Related Experiment Video
Updated: Jan 31, 2026

13:38
Synthesis and Characterization of an Aspirin-fumarate Prodrug that Inhibits NFκB Activity and Breast Cancer Stem Cells
Published on: January 18, 2017
12.7K
On the pH-Modulated Ru-Based Prodrug Activation Mechanism
Marco Caterino1, Mona Herrmann2, Antonello Merlino1
1Department of Chemical Sciences , University of Naples Federico II , via Cinthia , Naples I-80126 , Italy.
Inorganic Chemistry
|January 8, 2019
Summary
Ruthenium (Ru) prodrug AziRu binds proteins, with release dependent on reduction and reducing agents. Its pH-dependent properties suggest selective cancer cell targeting.
Area of Science:
- Inorganic Chemistry
- Biochemistry
- Materials Science
Background:
- Ruthenium (Ru)-based prodrugs are promising anticancer agents.
- AziRu efficiently binds to proteins, but its release mechanism remains unclear.
- Understanding Ru release is crucial for optimizing drug efficacy.
Purpose of the Study:
- To investigate the reduction-mediated release of AziRu from proteins.
- To elucidate the pH-dependent behavior of AziRu.
- To explore AziRu as a model for Ru-based anticancer drugs.
Main Methods:
- Raman-assisted crystallography of AziRu with hen egg white lysozyme (HEWL) in Ru(II) and Ru(III) states.
- pH-dependent, spectroelectrochemical Surface-Enhanced Raman Scattering (SERS) on AziRu-functionalized gold electrodes.
Main Results:
- Ru reduction was observed, but release was agent-dependent.
- A pKa of 6.0 ± 0.4 was determined for aquated AziRu in the Ru(III) state.
- Acidification shifted the redox potential by >600 mV, indicating selective reduction in acidic cancer environments.
Conclusions:
- Ru reduction is necessary but not sufficient for AziRu release.
- AziRu's pH-dependent properties enable selective targeting of cancer cells.
- Ligand modification can tune pKa and redox potential without altering the core mechanism.
Related Concept Videos
Prodrugs
4.2K
Prodrugs are a class of pharmaceutical compounds that undergo a biotransformation process within the body to be converted into a pharmacologically active drug. Prodrugs are designed to improve the therapeutic properties of the parent drug, such as enhancing bioavailability, increasing stability, or reducing toxicity. The concept of prodrugs revolves around modifying the chemical structure of the original drug to make it more effective or convenient for administration.
Prodrugs help overcome...
Prodrugs help overcome...
4.2K
Acid–Base Equilibria: Activity-Based Definition of pH
1.3K
For an ideal solution, the pH is defined as the negative logarithm of the hydrogen ion concentration. For a non-ideal solution, an accurate measurement of the pH must consider the negative logarithm of the hydrogen ion activity rather than concentration. In such a solution, the pH can be more accurately defined as the negative logarithm of a product of the hydrogen ion concentration and its activity coefficient.
In solutions of very low ionic strength—for example, pure water—the...
In solutions of very low ionic strength—for example, pure water—the...
1.3K
Reaction Mechanisms
30.8K
Chemical reactions often occur in a stepwise fashion, involving two or more distinct reactions taking place in a sequence. A balanced equation indicates the reacting species and the product species, but it reveals no details about how the reaction occurs at the molecular level. The reaction mechanism (or reaction path) provides details regarding the precise, step-by-step process by which a reaction occurs.
For instance, the decomposition of ozone appears to follow a mechanism with two steps:
For instance, the decomposition of ozone appears to follow a mechanism with two steps:
30.8K
tRNA Activation
22.9K
Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the...
22.9K
Mechanical Protein Functions
5.6K
Proteins perform many mechanical functions in a cell. These proteins can be classified into two general categories- proteins that generate mechanical forces and proteins that are subjected to mechanical forces. Proteins providing mechanical support to the structure of the cell, such as keratin, are subjected to mechanical force, whereas proteins involved in cell movement and transport of molecules across cell membranes, such as an ion pump, are examples of generating mechanical force.
5.6K
The Quantum-Mechanical Model of an Atom
57.3K
Shortly after de Broglie published his ideas that the electron in a hydrogen atom could be better thought of as being a circular standing wave instead of a particle moving in quantized circular orbits, Erwin Schrödinger extended de Broglie’s work by deriving what is now known as the Schrödinger equation. When Schrödinger applied his equation to hydrogen-like atoms, he was able to reproduce Bohr’s expression for the energy and, thus, the Rydberg formula governing hydrogen spectra.
57.3K

