Marioni Juliana, Bresolí-Obach Roger, Agut Montserrat, Comini Laura R, Cabrera José L, Paraje María G, Nonell Santi, Núñez Montoya Susana C
IMBIV, CONICET and Departamento de Ciencias Farmacéuticas, Facultad de Ciencias Químicas, Universidad Nacional Córdoba, Córdoba, Argentina.
Institut Químic de Sarrià, Universitat Ramon Llull, Barcelona, Spain.
PLoS One. 2017 Jul 19;12(7):e0181517. doi: 10.1371/journal.pone.0181517. eCollection 2017.
The photoprocesses involved in the photo-induced Candida tropicalis biofilm reduction by two natural anthraquinones (AQs), rubiadin (1) and rubiadin-1-methyl ether (2), were examined. Production of singlet oxygen (1O2) and of superoxide radical anion (O2•-) was studied. Although it was not possible to detect the triplet state absorption of any AQs in biofilms, observation of 1O2 phosphorescence incubated with deuterated Phosphate Buffer Solution, indicated that this species is actually formed in biofilms. 2 was accumulated in the biofilm to a greater extent than 1 and produced measurable amounts of O2•- after 3h incubation in biofilms. The effect of reactive oxygen species scavengers on the photo-induced biofilm reduction showed that Tiron (a specific O2•- scavenger) is most effective than sodium azide (a specific 1O2 quencher). This suggests that O2•- formed by electron transfer quenching of the AQs excited states, is the main photosensitizing mechanism involved in the photo-induced antibiofilm activity, whereas 1O2 participation seems of lesser importance.
研究了两种天然蒽醌（AQs），即茜草素（1）和茜草素-1-甲醚（2）光诱导热带假丝酵母生物膜减少过程中的光化学过程。研究了单线态氧（1O2）和超氧阴离子自由基（O2•-）的产生。尽管无法检测到生物膜中任何AQs的三线态吸收，但观察到与氘代磷酸盐缓冲溶液孵育的1O2磷光，表明该物质实际上在生物膜中形成。2在生物膜中的积累程度比1更大，并且在生物膜中孵育3小时后产生了可测量量的O2•-。活性氧清除剂对光诱导生物膜减少的影响表明，钛铁试剂（一种特定的O2•-清除剂）比叠氮化钠（一种特定的1O2猝灭剂）更有效。这表明由AQs激发态的电子转移猝灭形成的O2•-是光诱导抗生物膜活性的主要光敏机制，而1O2的参与似乎不太重要。
