Molecular structure and chirality

Brand, David J.

doi:10.1021/ed067p358.2

Cited by 3 publications

(3 citation statements)

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“…Many biologically significant molecules, including amino acids, nucleotides, and saccharides, are chiral in nature. 1,2 Enantiomers, which are chiral isomers with opposite chirality, 3 usually demonstrate differences in their pharmacology, metabolism, and toxicity and have the same chemical composition and very similar physiochemical properties. 4−7 Accordingly, direct discrimination between them is difficult.…”

Section: Introductionmentioning

confidence: 99%

Identification of Single-Molecule Catecholamine Enantiomers Using a Programmable Nanopore

Jia

Wang

et al. 2022

ACS Nano

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Enantiomers, chiral isomers with opposite chirality, typically demonstrate differences in their pharmacological activity, metabolism, and toxicity. However, direct discrimination between enantiomers is challenging due to their similar physiochemical properties. Following the strategy of programmable nanoreactors for stochastic sensing (PNRSS), introduction of phenylboronic acid (PBA) to a Mycobacterium smegmatis porin A (MspA) assists in the identification of the enantiomers of norepinephrine and epinephrine. Using a machine learning algorithm, identification of the enantiomers has been achieved with an accuracy of 98.2%. The enantiomeric excess (ee) of a mixture of enantiomeric catecholamines was measured to determine the enantiomeric purity. This sensing strategy is a faster method for the determination of ee values than liquid chromatography−mass spectrometry and is useful as a quality control in the industrial production of enantiomeric drugs.

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Section: Introductionmentioning

confidence: 99%

Identification of Single-Molecule Catecholamine Enantiomers Using a Programmable Nanopore

Jia

Wang

et al. 2022

ACS Nano

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“…Stereochemistry is frequently a source of confusion when students are first exposed to it, and unfortunately, this feeling may linger even after repeated exposure (Bowen and Bodner, 1991;Bodner, 2003). Visualizing the three-dimensional aspects of molecules and their relationships to other molecules is difficult (Brand, 1987). When dealing with principles that are particularly difficult to visualize or conceptualize, such as stereochemistry, teaching aids and mnemonic devices have been invaluable in the learning process.…”

Section: Introductionmentioning

confidence: 99%

Programmed instruction revisited: a study on teaching stereochemistry

Kurbanoğlu

Taşkesenligil

Sözbilir

2006

Chem. Educ. Res. Pract.

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This study is aimed at comparing the success of programmed instruction with the conventional teaching approach on teaching stereochemistry, and whether gender has any effect on student success. Forty chemistry teacher trainees attending the same class in the Department of Chemistry Education in a large state university in eastern Turkey were the subjects of the study. Of the forty trainees twenty were selected as the experimental group and the other twenty as the control group. The study was implemented in a total of sixteen lecture hours (each 50 min) in four weeks (four lecture hours per week). The subject, stereochemistry in organic chemistry, was taught to the experimental group by the researcher through 'programmed instruction' and the control group was taught by the course lecturer through traditional teaching. The data collection tools were: Stereochemistry Achievement Test (SAT), programmed stages (frames), and the views of the students. An ANCOVA (Analysis of CoVariance) showed that there was a statistically significant difference between programmed instruction and conventional teaching approach on the success level of students' learning in stereochemistry. In addition, it was found that female students were more successful than their male counterparts in the experimental group. The findings suggest that programmed learning could be considered as a better alternative to conventional lecturing in teaching stereochemistry. [Chem. Educ. Res. Pract., 2006, 7 (1), 13-21]

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“…One of the most difficult concepts in introductory undergraduate organic chemistry laboratories is the idea of chirality and its application to understanding stereochemistry. − A laboratory experiment was developed that highlights the overarching topic of chirality using a benchtop chemistry protocol that involves problem-solving and critical thinking. , The experimental content covers a variety of learning styles (visual, audio, reading/writing, and kinesthetic) as well as both a qualitative and a quantitative analysis. An effective experiment topic for discussing chirality and stereochemistry is the determination of absolute configuration of a stereocenter in a chiral molecule.…”

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confidence: 99%

Undergraduate Laboratory Experiment To Determine Absolute Configuration Using Thin-Layer Chromatography

et al. 2014

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A new undergraduate organic chemistry laboratory experiment has been developed to determine the absolute configuration of enantioenriched secondary alcohols with the competing enantioselective conversion (CEC) method. The CEC method uses both enantiomers of a chiral kinetic resolution reagent in parallel reactions to identify the fast-reacting reagent and thus the configuration of the alcohol. Students working in pairs are given one of three enantioenriched secondary alcohols with an unknown absolute configuration. They assign the molecular structure using the corresponding 1H NMR spectrum and determine the absolute configuration via the CEC method. The parallel reactions are run at room temperature for 1 h using small quantities of solvent, substrate, and catalyst. Students use thin-layer chromatography (TLC) to analyze the parallel reactions and determine the fast reaction qualitatively. The free program ImageJ is used with a picture of the TLC plate to carry out a quantitative analysis of reaction conversion. Data collected in the spring 2013 laboratory course (n = 1036) show that 93.6% of students determined the absolute configuration of their unknown correctly with just a qualitative analysis of the TLC plate. This experiment provides a platform for discussions of stereochemistry, mechanism, kinetics, energy diagrams, and transition states.

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Molecular structure and chirality

Cited by 3 publications

References 0 publications

Identification of Single-Molecule Catecholamine Enantiomers Using a Programmable Nanopore

Identification of Single-Molecule Catecholamine Enantiomers Using a Programmable Nanopore

Programmed instruction revisited: a study on teaching stereochemistry

Undergraduate Laboratory Experiment To Determine Absolute Configuration Using Thin-Layer Chromatography

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