The Preparation of Methyl-substituted DL-Phenylalanines

Herr, Ross R.; Enkoji, Takashi; Dailey, Joseph P.

doi:10.1021/ja01572a065

Cited by 16 publications

(5 citation statements)

References 1 publication

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“…Amino acids. The three chlorophenylalanines were given by Dr H. Blaschko (University of Oxford) (Blaschko & Stiven, 1950), the m-methylphenylalanine and the sulphurcontaining amino acids of Table 4 by Dr R. L. Colescott (Armour Pharmaceutical Co., Kankakee, Ill., U.S.A.) (Herr, Enkoji & Dailey, 1957;Colescott, Herr & Dailey, 1957), the amino acids listed in Table 3 by Sir Charles Harington (Medical Research Council, London, W.1) (Elliott, Fuller & Harington, 1948;Elliott & Harington, 1949), L-tryptophan, L-phenylalanine and L-histidine by Hoffmann-La Roche (Nutley, N.J., U.S.A.), and thienylalanine by Eli Lilly Research Laboratories (Indianapolis, Ind., U.S.A.). Bromo-, iodo-, and nitro-phenylalanines and o-and p-methylphenylalanine were synthesized in this Laboratory from the corresponding benzyl bromides, which were condensed with diethyl acetamidomalonate and isolated as hydrochlorides (Albertson & Archer, 1945;Snyder, Shekleton & Lewis, 1945;Burckhalter & Stephen, 1951).…”

Section: Ophidian L-amino Acid Oxidasementioning

confidence: 99%

OPHIDIAN l-AMINO ACID OXIDASE. THE NATURE OF THE ENZYME-SUBSTRATE COMPLEXES

Ea¹,

Ramachander²,

Ga³

et al. 1965

Biochemical Journal

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1. To investigate the kinetics of ophidian l-amino acid oxidase, V and K(m) were determined for phenylalanines that were substituted in every ring position with groups of various size and reactivity, and for a few ring-substituted tryptophans and histidines. The venom of one representative from each of three major classes of poisonous snakes, Naja melanoleuca, Vipera russelli and Crotalus adamanteus, served as a source of the ophidian l-amino acid oxidase. Both crude and crystalline enzyme from the venom of C. adamanteus were tested. 2. The introduction of a benzene ring into glycine and alanine caused some increase of V and a very marked depression of K(m). 3. With the exception of fluorine, residues in the ortho position of phenylalanine led to a decrease of V. The rates induced by various substitutions follow the pattern: meta >/= para >/= ortho. Within the halogen series, the effects become more pronounced with increasing atomic number. 4. Ring substitution in heterocyclic amino acids also affected the V values markedly. For methyl-substituted tryptophans the pattern was: 5-methyl >/= 6-methyl >/= 4-methyl. In a few instances ring substitution accounts for a considerable elevation of V, as shown for beta-quinol-4-ylalanine and its 6-methoxy derivative. 5. The kinetic constants appear to be unaffected by relatively high concentrations of the corresponding d-amino acids. 6. A general principle that permits a uniform interpretation of a vast body of information is suggested. It is based on the assumption that most substrates form not only eutopic but also dystopic complexes with the enzyme. The latter, in contrast with the former, do not permit the formation of reaction products. K values for eutopic and dystopic complexes are computed. Similar concepts have been presented to elucidate the action of alpha-chymotrypsin (Hein & Niemann, 1962) and of monoamine oxidase.

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Section: Ophidian L-amino Acid Oxidasementioning

confidence: 99%

OPHIDIAN l-AMINO ACID OXIDASE. THE NATURE OF THE ENZYME-SUBSTRATE COMPLEXES

Ea¹,

Ramachander²,

Ga³

et al. 1965

Biochemical Journal

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“…Ϫ Elemental analyses: Heraeus CHN-O-Rapid. Ϫ Precursors for the syntheses have already been reported in the literature and were prepared as described or according to literature procedures: ethyl 3,4-dimethylbenzoate [22] [23] , 3,4-dimethylbenzyl alcohol [24] [25] , 3,4-dimethylbenzyl chloride [26] , ethyl 3,5-dimethylbenzoate [22] [27] , 3,5-dimethylbenzyl alcohol [24] [28] , 3,5-dimethylbenzyl chloride [26] [29] , 2,3-dichlorobenzoyl chloride [30] [31] , 2,3-dichlorobenzyl alcohol [24] [32] , 2,3-dichlorobenzyl chloride [33] [34] , 2,5-dichlorobenzyl alcohol [24] [35] , 2,5-dichlorobenzyl chloride [33] [36] , 3,5-dichlorobenzyl alcohol [24] [33] , 3,5-dichlorobenzyl chloride [33] , 3-chloro-2-methylbenzyl alcohol [37] , 3-chloro-2-methylbenzyl chloride [26] [38] , 4-bromomethylbenzoic acid [39] , methyl 4-bromomethylbenzoate [39] , 2,5-dimethoxybenzyl alcohol [40] [41] , 2,5-dimethoxybenzyl chloride [41] , diethyl benzylphosphonates 2a [42] , 2b [43] , 2c [44] , 2d [44] [ 45] , 2e [46] , 2g [47] , 2h [43] , 2i [45] , 2k [45] , 2m …”

Section: Methodsmentioning

confidence: 99%

Synthesis, Structures and Topochemistry of 2-Monovinyl-Substituted 1,4-Benzoquinones

Irngartinger¹,

Stadler

1998

Eur. J. Org. Chem.

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In the course of topochemical investigations of substituted quinones the 2‐monovinyl‐substituted 1,4‐benzoquinones 1 were synthesized by electrochemical oxidation of the corresponding 1,4‐dimethoxybenzene derivatives 3 to the quinone bisketals 4 and subsequent hydrolysis. In solution, the aryl‐substituted vinylquinones 1a−1t underwent unexpected Diels‐Alder additions. The stereochemically unique course of the reaction was proved spectroscopically and by X‐ray structure analysis of the dimer 8k. As a basic requirement for the topochemical studies, the crystal structures of eight quinones 1 were determined by X‐ray diffraction. In the crystals of 1a, 1c, 1e, 1f, 1i and 1n with an α‐type packing arrangement, the vinylic double bonds have short contacts (< 4.4 Å) across a centre of symmetry. The quinone 1k crystallizes in a β arrangement with short distances (< 4.0 Å) between molecules related by translation and in a γ arrangement without suitable contacts. The crystals of all quinones 1 were irradiated with UV light to perform [2+2] cycloadditions. The photoreactive quinones dimerized exclusively at the vinylic double bonds, resulting in the corresponding cyclobutanes 9. Topochemically controlled the dimers 9a−9c, 9e, 9l−9n, 9q, 9r and 9u with molecular Ci symmetry were formed whereas the dimers 9k and 9t have Cs symmetry. The structures of the cyclobutanes were determined by spectroscopical investigations and in the case of 9b, 9e and 9r additionally by X‐ray analysis. Despite short contacts, crystals of 1f and 1i were photostable. This is probably because of insufficient lattice flexibility indicated by relatively high densities.

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“…This procedure was always followed when a new mobile phase or temperature was chosen. phenylalanine (4, 29,49-diMePhe) [6], (R,S)-29,49,69-trimethylphenylalanine (5, 29,49,69-triMePhe) [7], racemic (2S,3S and 2R,3R)-and (2S,3R and 2R,3S)-b-methylphenylalanine (6 and 7, erythro-and threo-b-MePhe) [8], (R)-and (S)-29,39,49,59,69-pentafluorophenylalanine (10, F5F) [9], (R,S)-b-1-naphthylalanine (11, 1-Nal) [10] were synthesized in our laboratories (for their structures, see Fig. 1).…”

Section: Apparatusmentioning

confidence: 99%

“…The true enantioselectivity is a true = (k9 s ) 2 /(k9 s ) 1 (6) and can be observed when the nonselective retention term can be neglected.…”

Section: Introductionmentioning

confidence: 99%

Enantioseparation of phenylalanine analogs on a quinine‐based anion‐exchanger chiral stationary phase: Structure and temperature effects

Török¹,

Berkecz²,

Péter³

2006

J of Separation Science

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Application of a cinchona alkaloid-based chiral anion-exchanger stationary phase for the direct high-performance liquid chromatographic enantioseparation of N-protected unusual phenylalanine analogs is reported. The N-benzyloxycarbonyl, N-3,5-dinitrobenzyloxycarbonyl, N-benzoyl and N-3,5-dinitrobenzoyl derivatives were well separable with high resolution. To achieve optimal separation of the enantiomers, the chromatographic conditions and temperature were varied. Linear van't Hoff plots were observed in the studied temperature range, 278-343 K, and the apparent changes in enthalpy, delta(deltaH degrees), entropy, delta(delta S degrees), and Gibbs free energy, delta(delta G degrees), were calculated. The values of the thermodynamic parameters depended on the nature of the N-acyl groups, on the structures of the compounds, and especially on the nature of the substituent on C3 of phenylalanine.

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The Preparation of Methyl-substituted DL-Phenylalanines

Cited by 16 publications

References 1 publication

OPHIDIAN l-AMINO ACID OXIDASE. THE NATURE OF THE ENZYME-SUBSTRATE COMPLEXES

OPHIDIAN l-AMINO ACID OXIDASE. THE NATURE OF THE ENZYME-SUBSTRATE COMPLEXES

Synthesis, Structures and Topochemistry of 2-Monovinyl-Substituted 1,4-Benzoquinones

Enantioseparation of phenylalanine analogs on a quinine‐based anion‐exchanger chiral stationary phase: Structure and temperature effects

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