Stable Dioxetane Precursors as Selective Trap-and-Trigger Chemiluminescent Probes for Singlet Oxygen

Grossart

Environmental Microbiology

2010

Photolysis of dissolved organic matter (DOM) leads to contrasting effects on bacterioplankton dynamics, i.e. stimulation and inhibition of bacterial activity. In particular, the role of short-lived reactive oxygen species (ROS), e.g. singlet oxygen (¹O₂), in altering microbial activity and species composition has scarcely been investigated. Therefore, we have artificially increased the natural rate of ¹O₂ formation in short-term (∼4 h) in situ and long-term (72 h) laboratory incubations of surface water samples from a humic acid-rich lake. Denaturing gradient gel electrophoresis (DGGE) patterns revealed significant changes in occurrence of abundant bacterioplankton phylotypes upon ¹O₂ exposure. Cluster analysis of DGGE patterns showed that a moderate increase in ¹O₂ exposure leads to similar changes in different years indicating the establishment of bacterial communities adapted to ¹O₂ exposure. Bacterioplankton phylotypes favoured under these conditions belonged to Betaproteobacteria of the beta II cluster (e.g. Polynucleobacter necessarius) and the beta I cluster related to Limnohabitans (R-BT subcluster) as well as Alphaproteobacteria affiliated to Novosphingobium acidiphilum. In contrast, Actinobacteria of the freshwater acI-B cluster were sensitive even against moderate ¹O₂ exposure. We conclude that ¹O₂ exposure due to DOM photolysis represents an important natural selective factor affecting bacterial species dynamics in aquatic ecosystems in many ways.

Section: Discussionmentioning

confidence: 99%

Singlet oxygen, a neglected but important environmental factor: short‐term and long‐term effects on bacterioplankton composition in a humic lake

Grossart

Environmental Microbiology

2010

“…The surface-bound dioxetane did not absorb the 669-nm diode laser light and did not contribute to its scission since UV light is required. 38 …”

Section: Methodsmentioning

confidence: 99%

Autocatalytic-Assisted Photorelease of a Sensitizer Drug Bound to a Silica Support

et al. 2013

The photorelease of a sensitizer from a fluorinated silica surface occurs by a reaction of singlet oxygen with the vinyl ether bond linking with scission of a dioxetane intermediate. Irradiation of the released sensitizer generates singlet oxygen, which accelerates the release of more sensitizer via an autocatalytic reaction. Sigmoidal behavior of sensitizer release in n-butanol and n-octanol occurs at the optimal temperature of 20 °C. The photorelease efficiency was reduced at low temperatures, where the sensitizer was retained on the surface due to a long-lived dioxetane with inefficient scission; and also reduced at high temperatures, due to a slower reaction of 1O2 with the vinyl ether bond. Immediate acceleration is a result of released sensitizer being used as a dopant to eliminate the induction step further implicating an autocatalytic mechanism. However, the sigmoidal sensitizer release was not correlated to solvent viscosity, heat or light from the dioxetane decomposition, or to minor O2 solubility enhancements caused by the fluorinated silica. The mechanistic information collected here can be used to help control the pace of drug release; however, it remains to be seen whether an autocatalytic-based drug delivery system has an advantage to those with non-sigmoidal kinetics.

“…[10] Several years ago,M cNeill and co-workers reported a" trap-and-trigger" chemiluminescent probe for 1 O 2 . [11] They used the enol-ether precursor of Schaapsd ioxetane [12] to trap the 1 O 2 at the first step.Inasecond step,the dioxetane chemiluminescence was triggered by the addition of fluoride. In this system, chemiluminescence measurements were limited to organic solution owing to the quenching of the emitting species by water.…”

mentioning

confidence: 99%

A Highly Efficient Chemiluminescence Probe for the Detection of Singlet Oxygen in Living Cells

et al. 2017

Singlet oxygen is among the reactive oxygen species (ROS) with the shortest life-times in aqueous media because of its extremely high reactivity. Therefore, designing sensors for detection of O is perhaps one of the most challenging tasks in the field of molecular probes. Herein, we report a highly selective and sensitive chemiluminescence probe (SOCL-CPP) for the detection of O in living cells. The probe reacts with O to form a dioxetane that spontaneously decomposes under physiological conditions through a chemiexcitation pathway to emit green light with extraordinary intensity. SOCL-CPP demonstrated promising ability to detect and image intracellular O produced by a photosensitizer in HeLa cells during photodynamic therapy (PDT) mode of action. Our findings make SOCL-CPP the most effective known chemiluminescence probe for the detection of O . We anticipate that our chemiluminescence probe for O imaging would be useful in PDT-related applications and for monitoring O endogenously generated by cells in response to different stimuli.