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1.
J Am Chem Soc ; 141(16): 6468-6472, 2019 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-30957995

RESUMO

We report an expanded "Texas-sized" molecular box (AzoTxSB) that incorporates photoresponsive azobenzene bridging subunits and anion recognition motifs. The shape of this box can be switched through light induced E ↔ Z photoisomerization of the constituent azobenzenes. This allows various anionic substrates to be bound and released by using different forms of the box. Control can also be achieved using other environmental stimuli, such as pH and anion competition.


Assuntos
Compostos Azo/química , Ânions/química , Compostos Azo/síntese química , Concentração de Íons de Hidrogênio , Estrutura Molecular , Termodinâmica
2.
Free Radic Biol Med ; 134: 133-138, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30605714

RESUMO

UV irradiation is a major driver of DNA damage and ultimately skin cancer. UV exposure leads to persistent radicals that generate ROS over prolonged periods of time. Toward the goal of developing long-lasting antioxidants that can penetrate skin, we have designed a ROS-initiated protective (RIP) reagent that, upon reaction with ROS (antioxidant activity), self-cyclizes and then releases the natural product apocynin. Apocynin is a known antioxidant and inhibitor of NOX oxidase enzymes. A key phenol on the compound 1 controls ROS-initiated cyclization and makes 1 responsive to ROS with a EC50 comparable to common antioxidants in an ABTS assay. In an in vitro DNA nicking assay, the RIP reagent prevented DNA strand breaks. In cell-based assays, the reagent was not cytotoxic, apocynin was released only in cells treated with UVR, reduced UVR-induced cell death, and lowered DNA lesion formation. Finally, topical treatment of human skin explants with the RIP reagent reduced UV-induced DNA damage as monitored by quantification of cyclobutane dimer formation and DNA repair signaling via TP53. The reagent was more effective than administration of a catalase antioxidant on skin explants. This chemistry platform will expand the types of ROS-activated motifs and enable inhibitor release for potential use as a long-acting sunscreen.


Assuntos
Antioxidantes/administração & dosagem , Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Queratinócitos/efeitos dos fármacos , Estresse Oxidativo , Pele/efeitos dos fármacos , Raios Ultravioleta/efeitos adversos , Acetofenonas/administração & dosagem , Administração Tópica , Células Cultivadas , Ciclização , Dano ao DNA/efeitos da radiação , Reparo do DNA/efeitos da radiação , Humanos , Queratinócitos/efeitos da radiação , Oxirredução , Espécies Reativas de Oxigênio , Pele/efeitos da radiação
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