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Russo F, Ferri E, Pinetti D, Vandelli MA, Laganà A, Capriotti AL, Cavazzini A, Gigli G, Citti C, Cannazza G. Bidimensional heart-cut achiral-chiral liquid chromatography coupled to high-resolution mass spectrometry for the separation of the main chiral phytocannabinoids and enantiomerization studies of cannabichromene and cannabichromenic acid. Talanta 2024; 267:125161. [PMID: 37708768 DOI: 10.1016/j.talanta.2023.125161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 08/28/2023] [Accepted: 09/04/2023] [Indexed: 09/16/2023]
Abstract
In this work, a heart-cut bidimensional achiral-chiral liquid chromatography method coupled to high-resolution mass spectrometry was developed for the separation of the main carboxylated phytocannabinoids, namely cannabidiolic acid (CBDA), tetrahydrocannabinolic acid (THCA), cannabichromenic acid (CBCA), and cannabicyclolic acid (CBLA), and decarboxylated derivatives, namely cannabidiol (CBD), Δ9-tetrahydrocannabinol (Δ9-THC), cannabichromene (CBC), and cannabicyclol (CBL), and the evaluation of their enantiomeric composition in extracts of different Cannabis sativa L. varieties. Optimal conditions for the chiral analysis of CBC- and CBL-type compounds were found with methanol and water (95:5, v/v, with 0.1% formic acid, 1.5 mL/min) on an amylose-based chiral stationary phase. These settings also allowed to evaluate the parameters responsible for CBC and CBCA racemization.
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Affiliation(s)
- Fabiana Russo
- Clinical and Experimental Medicine PhD Program, University of Modena and Reggio Emilia, 41125, Modena, Italy; Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125, Modena, Italy
| | - Elena Ferri
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125, Modena, Italy
| | - Diego Pinetti
- Centro Interdipartimentale Grandi Strumenti (CIGS), University of Modena and Reggio Emilia, Via Campi 213/A, Modena, 41125, Italy
| | - Maria Angela Vandelli
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125, Modena, Italy
| | - Aldo Laganà
- Department of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185, Rome, Italy
| | - Anna Laura Capriotti
- Department of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185, Rome, Italy
| | - Alberto Cavazzini
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, Via L. Borsari 46, 44121, Ferrara, Italy
| | - Giuseppe Gigli
- Institute of Nanotechnology - CNR NANOTEC, Campus Ecotekne, Via Monteroni, 73100, Lecce, Italy
| | - Cinzia Citti
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125, Modena, Italy; Institute of Nanotechnology - CNR NANOTEC, Campus Ecotekne, Via Monteroni, 73100, Lecce, Italy.
| | - Giuseppe Cannazza
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125, Modena, Italy; Institute of Nanotechnology - CNR NANOTEC, Campus Ecotekne, Via Monteroni, 73100, Lecce, Italy
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Liao Y, Zhang S, Jiang X. Construction of Thioamide Peptides from Chiral Amino Acids. Angew Chem Int Ed Engl 2023; 62:e202303625. [PMID: 37118109 DOI: 10.1002/anie.202303625] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 04/21/2023] [Accepted: 04/28/2023] [Indexed: 04/30/2023]
Abstract
Thioamide peptides were synthesized in a straightforward one-pot process via the linkage of diverse natural amino acids in the presence of thiolphosphonate and trichlorosilane, wherein carbonyl groups were replaced with thiono compounds with minimal racemization. Experimental and computational mechanistic studies demonstrated that the trichlorosilane enables the activation of carboxylic acids via intense interactions with the Si-O bond, followed by coupling of the carboxylic acids with thiolphosphonate to obtain the key intermediate S-acyl dithiophosphate. Silyl-activated quadrangular metathesis transition states afforded the thioamide peptides. The potential applications of these thioamide peptides were further highlighted via late-stage linkages of diverse natural products and pharmaceutical drugs and the thioamide moiety.
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Affiliation(s)
- Yanyan Liao
- Shanghai Key Laboratory of Green Chemistry and Chemical Process, Institute of Eco-Chongming, School of Chemistry and Molecular Engineering, East China Normal University, 3663 North Zhongshan Road, Shanghai, 200062, P. R. China
| | - Shunmin Zhang
- Shanghai Key Laboratory of Green Chemistry and Chemical Process, Institute of Eco-Chongming, School of Chemistry and Molecular Engineering, East China Normal University, 3663 North Zhongshan Road, Shanghai, 200062, P. R. China
| | - Xuefeng Jiang
- Shanghai Key Laboratory of Green Chemistry and Chemical Process, Institute of Eco-Chongming, School of Chemistry and Molecular Engineering, East China Normal University, 3663 North Zhongshan Road, Shanghai, 200062, P. R. China
- State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071, P. R. China
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, P. R. China
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3
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Shiozaki M, Mizoguchi T, Harada J, Hirose M, Tamiaki H. Chiral-phase HPLC separation of (divinyl-)protochlorophyllide-a enantiomers as key precursors in chlorophyll biosynthesis from their 13(2)-stereoisomeric prime forms. Biochim Biophys Acta Bioenerg 2023; 1864:148960. [PMID: 36822491 DOI: 10.1016/j.bbabio.2023.148960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 02/13/2023] [Accepted: 02/15/2023] [Indexed: 02/25/2023]
Abstract
Protochlorophyllide(PChlide)-a and its 8-vinylated analog, divinyl(DV)-PChlide-a, are common and essential intermediates in the biosynthesis of all naturally occurring chlorophyll (Chl) pigments. These porphyrinoid-type pigments have a single optically active (asymmetric) carbon atom at the 132-position, so their stereoisomers are (132R)- and (132S)-enantiomers. The former and latter are called (DV-)PChlide-a and (DV-)PChlide-a', respectively. In this study, chiral-phase HPLC separation of enantiomeric (DV-)PChlides-a/a' was demonstrated. The (132R)-enantiomeric PChlide-a was eluted more slowly than the corresponding (132S)-enantiomeric PChlide-a' under the present HPLC conditions. On the other hand, the elution order of (132R)-DV-PChlide-a and (132S)-DV-PChlide-a' was reverse to that of PChlides-a/a'. After the separation of each enantiomer by the chiral-phase HPLC, the stereoisomeric configuration at the 132-position was characterized by means of circular dichroism spectroscopy. The present chiral-phase HPLC method enables us to evaluate optical purities of (DV-)PChlide-a species. For example, PChlide-a and/or DV-PChlide-a extracted from the spent medium and harvested cells of cultured purple photosynthetic bacterial mutants, the former of which has been often used as the source of (DV-)PChlide-a substrates for enzymatic reactions, were revealed to be mostly racemized, giving enantiomeric mixtures of (DV-)PChlides-a/a'.
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4
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Zuo Y, Liu X, Fu E, Zhang S. A Pair of Interconverting Cages Formed from Achiral Precursors Spontaneously Resolve into Homochiral Conformers. Angew Chem Int Ed Engl 2023; 62:e202217225. [PMID: 36748582 DOI: 10.1002/anie.202217225] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 02/06/2023] [Accepted: 02/07/2023] [Indexed: 02/08/2023]
Abstract
Without chiral induction the emergence of homochirality from achiral molecules is rather serendipitous, as the rationale is somewhat ambiguous. We herein provide a plausible solution. From achiral precursors are formed a pair of interconverting cage conformers that exhibit a C3 -axis as the only symmetry element. When their interconversion is impeded with intramolecular H-bonding, each conformer self-sorts into a homochiral crystal, which is driven by a helical network of multivalent intermolecular interactions during the self-assembly of homochiral cage conformers. As no chiral induction is involved throughout, we believe our study could enlighten the rational design for the emergence of homochirality with several criteria: 1) formation of a molecule without inversion center or mirror plane; 2) suppression of the enantiomeric interconversion, and introduction of multivalent interactions along the helical trajectory of screw symmetry within the resulting superstructure.
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Affiliation(s)
- Yong Zuo
- School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Xiaoning Liu
- School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Enguang Fu
- School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Shaodong Zhang
- School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
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Minegishi S, Utsuno H, Ohta J, Namiki S, Toya M, Sumi N, Saitoh H, Sakurada K. Comparison of racemization rates between vital and endodontically treated teeth for age estimation. Leg Med (Tokyo) 2023; 61:102189. [PMID: 36621071 DOI: 10.1016/j.legalmed.2022.102189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 11/16/2022] [Accepted: 12/26/2022] [Indexed: 12/29/2022]
Abstract
Amino acid racemization of dentin (AAR) is among the most precise methods for age estimation in unidentified adult cadavers. Although vital teeth are generally used for this technique, cases often have endodontically treated (Endo) teeth only. Therefore, the aim of this preliminary pilot study was to determine the applicability of Endo teeth by comparing AAR rates between vital and Endo teeth. Thirty-six dentin samples from vital teeth and 18 dentin samples from Endo teeth were analyzed, including the maxillary first premolar, maxillary second molar, and mandibular second premolar. Standard calibration curves for the mandibular second premolar and maxillary second molar were compared among vital teeth, Endo teeth, and mixed vital/Endo teeth. Discrepancies between estimated and actual ages were assessed by analyzing the AAR rates for the maxillary first premolar between vital and Endo teeth. The AAR rates for Endo teeth were higher than those for vital teeth in both the mandibular second premolar and maxillary second molar, and the correlation of the standard calibration curve for vital teeth only was highest (r = 0.982836; r = 0.92011467), followed by mixed (r = 0.949579; r = 0.76158) and Endo teeth only (r = 0.896082; r = 0.744991). In the maxillary first premolar, discrepancies were more than 10 years for all 5 Endo teeth, based on the standard calibration curve of vital teeth. The present study suggests that the AAR rates for Endo teeth might be affected by variation in dentin structure between vital and Endo teeth.
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Zhang F, Xia S, Lin H, Liu J, Huang W. Microbial Proline Racemase-Proline Dehydrogenase Cascade for Efficient Production of D-proline and N-boc-5-hydroxy-L-proline from L-proline. Appl Biochem Biotechnol 2022; 194:4135-4146. [PMID: 35635604 DOI: 10.1007/s12010-022-03980-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/16/2022] [Indexed: 11/02/2022]
Abstract
D-proline and N-boc-5-hydroxy-L-proline are key chiral intermediates in the production of eletriptan and saxagliptin, respectively. An efficient proline racemase-proline dehydrogenase cascade was developed for the enantioselective production of D-proline. It included the racemization of L-proline to DL-proline and the enantioselective dehydrogenation of L-proline in DL-proline. The racemization of L-proline to DL-proline used an engineered proline racemase (ProR). L-proline up to 1000 g/L could be racemized to DL-proline with 1 g/L of wet Escherichia coli cells expressing ProR within 48 h. The efficient dehydrogenation of L-proline in DL-proline was achieved using whole cells of proline dehydrogenase-producing Pseudomonas pseudoalcaligenes XW-40. Moreover, using a cell-recycling strategy, D-proline was obtained in 45.7% yield with an enantiomeric excess of 99.6%. N-boc-5-hydroxy-L-proline was also synthesized from L-glutamate semialdehyde, a dehydrogenated product of L-proline, in a 16.7% yield. The developed proline racemase-proline dehydrogenase cascade exhibits great potential and economic competitiveness for manufacturing D-proline and N-boc-5-hydroxy-L-proline from L-proline.
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Affiliation(s)
- Fanfan Zhang
- Chongqing Key Laboratory of Big Data On Bio-Intelligence, School of Bioinformatics, Chongqing University of Posts and Telecommunications, Chongqing, 400065, People's Republic of China
| | - Shiwen Xia
- Chongqing Key Laboratory of Big Data On Bio-Intelligence, School of Bioinformatics, Chongqing University of Posts and Telecommunications, Chongqing, 400065, People's Republic of China.
| | - Hui Lin
- College of Life Sciences, Henan Agricultural University, Zhengzhou, 450002, Henan, People's Republic of China
| | - Jiao Liu
- Chongqing Key Laboratory of Big Data On Bio-Intelligence, School of Bioinformatics, Chongqing University of Posts and Telecommunications, Chongqing, 400065, People's Republic of China
| | - Wenxin Huang
- Chongqing Key Laboratory of Big Data On Bio-Intelligence, School of Bioinformatics, Chongqing University of Posts and Telecommunications, Chongqing, 400065, People's Republic of China
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Šimon P, Krupčík J, Portillo AE, Májek P, Špánik I, Armstrong DW. Headspace study of chiral interconversion of N-acetyl-homocysteine thiolactones. J Chromatogr A 2021; 1653:462381. [PMID: 34280790 DOI: 10.1016/j.chroma.2021.462381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/24/2021] [Accepted: 06/26/2021] [Indexed: 10/20/2022]
Abstract
The rate constants for (L)-N-acetyl homocysteine thiolactone enantiomerization have been obtained from batch-wise studies and by dynamic gas chromatography of racemic mixtures. Results from the batch-wise experiments show that the kinetics of racemization at 150 °C is the same for vials made of glass, silanized glass or Teflon-coated glass so that the vial surface exhibited no effect on the kinetics of racemization. From the temperature dependence of the rate constants the preexponential factor, activation energy, the activation Gibbs energy and activation entropy have been obtained from transition state theory. The catalytic effect of G-DP, G-BP and B-DP GC chiral stationary phases on racemization has been observed and quantified by the values of rate constants; B-DP exhibited the greatest activity. The Eyring activation parameters obtained from batch-wise experiment were compared with theoretical values acquired from quantum chemical modelling. Agreement between the experimental and calculated values of activation Gibbs energy, activation enthalpy and activation entropy is good. The dynamic gas chromatography of racemic mixture on chiral B-DP, G-DP and G-BP capillary columns indicate that the rate constants of forward and reverse reactions are different in chiral environments. The greatest accelerating effect in the process of enantiomerization has been identified for G-BP both in the batch-wise experiments and by the dynamic gas chromatography.
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Affiliation(s)
- Peter Šimon
- Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology STU, Bratislava, Slovak Republic.
| | - Ján Krupčík
- Institute of Analytical Chemistry, Faculty of Chemical and Food Technology STU, Bratislava, Slovak Republic
| | - Abiud E Portillo
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, TX, USA
| | - Pavel Májek
- Institute of Analytical Chemistry, Faculty of Chemical and Food Technology STU, Bratislava, Slovak Republic
| | - Ivan Špánik
- Institute of Analytical Chemistry, Faculty of Chemical and Food Technology STU, Bratislava, Slovak Republic
| | - Daniel W Armstrong
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, TX, USA
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Harada M, Shimbo K, Karakawa S. Preparation of racemic α-amino acid standards for accurate mass spectrometric analysis via racemization catalyzed by a hydrophobic pyridoxal derivative. Talanta 2021; 234:122661. [PMID: 34364469 DOI: 10.1016/j.talanta.2021.122661] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/22/2021] [Accepted: 06/24/2021] [Indexed: 01/28/2023]
Abstract
Racemic α-amino acid standards for chiral metabolomics were prepared from l-α-amino acids using a hydrophobic pyridoxal derivative, namely 3-hydroxy-2-methyl-5-((octyloxy)methyl)isonicotinaldehyde (OPy), as the racemization catalyst. Among the 19 tested proteinogenic amino acids, 13 (including the generally unstable asparagine, glutamine, and tryptophan) underwent efficient racemization/epimerization under mildly basic conditions at room temperature, while solid-phase extraction allowed for effective and simple catalyst removal and amino acid recovery, obviating the need for chromatographic separation and recrystallization. Isotopically labeled racemic amino acids are commonly employed as internal standards for highly accurate mass spectrometric analysis. However, as isotopically labeled d-amino acids are often unavailable or highly expensive, the developed method was used to prepare racemic labeled amino acids, which were shown to enhance the repeatability and accuracy of d,l-amino acid quantitation in human urine by liquid chromatography-mass spectrometry (LC-MS). Given that our method should also be applicable to non-proteinogenic α-amino acids and the N-termini of peptides, the present study is expected to accelerate the development of LC-MS-based chiral metabolomics.
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Affiliation(s)
- Masashi Harada
- Research Institute for Bioscience Products & Fine Chemicals, 1-1, Suzuki-cho, Kawasaki-ku, Kawasaki-shi, 210-8681, Japan
| | - Kazutaka Shimbo
- Research Institute for Bioscience Products & Fine Chemicals, 1-1, Suzuki-cho, Kawasaki-ku, Kawasaki-shi, 210-8681, Japan
| | - Sachise Karakawa
- Research Institute for Bioscience Products & Fine Chemicals, 1-1, Suzuki-cho, Kawasaki-ku, Kawasaki-shi, 210-8681, Japan.
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Musiyak VV, Nizova IA, Chulakov EN, Sadretdinova LS, Tumashov AA, Levit GL, Krasnov VP. Stereochemical aspects in the synthesis of novel N-(purin-6-yl)dipeptides as potential antimycobacterial agents. Amino Acids 2021; 53:407-415. [PMID: 33599833 PMCID: PMC7889712 DOI: 10.1007/s00726-021-02958-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 02/06/2021] [Indexed: 11/08/2022]
Abstract
The synthesis of purine conjugates with natural amino acids is one of the promising directions in search for novel therapeutic agents, including antimycobacterial agents. The purpose of this study was to synthesize N-(purin-6-yl)dipeptides containing the terminal fragment of (S)-glutamic acid. To obtain the target compounds, two synthetic routes were tested. The first of them is based on coupling of N-(purin-6-yl)-(S)-amino acids to dimethyl (S)-glutamate in the presence of carbodiimide coupling agent followed by the removal of ester groups. However, it turned out that this coupling process was accompanied by racemization of the chiral center of N-(purin-6-yl)-α-amino acids and in all cases led to mixtures of (S,S)- and (R,S)-diastereomers (6:4). Individual (S,S)-diastereomers were obtained using an alternative approach based on the nucleophilic substitution of chlorine in 6-chloropurine or 2-amino-6-chloropurine with corresponding dipeptides as nucleophiles. The enantiomeric purity of the target compounds was confirmed by chiral HPLC. To test the assumption that racemization of the chiral center of N-(purin-6-yl)-α-amino acids occurs with the participation of nitrogen atoms of the imidazole ring via the stage of formation of a chirally labile intermediate, we obtained such structural analogs of N-(purin-6-yl)-(S)-alanine as N-(9-benzylpurin-6-yl)-(S)-alanine and N-(7-deazapurin-6-yl)-(S)-alanine. It was found that coupling of these compounds to dimethyl (S)-glutamate was also accompanied by racemization. This indicates that the imidazole fragment does not play a crucial role in this process. When testing the antimycobacterial activity of some of the obtained compounds, conjugates with moderate activity against the laboratory Mycobacterium tuberculosis H37Rv strain (MIC 3.1–6.25 μg/mL) were identified.
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Affiliation(s)
- Vera V Musiyak
- Postovsky Institute of Organic Synthesis of RAS (Ural Branch), 22/20, S. Kovalevskoy/Akademicheskaya St., Ekaterinburg, 620108, Russia
| | - Irina A Nizova
- Postovsky Institute of Organic Synthesis of RAS (Ural Branch), 22/20, S. Kovalevskoy/Akademicheskaya St., Ekaterinburg, 620108, Russia
| | - Evgeny N Chulakov
- Postovsky Institute of Organic Synthesis of RAS (Ural Branch), 22/20, S. Kovalevskoy/Akademicheskaya St., Ekaterinburg, 620108, Russia
| | - Liliya Sh Sadretdinova
- Postovsky Institute of Organic Synthesis of RAS (Ural Branch), 22/20, S. Kovalevskoy/Akademicheskaya St., Ekaterinburg, 620108, Russia
| | - Andrey A Tumashov
- Postovsky Institute of Organic Synthesis of RAS (Ural Branch), 22/20, S. Kovalevskoy/Akademicheskaya St., Ekaterinburg, 620108, Russia.,Ural Federal University, 19, Mira St., Ekaterinburg, 620002, Russia
| | - Galina L Levit
- Postovsky Institute of Organic Synthesis of RAS (Ural Branch), 22/20, S. Kovalevskoy/Akademicheskaya St., Ekaterinburg, 620108, Russia
| | - Victor P Krasnov
- Postovsky Institute of Organic Synthesis of RAS (Ural Branch), 22/20, S. Kovalevskoy/Akademicheskaya St., Ekaterinburg, 620108, Russia. .,Ural Federal University, 19, Mira St., Ekaterinburg, 620002, Russia.
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Lee Y, Bang E, Lee W, Na YC. Simultaneous enantioselective separation method for thyroid hormones using liquid chromatography-tandem mass spectrometry and its applications. J Pharm Biomed Anal 2021; 196:113904. [PMID: 33516122 DOI: 10.1016/j.jpba.2021.113904] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 01/13/2021] [Accepted: 01/13/2021] [Indexed: 01/25/2023]
Abstract
An analytical method for the simultaneous determination of chiral thyroxine and the related iodinated chiral compounds using LC-MS/MS is introduced in this study. D-Thyroid hormones (THs), which are not commercially available, were produced through the racemization reaction of the L-THs in acetic acid solution containing salicylaldehyde. The solution containing D- and L-THs after the reaction was used for optimizing the chiral separation. The D- and L-THs were well separated enantiomerically under isocratic conditions in 70 % acetonitrile containing 0.1 % formic acid on a CROWNPAK® CR-I (+) column, but some peaks, such as those of diiodo-D-tyrosine (D-DIT)/monoiodo-L-tyrosine, diiodo-D-thyronine/diiodo-L-tyrosine and D-thyroxine/triiodo-L-thyronine, overlapped chromatographically, causing misinterpretation in impurity analysis. This was overcome by using the gradient condition providing the best chiral selectivity (α) and resolution (Rs) ranging from 1.14 to 1.37 and from 2.39 to 4.52, respectively. The linearity was above 0.999 and the detection limits ranged from 8.2 to 57.7 ng/mL by the separation method. This method was applied to identify and quantify chiral impurities in authentic standards and pharmaceuticals. As a result, D-enantiomers corresponding to the L-THs standards as well as L-DIT were commonly observed as impurities. In the stability test of DL-thyroxine under acidic conditions for identifying the distribution of chiral products, it was observed that the formation of DIT by hydrolysis increased over time. Additional products formed through esterification, including thyroxine methyl ester and diiodo-tyrosine methyl ester, were newly separated and identified using a C18 column.
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Affiliation(s)
- Yunhee Lee
- Western Seoul Center, Korea Basic Science Institute, 150 Bugahyeon-ro, Seodaemun-gu, Seoul, 03759, Republic of Korea
| | - Eunjung Bang
- Western Seoul Center, Korea Basic Science Institute, 150 Bugahyeon-ro, Seodaemun-gu, Seoul, 03759, Republic of Korea
| | - Wonjae Lee
- College of Pharmacy, Chosun University, 309 Pilmun-dong, Dong-gu, Gwangju, 61452, Republic of Korea
| | - Yun-Cheol Na
- Western Seoul Center, Korea Basic Science Institute, 150 Bugahyeon-ro, Seodaemun-gu, Seoul, 03759, Republic of Korea.
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Cao CH, Cheng F, Xue YP, Zheng YG. Efficient synthesis of L-phosphinothricin using a novel aminoacylase mined from Stenotrophomonas maltophilia. Enzyme Microb Technol 2019; 135:109493. [PMID: 32146938 DOI: 10.1016/j.enzmictec.2019.109493] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 11/12/2019] [Accepted: 12/11/2019] [Indexed: 12/17/2022]
Abstract
L-phosphinothricin (L-PPT) is a competitive and environmentally friendly herbicide. To develop an efficient approach for synthesis of l-PPT, a kinetic resolution route with a novel aminoacylase (SmAcy) mined from Stenotrophomonas maltophilia using N-acetyl-PPT as a substrate was first constructed. This SmAcy exhibited high hydrolytic activity and excellent enantioselectivity (E > 200) toward N-acetyl-PPT. Optically pure l-PPT (> 99.9 % eep) was acquired with high conversion (> 49 %) within 4 h by the whole cells. On the basis of the docking analysis, a main reason for high enantioselectivity (E > 200) of SmAcy towards l-enantiomer would be that the D-N-acetyl-PPT cannot interact with the key general acid-base residue and the metal ions. A low-cost and simple preparation process of the substrate from commercially available racemic PPT for production of L-PPT was provided. A chemical racemization method of the unreacted D-enantiomer of substrate was also provided to recycle the unwanted substrate enantiomer. This study provides a potential route for the industrial production of L-PPT.
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Affiliation(s)
- Cheng-Hao Cao
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China; Engineering Research Center of Bioconversion and Biopurification of Ministry of Education, Zhejiang University of Technology, Hangzhou 310014, China; National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, China
| | - Feng Cheng
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China; Engineering Research Center of Bioconversion and Biopurification of Ministry of Education, Zhejiang University of Technology, Hangzhou 310014, China; National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, China
| | - Ya-Ping Xue
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China; Engineering Research Center of Bioconversion and Biopurification of Ministry of Education, Zhejiang University of Technology, Hangzhou 310014, China; National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, China.
| | - Yu-Guo Zheng
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China; Engineering Research Center of Bioconversion and Biopurification of Ministry of Education, Zhejiang University of Technology, Hangzhou 310014, China; National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, China
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12
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Horak J, Lämmerhofer M. Racemization without deamidation: Effect of racemization conditions on 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate tagged amino acids. J Chromatogr A 2019; 1604:460492. [PMID: 31488295 DOI: 10.1016/j.chroma.2019.460492] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/23/2019] [Accepted: 08/27/2019] [Indexed: 01/01/2023]
Abstract
The aim of this research study was to provide a more thorough understanding of the underlying mechanism and to broaden the application field of the recently introduced racemization method employing the amino acid derivatization tag 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC, AccQ) for heat-induced stereoisomerization of common amino acids as well as uniformly isotopically labeled [U-13C15N]-amino acids. The influence of different buffer types such as sodium borate buffer and sodium carbonate buffer as well as their pH and molarity on the racemization and deamidation of amino acids were investigated. It was found that a 0.4 M borate buffer with a pH of 8.0 +/- 0.2 was the most suitable derivatization as well as racemization buffer to ensure degradation free racemization of deamidation prone compounds such as glutamine. Hereby essential was the in-solution pH measurement before and after derivatization with AQC as well as after heat-induced racemization. This strategy provided further insight at which pH an actual racemization event was observed and when an unwanted deamidation of glutamine to glutamic acid occurred. In addition also the influence of the presence of oxygen during racemization was studied. In this context it was possible to determine ideal oxidation and racemization conditions for the production of scalemic mixtures of chiral isotopically labeled methionine AQC-DL-[U-13C15N]-Met as well as its oxidation products, AQC-DL-[U-13C15N]-Met-O and AQC-DL-[U-13C15N]-Met-O2. All stereoselective separations were performed on the zwitterionic Chiralpak ZWIX(+) column combined with HPLC-ESI-QTOF-MS analysis in positive ionization mode.
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Affiliation(s)
- Jeannie Horak
- Eberhard-Karls-University Tuebingen, Institute of Pharmaceutical Sciences, Pharmaceutical (Bio-)Analysis, Auf der Morgenstelle 8 (Haus B), 72076 Tuebingen, Germany.
| | - Michael Lämmerhofer
- Eberhard-Karls-University Tuebingen, Institute of Pharmaceutical Sciences, Pharmaceutical (Bio-)Analysis, Auf der Morgenstelle 8 (Haus B), 72076 Tuebingen, Germany
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13
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Ballard A, Narduolo S, Ahmad HO, Cosgrove DA, Leach AG, Buurma NJ. The problem of racemization in drug discovery and tools to predict it. Expert Opin Drug Discov 2019; 14:527-539. [PMID: 30882254 DOI: 10.1080/17460441.2019.1588881] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
INTRODUCTION Racemization has long been an ignored risk in drug development, probably because of a lack of convenient access to good tools for its detection and an absence of methods to predict racemization risk. As a result, the potential effects of racemization have been systematically underestimated. Areas covered: Herein, the potential effects of racemization are discussed through a review of drugs for which activity and side effects for both enantiomers are known. Subsequently, drugs known to racemize are discussed and the authors review methods to predict racemization risk. Application of a method quantitatively predicting racemization risk to databases of compounds from the medicinal chemistry literature shows that success in clinical trials is negatively correlated with racemization risk. Expert opinion: It is envisioned that a quantitative method of predicting racemization risk will remove a blind spot from the drug development pipeline. Removal of the blind spot will make drug development more efficient and result in less late-stage attrition of the drug pipeline.
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Affiliation(s)
- Andrew Ballard
- a Physical Organic Chemistry Centre , School of Chemistry, Cardiff University , Cardiff , UK
| | - Stefania Narduolo
- a Physical Organic Chemistry Centre , School of Chemistry, Cardiff University , Cardiff , UK
| | - Hiwa O Ahmad
- a Physical Organic Chemistry Centre , School of Chemistry, Cardiff University , Cardiff , UK.,b Pharmaceutical Chemistry Department , College of Pharmacy, Hawler Medical University , Erbil , Kurdistan Region , Iraq
| | | | - Andrew G Leach
- d School of Pharmacy and Biomolecular Sciences , Liverpool John Moores University , Liverpool , UK
| | - Niklaas J Buurma
- a Physical Organic Chemistry Centre , School of Chemistry, Cardiff University , Cardiff , UK
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Ruggieri F, van Langen LM, Logan DT, Walse B, Berglund P. Transaminase-Catalyzed Racemization with Potential for Dynamic Kinetic Resolutions. ChemCatChem 2018; 10:5012-5018. [PMID: 30546495 PMCID: PMC6282829 DOI: 10.1002/cctc.201801049] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Indexed: 11/11/2022]
Abstract
Dynamic kinetic resolution (DKR) reactions in which a stereoselective enzyme and a racemization step are coupled in one pot would represent powerful tools for the production of enantiopure amines through enantioconvergence of racemates. The exploitation of DKR strategies is currently hampered by the lack of effective, enzyme-compatible and scalable racemization strategies for amines. In the present work, the proof of concept of a fully biocatalytic method for amine racemization is presented. Both enantiomers of the model compound 1-methyl-3-phenylpropylamine could be racemized in water and at room temperature using a couple of wild-type, non-proprietary, enantiocomplementary amine transaminases and a minimum amount of pyruvate/alanine as a co-substrate couple. The biocatalytic simultaneous parallel cascade reaction presented here poses itself as a customizable amine racemization system with potential for the chemical industry in competition with traditional transition-metal catalysis.
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Affiliation(s)
- Federica Ruggieri
- Department of Industrial Biotechnology KTH Royal Institute of TechnologyAlbaNova University CenterStockholmSE-106 91Sweden
- SARomics Biostructures AB Medicon VillageLundSE-223 81Sweden
| | | | - Derek T. Logan
- SARomics Biostructures AB Medicon VillageLundSE-223 81Sweden
| | - Björn Walse
- SARomics Biostructures AB Medicon VillageLundSE-223 81Sweden
| | - Per Berglund
- Department of Industrial Biotechnology KTH Royal Institute of TechnologyAlbaNova University CenterStockholmSE-106 91Sweden
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15
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Li Y, Han H, Yin J, Li T, Yin Y. Role of D-aspartate on biosynthesis, racemization, and potential functions: A mini-review. ACTA ACUST UNITED AC 2018; 4:311-315. [PMID: 30175260 PMCID: PMC6116324 DOI: 10.1016/j.aninu.2018.04.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 03/20/2018] [Accepted: 04/03/2018] [Indexed: 12/28/2022]
Abstract
D-aspartate, a natural and endogenous amino acid, widely exists in animal tissues and can be synthesized through aspartate racemase and transformed by D-aspartate oxidase (DDO). D-aspartate mainly serves as a neurotransmitter and has been demonstrated to exhibit various physiological functions, including nutritional potential, regulation on reproduction and hormone biology, and neuron protection. This article mainly reviews the synthesis, racemization, and physiological functions of D-aspartate with emphasis on the potential in diseases.
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Affiliation(s)
- Yuying Li
- Key Laboratory of Agro-Ecological Processes in Subtropical Region, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Hui Han
- Key Laboratory of Agro-Ecological Processes in Subtropical Region, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Jie Yin
- Key Laboratory of Agro-Ecological Processes in Subtropical Region, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Tiejun Li
- Key Laboratory of Agro-Ecological Processes in Subtropical Region, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China
- Hunan Co-Innovation Center of Animal Production Safety, Changsha 410128, China
- Corresponding authors.
| | - Yulong Yin
- Key Laboratory of Agro-Ecological Processes in Subtropical Region, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China
- Hunan Co-Innovation Center of Animal Production Safety, Changsha 410128, China
- Corresponding authors.
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16
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Cluzeau J, Stavber G. Development and optimization of a new synthetic process for lorcaserin. Bioorg Med Chem 2018; 26:977-83. [PMID: 29254893 DOI: 10.1016/j.bmc.2017.12.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 11/27/2017] [Accepted: 12/04/2017] [Indexed: 02/01/2023]
Abstract
A two-step process to synthesize racemic lorcaserin was developed from 2-(4-chlorophenyl)ethanol via formation of bromide or tosylate derivatives. These derivatives were reacted with allylamine in neat conditions to provide pure N-(4-chlorophenethyl)allylammonium chloride. This compound was cyclized in neat conditions using aluminum or zinc chloride to give racemic lorcaserin. After resolution of enantiomers, the wrong enantiomer was racemized and recycled to give new R-lorcaserin.
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17
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Malapati P, Krishna VS, Nallangi R, Srilakshmi RR, Sriram D. Identification and development of benzoxazole derivatives as novel bacterial glutamate racemase inhibitors. Eur J Med Chem 2017; 145:23-34. [PMID: 29310027 DOI: 10.1016/j.ejmech.2017.12.088] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 12/27/2017] [Accepted: 12/27/2017] [Indexed: 02/07/2023]
Abstract
In the present study, we attempted to develop novel class of Mycobacterium tuberculosis (Mtb) inhibitors by exploring the pharmaceutically underexploited enzyme targets which are majorly involved in cell wall biosynthesis of mycobacteria. For this purpose glutamate racemase was selected which racemizes d-glutamate from l-glutamate, a key step in peptidoglycan synthesis. Furthermore, enzyme is neither expressed nor its product, d-glutamate is produced in mammals, and hence inhibiting this enzyme will have no vulnerable effect in host organism. A library of our in-house compounds were screened against glutamate racemase using a biophysical technique; thermal shift assay and further by enzyme inhibition assay to identify Lead 1 molecule. Lead 1 optimization and expansion resulted in twenty four compounds. Among the synthesized compounds twelve compounds shown good enzyme inhibition than Lead 1 (IC50 20.07 ± 0.29 μM). Among all the compounds; compound 22 (IC50 1.1 ± 0.52 μM) showed potent non-competitive mode of inhibition in enzyme assay. Further showed good susceptibility (in replicating bacteria) of MIC 8.72 μM and bactericidal time dependant kill on dormant culture. It also exhibited significant activity in Mtb nutrient starvation model (2.5) and Mtb biofilm model (2.4) and in vivo M. marinum infected Zebra fish model studies (3.6) reduction at logarithmic scale.
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Affiliation(s)
- Prasanthi Malapati
- Department of Pharmacy, Birla Institute of Technology & Science-Pilani, Hyderabad Campus, Shameerpet, Jawaharnagar, RangaReddy District, Hyderabad 500 078, India
| | - Vagolu Siva Krishna
- Department of Pharmacy, Birla Institute of Technology & Science-Pilani, Hyderabad Campus, Shameerpet, Jawaharnagar, RangaReddy District, Hyderabad 500 078, India
| | - Radhika Nallangi
- Department of Pharmacy, Birla Institute of Technology & Science-Pilani, Hyderabad Campus, Shameerpet, Jawaharnagar, RangaReddy District, Hyderabad 500 078, India
| | - Rudraraju Reshma Srilakshmi
- Department of Pharmacy, Birla Institute of Technology & Science-Pilani, Hyderabad Campus, Shameerpet, Jawaharnagar, RangaReddy District, Hyderabad 500 078, India
| | - Dharmarajan Sriram
- Department of Pharmacy, Birla Institute of Technology & Science-Pilani, Hyderabad Campus, Shameerpet, Jawaharnagar, RangaReddy District, Hyderabad 500 078, India.
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18
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Matsui D, Fuhshuku KI, Nagamori S, Takata M, Asano Y. Isolation and characterization of racemase from Ensifer sp. 23-3 that acts on α-aminolactams and α-amino acid amides. J Ind Microbiol Biotechnol 2017; 44:1503-1510. [PMID: 28929416 DOI: 10.1007/s10295-017-1981-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 09/10/2017] [Indexed: 11/30/2022]
Abstract
Limited information is available on α-amino-ε-caprolactam (ACL) racemase (ACLR), a pyridoxal 5'-phosphate-dependent enzyme that acts on ACL and α-amino acid amides. In the present study, eight bacterial strains with the ability to racemize α-amino-ε-caprolactam were isolated and one of them was identified as Ensifer sp. strain 23-3. The gene for ACLR from Ensifer sp. 23-3 was cloned and expressed in Escherichia coli. The recombinant ACLR was then purified to homogeneity from the E. coli transformant harboring the ACLR gene from Ensifer sp. 23-3, and its properties were characterized. This enzyme acted not only on ACL but also on α-amino-δ-valerolactam, α-amino-ω-octalactam, α-aminobutyric acid amide, and alanine amide.
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Affiliation(s)
- Daisuke Matsui
- Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
- Asano Active Enzyme Molecule Project, ERATO, JST, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
| | - Ken-Ichi Fuhshuku
- Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
- Department of Interdisciplinary Science and Engineering, Meisei University, 2-1-1 Hodokubo, Hino, Tokyo, 191-8506, Japan
| | - Shingo Nagamori
- Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
| | - Momoko Takata
- Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
| | - Yasuhisa Asano
- Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan.
- Asano Active Enzyme Molecule Project, ERATO, JST, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan.
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Abstract
d-Arginine dehydrogenase from Pseudomonas aeruginosa (PaDADH) is a flavin-dependent oxidoreductase, which is part of a novel two-enzyme racemization system that functions to convert d-arginine to l-arginine. PaDADH contains a noncovalently linked FAD that shows the highest activity with d-arginine. The enzyme exhibits broad substrate specificity towards d-amino acids, particularly with cationic and hydrophobic d-amino acids. Biochemical studies have established the structure and the mechanistic properties of the enzyme. The enzyme is a true dehydrogenase because it displays no reactivity towards molecular oxygen. As established through solvent and multiple kinetic isotope studies, PaDADH catalyzes an asynchronous CH and NH bond cleavage via a hydride transfer mechanism. Steady-state kinetic studies with d-arginine and d-histidine are consistent with the enzyme following a ping-pong bi-bi mechanism. As shown by a combination of crystallography, kinetic and computational data, the shape and flexibility of loop L1 in the active site of PaDADH are important for substrate capture and broad substrate specificity.
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Affiliation(s)
- Daniel Ouedraogo
- Department of Chemistry, Georgia State University, Atlanta, GA 30302, United States
| | - Jacob Ball
- Department of Chemistry, Georgia State University, Atlanta, GA 30302, United States
| | - Archana Iyer
- Department of Chemistry, Georgia State University, Atlanta, GA 30302, United States
| | - Renata A G Reis
- Department of Chemistry, Georgia State University, Atlanta, GA 30302, United States
| | - Maria Vodovoz
- Department of Chemistry, Georgia State University, Atlanta, GA 30302, United States
| | - Giovanni Gadda
- Department of Chemistry, Georgia State University, Atlanta, GA 30302, United States; Department of Biology, Georgia State University, Atlanta, GA 30302, United States; Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30302, United States; Center for Biotechnology and Drug Design, Georgia State University, Atlanta, GA 30302, United States.
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Javierre G, Fortrie R, Jean M, Moraleda D, Naubron JV, Fotiadu F. Racemization and transesterification of alkyl hydrogeno-phenylphosphinates. J Mol Model 2017; 23:168. [PMID: 28451880 DOI: 10.1007/s00894-017-3343-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 04/03/2017] [Indexed: 11/30/2022]
Abstract
In this article, we explore, both theoretically and experimentally, the general reactivity of alkyl hydrogeno-phenylphosphinates with alcohols. We show that alcohol molecules act exclusively as nucleophilic species, and add to alkyl hydrogeno-phenylphosphinates, leading to pentacoordinated intermediates. These intermediates are shown to subsequently competitively undergo alcohol eliminations and/or Berry pseudorotations. This offers several possible routes for racemizations and/or alcohol exchange reactions. Transition standard Gibbs free energies predicted from DFT calculations for the overall alcohol exchange mechanism are shown to be compatible with those experimentally measured in case ethanol reacts with ethyl hydrogeno-phenylphosphinate (134.5∼136.0 kJ mol-1 at 78 °C). Graphical abstract ᅟ.
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Affiliation(s)
- Guilhem Javierre
- Aix Marseille Univ, CNRS, Centrale Marseille, iSm2, Marseille, France
| | - Rémy Fortrie
- Aix Marseille Univ, CNRS, Centrale Marseille, iSm2, Marseille, France.
| | - Marion Jean
- Aix Marseille Univ, CNRS, Centrale Marseille, iSm2, Marseille, France
| | - Delphine Moraleda
- Aix Marseille Univ, CNRS, Centrale Marseille, iSm2, Marseille, France
| | | | - Frédéric Fotiadu
- Aix Marseille Univ, CNRS, Centrale Marseille, iSm2, Marseille, France
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Chen S, Lv Y, Wang D, Yu X. Aspartic acid racemization in dentin of the third molar for age estimation of the Chaoshan population in South China. Forensic Sci Int 2016; 266:234-238. [PMID: 27337639 DOI: 10.1016/j.forsciint.2016.06.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 05/29/2016] [Accepted: 06/07/2016] [Indexed: 02/05/2023]
Abstract
Aspartic acid racemization in teeth has been increasingly used to estimate chronological age with a considerably high accuracy in forensic practice. The Chaoshan population in South China is relatively isolated in geography, and has specific lifestyle and dietary inhibits. It is still unknown whether this method is suitable for this population. The aim of this study was to analyze the relationship between chronological age and the d/l aspartic acid ratio in dentin in the third molar tooth of the Chaoshan population. Fifty-eight non-carious third molar teeth (31 mandibles and 27 maxillae), from 58 living individuals of known age (24 males and 34 females), were retrieved. Dentin was extracted from these teeth. The d- and l-aspartic acids in dentins were separated and detected by high performance liquid chromatography (HPLC). Linear regression was performed between the d/l aspartic acid ratio of dentins and chronological age. Results showed that the correlation coefficient (r) was 0.969, and the mean absolute error (MAE) was 2.19 years, its standard deviation (SD) was ±1.53 years, indicating excellent correlation. There was no significant difference in racemization rates of dentin between sexes (P=0.113, F=2.6), or between mandibles and maxillae (P=0.964, F=0.000). Results indicate that the ratio of the d and l forms of aspartic acid of dentins, in the third molar, is closely correlated with chronological age, special lifestyle do no obviously affect the accuracy of the age estimations by aspartic acid racemization of the dentin in the third molar and that aspartic acid racemization in the third molar dentin can be used as an accurate method to estimate chronological age in the Chaoshan population in South China.
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Affiliation(s)
- Shisheng Chen
- Department of Dentistry, Shantou University Medical College 2nd Affiliated Hospital, Shantou 515041, Guangdong Province, People's Republic China; Department of Forensic Medicine, Shantou University Medical College, Shantou 515041, Guangdong Province, People's Republic of China
| | - Yanyi Lv
- Department of Forensic Medicine, Shantou University Medical College, Shantou 515041, Guangdong Province, People's Republic of China
| | - Dian Wang
- Department of Forensic Medicine, Shantou University Medical College, Shantou 515041, Guangdong Province, People's Republic of China
| | - Xiaojun Yu
- Department of Forensic Medicine, Shantou University Medical College, Shantou 515041, Guangdong Province, People's Republic of China.
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Lowenson JD, Shmanai VV, Shklyaruck D, Clarke SG, Shchepinov MS. Deuteration protects asparagine residues against racemization. Amino Acids 2016; 48:2189-96. [PMID: 27169868 DOI: 10.1007/s00726-016-2250-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 05/02/2016] [Indexed: 12/24/2022]
Abstract
Racemization in proteins and peptides at sites of L-asparaginyl and L-aspartyl residues contributes to their spontaneous degradation, especially in the biological aging process. Amino acid racemization involves deprotonation of the alpha carbon and replacement of the proton in the opposite stereoconfiguration; this reaction is much faster for aspartate/asparagine than for other amino acids because these residues form a succinimide ring in which resonance stabilizes the carbanion resulting from proton loss. To determine if the replacement of the hydrogen atom on the alpha carbon with a deuterium atom might decrease the rate of racemization and thus stabilize polypeptides, we synthesized a hexapeptide, VYPNGA, in which the three carbon-bound protons in the asparaginyl residue were replaced with deuterium atoms. Upon incubation of this peptide in pH 7.4 buffer at 37 °C, we found that the rate of deamidation via the succinimide intermediate was unchanged by the presence of the deuterium atoms. However, the accumulation of the D-aspartyl and D-isoaspartyl-forms resulting from racemization and hydrolysis of the succinimide was decreased more than five-fold in the deuterated peptide over a 20 day incubation at physiological temperature and pH. Additionally, we found that the succinimide intermediate arising from the degradation of the deuterated asparaginyl peptide was slightly less likely to open to the isoaspartyl configuration than was the protonated succinimide. These findings suggest that the kinetic isotope effect resulting from the presence of deuteriums in asparagine residues can limit the accumulation of at least some of the degradation products that arise as peptides and proteins age.
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Catterall JB, Zura RD, Bolognesi MP, Kraus VB. Aspartic acid racemization reveals a high turnover state in knee compared with hip osteoarthritic cartilage. Osteoarthritis Cartilage 2016; 24:374-81. [PMID: 26417696 DOI: 10.1016/j.joca.2015.09.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 06/23/2015] [Accepted: 09/01/2015] [Indexed: 02/02/2023]
Abstract
OBJECTIVE We investigated tissue turnover in healthy and osteoarthritic cartilage. We challenge long held views that osteoarthritis (OA) is dominated by a similar turnover process in all joints and present evidence that hip and knee cartilage respond very differently to OA. METHODS d- and l-Aspartate (Asp) were quantified for whole cartilage, collagen and non-collagenous components of cartilage obtained at the time of joint replacement. We computed the Asp racemization ratio (Asp-RR = d/d + l Asp), reflecting the proportion of old to total protein, for each component. RESULTS Compared with hip OA, knee OA collagen fibrils (P < 0.0001), collagen (P = 0.007), and non-collagenous proteins (P = 0.0003) had significantly lower age-adjusted mean Asp-RRs consistent with elevated protein synthesis in knee OA. Knee OA collagen had a mean hydroxyproline/proline (H/P) ratio of 1.2 consistent with the presence of type III collagen whereas hip OA collagen had a mean H/P ratio of 0.99 consistent with type II collagen. Based on Asp-RR, the relative age was significantly different in knee and hip OA (P < 0.0005); on average OA knees were estimated to be 30 yrs 'younger', and OA hips 10 yrs 'older' than non-OA. CONCLUSIONS The metabolic response to OA was strikingly different by joint site. Knee OA cartilage evinced an anabolic response that appeared to be absent in hip OA cartilage. These results challenge the long held view that OA cartilage is capable of only minimal repair and that collagen loss is irreversible.
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Kaji Y, Oshika T, Nejima R, Mori S, Miyata K, Fujii N. Immunohistochemical localization of D-β-aspartic acid-containing proteins in pterygium. J Pharm Biomed Anal 2015; 116:86-9. [PMID: 25749304 DOI: 10.1016/j.jpba.2015.01.057] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2014] [Revised: 01/22/2015] [Accepted: 01/31/2015] [Indexed: 11/26/2022]
Abstract
Biologically uncommon D-β-aspartic acid (D-β-Asp) residues have been reported to accumulate in organs affected by age-related disorders. In the present study, we investigated the localization of D-β-Asp-containing proteins in cases of pterygium, one of the most prominent age-related ocular conditions. Immunohistochemical localization of D-β-Asp-containing proteins was investigated in surgical specimens of pterygium from 20 patients and control specimens from 10 patients. Strong immunoreactivity to D-β-Asp-containing proteins was observed in subepithelial elastotic lesions and surrounding collagenous lesions from all surgical specimens with pterygia. In contrast, no immunoreactivity to D-β-Asp-containing proteins was seen in pterygium-free specimens. D-β-Asp-containing proteins are produced in organs as they are affected by the aging process. In addition, conversion of L- to D-aspartyl residues is accelerated by ultraviolet (UV) irradiation. Since pterygia can form due to aging or UV exposure, it is reasonable to find D-β-Asp-containing proteins in specimens with pterygia. Furthermore, since D-β-Asp is a non-native amino acid, D-β-Asp-containing proteins may be recognized as allogeneic antigens. Therefore, D-β-Asp-containing proteins in pterygia may responsible for the fibrovascular changes seen in the disorder.
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Affiliation(s)
- Yuichi Kaji
- Department of Ophthalmology, Institute of Clinical Sciences, University of Tsukuba, Ibaraki, Japan.
| | - Tetsuro Oshika
- Department of Ophthalmology, Institute of Clinical Sciences, University of Tsukuba, Ibaraki, Japan
| | | | | | | | - Noriko Fujii
- Research Reactor Institute, Kyoto University, Osaka, Japan
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Wahl O, Holzgrabe U. Evaluation of enantiomeric purity of magnesium-L-aspartate dihydrate. J Pharm Biomed Anal 2014; 102:100-9. [PMID: 25262412 DOI: 10.1016/j.jpba.2014.08.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 08/06/2014] [Accepted: 08/07/2014] [Indexed: 10/24/2022]
Abstract
Magnesium supplementation in form of organic magnesium salts is a very popular practice. We examined the enantiomeric purity of "Magnesium aspartate dihydrate" monographed in the European Pharmacopeia. A chiral capillary zone electrophoresis using (2-hydroxypropyl)-β-cyclodextrin coupled to laser induced fluorescence detection and a HPLC-fluorescence method with chiral derivatization using o-phthaldialdehyde and N-acetyl-L-cysteine as an orthogonal method were developed and validated. Two batch samples of this substance and three drug products containing the salt were analyzed by means of both methods. The concentration of the D-enantiomer of aspartic acid ranged from 0.03 to 0.12%. Simulations of the synthesis revealed that the d-aspartic acid content is elevated if the dissolution of L-aspartic acid was performed at acidic pH values.
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Affiliation(s)
- Oliver Wahl
- University of Würzburg, Institute for Pharmacy and Food Chemistry, Würzburg 97074, Germany
| | - Ulrike Holzgrabe
- University of Würzburg, Institute for Pharmacy and Food Chemistry, Würzburg 97074, Germany.
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Pignard J, Bourdeaux D, Kauffmann S, Constantin JM, Sautou V. [Physicochemical stability study of injectable solutions of cisatracurium besilate in clinical conditions]. Ann Fr Anesth Reanim 2014; 33:304-9. [PMID: 24784917 DOI: 10.1016/j.annfar.2014.03.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 03/06/2014] [Indexed: 10/25/2022]
Abstract
OBJECTIVES To assess the stability of cisatracurium besilate solution stored at 5°C and 25°C. MATERIALS AND METHODS Cisatracurium solutions at 2, 5 and 0.1mg/mL in 0.9 % sodium chloride or 5 % glucose were exposed to 5°C and 25°C under 60 % relative humidity for seven days. The physicochemical stability was assessed at 24, 48hours and seven days with dosage of the active substance, detection of degradation products and a possible racemization, measuring pH, osmolality and turbidity, assessment of coloration, visible particles and invisible particles count. RESULTS Cisatracurium besilate present good stability for 24hours at 5°C and 25°C for concentrations between 0.1 and 5mg/mL. Beyond 24hours, the solutions at 2 and 5mg/mL remained stable for seven days at 5°C. At 25°C, potentially toxic degradation products appear in solutions of 0.1mg/mL between 24 and 48hours. No racemization was detected, the drug remains in its active form cis. CONCLUSION Cisatracurium solutions at 2 and 5mg/mL may be stored at 5°C or 25°C for seven days. It's advisable to keep the solutions in a dilution of 0.1mg/mL in 0.9 % sodium chloride or 5 % glucose in the refrigerator. No diluted solution should be stored at room temperature beyond 24hours.
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Affiliation(s)
- J Pignard
- Pôle pharmacie, CHU G.-Montpied, rue Montalembert, 63003 Clermont-Ferrand, France
| | - D Bourdeaux
- Pôle pharmacie, CHU G.-Montpied, rue Montalembert, 63003 Clermont-Ferrand, France; Université d'Auvergne, EA 4676C-Biosenss, UFR médecine-pharmacie, place Henri-Dunant, 63001 Clermont-Ferrand, France
| | - S Kauffmann
- Pôle bloc chirurgical, chirurgie et anesthésie-réanimation, CHU G.-Montpied, rue Montalembert, 63000 Clermont-Ferrand, France
| | - J M Constantin
- Pôle ressources interventionnelles - anesthésie-réanimation, CHU Estaing, rue Lucie-Aubrac, 63100 Clermont-Ferrand, France
| | - V Sautou
- Pôle pharmacie, CHU G.-Montpied, rue Montalembert, 63003 Clermont-Ferrand, France; Université d'Auvergne, EA 4676C-Biosenss, UFR médecine-pharmacie, place Henri-Dunant, 63001 Clermont-Ferrand, France.
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Truscott RJW, Friedrich MG. Old proteins and the Achilles heel of mass spectrometry. The role of proteomics in the etiology of human cataract. Proteomics Clin Appl 2014; 8:195-203. [PMID: 24458544 DOI: 10.1002/prca.201300044] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 12/10/2013] [Accepted: 12/16/2013] [Indexed: 11/09/2022]
Abstract
Proteomics may have enabled the root cause of a major human-blinding condition, age-related cataract, to be established. Cataract appears to result from the spontaneous decomposition of long-lived macromolecules in the human lens, and recent proteomic analysis has enabled both the particular crystallins, and the specific sites of amino acid modification within each polypeptide, to be identified. Analysis of proteins from cataract lenses has demonstrated that there are key sites on some structural proteins that show a consistently greater degree of deterioration than age-matched normal lenses. Proteomic analysis, using MS, revealed that the most abundant posttranslational modification of aged lens proteins is racemization. This is somewhat ironic, since structural isomers can be viewed as the "Achilles heel" of MS and there are typically few, if any, differences in the MS/MS spectra of tryptic peptides containing one d-amino acid. It is proposed that once a certain level of spontaneous PTM at key sites occurs, that protein-protein interactions are disrupted, and binding of complexes to cell membranes takes place that impairs cell-to-cell communication. These findings may apply more widely to age-related human diseases, in particular where the deterioration of long-lived proteins is a crucial component in the etiology.
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Affiliation(s)
- Roger J W Truscott
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
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Cai S, Fujii N, Saito T, Fujii N. Simultaneous ultraviolet B-induced photo-oxidation of tryptophan/tyrosine and racemization of neighboring aspartyl residues in peptides. Free Radic Biol Med 2013; 65:1037-1046. [PMID: 23999504 DOI: 10.1016/j.freeradbiomed.2013.08.171] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 07/30/2013] [Accepted: 08/17/2013] [Indexed: 11/21/2022]
Abstract
Although proteins consist exclusively of l-amino acids, it is well known that d-isomers of aspartyl (Asp) residues occur at specific sites in lens crystallins of elderly people with cataracts. The presence of d-isomers is thought to result from the racemization of Asp residues in the crystallins during aging. It has been reported that this racemization progresses owing to UV-B exposure; however, the underlying mechanism remains unknown because Asp is not a photosensitive residue because there is no aromatic group in its chemical structure. In this study, we synthesized peptides in which the residue neighboring the Asp was the photosensitive residue tryptophan (Trp) or tyrosine (Tyr). After exposing these peptides to UV-B, we used RP-HPLC to confirm that racemization of Asp residues occurred in peptides in which a Trp or Tyr residue was inserted near the Asp; simultaneously, several varieties of photoproducts derived from Trp and Tyr were detected by mass spectroscopy. Promotion of the racemization of Asp residues in peptides with a neighboring Trp was much more significant than in those with Tyr. In particular, when Trp was next to an Asp residue on the C-terminal side of the peptide, the racemization reaction was accelerated.
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Affiliation(s)
- Simin Cai
- Research Reactor Institute, Kyoto University, Kumatori, Osaka 590-0494, Japan
| | - Norihiko Fujii
- Research Reactor Institute, Kyoto University, Kumatori, Osaka 590-0494, Japan
| | - Takeshi Saito
- Research Reactor Institute, Kyoto University, Kumatori, Osaka 590-0494, Japan
| | - Noriko Fujii
- Research Reactor Institute, Kyoto University, Kumatori, Osaka 590-0494, Japan.
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Abstract
The tylophorine alkaloid anticancer compounds antofine and cryptopleurine have been synthesized in optically active form. Both syntheses employ optically pure α-amino acids as the starting materials, require only seven steps from known 2-ethynylpyrrolidine or 2-ethynylpiperidine derivatives, and are free of protecting groups. Key steps include an alkyne hydration and a chromium carbene complex based net [5+5]-cycloaddition step. Alkyne hydration was accompanied by racemization of the resulting β-aminoketone under most of the conditions examined, and successful minimization of this side reaction was achieved through careful pH control and choice of metal additive. Final ring closure involves a Bischler-Napieralski reaction using a carbamate (antofine) or urea (cryptopleurine) precursor.
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Affiliation(s)
- Weijiang Ying
- Department of Chemistry and Biochemistry, New Mexico State University, MSC 3C, Las Cruces, NM 88003 USA
| | - James W. Herndon
- Department of Chemistry and Biochemistry, New Mexico State University, MSC 3C, Las Cruces, NM 88003 USA
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Kim JS, Lee YS. Effect of reaction pH on enolization and racemization reactions of glucose and fructose on heating with amino acid enantiomers and formation of melanoidins as result of the Maillard reaction. Food Chem 2008; 108:582-92. [PMID: 26059136 DOI: 10.1016/j.foodchem.2007.11.014] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2007] [Revised: 11/06/2007] [Accepted: 11/07/2007] [Indexed: 02/07/2023]
Abstract
This study investigates the effect of reaction pH on enolization and racemization reactions of glucose and fructose on heating with amino acid enantiomers, can influence the formation of melanoidins as result of the Maillard reaction. Remarkable enolization reaction of sugars was observed in the course of the Maillard reaction. Especially, the degree of sugar enolization was increased as the pH levels increased, which was higher in fructose than glucose systems. Otherwise, enolization of sugars on heating with amino acid was higher in glucose than fructose systems. Formation of isomer in Glc/d-Lys, Fru/d-Asn and Fru/d-Lys were increased upon increase of pH levels. The relative amounts of isomers in Glc/l-Asn and Glc/d-Asn were decreased upon increase of pH levels. Browning development was dependent on the pH levels, being more significant for model systems apart from heated glucose solution alone. Browning development of fructose systems was higher than glucose-amino acid systems. The l- and d-isomers both showed different absorption in the UV-vis spectra and that these occur at similar shape. Every peak has a stable absorbance appeared in the range between 260 and 320nm, characteristic of melanoidins.
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