Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

¹H NMR of Conformationally Flexible Molecules: Temporal Resolution00:52

¹H NMR of Conformationally Flexible Molecules: Temporal Resolution

807
At room temperature, the chair conformer of cyclohexane undergoes rapid ring flipping between two equivalent chair conformers at a rate of approximately 105 times per second. These two chair conformers are in equilibrium. The rapid ring flipping results in the interconversion of the axial proton to an equatorial proton and an equatorial to the axial proton. Such interconversions are too rapid and cannot be detected on the NMR timescale. Hence, the NMR spectrometer cannot distinguish between the...
807
2D NMR: Overview of Homonuclear Correlation Techniques01:16

2D NMR: Overview of Homonuclear Correlation Techniques

171
Homonuclear correlation spectroscopy (COSY) is a powerful technique used in Nuclear Magnetic Resonance (NMR) spectroscopy to study the correlations between nuclei of the same type within a molecule. It provides information about scalar couplings between adjacent nuclei, which helps determine connectivity and structural information. There are several COSY variants, each with its unique strengths and experimental parameters.
COSY90 is the standard two-dimensional (2D) COSY experiment that...
171
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR01:15

¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR

1.1K
The axial and equatorial protons in cyclohexane can be distinguished by performing a variable-temperature NMR experiment. In this process, except for one proton, the remaining eleven protons are replaced by deuterium. The deuterium substitution avoids the possible peak splitting caused by the spin-spin coupling between the adjacent protons. The remaining proton flips between the axial and equatorial positions.
1.1K
2D NMR: Overview of Heteronuclear Correlation Techniques01:18

2D NMR: Overview of Heteronuclear Correlation Techniques

157
Heteronuclear correlation spectroscopy is an analytical technique that investigates the coupling between different types of nuclei, often a proton and an X-nucleus, such as carbon-13 or nitrogen-15. This method is commonly used in nuclear magnetic resonance (NMR) spectroscopy to gain insights into complex chemical compounds' structural and compositional aspects. A typical heteronuclear correlation spectrum displays X-nucleus chemical shifts on one axis and a proton spectrum on the other...
157
NMR Spectroscopy of Aromatic Compounds01:14

NMR Spectroscopy of Aromatic Compounds

4.5K
Aromatic compounds can be identified or analyzed using proton NMR and carbon‐13 NMR. Typically, aromatic hydrogens or hydrogens directly bonded to the aromatic rings are strongly deshielded by the aromatic ring current. Therefore, they absorb in the range of 6.5–8.0 ppm in proton NMR spectra. For instance, aromatic hydrogens directly bonded to the benzene ring absorb at 7.3 ppm. However, aromatic hydrogens of larger rings absorb farther upfield or downfield than the ideal range.
4.5K
Two-Dimensional (2D) NMR: Overview01:12

Two-Dimensional (2D) NMR: Overview

619
The 1D NMR spectrum of large and complex molecules like natural products has complicated splitting patterns and overlapping signals, which can be easily interpreted using 2-dimensional (2D) NMR. Unlike 1D NMR, 2D NMR has two frequency axes that provide the coupling information between the nucleus A and nucleus B in a molecule. The process from which 2D spectra are obtained has four steps.
The first step is the preparation period, during which nucleus A is excited with a radiofrequency pulse....
619

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Mechanical performance enhancement of cassava starch and açaí residue films through optimized hydroxypropylation reaction.

International journal of biological macromolecules·2026
Same author

Development and validation of a time domain NMR relaxometric method for rapid screening of soybean oil adulteration in copaiba oil-resin.

Journal of pharmaceutical and biomedical analysis·2026
Same author

Mapping the Technological and Pharmacological Landscape of Casearia sylvestris: An Evidence-Based Prospection for Wound Healing and Pain Management.

Chemistry & biodiversity·2026
Same author

Serum metabolomics identifies metabolic changes in obese cats fed enzymatically hydrolyzed poultry byproduct meal.

Journal of veterinary internal medicine·2026
Same author

Efficiency of Imazapic Degradation: an Assessment of LacMeta Treatments Utilizing Whole Cell.

Current microbiology·2026
Same author

Functional Characterization and Antifungal Activity of Insect-Derived Chitinases Expressed in <i>Pichia pastoris</i>.

Polymers·2026

Related Experiment Video

Updated: Jun 5, 2025

Author Spotlight: Exploring Intrinsically Disordered Protein Dynamics Through NMR Relaxation Experiments
09:25

Author Spotlight: Exploring Intrinsically Disordered Protein Dynamics Through NMR Relaxation Experiments

Published on: November 1, 2024

1.8K

Time domain NMR for polymorphism characterization: Current status and future perspectives.

Luisa Souza Almeida1, Jaqueline Carneiro2, Luiz Alberto Colnago3

  • 1São Carlos Institute of Chemistry, University of São Paulo, Avenida Trabalhador São Carlense, 400, 13566-590 São Carlos, SP, Brazil.

International Journal of Pharmaceutics
|December 5, 2024
PubMed
Summary

Time Domain Nuclear Magnetic Resonance (TD-NMR) offers a convenient and efficient method for assessing polymorphism in Active Pharmaceutical Ingredients (APIs). This technique provides valuable insights into solid-state properties, aiding pharmaceutical development.

Keywords:
Active Pharmaceutical IngredientNMRPolymorphismRelaxometry

More Related Videos

Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
14:55

Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy

Published on: September 17, 2017

15.4K
15N CPMG Relaxation Dispersion for the Investigation of Protein Conformational Dynamics on the &#181;s-ms Timescale
08:09

15N CPMG Relaxation Dispersion for the Investigation of Protein Conformational Dynamics on the µs-ms Timescale

Published on: April 19, 2021

5.1K

Related Experiment Videos

Last Updated: Jun 5, 2025

Author Spotlight: Exploring Intrinsically Disordered Protein Dynamics Through NMR Relaxation Experiments
09:25

Author Spotlight: Exploring Intrinsically Disordered Protein Dynamics Through NMR Relaxation Experiments

Published on: November 1, 2024

1.8K
Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
14:55

Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy

Published on: September 17, 2017

15.4K
15N CPMG Relaxation Dispersion for the Investigation of Protein Conformational Dynamics on the &#181;s-ms Timescale
08:09

15N CPMG Relaxation Dispersion for the Investigation of Protein Conformational Dynamics on the µs-ms Timescale

Published on: April 19, 2021

5.1K

Area of Science:

  • Solid-state chemistry
  • Pharmaceutical sciences
  • Analytical chemistry

Background:

  • Polymorphism, the existence of multiple crystal forms of a compound, significantly impacts physicochemical and pharmacokinetic properties of Active Pharmaceutical Ingredients (APIs).
  • Accurate characterization of API solid-state properties is crucial for drug development and ensuring final product efficacy.
  • Traditional characterization methods include X-Ray Diffraction, Differential Scanning Calorimetry, and various spectroscopic techniques.

Purpose of the Study:

  • To provide an overview of current advancements in Time Domain Nuclear Magnetic Resonance (TD-NMR) for polymorphism assessment in pharmaceutical products.
  • To highlight the growing application and advantages of TD-NMR in evaluating API solid-state characteristics.
  • To compare various TD-NMR applications for API solid-state characterization and suggest future research directions.

Main Methods:

  • Review of recent literature (past five years) focusing on Time Domain Nuclear Magnetic Resonance (TD-NMR) applications for solid-state characterization.
  • Analysis of TD-NMR's utility in evaluating polymorphism in Active Pharmaceutical Ingredients (APIs).
  • Comparison of TD-NMR with conventional high-field NMR devices for industrial applicability.

Main Results:

  • TD-NMR is increasingly reported for evaluating polymorphism in APIs, demonstrating growing interest in this technique.
  • TD-NMR offers advantages over high-field NMR, including smaller equipment size and shorter measurement times, making it suitable for industrial applications.
  • The study compares diverse TD-NMR applications for API solid-state characterization.

Conclusions:

  • TD-NMR is a compelling and industrially convenient technique for assessing polymorphism in pharmaceutical APIs.
  • Further research and application of TD-NMR are encouraged for robust solid-state characterization in drug development.
  • TD-NMR provides a valuable alternative or complementary method to existing techniques for polymorphism analysis.