Amines, lipophilic

Dyestuffs in general, and azo dyes in particular, are likely to undergo. substantial primary biodegradation in an anaerobic environment through reductive cleavage of azo bonds into aromatic amines. Lipophilic aromatic... 

Lehn s approach is slightly more complex than that illustrated above in that the diol is chloromethylated and then treated with cyanide. Hydrolysis then affords the diacid which may be carried through as shown. It should also be noted that once the bis-acyl halide is in hand, it may be treated directly with an open-chained amine to yield a lipophilic diazacrown, after reduction ... 

By structural complementarity, dicationic l,4-diazabicyclo[2.2.2]octane (VII) provides an appropriate recognition site for phosphate ions and two stearyl side chains attached to the amines add lipophilic properties 59,60). Such a carrier model can selectively extract nucleotides from aqueous solution to chloroform solution via lipophilic salt formation. The order of nucleotide affinity is ATP > ADP > AMP. The selectivity ratios were 45 for ADP/AMP and 7500 for ATP/AMP at pH 3. The relative transport rate was ATP > ADP > AMP. The ratios were 60 for ATP/AMP and 51 for ADP/AMP. The modes of interaction of ADP and ATP are proposed to be as shown in Fig. 6. 

Local Anaesthetics. Figure 1 Common structure of local anaesthetics. A lipophilic moiety on the left, an aliphatic spacer containing an ester or amide bond in the middle and an amine group on the right are the typical structural elements for local anaesthetic drugs. 

The ending caine stems from cocaine, the first clinically employed local anaesthetic. Procaine and tetracaine are ester-linked substances, the others are amides. Amide bonded local anaesthetics usually contain two i s in their name, ester-bonded only one. In the structure drawings, the lipophilic portion of the molecule is depicted at the left, the amine at the right. The asterisk marks the chiral centre of the stereoisomeric drugs. Lipid solubility is given as the logarithm of the water octanol partition coefficient, log(P). 

Due to their physicochemical properties trace amines can pass the cell membrane to a limited extent by passive diffusion, with the more lipophilic PEA and TRP crossing membranes more readily than the more polar amines TYR. and OCT. In spite of these features, trace amines show a heterogeneous tissue distribution in the vertebrate brain, and for TYR. and OCT storage in synaptic vesicles as well as activity-dependent release have been demonstrated. So far, trace amines have always been found co-localized with monoamine neurotransmitters, and there is no evidence for neurons or synapses exclusively containing trace amines. 

Aliphatic phosphoric acid and phosphonic acid amides containing lipophilic groups were prepared and used as antimicrobial surfactants. For example, 100 g ethylmethanephosphonate chloride was added to a solution of 130 g dodecyl-amine and 72 g triethylamine in 500 ml anhydrous benzene at 20-30°C to give 192 g ethylmethanephosphonate N-dodecylamide [125]. 

The effects of a series of added tertiary amines on the rate of chedn scission of other polyesters, including poly( e-caprolactone-co-lactic acid), has been studied and found to be equally great (65). The mechanism with tertiary amines can only be general base catalysis for the effectiveness of the amines was not related to their pK values or lipophilicities. The acceleration of the hydrolysis of the polyesters was used as a strategy for controlling the drug release rate. 

Evidence exists that the relative solubility of amines and inhibitors in heterogeneous oil-water systems could be decisive in formation of nitrosamines and blocking these reactions, Nitrosopyrrolidine formation in bacon predominates in the adipose tissue despite the fact that its precursor, proline, predominates in the lean tissue (5,6,7). Mottram and Patterson (8) partly attribute this phenomenon to the fact that the adipose tissue furnishes a medium in which nitrosation is favored, Massey, et al, (9) found that the presence of decane in a model heterogeneous system caused a 20-fold increase in rate of nitrosamine formation from lipophilic dihexylamine, but had no effect on nitrosation of hydrophilic pyrrolidine. Ascorbic acid in the presence of decane enhanced the synthesis of nitrosamines from lipophilic amines, but had no effect on nitrosation of pyrrolidine. The oil-soluble inhibitor ascorbyl palmitate had little influence on the formation of nitrosamines in the presence or absence of decane. 

Fe(II)-tetrakis-N, N, N, N (2-pytidylmethyl-2-amino-ethyl)amine (Fe-TPEN) and Fe(III)-ttis [N-(2-pyridylmethyl)2-aminoethyl]amine (Fe-TPAA) are novel iron complexes containing lipophilic and neutral ligands. 

Use of the relatively small cyclopropane ring drastically reduces the potential for deleterious steric bulk effects and adds only a relatively small lipophilic increment to the partition coefficient of the drug. One of the clever elements of the rolicyprine synthesis itself is the reaction of d,l tranylcypromine (67) with L-5-pyrrolidone-2-carboxylic acid (derived from glutamic acid) to form a highly crystalline diastereomeric salt, thereby effecting resolution. Addition of dicyclohexylcarbodiimide activates the carboxyl group to nucleophilic attack by the primary amine thus forming the amide rolicyprine (68). 

Acidic compounds with N—H bonds such as amides, carbamates, and hydan-toins, may be transformed to /V-rnannich bases to form oral prodrugs [2], These prodrugs are generally made by reacting an amide, carbamate, or hydantoin with formaldehyde and a primary or secondary aliphatic or aromatic amine (Fig. 4). The (V-mannich prodrugs tend to have better physicochemical properties than the parent compounds. The derivatives may have increased water solubility, dissolution rate, and/or lipophilicity. 

Sensors for acidic (HC1, SO2, CO2, acetic acid) or basic gases (NH3, amines) often make use of pH indicator dyes immobilised in polymers. Lipophilic Bromophenol Blue (see section 4.2) dissolved in silicone is... 

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