Precision neutron diffraction structure determination of protein and nucleic acid components. XVII. Molecular and crystal structure of the amino acid glycine hydrochloride

Al-Karaghouli, A. R.; Cole, F. E.; Lehmann, M. S.; Miskell, C. R.; Verbist, J.; Koetzle, T. F.

doi:10.1063/1.431523

Cited by 45 publications

(33 citation statements)

References 15 publications

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“…3 shows the powder XRD pattern of DGHCl, from which the lattice parameters and the cell volume have been calculated. These reveal a close agreement with the reported values [8]. The prominent peaks in the XRD pattern have been indexed (and quantitative data also given in Table 2).…”

Section: Powder Xrdsupporting

confidence: 83%

“…When glycine reacts with HCl, either glycine hydrochloride (GHCl) or diglycine hydrochloride (DGHCl) may be formed depending on the ratio of the reactants taken and physical conditions of the reaction mixture. The crystal structures of both of these compounds are reported [8,9]. However, the description of bulk crystal growth of these complexes is not available in the literature.…”

Section: Introductionmentioning

confidence: 97%

See 1 more Smart Citation

Nonlinear optical diglycine hydrochloride: Synthesis, crystal growth and structural characteristics

Moolya

Darmaprakash

2006

Journal of Crystal Growth

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Section: Powder Xrdsupporting

confidence: 83%

Section: Introductionmentioning

confidence: 97%

Nonlinear optical diglycine hydrochloride: Synthesis, crystal growth and structural characteristics

Moolya

Darmaprakash

2006

Journal of Crystal Growth

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“…These molecular geometries including hydrogen-bond angle, ∠C-O· · ·X, were obtained from the crystal structure of glycine hydrochloride molecules determined by the neutron-diffraction technique. [35] Table 4 summarized the results for 17 O CS and EFG tensors calculated with the B3LYP/6-311 + G * * level for the above model.…”

Section: Theoretical Investigations Of Hydrogen-bond Modelsmentioning

confidence: 99%

A solid‐state ¹⁷O NMR study of L ‐phenylalanine and L ‐valine hydrochlorides

Yamada¹,

Shimizu²,

Ohki³

et al. 2008

Magnetic Reson in Chemistry

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We have presented an experimental investigation of the oxygen-17 chemical shielding (CS) and electric-field-gradient (EFG) tensors for alpha-COOH groups in polycrystalline amino acid hydrochlorides. The 17O CS and EFG tensors including the relative orientations between the two NMR tensors are determined in [17O]-L-phenylalanine hydrochloride and [17O]-L-valine hydrochloride by the analysis of the 17O magic-angle-spinning (MAS) and stationary NMR spectra obtained at 9.4, 11.7, 16.4, and 21.8 T. The quadrupole coupling constants (CQ) and the span of the CS tensors are found to be 8.41-8.55 MHz and 7.35-7.41MHz, and 548-570 ppm and 225-231 ppm, for carbonyl and hydroxyl oxygen atoms, respectively. Extensive quantum chemical calculations using density functional theory (DFT) have been also carried out for a hydrogen-bonding model. It is demonstrated that the behavior of the dependence of hydrogen-bond distances on 17O NMR tensors for the halogen ions is different from those for the water molecule.

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“…The dubious nature of the crystal can be evidenced from the reported infrared (IR) spectrum in the title paper which is identical to that of L-alanine [7,8]. As it is well known that glycine (or L-alanine) reacts with aqueous HCl to form glycine hydrochloride [9] diglycine hydrochloride [10] and L-alanine hydrochloride [11], we reinvestigated the reported crystal growth of a so-called glycyl-L-alanine hydrochloride in order to identify its exact nature.…”

mentioning

confidence: 74%

Comments on “Crystal growth, spectral, optical, and thermal characterization of glycyl-l-alanine hydrochloride (GLAH) single crystal”

Srinivasan

Moovendaran

Natarajan

2014

J Therm Anal Calorim

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The authors of the title paper (J Therm Anal Calorim 2012,110:873-878) report to have grown a dipeptide hydrochloride crystal namely glycyl-L-alanine hydrochloride by the slow evaporation of an aqueous solution containing stoichiometric amounts of L-alanine and glycine and an excess of hydrochloric acid. In this letter, we prove that no such dipeptide hydrochloride can be crystallized simply by mixing two amino acids in aqueous hydrochloric acid.Keywords Dipeptide Á Crystal growth Á Glycyl-L-alanine hydrochloride Á Glycine hydrochloride CommentDuring a literature survey of nonlinear optical (NLO) materials from the amino acid family, we came across the title paper by Malliga et al. [1] reporting NLO properties of glycyl-L-alanine hydrochloride. As it appeared to be the first case of a NLO material from the peptide family, the title paper attracted our attention and was taken up for scrutiny. We found the synthetic methodology for the growth of a dipeptide (hydrochloride) crystal involving the reaction of glycine and L-alanine with excess aqueous hydrochloric acid at ambient temperature very unusual as it differed from the reported procedure of reaction of the dipeptide glycyl-L-alanine with 2 N HCl followed by evaporation to dryness in vacuum [2]. It is well documented in all standard chemistry and biochemistry text books [3,4] that the synthesis of a dipeptide is accomplished using a multi step reaction protocol which includes (i) incorporation of protecting groups for the amino (or carboxyl) functionalities of the concerned amino acids (ii) reaction of the protected amino acids to form peptide bond, and (iii) deprotection reaction to obtain the dipeptide. The importance of protecting group for peptide synthesis is highlighted in the text book by Morrison and Boyd [3] taking as an example the dipeptide glycyl-L-alanine, the synthesis of which was accomplished by Tranter [5] employing the N-carbobenzoxy method. It is quite intriguing to note that the authors of the title paper used aqueous HCl as a reagent for formation of peptide at room temperature (which is a dehydration reaction), in contrast to the well-known procedure of employing concentrated HCl albeit at elevated temperatures for the hydrolysis of proteins (polypeptides) to the individual amino acids as the hydrochloride salts [4].Although the reported procedure in the title paper using excess HCl as a reagent appears to be a convenient single pot reaction for peptide bond formation without use of any protecting groups and conversion of the dipeptide into its hydrochloride, the claim of the growth of this crystal is untenable, as the unit cell data reported in the title paper do not correspond to either glycyl-L-alanine hydrochloride [2] or glycyl-L-alanine hydrochloride monohydrate [6] ( Table 1). The dubious nature of the crystal can be evidenced from the reported infrared (IR) spectrum in the title paper which is identical to that of L-alanine [7,8]. As it is Electronic supplementary material The online version of this article (

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Precision neutron diffraction structure determination of protein and nucleic acid components. XVII. Molecular and crystal structure of the amino acid glycine hydrochloride

Cited by 45 publications

References 15 publications

Nonlinear optical diglycine hydrochloride: Synthesis, crystal growth and structural characteristics

Nonlinear optical diglycine hydrochloride: Synthesis, crystal growth and structural characteristics

A solid‐state ¹⁷O NMR study of L ‐phenylalanine and L ‐valine hydrochlorides

Comments on “Crystal growth, spectral, optical, and thermal characterization of glycyl-l-alanine hydrochloride (GLAH) single crystal”

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Precision neutron diffraction structure determination of protein and nucleic acid components. XVII. Molecular and crystal structure of the amino acid glycine hydrochloride

Cited by 45 publications

References 15 publications

Nonlinear optical diglycine hydrochloride: Synthesis, crystal growth and structural characteristics

Nonlinear optical diglycine hydrochloride: Synthesis, crystal growth and structural characteristics

A solid‐state 17O NMR study of L ‐phenylalanine and L ‐valine hydrochlorides

Comments on “Crystal growth, spectral, optical, and thermal characterization of glycyl-l-alanine hydrochloride (GLAH) single crystal”

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A solid‐state ¹⁷O NMR study of L ‐phenylalanine and L ‐valine hydrochlorides