Related Experiment Video
Updated: Aug 10, 2026

07:44
Synthesis of Wavelength-shifting DNA Hybridization Probes by Using Photostable Cyanine Dyes
Published on: July 6, 2016
Summary
Researchers developed a new method for synthesizing spin-labeled steroids like cortisol and testosterone. This technique utilizes N,N'-cyclohexylcarbodiimide (DCC) for efficient esterification, creating valuable tools for scientific research.
Area of Science:
- Organic Chemistry
- Biochemistry
- Medicinal Chemistry
Background:
- Steroids are crucial biomolecules with diverse physiological roles.
- Spin-labeled steroids are valuable probes for studying steroid-protein interactions and biological systems.
- Existing synthesis methods may have limitations in yield or specificity.
Purpose of the Study:
- To report an improved synthesis of spin-labeled cortisol, cortisone, and testosterone.
- To investigate the regioselectivity of the spin-labeling reaction.
- To describe a method for oxidizing the cortisol spin label to the cortisone spin label.
Main Methods:
- Synthesis of spin-labeled steroids using N,N"-cyclohexylcarbodiimide (DCC).
- Esterification reactions targeting the hydroxyl groups of steroid precursors.
- Oxidation of cortisol spin label to cortisone spin label using chromium trioxide-pyridine complex.
Main Results:
- Successful synthesis of spin-labeled cortisol, cortisone, and testosterone.
- Demonstration that esterification occurs preferentially at the C(21) and C(17) hydroxyl groups.
- Achieved high yield and mild conditions for the oxidation of cortisol spin label to cortisone spin label.
Conclusions:
- The DCC-mediated esterification provides an efficient route to spin-labeled steroids.
- The regioselectivity observed allows for targeted modification of steroid structures.
- The developed methods offer valuable tools for biochemical and biophysical studies of steroids.
Related Concept Videos
Stereoisomerism
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
Stereoisomerism of Cyclic Compounds
In this lesson, we delve into the role of ring conformation and its stability, which determines the spatial arrangement and, consequently, the molecular symmetry and stereoisomerism of cyclic compounds. 1,2-Dimethylcyclohexane is used as a case study to evaluate the possible number of stereoisomers. Here, given the multiple (n = 2) chiral centers, there are 2n = 4 possible configurations that lack a plane of symmetry, as the ring skeleton exists in a non-planar chair conformation. In addition,...
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...
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...
Synthesis of α-Substituted Carbonyl Compounds: The Stork Enamine Reaction
α-Substituted ketones or aldehydes can be synthesized from enamines by the Stork enamine reaction, named after its pioneer Gilbert Stork. Enamines are useful synthetic intermediates where the lone pair on nitrogen is in conjugation with the C=C bond. They resemble enolate ions, as the resonance forms of both species have a nucleophilic α carbon.
Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
¹H NMR: Pople Notation
The Pople nomenclature system classifies spin systems based on the difference between their chemical shifts. Coupled spins are denoted by capital letters with subscripts indicating the number of equivalent nuclei. When the coupled nuclei have well-separated chemical shifts, they are assigned letters that are far apart in the alphabet, such as A and X. When the difference in chemical shifts is small, coupled nuclei are named using adjacent letters of the alphabet (AB, MN, or XY).
A proton...
A proton...

![Solid-phase Synthesis of [4.4] Spirocyclic Oximes](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F58508.jpg&w=3840&q=50)