923-27-3Relevant academic research and scientific papers
Preparation and characterization of a new open-tubular capillary column for enantioseparation by capillary electrochromatography
Li, Yingjie,Tang, Yimin,Qin, Shili,Li, Xue,Dai, Qiang,Gao, Lidi
, p. 283 - 292 (2019/02/05)
In order to use the enantioseparation capability of cationic cyclodextrin and to combine the advantages of capillary electrochromatography (CEC) with open-tubular (OT) column, in this study, a new OT-CEC, coated with cationic cyclodextrin (1-allylimidazolium-β-cyclodextrin [AI-β-CD]) as chiral stationary phase (CSP), was prepared and applied for enantioseparation. Synthesized AI-β-CD was characterized by infrared (IR) spectrometry and mass spectrometry (MS). The preparation conditions for the AI-β-CD-coated column were optimized with the orthogonal experiment design L9(34). The column prepared was characterized by scanning electron microscopy (SEM) and elemental analysis (EA). The results showed that the thickness of stationary phase in the inner surface of the AI-β-CD-coated columns was about 0.2 to 0.5?μm. The AI-β-CD content in stationary phase based on the EA was approximately 2.77?mmol·m?2. The AI-β-CD-coated columns could separate all 14 chiral compounds (histidine, lysine, arginine, glutamate, aspartic acid, cysteine, serine, valine, isoleucine, phenylalanine, salbutamol, atenolol, ibuprofen, and napropamide) successfully in the study and exhibit excellent reproducibility and stability. We propose that the column, coated with AI-β-CD, has a great potential for enantioseparation in OT-CEC.
Chiral Metal–Organic Framework Hollow Nanospheres for High-Efficiency Enantiomer Separation
Wang, Xiaoshi,Zhu, Yanan,Liu, Jian,Liu, Chang,Cao, Changyan,Song, Weiguo
, p. 1535 - 1538 (2018/06/26)
Chiral ZIF-8 hollow nanospheres with d-histidine as part of chiral ligands (denoted as H-d-his-ZIF-8) were prepared for separation of (±)-amine acids. Compared to bulk d-his-ZIF-8 without a hollow cavity, the prepared H-d-his-ZIF-8 showed 15 times higher separation capacity and higher ee values of 90.5 % for alanine, 95.2 % for glutamic acid and 92.6 % for lysine, respectively.
Covalent Organic Frameworks with Chirality Enriched by Biomolecules for Efficient Chiral Separation
Zhang, Sainan,Zheng, Yunlong,An, Hongde,Aguila, Briana,Yang, Cheng-Xiong,Dong, Yueyue,Xie, Wei,Cheng, Peng,Zhang, Zhenjie,Chen, Yao,Ma, Shengqian
supporting information, p. 16754 - 16759 (2018/11/27)
The separation of racemic compounds is important in many fields, such as pharmacology and biology. Taking advantage of the intrinsically strong chiral environment and specific interactions featured by biomolecules, here we contribute a general strategy is developed to enrich chirality into covalent organic frameworks (COFs) by covalently immobilizing a series of biomolecules (amino acids, peptides, enzymes) into achiral COFs. Inheriting the strong chirality and specific interactions from the immobilized biomolecules, the afforded biomolecules?COFs serve as versatile and highly efficient chiral stationary phases towards various racemates in both normal and reverse phase of high-performance liquid chromatography (HPLC). The different interactions between enzyme secondary structure and racemates were revealed by surface-enhanced Raman scattering studies, accounting for the observed chiral separation capacity of enzymes?COFs.
Stereospecific radiosynthesis of 3-fluoro amino acids: Access to enantiomerically pure radioligands for positron emission tomography
Alluri, Santosh R.,Riss, Patrick J.
supporting information, p. 2219 - 2224 (2018/04/05)
A variety of substituted non-racemic aziridine-2-carboxylates equivalent to amino acids were prepared and subjected to ring opening reaction by [18F/19F]fluoride. The regio and stereospecific ring opening depends on the substituents on the nitrogen as well as both the carbons of aziridines. The applicability of the methods to afford access to 3-[18F/19F]fluoro amino acids are illustrated.
Chromatographic Resolution of α-Amino Acids by (R)-(3,3'-Halogen Substituted-1,1'-binaphthyl)-20-crown-6 Stationary Phase in HPLC
Wu, Peng,Wu, Yuping,Zhang, Junhui,Lu, Zhenyu,Zhang, Mei,Chen, Xuexian,Yuan, Liming
supporting information, p. 1037 - 1042 (2017/07/25)
Three new chiral stationary phases (CSPs) for high-performance liquid chromatography were prepared from R-(3,3'-halogen substituted-1,1'-binaphthyl)-20-crown-6 (halogen = Cl, Br and I). The experimental results showed that R-(3,3'-dibromo-1,1'-binaphthyl)-20-crown-6 (CSP-1) possesses more prominent enantioselectivity than the two other halogen-substituted crown ether derivatives. All twenty-one α-amino acids have different degrees of separation on R-(3,3'-dibromo-1,1'-binaphthyl)-20-crown-6-based CSP-1 at room temperature. The enantioselectivity of CSP-1 is also better than those of some commercial R-(1,1'-binaphthyl)-20-crown-6 derivatives. Both the separation factors (α) and the resolution (Rs) are better than those of commercial crown ether-based CSPs [CROWNPAK CR(+) from Daicel] under the same conditions for asparagine, threonine, proline, arginine, serine, histidine and valine, which cannot be separated by commercial CR(+). This study proves the commercial usefulness of the R-(3,3'-dibromo-1,1'-binaphthyl)-20-crown-6 chiral stationary phase.
Thalassosamide, a Siderophore Discovered from the Marine-Derived Bacterium Thalassospira profundimaris
Zhang, Fan,Barns, Kenneth,Hoffmann, F. Michael,Braun, Doug R.,Andes, David R.,Bugni, Tim S.
, p. 2551 - 2555 (2017/09/27)
Here we describe the rapid identification and prioritization of novel active marine natural products using an improved dereplication strategy. During the course of our screening of marine natural product libraries, a new cyclic trihydroxamate compound, thalassosamide, was discovered from the α-proteobacterium Thalassospira profundimaris. Its structure was determined by 2D NMR and MS/MS experiments, and the absolute configuration of the lysine-derived units was established by Marfey's analysis, whereas that of C-9, 9′, and 9″ was determined via the circular dichroism data of the [Rh2(OCOCF3)4] complex and DFT NMR calculations. Thalassosamide showed moderate in vivo efficacy against Pseudomonas aeruginosa.
A method for preparing DL-lysine
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Paragraph 0032; 0033, (2017/04/03)
The invention provides a method for preparing DL-lysine with chiral lysine salt as a raw material. The method specifically comprises the following steps: dissolving chiral lysine salt in an acetic acid water solution, adding salicylaldehyde or benzaldehyde as a catalyst, carrying out heating and racemization, removing solvents through vacuum distillation after racemization is completed, washing a residual solid with ethanol, obtaining DL-lysine salt, removing salt with an ion exchange column and carrying out concentration and decoloration, thus obtaining a DL-lysine solid. The preparation method has the advantages that the preparation method is lower in production cost and simple in process; pollution is not easily caused in the production process; the racemization rate of L-lysine hydrochloride can be 100%; the purity of the obtained DL-lysine finished product is more than 98%.
COMPOSITIONS AND METHODS FOR THE PREPARATION OF KIDNEY PROTECTIVE AGENTS COMPRISING AMIFOSTINE AND AMINO ACIDS
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, (2016/06/13)
This invention relates to composition and method of preparation of AminoMedix? comprising of Amifostine, at least one amino acid (Arginine, Lysine, Histidine) with or without other pharmaceutically active compounds. The AminoMedix? composition can be applied for kidney protection during therapy using radiolabeled and non-radiolabeled compounds, contrast agents, chemotherapeutics, antibiotics and drugs showing nephrotoxic effect.
AXIAL-ASYMMETRIC N-(2-ACYLARYL)-2-[5, 7-DIHYDRO-6H-DIBENZO [C, E] AZEPINE-6-YL] ACETAMIDE COMPOUND AND CHIRALITY CONVERSION METHOD FOR A-AMINO ACID USING SAME
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Paragraph 0152; 0153; 0154, (2015/11/27)
An object of the present invention is to provide a method for producing an optically active amino acid in high yield and in a highly enantioselective manner, which method has fewer restrictions on the material that can be used as the substrate, and to provide, among others, a compound useful as a chiral auxiliary for the method. The present invention provides an N-(2-acylaryl)-2-[5,7-dihydro-6H-dibenzo[c,e]azepin-6-yl]ac etamide compound represented by Formula (1): or a salt thereof, or a metal complex represented by Formula (3) :
Chemical dynamic kinetic resolution and S/R interconversion of unprotected α-amino acids
Takeda, Ryosuke,Kawamura, Akie,Kawashima, Aki,Sato, Tatsunori,Moriwaki, Hiroki,Izawa, Kunisuke,Akaji, Kenichi,Wang, Shuni,Liu, Hong,Ace?a, José Luis,Soloshonok, Vadim A.
supporting information, p. 12214 - 12217 (2016/02/18)
Reported herein is the first purely chemical method for the dynamic kinetic resolution (DKR) of unprotected racemic α-amino acids (α-AAs), a method which can rival the economic efficiency of the enzymatic reactions. The DKR reaction principle can be readily applied for S/R interconversions of α-AAs, the methodological versatility of which is unmatched by biocatalytic approaches. The presented process features a virtually complete stereochemical outcome, fully recyclable source of chirality, and operationally simple and convenient reaction conditions, thus allowing its ready scalability. A quite unique and novel mode of the thermodynamic control over the stereochemical outcome, including an exciting interplay between axial, helical, and central elements of chirality is proposed. A new player for DKR: Dynamic kinetic resolution of α-amino acids has been achieved upon complexation with nickel(II) and a chiral ligand derived from optically active bis(naphthyl)amine under thermodynamic control, thus affording excellent diastereoselectivities and chemical yields. The S to R interconversion of α-amino acids is also described.
