http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Reactivity of hydroxyl radicals with neonicotinoid insecticides: mechanism and changes in toxicity
Dell'Arciprete, Maria L.,Santos-Juanes, Lucas,Sanz, Antonio Arques,Vicente, Rafael,Amat, Ana M.,Furlong, Jorge P.,Martirea, Daniel O.,Gonzalez, Monica C. Korean Society of Photoscience 2009 Photochemical & photobiological sciences Vol.8 No.7
The reactivity of hydroxyl radicals ($HO^{\cdot}$) towards three neonicotonoid insecticides, namely imidacloprid, thiacloprid and acetamiprid was investigated. These radicals were generated by photolysis of $H_2O_2$ solutions. Flash photolysis experiments were used to determine the rate constants of $5.5{\times}10^{10}M^{-1}s{-1}$, $6{\times}10^{10}M^{-1}s^{-1}$, and $7.5{\times}10^{10}M^{-1}s^{-1}$, for the reactions of $HO^{\cdot}$ with acetamiprid, imidacloprid, and thiacloprid, respectively. Continuous irradiation experiments in the absence and presence of $H_2O_2$ allowed the identification and toxicity evaluation of the primary photo- and oxidation products of the insecticides. In all cases, the less toxic 6-chloronicotinic acid was found to be the major product at higher degrees of oxidation. The results reported here indicate that the half life of the insecticides due to their reaction with $HO^{\cdot}$ radicals in natural aquatic reservoirs may vary between 5 h and 19 days, and therefore the hydroxyl radical-mediated oxidation may be a significant abiotic elimination route. However, elimination of the insecticide under such conditions might not improve the quality of the contaminated water, as the primary products of degradation still show considerable toxicity to Vibrio fischeri assays.
Phytochemical Analysis and Antinociceptive Properties of the Seeds of Garcinia achachairu
Marlova Manhabosco Dal Molin,Rivaldo Niero,Suellen Silva,Douglas Rafael Alves,Nara Lins Meira Quintão,Franco Delle Monache,Valdir Cechinel Filho 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.4
In a search for new and effective analgesic substances from the Brazilian biodiversity, the present study evaluates the chemical composition and antinociceptive potential of the methanol extract and a pure compound obtained from the seeds of Garcinia achachairu Rusby (Clusiaceae). The methanolic seed extract was directly subjected to purification by column chromatography and the purification was monitored by thin-layer chromatography. The main isolated compound was identified as Guttiferone A by comparison of conventional spectroscopic data (IR, NMR-1H and 13C) to the literature data which was isolated for the first time from this plant. When evaluated in the acetic acid-induced nociception model in mice, the methanolic seed extract had an ID50 (Inhibitory dose) of 13.1 (11.23-14.91) mg/kg and a maximal inhibition of 72 ± 4%. In the same model, Guttiferone A had an ID50 of 4.54 (3.29-6.24) mg/kg and a maximal inhibition of 73 ± 5%. The methanolic seed extract and Guttiferone A were also active in pain models induced by formalin, capsaicin, glutamate and carrageenan. These data suggest that the antinociceptive effect of Guttiferone A partly depends on its interference with the synthesis or activity of the cytokine TNF-α, the keratinocyte-derived chemokine KC, and/or PGE2. These data support, at least in part, the use of G. achachairu in folk medicine and suggest that this plant is an important source of compounds with a suitable profile for development as new and effective medicinal agents to treat pain processes.
Fernandez-Ayala, Daniel J.M.,Sanz, Alberto,Vartiainen, Suvi,Kemppainen, Kia K.,Babusiak, Marek,Mustalahti, Eero,Costa, Rodolfo,Tuomela, Tea,Zeviani, Massimo,Chung, Jongkyeong,O'Dell, Kevin M.C.,Rustin Elsevier 2009 Cell metabolism Vol.9 No.5
<P><B>Summary</B></P><P>Defects in mitochondrial OXPHOS are associated with diverse and mostly intractable human disorders. The single-subunit alternative oxidase (AOX) found in many eukaryotes, but not in arthropods or vertebrates, offers a potential bypass of the OXPHOS cytochrome chain under conditions of pathological OXPHOS inhibition. We have engineered <I>Ciona intestinalis</I> AOX for conditional expression in <I>Drosophila melanogaster.</I> Ubiquitous AOX expression produced no detrimental phenotype in wild-type flies. However, mitochondrial suspensions from AOX-expressing flies exhibited a significant cyanide-resistant substrate oxidation, and the flies were partially resistant to both cyanide and antimycin. AOX expression was able to complement the semilethality of partial knockdown of both <I>cyclope</I> (COXVIc) and the complex IV assembly factor <I>Surf1</I>. It also rescued the locomotor defect and excess mitochondrial ROS production of flies mutated in <I>dj-1</I>β, a <I>Drosophila</I> homolog of the human Parkinson's disease gene <I>DJ1</I>. AOX appears to offer promise as a wide-spectrum therapeutic tool in OXPHOS disorders.</P>