Toluidine blue O demethylated photoproducts as type II photosensitizers DOI Open Access

Whitney Querini‐Sanguillén,

Jennifer Otero‐González,

Melannie García‐Sánchez

et al.

Photochemistry and Photobiology, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 20, 2025

Abstract Toluidine blue O (TBO) is a type I–type II photosensitizer that has shown good efficacy and selectivity in antimicrobial anticancer photodynamic therapy applications. However, its complex photochemistry with multiple photoproducts hinders application as photosensitizer. We have previously described the mechanism for photooxidative demethylation of TBO which acetonitrile yields two main products: demethylated‐TBO (d‐TBO) double‐demethylated‐TBO (dd‐TBO). In current work, we describe photophysical properties these photoproducts. phosphate buffer, induces an hypsochromic shift absorption fluorescence emission maxima. Fluorescence quantum increase slightly demethylated photoproducts, agreement lengthening lifetimes. Triplet excited states lifetimes presence oxygen decreased upon demethylation. singlet yield increased significantly reaching unity dd‐TBO photoproduct. These results are interpreted terms competing pathways photochemistry. For TBO, pathway deactivation state, while d‐TBO, generation significant. dd‐TBO, pathway. Overall, demonstrate potential candidates

Language: Английский

Toluidine blue O demethylated photoproducts as type II photosensitizers DOI Open Access

Whitney Querini‐Sanguillén,

Jennifer Otero‐González,

Melannie García‐Sánchez

et al.

Photochemistry and Photobiology, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 20, 2025

Abstract Toluidine blue O (TBO) is a type I–type II photosensitizer that has shown good efficacy and selectivity in antimicrobial anticancer photodynamic therapy applications. However, its complex photochemistry with multiple photoproducts hinders application as photosensitizer. We have previously described the mechanism for photooxidative demethylation of TBO which acetonitrile yields two main products: demethylated‐TBO (d‐TBO) double‐demethylated‐TBO (dd‐TBO). In current work, we describe photophysical properties these photoproducts. phosphate buffer, induces an hypsochromic shift absorption fluorescence emission maxima. Fluorescence quantum increase slightly demethylated photoproducts, agreement lengthening lifetimes. Triplet excited states lifetimes presence oxygen decreased upon demethylation. singlet yield increased significantly reaching unity dd‐TBO photoproduct. These results are interpreted terms competing pathways photochemistry. For TBO, pathway deactivation state, while d‐TBO, generation significant. dd‐TBO, pathway. Overall, demonstrate potential candidates

Language: Английский

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