NIR-emissive iridium(iii) corrole complexes as efficient singlet oxygen sensitizers

2015 ◽  
Vol 44 (40) ◽  
pp. 17767-17773 ◽  
Author(s):  
Woormileela Sinha ◽  
Luca Ravotto ◽  
Paola Ceroni ◽  
Sanjib Kar
Keyword(s):  
Ambient Temperature ◽  
Singlet Oxygen ◽  
First Time

The observed phosphorescence of the studied Ir(iii)corroles at ambient temperature appears at much longer wavelengths than the previously reported Ir(iii) porphyrin/corrole derivatives. Efficiencies of these compounds in the generation of singlet oxygen are also studied for the first time.

UV-Vis Spectrophotometrical and Analytical Methodology for the Determination of Singlet Oxygen in New Antibacterials Drugs

2007 ◽  
Vol 2 ◽  
pp. 117739010700200 ◽  
Author(s):  
Tamara Zoltan ◽  
Franklin Vargas ◽  
Carla Izzo
Keyword(s):  
Reactive Oxygen Species ◽  
Singlet Oxygen ◽  
Nalidixic Acid ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Inexpensive Method ◽  
Analytical Methodology ◽  
First Time

We have determined and quantified spectrophotometrically the capacity of producing reactive oxygen species (ROS) as 1O2 during the photolysis with UV-A light of 5 new synthesized naphthyl ester derivates of well-known quinolone antibacterials (nalidixic acid (1), cinoxacin (2), norfloxacin (3), ciprofloxacin (4) and enoxacin (5)). The ability of the naphthyl ester derivatives (6-10) to generate singlet oxygen were detecting and for the first time quantified by the histidine assay, a sensitive, fast and inexpensive method. The following tendency of generation of singlet oxygen was observed: compounds 7 >10 > 6 > 8 > 9 >> parent drugs 1-5.

scholarly journals Singlet Oxygen Quenching by Phenylamides and their Parent Compounds

2007 ◽  
Vol 62 (11-12) ◽  
pp. 833-838 ◽  
Author(s):  
Violeta B. Velikova ◽  
Aglika M. Edreva ◽  
Tsonko D. Tsonev ◽  
Hamlyn G. Jones
Keyword(s):  
Singlet Oxygen ◽  
Hydroxycinnamic Acids ◽  
Oxygen Quenching ◽  
Amino Groups ◽  
Plant Metabolites ◽  
Antioxidant Defence ◽  
Enzymatic Antioxidant ◽  
Singlet Oxygen Quenching ◽  
First Time ◽  
Photosynthetic Centers

This paper demonstrates for the first time that plant metabolites of the phenylamide type, conjugates of putrescine with hydroxycinnamic acids (p-coumaric, caffeic and ferulic), possess 1O2 quenching properties. Data were obtained confirming that their acidic parent compounds were also able to quench 1O2, as did polyamines (putrescine, spermidine and spermine), and that this ability depends on the number of amino groups. Potentiation of the 1O2 quenching ability of the conjugates relative to both parent components was established. The importance of polyamines and phenylamides in the plant non-enzymatic antioxidant defence at sites of intensive 1O2 generation, such as the photosynthetic centers, was suggested.

Ambient Temperature as a Strong Zeitgeber of Circadian Rhythms in Response to Temperature Sensitivity and Poor Heat Dissipation Abilities in Subterranean African Mole-Rats

2021 ◽  
pp. 074873042110342
Author(s):  
Daniel W. Hart ◽  
Barry van Jaarsveld ◽  
Kiara G. Lasch ◽  
Kerryn L. Grenfell ◽  
Maria K. Oosthuizen ◽  
...  
Keyword(s):  
Circadian Rhythms ◽  
Ambient Temperature ◽  
Heat Dissipation ◽  
Direct Consequence ◽  
Ecological Constraints ◽  
Photic Entrainment ◽  
Mole Rat ◽  
Intimate Link ◽  
Response To Temperature ◽  
First Time

Mammals have evolved circadian rhythms in internal biological processes and behaviors, such as locomotor activity (LA), to synchronize to the environmental conditions they experience. Photic entrainment of LA has been well established; however, non-photic entrainment, such as ambient temperature ( Ta), has received much less attention. To address this dearth of knowledge, we exposed two subterranean endothermic-homeothermic African mole-rat species, the solitary Cape mole-rat ( Georychus capensis [GC]) and social Mahali mole-rat ( Cryptomys hottentotus mahali [CHM]), to varying Ta cycles in the absence of light. We showed that the LA rhythms of these two species entrain to Ta cycles and that the majority of LA occurred during the coolest 12-h period. LA confined to the coolest Ta periods may be the direct consequence of the poor heat dissipation abilities of African mole-rats brought about by physiological and ecological constraints. Recently, it has been hypothesized that Ta is only a strong zeitgeber for circadian rhythms in species whose thermoregulatory abilities are sensitive to changes in Ta (i.e., heterotherms and ectotherms), which previously has excluded endothermic-homeothermic mammals. However, this study demonstrates that Ta is a strong zeitgeber or entrainer for circadian rhythms of LA in subterranean endothermic-homeothermic mammals as a consequence of their sensitivity to changes in Ta brought about by their poor heat dissipation abilities. This study reinforces the intimate link between circadian rhythms and thermoregulation and conclusively, for the first time, provides evidence that Ta is a strong zeitgeber for endothermic-homeothermic mammals.

Directly decorated CeY zeolite for O2-selective adsorption in O2/N2 separation at ambient temperature

2021 ◽  
Author(s):  
Hanbang Liu ◽  
Danhua Yuan ◽  
Liping Yang ◽  
Jiacheng Xing ◽  
Shu Zeng ◽  
...  
Keyword(s):  
Ambient Temperature ◽  
Selective Adsorption ◽  
Air Separation ◽  
Adsorption Selectivity ◽  
First Time

The traditional zeolites used in air separation are generally N2-selective adsorbents. It was found for the first time that the O2/N2 adsorption selectivity can be reversed by directly decorating the...

scholarly journals High-Efficiency Catalysis of Peroxymonosulfate by MgO for the Degradation of Organic Pollutants

Minerals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 2 ◽  
Author(s):  
Qian Peng ◽  
Xuekun Tang ◽  
Kun Liu ◽  
Xianping Luo ◽  
Dongsheng He ◽  
...  
Keyword(s):  
Singlet Oxygen ◽  
Organic Pollutants ◽  
High Efficiency ◽  
The Novel ◽  
Ph Values ◽  
Interesting Insight ◽  
Wide Range ◽  
First Time ◽  
Insight Into ◽  
Single Factor Experiment

In the study, magnesium oxide (MgO) was used to catalyze peroxymonosulfate (PMS) for the degradation of organic pollutants for the first time. According to the single-factor experiment results, it was determined that MgO could efficiently catalyze PMS to degrade organic matters in a wide range of pH values. Based on radical quenching experiments and electron spinning resonance spectra, singlet oxygen was identified to be the crucial reactive species. Importantly, the oxygen vacancy on the surface of MgO was determined as the key active site, which accelerated the decomposition of PMS to produce singlet oxygen. This study provides an interesting insight into the novel and ignored catalyst of MgO for the highly efficient activation of PMS, which will greatly benefit the Fenton-like catalytic degradation of organic wastewater.

scholarly journals Integrated Band Intensities of Ethylene (C212H4) by Fourier Transform Infrared Spectroscopy

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
G. B. Lebron ◽  
T. L. Tan
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Ambient Temperature ◽  
Ftir Spectroscopy ◽  
Fourier Transform Infrared ◽  
Vapor Pressures ◽  
Infrared Band ◽  
Combination Bands ◽  
First Time ◽  
Absorbance Spectra

The integrated band intensities of ethylene (12C2H4) in the 640–3260 cm−1 region were determined by Fourier transform infrared (FTIR) spectroscopy. The infrared absorbance spectra of the ν7 and ν10, ν12, ν7+ν8, ν6+ν10, v11, and ν9 and ν2+ν12 bands of ethylene recorded at a resolution of 0.5 cm−1 were measured at an ambient temperature of 296 K at various vapor pressures ranging from 3×10−5 to 1×10−3 atm to obtain respective Beer-Lambert's law plots. The measured integrated band intensities in cm−1/cm atm were S(ν9andν2+ν12)=112.20±0.24, S(ν11)=55.35±0.14, S(ν12)=41.22±0.30, and S(ν7andν10)=328.66±16.55. In addition, the measured infrared band intensities of the ν7+ν8 and ν6+ν10 combination bands of ethylene are reported for the first time: S(ν7+ν8)=21.701±0.028 cm−1/cm atm and S(ν6+ν10)=2.568±0.025 cm−1/cm atm.

Identification and composition of conformational isomers and their cations in crotonaldehyde by VUV-MATI spectroscopy

2018 ◽  
Vol 20 (42) ◽  
pp. 27162-27168 ◽  
Author(s):  
Sung Man Park ◽  
Hong Lae Kim ◽  
Chan Ho Kwon
Keyword(s):  
Ambient Temperature ◽  
Conformational Isomers ◽  
Mati Spectroscopy ◽  
First Time

Composition of the crotonaldehyde sample at ambient temperature was determined as 93.0%, 3.4%, 3.4%, and 0.2% for the tt-/tc-/ct-/cc-conformers, respectively, for the first time.

Non-thermal polyimidization reaction using base–ionic liquid medium as a dual catalyst–solvent

RSC Advances ◽  
2016 ◽  
Vol 6 (99) ◽  
pp. 96914-96917 ◽  
Author(s):  
Ming Chen ◽  
Shuanglong Wang
Keyword(s):  
Ionic Liquid ◽  
Ambient Temperature ◽  
Liquid Medium ◽  
One Step ◽  
First Time ◽  
Ionic Liquid Medium

A one-step synthesis of PMDA–ODA polyimide at ambient temperature was reported for the first time, in which a polyimidization reaction was rapidly accomplished in 99% yield in an imidazolium-based ionic liquid containing a non-nucleophilic base.

scholarly journals Temperature dependence of singlet oxygen generation by different photosensitizers

2019 ◽  
Vol 220 ◽  
pp. 01012
Author(s):  
Aleksander Starukhin ◽  
Aleksander Gorski ◽  
Jacek Dobkowski
Keyword(s):  
Quantum Yield ◽  
Ambient Temperature ◽  
Singlet Oxygen ◽  
Temperature Dependence ◽  
Molecular Oxygen ◽  
Oxygen Generation ◽  
Singlet Oxygen Generation ◽  
Temperature Dependences

The temperature dependences of the lifetimes and the efficiency of singlet oxygen generation for a set of compounds (porphyrins, metalloporphyrins, porphycene, terrylene etc.) has been measured and characterized. Based on the character of the temperature dependence of singlet oxygen generation for metalloporphyrins and porphycene it was assumed a possibility of creation a complex between organic moieties and molecular oxygen. Singlet oxygen generation of terrylene with the quantum yield of 22% was recorded in toluene at ambient temperature.

scholarly journals Mechanism of Resveratrol Dimers Isolated from Grape Inhibiting 1O2 Induced DNA Damage by UHPLC-QTOF-MS2 and UHPLC-QQQ-MS2 Analyses

Biomedicines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 271
Author(s):  
Qingjun Kong ◽  
Qingzhi Zeng ◽  
Jia Yu ◽  
Hongxi Xiao ◽  
Jun Lu ◽  
...  
Keyword(s):  
Dna Damage ◽  
Oxidative Damage ◽  
Singlet Oxygen ◽  
Theoretical Basis ◽  
Antioxidative Activity ◽  
Oxidation Products ◽  
Characteristic Structure ◽  
First Time ◽  
Quench Singlet Oxygen

Resveratrol dimers have been extensively reported on due to their antioxidative activity. Previous studies revealed that resveratrol dimer has been shown to selectively quench singlet oxygen (1O2), and could protect DNA from oxidative damage. The mechanism of resveratrol dimers protecting DNA against oxidative damage is still not clear. Therefore, in this project, the reactants and products of resveratrol dimers protecting guanine from oxidative damage were qualitatively monitored and quantitatively analyzed by UHPLC-QTOF-MS2 and UHPLC-QQQ-MS2. Results showed that when guanine and resveratrol dimers were attacked by 1O2, mostly resveratrol dimers were oxidized, which protected guanine from oxidation. Resveratrol dimers’ oxidation products were identified and quantified at m/z 467.1134 [M-H]− and 467.1118 [M-H]−, respectively. The resorcinol of resveratrol dimers reacted with singlet oxygen to produce p-benzoquinone, protecting guanine from 1O2 damage. Therefore, it is hereby reported for the first time that the resorcinol ring is the characteristic structure in stilbenes inhibiting 1O2 induced-DNA damage, which provides a theoretical basis for preventing and treating DNA damage-mediated diseases.

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