- Evaluation of the Edman degradation product of vancomycin bonded to core-shell particles as a new HPLC chiral stationary phase
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A modified macrocyclic glycopeptide-based chiral stationary phase (CSP), prepared via Edman degradation of vancomycin, was evaluated as a chiral selector for the first time. Its applicability was compared with other macrocyclic glycopeptide-based CSPs: TeicoShell and VancoShell. In addition, another modified macrocyclic glycopeptide-based CSP, NicoShell, was further examined. Initial evaluation was focused on the complementary behavior with these glycopeptides. A screening procedure was used based on previous work for the enantiomeric separation of 50 chiral compounds including amino acids, pesticides, stimulants, and a variety of pharmaceuticals. Fast and efficient chiral separations resulted by using superficially porous (core-shell) particle supports. Overall, the vancomycin Edman degradation product (EDP) resembled TeicoShell with high enantioselectivity for acidic compounds in the polar ionic mode. The simultaneous enantiomeric separation of 5 racemic profens using liquid chromatography-mass spectrometry with EDP was performed in approximately 3?minutes. Other highlights include simultaneous liquid chromatography separations of rac-amphetamine and rac-methamphetamine with VancoShell, rac-pseudoephedrine and rac-ephedrine with NicoShell, and rac-dichlorprop and rac-haloxyfop with TeicoShell.
- Hellinghausen, Garrett,Lopez, Diego A.,Lee, Jauh T.,Wang, Yadi,Weatherly, Choyce A.,Portillo, Abiud E.,Berthod, Alain,Armstrong, Daniel W.
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p. 1067 - 1078
(2018/08/01)
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- Synthesis of diastereomeric anhydrides of (RS)-ketorolac and (RS)-etodolac, semi-preparative HPLC enantioseparation, establishment of molecular asymmetry and recovery of pure enantiomers
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Herein, enantioseparation of two anti-inflammatory drugs, namely, (RS)-ketorolac and (RS)-etodolac, commonly marketed and administered as racemates, was achieved by RP-HPLC. This method provided very low limit of detection values (3.69 and 3.02 ng mL-1 for diastereomeric derivatives of (R)- and (S)-Ket, respectively) as compared to those reported in literature. (S)-Naproxen benzotriazole ester, which was used as a chiral reagent, was synthesized and characterized by UV, IR, and 1H NMR spectroscopies, elemental analysis, and polarimetry. The diastereomeric derivatives were synthesized via microwave irradiation, separated on an analytical scale by RP-HPLC, and then isolated by preparative HPLC. The use of a mobile phase containing methanol and aqueous triethylamine phosphate (TEAP) in the isocratic mode was found to be successful for the separation of diastereomeric derivatives, and the separation conditions with respect to pH, flow rate, and buffer concentration were optimized. The diastereomeric derivatives were characterized, and their absolute configuration was established. Hydrolysis of the derivatives provided native enantiomers under mild reaction conditions. This study describes the successful enantioseparation of the above mentioned two analytes by semi-preparative HPLC with easy recovery of the native enantiomers without racemization and with the establishment of molecular asymmetry.
- Malik, Poonam,Bhushan, Ravi
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p. 13681 - 13691
(2017/11/27)
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- Chiral separation and modeling of baclofen, bupropion, and etodolac profens on amylose reversed phase chiral column
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Chiral resolution of baclofen, bupropion, and etodolac profens was obtained with amylose derivatized chiral reversed stationary phase (carbamate groups). The eluent used for bupropion and etodolac was MeOH–water (20:80, v/v) and for baclofen was water–methanol (95:5, v/v). The eluent run rates, finding wavelength and temperature, were 1.0?mL/min, 220?nm and 27?±?1?°C for all the eluents. The magnitude of the retardation factors for S- and R-enantiomers of baclofen, bupropion, and etodolac were 1.37, 2.62, 2.25, 3.25, 1.8, and 3.0. The magnitudes of separation and resolution factors were 1.90, 1.44, and 1.67 and 2.77, 2.35, and 2.04. Limits of detection and quantitation were 1.0–2.0 and 5.1–10.0?μg/mL. Chiral recognition mechanisms were recognized by simulation and high-performance liquid chromatography (HPLC) experiments. It was seen that hydrogen interactions, hydrophobic interactions, and π–π exchanges were the chief interactions for chiral recognition mechanisms. The described methods may be exploited for the chiral separation of baclofen, bupropion, and etodolac profens in any unknown sample.
- Ali, Imran,Suhail, Mohd.,Alothman, Zeid A.,Alwarthan, Abdulrahman
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p. 386 - 397
(2017/06/19)
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- Cyclodextrins functionalised with etodolac as specific site release agents
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β-Cyclodextrin was functionalized with (+/-) etodolac through an ester bond, and the two diastereomers were isolated and characterized as molecules with anti-infiammatory or antitumoral activity. The presence of cyclodextrin ensures the specific delivery to the intestine.
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Page/Page column 4-5
(2008/06/13)
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- Method for the racemization of etodolic acid
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A method for the resolution of etodolic acid by crystallization of its salt with optically active 1-phenylethylamine and subsequent recovery of the (R,S) etodolic acid from the mother liquors of crystallization by racemization and crystallization is described.
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Page column 2
(2008/06/13)
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- Exploration of an efficient method for optical resolution of etodolac
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The exploration of an efficient method for resolving etodolac using either L-cinchonidinium salt or chiral isopinocamphenol diastereomeric esters is described herein. Furthermore, racemization mechanism of chiral etodolac is rationalized in terms of an is
- Chou, Shan-Yen,Tseng, Chin-Lu,Chang, Lien-Shange
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p. 229 - 234
(2007/10/03)
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- Enzymatic resolution of new anti-inflammatory drug etodolac
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Optically active etodolac (1) was easily prepared by lipase-catalyzed kinetic resolution. The unnecessary enantiomer as a by-product of the resolution could be racemized and was converted to a repeated substrate for the enzymatic reaction.
- Mizuguchi, Eisaku,Itanami, Makiko,Achiwa, Kazuo
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p. 149 - 152
(2007/10/03)
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