Ornithine, preparation

This technique can be applied to prepare DL-a-fluoromethylputrescme (5-fluoropentane 1,4-diamine), a potent irreversible inhibitor of E colt ornithine decarboxylase, from 4-phthalimido-l -butyryl chloride, diazomethane, and hydro gen fluonde-pyridine [94 95]... 

A -Pyrroline has been prepared in low yield by oxidation of proline with sodium hypochlorite (71), persulfate (102), and periodate (103). A -Pyrroline and A -piperideine are products of enzymic oxidation via deamination of putrescine and cadaverine or ornithine and lysine, respectively (104,105). This process plays an important part in metabolism and in the biosynthesis of various heterocyclic compounds, especially of alkaloids. 

Also N, N -bisprotected pyrazole-l-carboxamidines are applied for preparation of guanidines.[91,[9al A variation of this reaction permitted the copper salt of ornithine to be converted to the copper salt of arginine [10]... 

A series of 1-aminoalkanediphosphonic acids has been reported by the treatment of the N-phenylthiourea derivatives of a>-diethoxyphos-phinoylaldehydes with triphenyl phosphite.343 This constitutes an approach toward the analogues of aspartic and glutamic acid in which both carboxylate sites have been replaced by phosphonic acid functions. A similar approach has also been reported to be of use for the preparation of (diphenyl ester) phosphonate analogues of ornithine, lysine, and homolysine.344345... 

In the next 2 to 3 years further experiments, particularly by Eggleston, who had joined Krebs in January 1936, confirmed and extended the observations. Careful quantitative evaluation of the data indicated that citrate like fumarate (Szent-Gyorgi) and like ornithine in the urea cycle exerted a catalytic effect on muscle metabolism. If arsenite, which blocks 2-oxoglutarate oxidation, was added with citrate to a respiring pigeon-muscle preparation, 2-oxoglutarate accumulated. 

Major interfering substances found in the crude toxin preparation are citrulline, ethanolamine, ornithine, lysine and arginine. 

Diaminobutyric Acid.—a-7-Diaminobutyric acid was prepared in 1901 by E. Fischer by the same method as he employed in the synthesis of ornithine. 

Ornithine or a, h-diamimrvalerianic Acid.—In 1877 JafTe obtained from the urine of birds, which he had fed with benzoic acid, dibenzoyl ornithine or ornithuric acid, and from this substance he prepared ornithine chloride. He regarded it as a diaminovalerianic acid, the first known representative of the series of diamino acids, but only in 1898 was the position of the two amino groups definitely determined by Ellinger, who obtained putrescine from it by putrefaction the identity of putrescine with tetramethylenediamine had been previously shown by... 

It was also synthesised by E. Fischer in 1901 from 7-phthalimido-propylmalonic ester which he employed in the preparation of ornithine. The bromine derivative of this compound when treated with ammonia gave a complex mixture of products which after hydrolysis by hydrochloric acid at 100° C. gave phthalimide and a-pyrrolidine carboxylic acid —... 

The ban of halogenofluoromethanes (halons) for environmental reasons may reduce the benefit of this straightforward method, at least on the industrial level. Difluoromethyl ornithine (DFMO) was prepared industrially by this path (alkylation with CHCIF2). New approaches are currently the focus of research in order to restart its production. 

Taste of Orn-p-Ala Derivatives. We reported in the previous paper (5) that omithyl-p-alanine monohydrochloride produced the salty taste as omithyltaurine. We prepared two tetrapeptides composed of ornithine and p-alanine. Both tetrapeptides, however, produced mainly an astringent taste instead of the salty or the umami taste (Table Xffl). 

Several 0-aminoacyl sugars were prepared to study a relationship between taste and chemical structure. Methyl a-D-glucopyranoside, methyl a-D-galactopyranoside and methyl a-D-mannopyranoside were selected as sugar skeletons. As basic amino acids, esters of lysine, ornithine, a,Y-diaminobutyric acid, and a,p-diaminopropionic acid were introduced into 2-0-, 3-0-, and 4-0- positions of sugars leaving only 6-hydroxyl group free. The results of sensory analysis are list in Table VI. O-... 

Enantiomerically pure tripeptide aldehydes are typically synthesized by azide or mixed anhydride coupling of dipeptides to a-amino aldehydes or their semicarbazone derivatives. For example, Ac-Leu-Leu-Phe-H was synthesized by the azide coupling of Ac-Leu-Leu-OH with Phe-H semicarbazone, prepared by catalytic hydrogenation of Z-Phe-H semicarbazone. The tripeptide semicarbazone was deprotected with 37% HCHO/HC1 solution (Table 2)J5 C-terminal argininal, ornithinal, and lysinal peptides such as Z-Leu-Leu-Orn(Boc)-H and Z-Leu-Leu-Lys(Boc)-H were prepared by mixed anhydride coupling of Z-Leu-Leu-OH with Orn(Boc)-H semicarbazone or Lys(Boc)-H semicarbazone. 3 Z-Leu-Leu-Arg(N02)-H was prepared by mixed anhydride coupling of Z-Leu-Leu-OH with Arg(N02)-H semicarbazone trifluoroacetate, prepared from the reaction of TFA and Boc-Arg(N02)-H semicarbazone (Table 2) J31... 

Shin et al. [88] Ornithine Kuruma prawn Ornithine carbamyl transferase, nucleoside phosphorylase and xanthine oxidase/in membranes prepared from cellulose triacetate, glutaraldehyde and 1,8-diamino-4-am i nomethyl octane Oxygen electrode ... 

These reliable Michael technologies have been successfully applied to the preparation of all possible 13C and 1SN isotopomers of L-lysine, L-ornithine, and L-proline by the group of Lugtenburg [37]. 

The 13C-labelled ornithine was prepared so that individual molecules bore both labels. Consequently the 13C n.m.r. resonances appeared as doublets. Likewise, the 13C signals due to precursor label in the derived alkaloid appeared as (low-intensity) doublets on either side of the natural-abundance singlets, and were thus separate from them. This allowed an estimation of the extent to which label was incorporated into each site, even though that extent was low (0.05— 0.07%). Clearly, this novel application of 13C-labelling will find use elsewhere, since incorporation of a precursor can be measured at high dilution (ca 4000 times). 

A transaminase patented by Celgene Corporation (Warren, NJ), called an co-aminotransferase [(co-AT)E.C. 2.6.1.18] does not require an a-amino acid as amino donor instead it requires a primary amine and hence has the ability to produce chiral amines.125 126 A similar co-AT from Vibrio fluvialis has been described for the production of chiral amines along with chiral alcohols when coupled with AdH or chiral amino acids when coupled with an a-amino acid aminotransferase.127130 Another co-AT, ornithine (lysine) aminotransferase (E.C. 2.6.1.68), has been described for the preparation of a chiral pharmaceutical intermediate used in the synthesis of Omapatrilat, a vasopep-tidase inhibitor developed by Bristol-Myers Squibb, as well as the UAA A1 -piperidinc-6-carboxylic acid.131-132... 

The structure of most of these compounds must be considered as quite well established. Deferrideoxyferrichrome, prepared from the parent compound with Raney nickel and H2 at 50 lbs pressure, is identical to a synthetic cyclic hexapeptide obtained by stepwise addition of three residues of NS-acetyl-L-ornithine to triglycine, followed by cyclization (112). The amino acid sequence in ferrichrome A has been established by degradation (112, 113) and confirmed by crystallography (150). Removal of the a—p unsaturated residue of ferrichrome A, ferrirubin and ferrirho-din followed by re-acylation with acetyl gives, in each case, ferrichrysin (63). All four substances must hence have an identical amino acid sequence and we assume for all of these compounds the configuration shown in Fig. 5. 

A variety of 2-substituted 4,5,6,7-tetrahydrothiazolo[5,4- ]pyridines have been prepared from 3-aminopiperidin-2-one (506), synthesized by lactamization of ornithine (505) (Scheme 62). After acylation at the exocyclic amine group, the amides (507) were reacted with phosphorus pentasulfide (or Lawesson s reagent) in pyridine to give 2-substituted 4,5,6,7-tetrahydrothiazolo[5,4- ]pyridines (508) in moderate yield <94JHC877>. 

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