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Novel Insights into Bioremediation of Petroleum-Polluted Environments and Bacterial Catabolic Pathways
Published in Wael Ahmed Ismail, Jonathan Van Hamme, Hydrocarbon Biotechnology, 2023
Laura Rodríguez-Castro, Roberto E. Durán, Constanza C. Macaya, Flavia Dorochesi, Lisette Hernández, Felipe Salazar-Tapia, Vanessa Ayala-Espinoza, Patricio Santis-Cortés, Ximena Báez-Matus, Michael Seeger
Three catabolic pathways were reported for aerobic fluorene degradation in bacteria. The first proceeds via dioxygenation at C-1,2 of the aromatic ring and the subsequent formation of 3-chromanone after several reactions. A second pathway starts with a 3,4-dioxygenation, leading to the formation of salicylate, which is further metabolized via the naphthalene pathway. A third pathway, described in Brevibacterium sp. DPO1361 and Pseudomonas sp. F274, involves an initial monooxygenation at C-9, converting fluorene to 9-fluoroenol, which is dehydrogenated to 9-fluorenone. An angular carbon dioxygenation transforms 9-fluorenone into 1,10-dihydro-11,10-dihydroxy-fluorene-9-one. Subsequently, this intermediate is transformed to phthalate and eventually to protocatechuate (Mrozik et al., 2003; Seo et al., 2009).
Reactions With Disinfectants
Published in Richard A. Larson, Eric J. Weber, Reaction Mechanisms in Environmental Organic Chemistry, 2018
Richard A. Larson, Eric J. Weber
Alben (1980) chlorinated a coal-tar leachate that contained many polycyclic aromatic hydrocarbons and demonstrated that many hydrocarbons were significantly reduced in concentration. Oxygenated compounds, such as dibenzofuran (17), were formed, together with low concentrations of chlorinated and brominated derivatives of naphthalene and fluorene. Chlorinated polycyclic compounds have been demonstrated to occur in drinking water samples (Shiriashi et al., 1985), including mono- and dichloro derivatives of naphthalene, fluorene, dibenzofuran, phenanthrene, fluoranthene, and fluorenone (Figure 5.3).
Distribution, sources and toxicity of polycyclic aromatic hydrocarbons in Liuxi River, China
Published in Chemistry and Ecology, 2022
Wang Min, Tian Lei, Sun Jingxin, Yutong Zhang, Zhai Hongqin, Li Dong, Wan Lin
Fluorene is a low molecular weight, tricyclic aromatic hydrocarbon. The relationship between its dose and injury stress response was studied, and it was found that the stress response did not change (increase or decrease) with dose. However, at low concentration (0.5 μg/L), certain protein stress and DNA damage stress were observed (not obvious). When the concentration of fluorene was 50 mg/L, the oxidative stress, membrane stress and DNA damage stress were strong, but other types of stresses were weak. The oxidative damage stress of fluorene was relatively strong when exposed at a concentration of 50 mg/L. Detailed expression level analysis was performed on the genes involved, and the results are shown in Figure 7. Fluorene exposure made the TELI values of dps and msrA reach above 5.1, and the TELI value of sodA, sodB, norR, ahpF, yeaE and fpr genes reach 2.39-3.82. These genes were mostly related to the H2O2 removal process, and these genes were also involved in the metabolism of pyruvic acid and nitric oxide, indicating that fluorine mainly caused oxidative damage (induced by H2O2).
Synthesis and mesomorphic properties of four ring, rod-like fluorene derivatives – the influence of the lateral substitution on mesomorphic properties of 2,7-bis(4-alkylphenyl)-fluorenes
Published in Liquid Crystals, 2020
Ewelina Dmochowska, Aneta Bombalska, Przemysław Kula
Fluorene is one of the most prominent polycyclic aromatic hydrocarbons (PAHs) and it is commonly used for the synthesis of polymer light-emitting diodes (PLEDs) or organic light-emitting diodes (OLEDs) [1]. Fluorene derivatives are promising materials for the emission of blue light and electric charge transport [2]. Solid-state lighting is the ecofriendly and energy efficient alternative lighting [3]. Fluorene derivatives are used as ligands in organometallic chemistry and protecting groups (Fmoc) in peptide synthesis [4–6].
Mesophase properties of fluorene-core mesogens and their effects on blue phase liquid crystals
Published in Liquid Crystals, 2022
Ying Shi, WanLi He, YaQian Zhang, YongFeng Cui, Lei Zhang, Zhou Yang, YuZhan Li, Hui Cao, Dong Wang
It can also be seen from Table 2 that the quantum efficiency of fluorene compounds was much higher than that of thiophene compounds, and the fluorescence quantum yield of Flu-C5 reached as high as 41.14%. It was possible that the larger conjugated structure of fluorene compounds was beneficial to improve the electron transport ability and the fluorescence properties of molecules, thus fluorene compounds may have well application prospects in display fields.