Tyrosine betaine

L-Tyrosine reacted with dimethyl sulfate in NaOH, first at room temp., finally with heating on a water bath —p-methoxycinnamic acid. Y 88.9%.—N-Methyltyrosine and tyrosine betaine can be obtained with a smaller amount of dimethyl sulfate. (U. A. Corti, Helv. 32, 681 (1949).)... 

N-Tris(hydroxymethyl)methyl]glycine, 408 Tyrosine betaine, 397 DL-Valyl-DL-leucine, 410 L-Valyl-L-alanine, 401... 

Root (maHUANGgen) contains macrocy-clic spermine alkaloids (ephedradines A, B, C, and D) an imidazole alkaloid (feruloyUiista-mine) /-tyrosine betaine (maokonine) and diflavonols (mahuannins A and B) (imm-4 wang). °... 

MaHUANGgcn extract when injected intravenously into cats and rabbits caused vasodilation and lowered blood pressure, as well as stimulated respiration and inhibited perspiration it also contracted isolated guinea pig and rabbit smooth muscle preparations (e.g., utems and intestine) (hu). The ephedradines, tyrosine betaine, and feruloylhistamine are the hypotensive principles (imm-4). ... 

Certain amino acids and their derivatives, although not found in proteins, nonetheless are biochemically important. A few of the more notable examples are shown in Figure 4.5. y-Aminobutyric acid, or GABA, is produced by the decarboxylation of glutamic acid and is a potent neurotransmitter. Histamine, which is synthesized by decarboxylation of histidine, and serotonin, which is derived from tryptophan, similarly function as neurotransmitters and regulators. /3-Alanine is found in nature in the peptides carnosine and anserine and is a component of pantothenic acid (a vitamin), which is a part of coenzyme A. Epinephrine (also known as adrenaline), derived from tyrosine, is an important hormone. Penicillamine is a constituent of the penicillin antibiotics. Ornithine, betaine, homocysteine, and homoserine are important metabolic intermediates. Citrulline is the immediate precursor of arginine. 

The relation of many of the simpler alkaloids to the aromatic amino acids is obvious. For example, germinating barley contains (241), besides tyrosine and tyramine, A -methyltyramine, JViV -dimethyltyramine (hordenine), and the trimethylammonium derivative (candicine). In this simple case the. AT-methylated derivatives are known to be derivable from isotopically labeled tyramine (538) and the methyl groups are known to arise from methionine by transmethylation (540, 586). Similarly AT-methyl derivatives of phenylethylamine, 3,4-dihydroxyphenylethylamine, and 3,4,5-trihy-droxyphenylethylamine are well known alkaloids (cf. review, 701). N-Methylated derivatives of tryptamine and hydroxytryptamine equally occur for example, eserine has an obvious relation to 5-hydroxy tryptamine. Methylated derivatives of metabolites of the aromatic amino acids also occur, for example, trigonelline (67), which is the betaine of nicotinic acid, and damascenine is probably similarly related to hydroxyanthranilic acid. 

The demonstration by Phillips and Laiigdon (1956) that the level of TPNH-cytochromc c reductase is increased in the livers of hyperthyroid rats and reduced in those of hypothyroid animals is of particular interest. Since the activity of this enzyme results in the production of triphospho-pyridiiie nucleotide (TPN), a cofactor required for many oxidative enzymes, this change is probably a direct reflection of the general over-all acceleration of oxidative processes, and, more specifically, of those which are TPN-linked. Decreased activity of lactic dehydrogenase (Vcstling and Knocpfelmacher, 1950) is compatible with the demonstrated ability of thyroxine to inhibit this enzyme in vitro (Wolff and Wolff, 1957 Radsma et al., 1957). Decreases in the in vivo activity of such enzymes as tyrosine oxidase, DOPA-decarboxylase, betaine-homocysteine transmethylase, and... 

Calcium gluconate Canolamidopropyl betaine Capryl glycol Carboxymethyl chitosan succinamide Chitosan PCA Chloro-2-hydroxypropyl trimonium chloride Collagen amino acids Copper acetyl tyrosinate methylsilanol Copper PCA Copper PCA methylsilanol... 

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