Biological amines

Symmetrical dinucleoside phosphoramidates and iV-substituted phosphora-midates (63) and (64) were obtained after oxidative coupling of the symmetrical //-phosphonate diester of AZT with the appropriate amine Biological evaluation on HIV-infected TK-deficient cell lines suggested that such dinucleoside phosphoramidates could not be regarded as pronucleotides, as they were unable to deliver the corresponding 5 -nucleotide inside the cells. 

Nitrates and nitrites Type 2 facilitated Amines Biological 2, 11, 12... 

Introduction Simple Amines Biogenesis of Simple Amines Biological Activity of Amines in Plants Biological Activity of Amines in Animals Amines from Capsicum Species Diamines and Polyamines in Plants Polyamine Alkaloids Simple Aromatic Alkaloids Hordenine Ephedrine Khat... 

Biogenic amines, biological amines biologically and pharmacologically important naturally occurring amines, occurring widely in plants and animals. They can be divided into 1. derivatives of ethanolamine, e.g. choline, acetylcholine, muscarine 2. polymethylene diamines, e.g. putrescine, cadaverine 3.polyamines, e.g. spermine 4. imidazolylalkylamines, e.g. histamine 5.phenylalkylamines, e.g. mescaline, tyra-mine, hordenine 6. catecholamines, e. g. adrenalin, nor-adrenalin and dopamine 7. indolylalkylamines, e.g. tryptamine, serotonin and 8. betaines, e.g. carnitine. 

This chapter will present the most fundamental concepts for structure, nomenclature, and chemical reactions of amines. Biological applications will focus on the characteristics, formation, and reactions of amino acids. The use of amino acids in proteins and relatively simple reactions that form peptides will be discussed. In addition, several chemical reactions that lead to controlled degradation of peptides and proteins will be introduced. 

Fluorescence techniques can be applied to all kinds of material. Because fluorescence microscopy requires more complex and expensive instrumentation than conventional transmitted-light microscopy, fluorescence microscopy is usually reserved for those applications in which its high sensitivity is of importance i.e., to examine substances present in low concentrations. Fluorescence microscopy can also be applied to detect particles below the resolution of a light microscope, and in histochemistry to visualize substances which cannot be seen by conventional microscopy - e.g. neurotransmitter amines. Biological material is commonly stained in some manner with a fluorescent stain. 

Many biological processes involve an associa tion between two species in a step prior to some subsequent transformation This asso ciation can take many forms It can be a weak associ ation of the attractive van der Waals type or a stronger interaction such as a hydrogen bond It can be an electrostatic attraction between a positively charged atom of one molecule and a negatively charged atom of another Covalent bond formation between two species of complementary chemical re activity represents an extreme kind of association It often occurs in biological processes in which aide hydes or ketones react with amines via imine inter mediates... 

Amines like ammonia are weak bases They are however the strongest uncharged bases found m significant quantities under physiological conditions Amines are usually the bases involved m biological acid-base reactions they are often the nucleophiles m biological nucleophilic substitutions... 

Our word vitamin was coined m 1912 m the belief that the substances present m the diet that prevented scurvy pellagra beriberi rickets and other diseases were vital amines In many cases that belief was confirmed certain vitamins did prove to be amines In many other cases however vitamins were not amines Nevertheless the name vitamin entered our language and stands as a reminder that early chemists recognized the crucial place occupied by amines m biological processes... 

Toxic or malodorous pollutants can be removed from industrial gas streams by reaction with hydrogen peroxide (174,175). Many Hquid-phase methods have been patented for the removal of NO gases (138,142,174,176—178), sulfur dioxide, reduced sulfur compounds, amines (154,171,172), and phenols (169). Other effluent treatments include the reduction of biological oxygen demand (BOD) and COD, color, odor (142,179,180), and chlorine concentration. 

Reactions. The chemistry of the /V-nitrosamines is extensive and will be only summarized here (8,35,42). Most of the reactions of the nitrosamines, with respect to thek biological or environmental behavior, involve one of two main reactive centers, either the nitroso group itself or the C—H bonds adjacent (a) to the amine nitrogen. The nitroso group can be removed readily by a reaction which is essentially the reverse of the nitrosation reaction, or by oxidation or reduction (68,69). 

A wide variety of quaternaries can be prepared. Alkylation with benzyl chloride may produce quaternaries that are biologically active, namely, bactericides, germicides, or algaecides. Reaction of a tertiary amine with chloroacetic acid produces an amphoteric compound, a betaine. 

Furylfuramide. a[(5-Nitro-2-furaiiyl)-2-methylene]-2-furaiiacetamide, withdrawn from the market in Japan in 1974 because of mutagenicity, is prepared by condensation of 5-nitro-2-furancarboxaldehyde with 2-furanacetic acid followed by chlorination and amination (30). The isomerization of cis to trans form of fudyfuramide has been shown to occur in the presence of a variety of biological reducing agents (31). 

The chromaffin cells of the adrenal medulla may be considered to be modified sympathetic neurons that are able to synthesize E from NE by /V-methylation. In this case the amine is Hberated into the circulation, where it exerts effects similar to those of NE in addition, E exhibits effects different from those of NE, such as relaxation of lung muscle (hence its use in asthma). Small amounts of E are also found in the central nervous system, particularly in the brain stem where it may be involved in blood pressure regulation. DA, the precursor of NE, has biological activity in peripheral tissues such as the kidney, and serves as a neurotransmitter in several important pathways in the brain (1,2). 

Histamine is the biological amine, playing an important role in living systems, but it can also cause unnatural or toxic effects when it is consumed in lai ge amounts. It can occur with some diseases and with the intake of histamine-contaminated food, such as spoiled fish or fish products, and can lead to undesirable effects as headache, nausea, hypo- or hypertension, cai diac palpitations, and anaphylactic shock syndrome. So, there is a need to determine histamine in biological fluids and food. 

In other sections in this chapter, we have referred to a variety of macropolycyclic structures which are more elaborate than the simple three-stranded bicyclic cryptands. This includes bridged double-macrocycles " , in-out bicyclic amines and the macrotricyclic quaternary ammonium salts of Schmidtchen. In addition to these, there are two other types of compounds which deserve special note. The first of these is a stacked twin-ring cryptand, but it is a hybrid molecule rather than a double-cryptand . The species shown below as 20 is a crowned porphyrin, and was designed to provide a pair of metal cation binding sites similar to those which might be available in natural biological systems . 

Tetrahydroharman, m.p. 179-80°, has been prepared by a number of workers by a modification of this reaction, viz., by the interaction of tryptamine (3-)5-aminoethylindole) with acetaldehyde or paraldehyde and Hahn et al. have obtained a series of derivatives of tetrahydronorharman by the use of other aldehydes and a-ketonic acids under biological conditions of pH and temperature, while Asahina and Osada, by the action of aromatic acid chlorides on the same amine, have prepared a series of amides from which the corresponding substituted dihydronorharmans have been made by effecting ring closure with phosphorus pentoxide in xylene solution. 

For the purposes of this book, an alkaloid is regarded as a relatively complex, organic base, occurring naturally in a plant and usually possessing marked pharmacological activity. This excludes simple, naturally Occurring bases and the biological amines, which are adequately dealt with... 

Dmitrofluorobenzene also serves as an arylation agent for a wide vanety of biologically useful amines including aromatic amines [5b], ammo acids [57], and ammocarbohydrates [55,59] Weak nucleophilic amines such as benzimidazole [60] and fluoroamines [61] can also be arylated (equation 30)... 

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