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

Carbon-13 (¹³C) NMR: Overview01:10

Carbon-13 (¹³C) NMR: Overview

Carbon-13 is a naturally occurring NMR-active isotope of carbon with a low natural abundance of 1.1%. In contrast, carbon-12 is the most abundant isotope of carbon with zero nuclear spin. Therefore, it is NMR inactive. The gyromagnetic ratio of carbon-13 is smaller than that of protons. As a result, carbon-13 resonance is about 6000 times weaker than proton resonance. For a given magnetic field strength, the resonance frequency of carbon-13 is about one-fourth of the resonance frequency for...
¹³C NMR: ¹H–¹³C Decoupling01:04

¹³C NMR: ¹H–¹³C Decoupling

The probability of having two carbon-13 atoms next to each other is negligible because of the low natural abundance of carbon-13. Consequently, peak splitting due to carbon-carbon spin-spin coupling is not observed in spectra. However, protons up to three sigma bonds away split the carbon signal according to the n+1 rule, resulting in complicated spectra.
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)01:20

¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)

When proton-coupled carbon-13 spectra are simplified by a broadband proton decoupling technique, structural information about the coupled protons is lost. Distortionless enhancement by polarization transfer (DEPT) is a technique that provides information on the number of hydrogens attached to each carbon in a molecule. While the DEPT experiment utilizes complex pulse sequences, the pulse delay and flip angle are specifically manipulated. The resulting signals have different phases depending on...
NMR Spectroscopy of Aromatic Compounds01:14

NMR Spectroscopy of Aromatic Compounds

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. Consider...
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR01:15

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

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.
2D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)01:19

2D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)

Heteronuclear single-quantum correlation spectroscopy (HSQC) is a 2D NMR technique that reveals one-bond correlations between hydrogen and a heteronucleus. The HSQC experiment is similar to the heteronuclear correlation experiment (HETCOR) but is more sensitive. In the HSQC spectrum, the proton chemical shift is plotted on the horizontal F2 axis, while the 13C chemical shift is plotted on the vertical F1 axis. The corresponding proton and 13C spectra are also shown. The HSQC contour plot does...

You might also read

Related Articles

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

Sort by
Same author

Unique Organic-Inorganic Hybrid Copper(I) Phosphate with Ultralow Ractopamine Detection Limit and In Situ Sensing Ability.

Inorganic chemistry·2025
Same author

Investigation of pH-dependent <sup>1</sup>H NMR urine metabolite profiles for diagnosis of obesity-related disordering.

International journal of obesity (2005)·2024
Same author

Molecular Mechanism of pH-Induced Protrusion Configuration Switching in Piscine Betanodavirus Implies a Novel Antiviral Strategy.

ACS infectious diseases·2024
Same author

Lithium-Ion Dynamic and Storage of Atomically Precise Halogenated Nanographene Assemblies via Bottom-Up Chemical Synthesis.

ACS applied materials & interfaces·2024
Same author

Constructing B─N─P Bonds in Ultrathin Holey g-C<sub>3</sub>N<sub>4</sub> for Regulating the Local Chemical Environment in Photocatalytic CO<sub>2</sub> Reduction to CO.

Small (Weinheim an der Bergstrasse, Germany)·2024
Same author

A Facile NMR Method for Pre-MRI Evaluation of Trigger-Responsive T<sub>1</sub> Contrast Enhancement.

Small methods·2024

Related Experiment Video

Updated: Jul 6, 2026

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

A 13C solid-state NMR analysis of steroid compounds.

Jen-Hsien Yang1, Yu Ho, Der-Lii M Tzou

  • 1Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC.

Magnetic Resonance in Chemistry : MRC
|April 15, 2008
PubMed
Summary

Solid-state NMR reveals distinct (13)C patterns in steroid compounds, indicating polymorphism. This technique reliably differentiates crystal forms by analyzing local differences in ring conformations.

More Related Videos

Preparation of Fungal and Plant Materials for Structural Elucidation Using Dynamic Nuclear Polarization Solid-State NMR
09:37

Preparation of Fungal and Plant Materials for Structural Elucidation Using Dynamic Nuclear Polarization Solid-State NMR

Published on: February 12, 2019

NMR Spectroscopy as a Robust Tool for the Rapid Evaluation of the Lipid Profile of Fish Oil Supplements
08:54

NMR Spectroscopy as a Robust Tool for the Rapid Evaluation of the Lipid Profile of Fish Oil Supplements

Published on: May 1, 2017

Related Experiment Videos

Last Updated: Jul 6, 2026

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

Preparation of Fungal and Plant Materials for Structural Elucidation Using Dynamic Nuclear Polarization Solid-State NMR
09:37

Preparation of Fungal and Plant Materials for Structural Elucidation Using Dynamic Nuclear Polarization Solid-State NMR

Published on: February 12, 2019

NMR Spectroscopy as a Robust Tool for the Rapid Evaluation of the Lipid Profile of Fish Oil Supplements
08:54

NMR Spectroscopy as a Robust Tool for the Rapid Evaluation of the Lipid Profile of Fish Oil Supplements

Published on: May 1, 2017

Area of Science:

  • Solid-state chemistry
  • Spectroscopy
  • Organic chemistry

Background:

  • Steroid compounds exhibit polymorphism, affecting their physical and chemical properties.
  • Characterizing different crystal forms is crucial for understanding steroid behavior.

Purpose of the Study:

  • To utilize (13)C Cross-Polarization Magic Angle Spinning (CP/MAS) solid-state Nuclear Magnetic Resonance (NMR) spectroscopy for analyzing polymorphism in six steroid compounds.
  • To assign (13)C resonances and characterize local ring conformations associated with different crystal forms.

Main Methods:

  • (13)C CP/MAS solid-state NMR spectroscopy was performed on testosterone, hydrocortisone, trans-dehydroandrosterone, prednisolone, prednisone, and estradiol.
  • Solution NMR data was used for resonance assignment.
  • Chemical shift tensor elements were extracted for detailed conformational analysis.

Main Results:

  • Distinct (13)C NMR spectral patterns (singlets vs. doublets) were observed, correlating with steroid structures and polymorphism.
  • Testosterone showed doublets for all residues, while prednisolone, prednisone, and estradiol exhibited singlets.
  • Hydrocortisone and trans-dehydroandrosterone displayed both singlet and doublet patterns.
  • Reversible phase transformation between delta- and alpha-crystal forms in testosterone was linked to singlet and doublet (13)C patterns, respectively.
  • Local differences in ring conformations, with splittings of 0.2-1.5 ppm, were attributed to the observed doublet signals.

Conclusions:

  • (13)C CP/MAS solid-state NMR spectroscopy is a reliable and sensitive method for characterizing steroid polymorphism.
  • The technique effectively distinguishes between different crystal forms by probing local conformational variations.
  • Observed spectral patterns provide insights into the hydration/dehydration processes and phase transformations in steroids.