Acids with Chiral Molecules as Essential Organic Compounds of Biogenic–Abiogenic Systems

Kotelnikova, E. N.; Isakov, Anton I.; Kryuchkova, Lyudmila Yu.; Zolotarev, Andrey A.; Bocharov, S.; Lorenz, Heike

doi:10.1007/978-3-030-21614-6_37

Cited by 5 publications

(5 citation statements)

References 31 publications

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“…A hinge mechanism can also be used to describe the thermal deformations of these diastereomers. Therefore, each one of L-ala, L-ser, L-thr and L-allo-thr has an orthorhombic crystal structure, while the L-valine, L-isoleucine, and L-leucine examined earlier [15][16][17][18][19] crystallize in monoclinic syngony. Figure 11b shows the projection of the L-ala crystal structure onto the bc plane.…”

Section: Discussionmentioning

confidence: 99%

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Limits of Solid Solutions and Thermal Deformations in the L-Alanine–L-Serine Amino Acid System

et al. 2020

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The limits of solid solutions and thermal deformations in the L-alanine–L-serine (L-ala–L-ser) amino acid system have been determined. Thirteen amino acid mixtures with various proportions of the components L-ser/L-ala were studied using powder X-ray diffraction techniques. It was found that the regions of solid solutions in the system are rather limited and cover less than 10 mol. % from each component side. The thermal behavior of the components L-ser and L-ala and the composition L-ser/L-ala = 90/10 were studied by temperature-resolved powder X-ray diffraction. The heating of L-ser and L-ala only causes thermal deformations, while two-phase mixtures with the 90/10 L-ser/L-ala ratio form solid solutions at elevated temperatures. Additionally, the parameters of the thermal deformation tensor for L-ser and L-ala were calculated, and the figures of their thermal expansion coefficients were plotted and analyzed. The study conducted is of high applicability, since amino acids are active components of various biological, geological, and technological processes, including those at elevated temperatures, and have numerous applications in life-science industries.

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Section: Discussionmentioning

confidence: 99%

“…This fact motivated our interest in binary systems of different amino acids with the same chirality. The reported studies of such systems are rather scarce and, according to our knowledge, include the publications [13,14] and our works [15][16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Limits of Solid Solutions and Thermal Deformations in the L-Alanine–L-Serine Amino Acid System

et al. 2020

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“…L -thr/ D -thr and L -allo-thr/ D -allo-thr form two enantiomeric pairs, and the enantiomers are non-superimposable mirror images; L -thr/ L -allo-thr, L -thr/ D -allo-thr, D -thr/ L -allo-thr and D -thr/ D -allo-thr are diastereomers of each other, and they are not mirror images between them. 2 The molecules of many organic substances have chiral centers, the chiral centers are usually deflected during the process of molecular epimerization, and there is a configuration transformation between the four stereoisomers of threonine (Fig. 1).…”

Section: Introductionmentioning

confidence: 99%

Terahertz Spectroscopy Study of the Stereoisomers of Threonine

et al. 2022

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The terahertz band contains a wealth of information about vibration and rotational energy levels, most of the vibration modes between amino acid molecules are in the THz band, so it reflects many unique absorption characteristics in the THz band. The use of terahertz time-domain spectroscopy can not only effectively identify different kinds of amino acids, but also distinguish various isomers of the same amino acid due to the varied vibration modes. The absorption spectra of four stereoisomers of threonine were investigated by terahertz time domain spectroscopy (THz-TDS) and Fourier transform infrared spectroscopy (FTIR). The results show that the isomers show similarity in the infrared band, while manifest evidently the similarity between enantiomers L-threonine and D-threonine, and between L-allo-threonine and D-allo-threonine, and the difference between diastereoisomer L-threonine/D-threonine and L-allo-threonine/D-allo-threonine in the terahertz band. In order to fully understand the origin of the terahertz absorption characteristics of isomer molecules, simulation calculations were carried out in combination with density functional theory (DFT) to connect the vibrational modes and molecular structures, Furthermore, the unit cell configurations of L-thr and L-allo-thr and the differences between various low-frequency vibrational modes are analyzed from the perspective of hydrogen bond configuration. By further extracting terahertz optical parameters such as refractive index and imaginary part of the dielectric constant of threonine isomers, the results show that the refractive index spectrum and dielectric loss spectrum can clearly show the response characteristics of the orientation polarization of dipole inside threonine isomers in terahertz band.

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“…Here, we demonstrate a novel process combining temperature cycling and enzymatic epimerization catalyzed by immobilized AArac12996 in a suspension of Thr to accelerate the solid-state conversion of Thr to aThr. The diastereomeric pair of d -Threonine ( d -Thr) and l -allothreonine ( l -aThr) was selected as a model system since it is of eutectic type and no formation of co-crystals nor stable solid solutions involving the two species are reported . In addition, this system is suitable for use of AArac in the epimerization.…”

Section: Introductionmentioning

confidence: 99%

“…The diastereomeric pair of D-Threonine (D-Thr) and L-allothreonine (L-aThr) was selected as a model system since it is of eutectic type and no formation of co-crystals nor stable solid solutions involving the two species are reported. 42 In addition, this system is suitable for use of AArac in the epimerization. Our process starts from a suspension of D-Thr in the presence of immobilized AArac12996 as an enzymatic catalyst under temperature cycling conditions.…”

Section: Introductionmentioning

confidence: 99%

Efficient Conversion of Threonine to Allothreonine Using Immobilized Amino Acid Racemase and Temperature Cycles

Intaraboonrod

Seidel‐Morgenstern

Lorenz

et al. 2021

Crystal Growth & Design

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Fast solution-mediated solid-state conversion of d-threonine (d-Thr) to l-allothreonine (l-aThr) was achieved using temperature cycles and enzymatic epimerization catalyzed by an immobilized amino acid racemase (imAAR). The conversion is due to the higher stability of the l-aThr crystals compared to the d-Thr crystals and the ability of the molecules to interconvert in the liquid phase. Applying temperature cycles greatly accelerated the conversion of Thr to aThr. Furthermore, the mechanism of the solid-state conversion was demonstrated via the progression of diastereomeric excess in the solid and liquid phases, the transmissivity of the suspension, and in situ images. The rate of the process can be altered via adjustment of the temperature difference used in the cycle, the cooling rate, and the dosage of imAAR. The process is reproducible and characterized by reasonable values for the productivity and yield.

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Acids with Chiral Molecules as Essential Organic Compounds of Biogenic–Abiogenic Systems

Cited by 5 publications

References 31 publications

Limits of Solid Solutions and Thermal Deformations in the L-Alanine–L-Serine Amino Acid System

Limits of Solid Solutions and Thermal Deformations in the L-Alanine–L-Serine Amino Acid System

Terahertz Spectroscopy Study of the Stereoisomers of Threonine

Efficient Conversion of Threonine to Allothreonine Using Immobilized Amino Acid Racemase and Temperature Cycles

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