Oxidative Degradation of Pharmaceuticals: The Role of Tetrapyrrole-Based Catalysts

Abstract

Nowadays, society’s widespread consumption of pharmaceutical drugs and the consequent accumulation of such compounds or their metabolites in effluents requires the development of efficient strategies and systems that lead to their effective degradation. This can be done through oxidative processes, in which tetrapyrrolic macrocycles (porphyrins, phthalocyanines) deserve special attention since they are among the most promising degradation catalysts. This paper presents a review of the literature over the past ten years on the major advances made in the development of oxidation processes of pharmaceuticals in aqueous solutions using tetrapyrrole-based catalysts. The review presents a brief discussion of the mechanisms involved in these oxidative processes and is organized by the degradation of families of pharmaceutical compounds, namely antibiotics, analgesics and neurological drugs, among others. For each family, a critical analysis and discussion of the fundamental roles of tetrapyrrolic macrocycles are presented, regarding both photochemical degradative processes and direct oxidative chemical degradation.

Heterogeneous V2O5/TiO2-Mediated Photocatalytic Reduction of Nitro Compounds to the Corresponding Amines under Visible Light

“…The 4-nitrobenzoic acid ( 1f ) can be successfully reduced to an amine product ( 2f ), which is the primary building block of folic acid and used to synthesize benzocaine ( 5g ) and butamben ( 5h ). These drugs are used as anesthetics and chronic pain relievers …”

Degradation of Pesticides Using Semiconducting and Tetrapyrrolic Macrocyclic Photocatalysts—A Concise Review

“…They usually serve as catalysts that, ideally, are not consumed during the photochemical reaction. Among the photosensitizer family, which can either be of inorganic (e.g., semiconductors) or organic origin, the tetrapyrrolic macrocycles are exceptional photosensitizing agents that have been used in a vast array of photonic applications [43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58]. The typical photochemical mechanism of oxidation of any molecule (e.g., pesticides) using photosensitizing catalysts, such as tetrapyrrolic macrocycles, is shown in The adapted Jablonski [59] diagram in Figure 4 illustrates the relevant electronic transitions that promote ROS formation in photocatalysis, causing intramolecular bond ruptures and ultimately leading to the desired mineralization and degradation of the target molecules.…”

Fluorinated Mn(III)/(II)‐Porphyrin with Redox‐Responsive 1H and 19F Relaxation Properties

“…Nevertheless, despite the favorable features of the complexes mentioned above, they may present some unfavorable issues, such as lack of biocompatibility, thermodynamic stability and kinetic inertness and non-ideal half-cell potential. [9,16] Porphyrins are tetrapyrrolic macrocycles, well known for their physico-chemical and biological features that make them appealing in a multitude of applications, such as catalysis, [38][39][40] materials science [42,43] and biomedicine [44][45][46] including MRI. [18,47,48] The capability of the porphyrin ligand to coordinate several metal ions, especially those of manganese, has been extensively studied.…”