Riboflavin analogs

P Nielsen, P Rauschenbach, A Bacher. Phosphates of riboflavin and riboflavin analogs a reinvestigation by high-performance liquid chromatography. Anal Biochem 130 359-368, 1983. 

Although the ribitol moiety is not involved in the redox function of the flavin coenzymes, both the stereochemistry and nature of the sugar alcohol are important. Although some riboflavin analogs have partial vitamin action. 

On the other hand, it has been shown that mutants isolated on the basis of their resistance to the toxic riboflavin analog roseoflavin also exhibit a riboflavin-overproduction phenotype (Kukanova et al. 1982). Moreover, roseoflavin has been used to obtain constitutive riboflavin overproducing strains of B. subtilis (Perkins and Pcto 2002), L. lactis (Burgess et al. 2004), Lact. plantarum, Leuc. mesenteroides, and Propionibacteriumfreudenreichii (Burgess et al. 2006). Some of these have been shown to provide beneficial effects in vitamin depleted animals and could be inserted as novel starter cultures (LeBlanc et al. 2005a,b, 2006)... 

Snell and Strong compared the activity of these riboflavin analogs with their reported activities as vitamin B2 by rat assay and in Kuhn and Rudy s enzyme tests (174). The correlation was close, analogs inactive for the... 

This occurs by a mechanism called static photosensitization, analogous to that followed by biologically acting photosensitizers like riboflavin. 

New derivatives of 4-amino and 2,4-diaminopteridines have been synthesized and their capability to inhibit neuronal nitric oxide synthase evaluated <99JMC4108>. The synthesis of folic acid multiply labeled with stable isotopes, for bioavailability studies in human nutrition, has been reported <99JCS(P1)1311>, Synthesis and antiviral evaluation of several 6-(methylenecarbomethoxy)pteridine-4,7-diones have been described <99JHC435>. Synthesis and biochemical evaluation of bis(6,7-dimethyl-8-D-ribityllumazines) as potential bisubstrate analog inhibitors of riboflavin synthase have been reported <99JOC4635>. Synthesis and cyclization of novel lumazine-enediyne chimeras have been reported <99H13>. 

These include 8a-(Ne2-histidyl)-FMN,221 8a-(N81-histidyl)-FA D,222 8a-(0-tyrosyl-FAD),223 and 6-(S-cysteinyl)-riboflavin 5 -phosphate, which is found in trimethylamine dehydrogenase (Fig. 15-9).224 An 8-hydroxy analog of FAD (-OH in place of the 8-CH3)... 

Since reduced flavins, pteridine derivatives, and PQQ can be readily oxidized by oxygen to regenerate the oxidized forms [59-62], these coenzyme analogs can act as photocatalysts when the oxidation of substrates by the coenzymes occurs photochemically. No appreciable photooxidation of benzyl alcohol by oxygen occurs when aminopterin (AP), lumazine (Lu), or riboflavin-tetraacetate (FI) is used as a photocatalyst in the absence of acid in MeCN. When HC104 is added to this system, however, the flavin and pteridine derivatives are protonated as described above, and each proton-ated species (catH+) can act as an efficient photocatalyst for the oxidation of benzyl alcohol derivatives (X-C6H4CH2OH) by oxygen [70] ... 

Fouty B, Frerman F, Reves R. Riboflavin to treat nucleoside analog-induced lactic acidosis. Lancet 1998 352(9124) 291-2. 

Carbohydrate metabolism provides the main energy source in coccidia. Diets deficient in thiamin, riboflavin, or nicotinic acid—all cofactors in carbohydrate metabolism—result in suppression of parasitic infestation of chickens by E tenella and E acervulina. A thiamin analog, amprolium—1-[(4-amino-2-propyl-5-pyrimidinyl)-methyl]-2-picolinium chloride—has long been used as an effective anticoccidial agent in chickens and cattle with relatively low host toxicity. The antiparasitic activity of amprolium is reversible by thiamin and is recognized to involve inhibition of thiamin transport in the parasite. Unfortunately, amprolium has a rather narrow spectrum of antiparasitic activity it has poor activity against toxoplasmosis, a closely related parasitic infection. 

The water soluble vitamins, B2(riboflavin), Biascorbic acid) provided a very interesting study. The spectra for B12 and some of its analogs were first reported by Williams et al., [58] and consist of very strong Cotton bands across almost the entire visible spectral range, Figure 3. 

The central topic of this volume is biomimetic chemistry. In this chapter we describe our recent studies using synthetic analogs of riboflavin-based coenzymes with specific atom substitutions in the... 

The malarial parasites may have a particularly high requirement for riboflavin. A number of flavin analogs have antimalarial action. 

The phenothiazines, such as chlorpromazine, used in the treatment of schizophrenia, the tricyclic antidepressant drugs such as imipramine and amitryp-tUine, antimalarials such as quinacrine, and the anticancer agent adriamycin are structural analogs of riboflavin (see Figure 7.6) and inhibit flavokinase. In experimental animals, administration of these drugs at doses equivalent to those used clinically results in an increase in the EGR activation coefficient (Section 7.5.2) and increased urinary excretion of riboflavin, with reduced tissue concentrations of riboflavin phosphate and FAD, despite feeding diets providing more riboflavin than is needed to meet requirements (Pinto et al., 1981). 

Figure 7.6. Drugs that are structural analogs of riboflavin and may cause deficiency. Relative molecular masses (Mr) riboflavin, 376.4 quinacrine, 472.9 (dihydrochloride) chlorpromazine, 318.9 imipramine, 280.4 amitryptyline, 277.4 and adriamycin (doxorubicin), 543.5.

Fo, 35), which is an analog of riboflavin, serves as the business end of coenzyme F420 (36, Fig. 3), whose designation is based on its characteristic absorption maximum at 420 mn. Factor Fo is biosynthesized from the pyrimidine type intermediate 23 of the riboflavin biosynthetic pathway, which affords the pyrimidine ring and the ribityl side chain, whereas the car-bocyclic moiety is derived from the shikimate pathway via 4-hydroxyphenylpyruvate (56, 57). In contrast to the coenzymes described below, deazaflavin-type coenzymes are not strictly limited to methanogenic bacteria and are also found in strepto-mycetes and mycobacteria. 

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