is thought to be a carbonic acid derivative of biotin involved in these carboxylations (L10, W10). Biotin has also been involved in... 

---