Folinates

A iridine traces in aqueous solution can be determined by reaction with 4-(p-nitroben25l)pyridine [1083-48-3] and potassium carbonate [584-08-7]. Quantitative determination is carried out by photometric measurement of the absorption of the blue dye formed (367,368). Alkylating reagents interfere in the determination. A iridine traces in the air can be detected discontinuously by absorption in Folin s reagent (l,2-naphthoquinone-4-sulfonate) [2066-93-5] (369,370) with subsequent chloroform extraction and hplc analysis of the red dye formed (371,372). The detection limit is ca 0.1 ppm. Nitrogen-specific thermal ionisation detectors can be used for continuous monitoring of the ambient air. 

The express method of phenolic compounds determination was designed. It is based on heterogeneous azo-coupling reaction of phenols, which different extracts of fresh raw material contain, with aryldiazonium salts grafted on the silica surface. We can carry out phenols analysis on-site, as formation of immobilized azocompounds leads to a drastic change in the sorbent s color. Thus, we pui pose a new method, that allows to indicate herb phenols in aqueous and non-aqueous medias and to compare it with a well-known Folin-Ciocalteau method. 

A method that has been the standard of choice for many years is the Lowry procedure. This method uses Cn ions along with Folin-Ciocalteau reagent, a combination of phosphomolybdic and phosphotnngstic acid complexes that react with Cn. Cn is generated from Cn by readily oxidizable protein components, such as cysteine or the phenols and indoles of tyrosine and tryptophan. Although the precise chemistry of the Lowry method remains uncertain, the Cn reaction with the Folin reagent gives intensely colored products measurable spectrophotometrically. 

Recently, a reagent that reacts more efficiently with Cn than Folin-Ciocalteau reagent has been developed for protein assays. Bieinehoninie aeid (BCA) forms a purple complex with Cu in alkaline solution. 

Methotrexate (MTX, chemical structure shown in Fig. 1.) competitively inhibits the dehyrofolate reductase, an enzyme that plays an essential role in purine synthesis. The dehydrofolate reductase regenerates reduced folates when thymidine monophosphate is formed from deoxyuridine monophosphate. Without reduced folates cells are unable to synthesize thymine. Administration of N-5 tetrahydrofolate or N-5 formyl-tetrahydrofolate (folinic acid) can bypass this block and rescue cells from methotrexate activity by serving as antidote. 

The folate antagonists, pyrimethamine and sulfadiazine, inhibit the parasite s DHFR/TS synthase enzyme complex and the DHPS, respectively (Fig. 4) (see antimalarial drugs). To avoid deficiency of folic acid in patients treated with antifolate antagonists, folinic acid supplementation is recommended to reduce bone-marrow suppression. 

LEUCOVORIN. When leucovorin is administered after a large dose of methotrexate, the timing of tiie administration is outlined by tiie primary health care provider. It is essential that the leucovorin be given at tiie exact time ordered because tiie purpose of folinic acid rescue is to allow a high dose of a toxic drug to remain in tiie body for only a limited time... 

Folinic acid rescue—Take this drug at the exact prescribed intervals. If nausea and vomiting, occur, contact the primary health care provider immediately. 

Trimethoprim (Trimpex) interferes with the ability of bacteria to metabolize folinic acid, thereby exerting bacteriostatic activity. Trimethoprim is used for UTIs that are caused by susceptible microorganisms. Trimethoprim administration may result in rash, pruritus, epigastric distress, nausea, and vomiting. When trimethoprim is combined with sulfamethoxazole (Septra), the adverse effects associated with a sulfonamide may also occur. The adverse reactions seen with other anti-infectives, such as ampicillin, the sulfonamides, and cephalosporins, are given in their appropriate chapters. 

Poulenc) wfm Leucovorin (Lederlc) wfm Rescuvolin (medac) wfm Elvorine (Wyeth-Lederle) Folinate de calcium (Aguettant)... 

Note Monohydroxybenzene derivatives and vicinal hydroxymethoxybenzene derivatives do not react under these conditions but can be made visible by spraying afterwards with Folin-Qocalteu s reagent [1]. Flavonoids, anthraquinone derivatives and a-nitroso-B-naphthol yield a red color with alkalis alone [1]. Steroids and aromatic amines do not react [1]. 

Fluorescence stabilization, porphyrins la 100-101 Fluorophors la 57 Flupentixol lb 354 Fluphenazine la 104 lb 354-356 Fluspirilen lb 354 Fluvalinates lb 86 Foam bath, brominated la 64 Folic acid la 223,225 Folin-Ciocalteu s reagent lb 180 Folin s reagent lb 321 Formaldehyde la 299,351 -, vapor la 86 Formazan lb 65... 

Before discussing these most commonly applied tests in detail, certain general principles should be presented. Converting a macro-method to a micro-method sometimes involves no more effort than decreasing all the volumes used in the procedure. This general procedure is well known to clinical chemists. A typical example would be the Folin method for doing sugar analysis, where a final volume of 25 ml was obtained. 

Glucose. There are four basic principles utilized for glucose analysis. The most widely used depends upon the reduction of some element such as copper or iron. This is the principle of the Folin-Wu method, the ferricyanide method, used on the Autoanalyzer, and the cupreine ( ) method used on the SMA-12/60. 

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