Quinine and Quinidine Derivatives as Photosensitizers for Photodynamic Inactivation of Bacterial Pathogens
Year: 2025
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide This study reports the synthesis and characterization of 5-azoniabenzo[ no ]tetraphene derivatives of Cinchona alkaloids with potential applications in antimicrobial photodynamic therapy (aPDT). These compounds exhibit absorption maxima at 430–441 nm, as well as in the UV-A (340–342 nm) and UV–C (270–275 nm) regions, with fluorescence emission peaks ranging from 519 to 534 nm. At nontoxic concentrations of 2 μg mL –1 and upon irradiation with blue light (418 nm), these compounds demonstrated potent bactericidal activity depending on the light dose. Staphylococcus aureus was eradicated after 5 min of irradiation (50 J cm –2 ) with the isomer of 7 R,2’ S configuration ( QN-1 ) as a photosensitizer. Gram-negative bacteria exhibited reduced sensitivity, with Acinetobacter baumannii requiring an energy dose of 150 J cm –2 for effective killing, whereas Proteus mirabilis showed no significant reduction after exposure to 200 J cm –2 . The differences in sensitivity are attributed to the structure of the cell envelopes, which influence the uptake of the photosensitizer: the compounds accumulated intracellularly in Gram-positive bacteria but remained extracellular in Gram-negative rods. It is suggested that the aPDT mechanism involves a combination of oxidative pathways for QN-1 and QD-1 as photosensitizers and a Type II mechanism when QN-2 was applied.
Source: Journal of Natural Products
Institution: Wrocław University of Science and Technology
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Funder: Ministerstwo Edukacji i Nauki
OpenAlex ID: W4413108013