Methyl alaninate

Schafer, L., I. S. Bin Drees, R. F. Frey, C. Van Alsenoy, and J. D. Ewbank. 1995c. Molecular Orbital Constrained Gas Electron Diffraction Study of N-Acetyl N -MEthyl Alanine Amide. J. Mol. Struct. (Theochem) 338, 71-82. 

Many of the conformational properties of peptide systems, including protein conformation, can be approximated in terms of the local interactions encountered in dipeptides, where the two torsional angles 4> (N-C(a)) and < i (C(a)-C ) are the main conformational variables. N-acetyl N -methyl alanine amide, shown in Fig. 7.11, is a model dipeptide that has been the subject of numerous computational studies. 

Fig. 7.11 N-acetyl N -methyl alanine amide. Identification of the 4> (N-C(a)) and i / (C(a)-C ) torsional angles.

Bacterial resistance to erythromycin can originate by two possible mechanisms the inability of reaching the cell membrane, which is particularly relevant in the case of the microorganisms Enterobacteriaceae, or in the case of the presence of a methylated alanine in the 23 S ribosomal RNA of the 50 S subunit, which lowers the affinity of erythromycin to it. 

Key conformational features of this model believed important for biological potency Include Phe-D-Trp-Lya-Thr and Thr-Phe-Pro-Phe B-turns of Types II and VI, respectively, the latter containing a els peptide bond between Phe and Pro. The model of 3b is very similar with N -methyl alanine replacing proline... 

The enantiomeric excess of isolated product is determined by polarimetry. The enantioselection can also be established in other ways directly by HPLC of the intermediate methylated Schiff base using a chiral Pirkle DNPG covalently bonded column, and indirectly, by GC of the Ar-trifluoroacetyl-L-pro]iiiylaniide of methyl alaninate. 

N A- methyl-alanin-dimethylamid N- ( Cyclohexylcarbonyl 82 92 59-61 175 2 2... 

Figure 1.5. Simulated NMR spectrum of methyl alanine in a chiral solvent.

The stereochemistry of the N-methyl-alanine residue connected to the end of the 3-hydroxy-2,4,6-trimethylheptanoic acid moiety as well as of the allo-threonin placed between the L-methylglutamine and L-threonin residues have been revised to the correct actual stereostructure of callipeltin A (57) [104]. Two additional members of this class, named callipeltins D and E, have been isolated from... 

Figure 20. CP/MAS NMR spectra (a) and the expanded NMR spectra of the methyl alanine region (b) of SF matrices. The dotted arrow indicates the chemical shift of alanine in the p-sheet conformation[75].

The nonenzymatic 1,2-migration of an amino group in Scheme 1 is an efficient way to transform 2-methyl-3-bromoalanine ethyl ester into 2-methyl- alanine ethyl ester. It is possible that this nonenzymatic counterpart to the enzymatic rearrangement may serve as the foundation for an efficient synthetic transformation of a-amino acid derivatives into P-amino acid derivatives, which may in turn be of some use in the drug industry. Under conditions of low concentrations of tributyltin hydride in the process of Scheme 1, the ratio of P-amino acid ester to a-amino acid ester is 13/1, presumably because the radical 5 is more stable than 4 owing to the delocalization of the unpaired electron into the adjoining carboethoxy group. 

The addition of ( )-l-phenylethylaminc to methacrylonitrile (9) in refluxing ethanol affords, after hydrolysis and hydrogenolysis, optically active (S)-a-methyl-/ -alanine in low overall yield (10 %) and only 11 % optical purity11. The corresponding reaction with the (S)-amine gives a 9% yield of adduct with 12% optical purity. Configurations are established and optical purities calculated with respect to the reported optical rotation for pure (-)-(/ )-a-methyl-jS-alanine1 The products are further characterized by their H-NMR and IR spectra and elemental analysis. 

C12H15N04 N-carbobenzyloxy-2-methyl alanine 15030-72-5 25.00 1.1892 2 24307 C12H17NO N-pivaloyl-o-toluidine 61495-04-3 23 1 050 ... 

The cyclic peptides tested in this study included tentoxin (Figure 2) and [Pro1] tentoxin. [Pro1] tentoxin contains a substitution of proline for N-methyl alanine, and is conformationally similar to tentoxin. Previous biochemical studies comparing these analogs have shown both similarities and... 

Boehringer, Ddrivds de la L-(3,4-dihydroxy-phenyl)-2-methyl alanine et leur preparation, Belg. Pat. 839,362 (March 9, 1976 to Boehringer Mannheim GMBH), 1976. 

Tremor-inducing mycotoxins were isolated from the mold Aspergillus clavatus, which infests rice. The mycotoxins were tetrapeptides of anthranilic acid (source of the quinazolin-4-ones), trypotophan, valine, and methyl-alanine or alanine. They were named tryptoquivaline (116 = OH,... 

Tremor-inducing mycotoxins were isolated from the mold Aspergillus clavatus, which infests rice. The mycotoxins were tetrapeptides of anthranilic acid (source of the quinazolin-4-ones), trypotophan, valine, and methyl-alanine or alanine. They were named tryptoquivaline (116 R1 = OH, R2 = R3 = Me X = H, OAc) and nortryptoquivalone (116 R =OH R2 = Me R3 = H X = O). The structures of the metabolites were deduced from spectral data, from the X-ray crystallographic analysis of the p-bromo-phenylurethan derivative of a transformation product of tryptoquivaline, and from chemical studies.259... 

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