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

2D NMR: Overview of Homonuclear Correlation Techniques01:16

2D NMR: Overview of Homonuclear Correlation Techniques

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...
2D NMR: Overview of Heteronuclear Correlation Techniques01:18

2D NMR: Overview of Heteronuclear Correlation Techniques

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 axis.
Two-Dimensional (2D) NMR: Overview01:12

Two-Dimensional (2D) NMR: Overview

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.
¹H NMR: Interpreting Distorted and Overlapping Signals01:02

¹H NMR: Interpreting Distorted and Overlapping Signals

Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or...
NMR Spectrometers: Overview01:20

NMR Spectrometers: Overview

NMR spectrometers consist of a strong magnet, a radiofrequency transmitter, and a detector attached to a computer console for recording spectra of samples containing NMR-active nuclei. In first-generation NMR instruments called continuous-wave spectrometers, the resonance frequencies of the nuclei are determined by frequency-sweep or field-sweep methods. The magnetic field strength is fixed and the rf signal is swept in the former, while the radiofrequency signal is fixed and the magnetic field...
¹H NMR: Long-Range Coupling01:27

¹H NMR: Long-Range Coupling

The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene π orbitals.

You might also read

Related Articles

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

Sort by
Same author

PFAS free chemically amplified resists enabled by low activation energy hydrocarbon cage monomers.

Chemical science·2026
Same author

Comparison of slow-paced breathing interventions with and without an inhalation-hold on physiological outcomes: A randomized cross-over pilot study.

International journal of psychophysiology : official journal of the International Organization of Psychophysiology·2026
Same author

Crystallization-regulated li deposition behavior on Fe<sub>78</sub>Si<sub>13</sub>B<sub>9</sub>amorphous-alloy current collectors.

Nanotechnology·2026
Same author

CALB2 Expression Is Associated with Tumor Progression and Prognosis in Colorectal Adenocarcinoma.

Genes·2026
Same author

Structural evolution of quinine derivatives for enhanced antifungal potency: key modifications and quantitative structure-activity relationship (QSAR) analysis.

Pest management science·2026
Same author

Gastrointestinal symptoms in Parkinson's disease treated in a controlled trial using traditional Chinese medicine (Jia-Wei-Ji-Chuan-Jian decoction) with network pharmacology analysis of active agents and mechanism of action.

International journal of clinical pharmacology and therapeutics·2026

Related Experiment Video

Updated: May 30, 2026

NMR 15N Relaxation Experiments for the Investigation of Picosecond to Nanoseconds Structural Dynamics of Proteins
09:25

NMR 15N Relaxation Experiments for the Investigation of Picosecond to Nanoseconds Structural Dynamics of Proteins

Published on: November 1, 2024

Multi-dimensional NMR without coherence transfer: minimizing losses in large systems.

Yizhou Liu1, James H Prestegard

  • 1Complex Carbohydrate Research Center, The University of Georgia, Athens, GA 30602, USA.

Journal of Magnetic Resonance (San Diego, Calif. : 1997)
|August 13, 2011
PubMed
Summary

This study introduces MD-DIRECT, a novel multi-dimensional NMR method that enhances sensitivity by avoiding coherence transfer steps. This technique improves signal detection for large biomolecules, overcoming limitations of traditional NMR experiments.

More Related Videos

Identification and Quantification of Deranged Metabolites in Critically Ill Patients Using NMR-Based Metabolomics
11:02

Identification and Quantification of Deranged Metabolites in Critically Ill Patients Using NMR-Based Metabolomics

Published on: November 29, 2024

Related Experiment Videos

Last Updated: May 30, 2026

NMR 15N Relaxation Experiments for the Investigation of Picosecond to Nanoseconds Structural Dynamics of Proteins
09:25

NMR 15N Relaxation Experiments for the Investigation of Picosecond to Nanoseconds Structural Dynamics of Proteins

Published on: November 1, 2024

Identification and Quantification of Deranged Metabolites in Critically Ill Patients Using NMR-Based Metabolomics
11:02

Identification and Quantification of Deranged Metabolites in Critically Ill Patients Using NMR-Based Metabolomics

Published on: November 29, 2024

Area of Science:

  • Biomolecular Nuclear Magnetic Resonance (NMR) Spectroscopy
  • Structural Biology
  • Biophysics

Background:

  • Traditional multi-dimensional solution NMR relies on scalar coupling-based coherence transfer, which suffers from sensitivity loss due to spin relaxation.
  • This signal degradation is particularly pronounced in large biomolecules (e.g., >100 kDa), limiting NMR's applicability.
  • Existing methods struggle to maintain sensitivity for increasingly large protein systems.

Purpose of the Study:

  • To develop a novel multi-dimensional NMR approach that circumvents coherence transfer steps to improve sensitivity.
  • To introduce and validate a technique called MD-DIRECT for enhanced signal detection in biomolecular NMR.
  • To demonstrate the practical application of MD-DIRECT for analyzing large protein structures.

Main Methods:

  • Developed a multi-dimensional NMR spectroscopy scheme utilizing direct frequency encoding of a second dimension.
  • Employed multi-frequency decoupling during acquisition, a technique termed MD-DIRECT.
  • Applied the MD-DIRECT method to (15)N-labeled alanine residues in a 21 kDa ADP-ribosylation factor (ARF) protein.

Main Results:

  • MD-DIRECT significantly improves sensitivity in (15)N-(1)H correlation spectra compared to conventional methods.
  • Demonstrated substantial sensitivity gains on a 21 kDa ARF protein, with performance mimicking larger proteins at higher temperatures.
  • The technique effectively mitigates signal loss associated with spin relaxation during transfer periods.

Conclusions:

  • MD-DIRECT offers a promising alternative to traditional NMR experiments for studying large biomolecules.
  • This method enhances sensitivity, enabling more effective structural analysis of challenging biological systems.
  • The MD-DIRECT technique represents a significant advancement in multi-dimensional NMR spectroscopy for structural biology.