Tryptophan, acetyl

Inactivation and Removal of Viruses. In developing methods of plasma fractionation, the possibiHty of transmitting infection from human vimses present in the starting plasma pool has been recognized (4,5). Consequentiy, studies of product stabiHty encompass investigation of heat treatment of products in both solution (100) and dried (101) states to estabHsh vimcidal procedures that could be appHed to the final product. Salts of fatty acid anions, such as sodium caprylate [1984-06-17, and the acetyl derivative of the amino acid tryptophan, sodium acetyl-tryptophanate [87-32-17, are capable of stabilizing albumin solutions to 60°C for 10 hours (100) this procedure prevents the transmission of viral hepatitis (102,103). The degree of protein stabilization obtained (104) and the safety of the product in clinical practice have been confirmed (105,106). The procedure has also been shown to inactivate the human immunodeficiency vims (HIV) (107). 

With 1-hydroxytryptophan derivatives, similar substituent effects are observed (99H2815). In order to realize better yields of 5-substituted tryptophans, car-boxy and amino groups are transformed to ester and/or amide groups, choosing the 1-methoxy moiety as a leaving group. As a result, ( )-Ab-acetyl-5-chlorotryptophan methyl ester (219, 52%) is obtained together with 220 (7%) from ( )-218 by the reaction with aqueous HCl (Scheme 32). ( )-5-Bromo-Ab-methoxycarbonyltryptophan methylamide (222, 50%) becomes readily available... 

CN 1-acetyl-L-tryptophan compd. with 3,7-dihydro-l,3,7-trimethyl-l//-purine-2,6-dione (1 1)... 

C HpNsO, 133186-23-9) see Aciclovir iV-acetyl-S-benzyloxy-DL-tryptophan (C2, H2,N204 53017-51-9) see Oxitriptan iV-aeetyl-lV,0-bis(trimethylsilyl)cytosine... 

CjH OS 1468-83-3) see Brinzolamide 5-acetylthiophene-2-carboxamide (C7H7NO2S 68257-89-6) see Arotinolol S-acetylthiophene-2-carboxylic acid (C7HSO3S 4066-41-5) see Arotinolol 0-acetyltropoyl chloride (CiiHiiClOj 14510-37-3) see Tropicamide A-acetyl-L-tryptophan... 

Three compounds acetoacetate, P-hydroxybutyrate, and acetone, are known as ketone bodies. They are suboxidized metabolic intermediates, chiefly those of fatty acids and of the carbon skeletons of the so-called ketogenic amino acids (leucine, isoleucine, lysine, phenylalanine, tyrosine, and tryptophan). The ketone body production, or ketogenesis, is effected in the hepatic mitochondria (in other tissues, ketogenesis is inoperative). Two pathways are possible for ketogenesis. The more active of the two is the hydroxymethyl glutarate cycle which is named after the key intermediate involved in this cycle. The other one is the deacylase cycle. In activity, this cycle is inferior to the former one. Acetyl-CoA is the starting compound for the biosynthesis of ketone bodies. 

From the fore gut of Laccophilus minutus, a Bacillus pumilus strain was isolated which produced maculosin, the diketopiperazine formed from proline and tyrosine [103] 24, phenyl malonate 25, N-acetylphenylalanine 26, N-acetyl-tryptophane 27 and 3,4-dihydroxybenzoic acid [ 103]. Maculosin which has also been isolated from several microorganisms and sponges shows phytotoxic and cytotoxic properties [103], 3,4-dihydroxybenzoic acid shows antioxidant properties and was already found in pygidial defensive glands of several dytis-cid beetles. 

In the case of carboxypeptidase B, Shaklai et al.(2lT> compared the relative contributions to the protein phosphorescence from tyrosine and tryptophan for the apoenzyme, the zinc-containing metalloenzyme in the absence of substrate, the metalloenzyme in the presence of the substrate iV-acetyl-L-arginine, and the metalloenzyme in the presence of the specific inhibitor L-arginine. The tyrosine tryptophan emission ratio of the metalloenzyme was about a factor of four smaller than that of the apoenzyme. Binding of either the substrate or the inhibitor led to an increase in the emission ratio to a value similar to that of the apoenzyme. The change in the tyrosine tryptophan phosphorescence ratio was attributed to an interaction between a tyrosine and the catalytically essential zinc. The emission ratio was also studied as a function of pH. The titration data are difficult to interpret, however, because a Tris buffer was used and the ionization of Tris is strongly temperature dependent. In general, the use of Tris buffers for phosphorescence studies should be avoided. 

Serotonin is an indolamine neurotransmitter, derived from the amino acid L-tryptophan. Tryptophan is converted to 5-hydroxytryptophan (5-HTP) by tryptophan hydroxylase. 5-HTP is converted to 5-hydroxytryptamine (serotonin, 5-HT) by aromatic amino acid decarboxylase. In the pineal gland, 5-HT may be further converted to /V-acetyl serotonin by 5-HT /V-acetyltransferase and then to melatonin by 5-hyroxyindole-O-methyltransferase. 5-HT is catabolized by monoamine oxidase, and the primary end metabolite is 5-hydroxyindoleacetic acid (5-HIAA). 

Bender et al, (1964) made an attempt to explain the rate constants attained in a-chymo trypsin reactions as follows for N-Acetyl-L-tryptophan amide ... 

For the preparation of 3,4-dihydro-/3-carbolines the Bischler-Napieralski reaction is widely used (510R74). Since this reaction requires rather drastic conditions, A-acetyl tryptophan and its analogs yielded l-methyl-/8-carboline (harman) rather than l-methyl-3,3-dihydro-j8-carboline-3-carboxylic acid derivatives owing to accompanying decarboxylation and aromatization (41JCS153 50JA2962). 

For the synthesis of the natural blue pigment trichotomine dimethyl ester, L-Trp-OMe was used as a starting material. The first step of this synthesis was conversion into methyl l-methyl-3,4-dihydro-/8-carboline-3-carboxylate with acetyl chloride in TFA (85JOC3322). An improved method starts from the corresponding thioamides via thioiminium salts which cyclize spontaneously in refluxing solvent (82CPB4226). A-Formyl-tryptophan also cyclized readily with no side reactions (68CJC3404). 

The synthesis of /./-pyridindolol 1064 started by acetonation of glyceric ester 1057 to give 1058, which was converted to the imidazoline 1059 by reaction with l,l-dimethyl-l,2-diaminoethane followed by acetylation. Its methylation gave 1060, which can be reduced to 1061 further reaction with tryptamine or tryptophan ester hydrochloride 1062 gave the respective diastreomeric mixture of carboline 1063 (80H947). Its conversion to racemic alkaloid d,/-pyridindolol 1064 could be readily achieved (79JOC535). 

The effect of the neglect of Eq. (5.30) can be quite large. For the peptide N-acetyl-a,/ -dehydrophenylalanine methylamide (space group Cc), for example, the underestimate of the density is reported to be as large as 0.19 eA. In /V-acetyl-i.-tryptophan methylamide, which crystallizes in the space group F2,2121 with centrosymmetric projections, the features are somewhat smaller (Fig. 5.14), but still important. 

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