7038-40-6Relevant articles and documents
Structures, Spectroscopic Properties, and Dioxygen Reactivity of 5- and 6-Coordinate Nonheme Iron(II) Complexes: A Combined Enzyme/Model Study of Thiol Dioxygenases
Gordon, Jesse B.,McGale, Jeremy P.,Prendergast, Joshua R.,Shirani-Sarmazeh, Zahra,Siegler, Maxime A.,Jameson, Guy N. L.,Goldberg, David P.
, p. 14807 - 14822 (2018/11/03)
The synthesis of four new FeII(N4S(thiolate)) complexes as models of the thiol dioxygenases are described. They are composed of derivatives of the neutral, tridentate ligand triazacyclononane (R3TACN; R = Me, iPr) and 2-aminobenzenethiolate (abtx X = H, CF3), a non-native substrate for thiol dioxygenases. The coordination number of these complexes depends on the identity of the TACN derivative, giving 6-coordinate (6-coord) complexes for FeII(Me3TACN)(abtx)(OTf) (1: X = H; 2: X = CF3) and 5-coordinate (5-coord) complexes for [FeII(iPr3TACN)(abtx)](OTf) (3: X = H; 4: X = CF3). Complexes 1-4 were examined by UV-vis, 1H/19F NMR, and M?ssbauer spectroscopies, and density functional theory (DFT) calculations were employed to support the data. M?ssbauer spectroscopy reveals that the 6-coord 1-2 and 5-coord 3- 4 exhibit distinct spectra, and these data are compared with that for cysteine-bound CDO, helping to clarify the coordination environment of the cys-bound FeII active site. Reaction of 1 or 2 with O2 at -95 °C leads to S-oxygenation of the abt ligand, and in the case of 2, a rare di(sulfinato)-bridged complex, [Fe2III(μ-O)((2-NH2)p-CF3C6H3SO2)2](OTf)2 (5), was obtained. Parallel enzymatic studies on the CDO variant C93G were carried out with the abt substrate and show that reaction with O2 leads to disulfide formation, as opposed to S-oxygenation. The combined model and enzyme studies show that the thiol dioxygenases can operate via a 6-coord FeII center, in contrast to the accepted mechanism for nonheme iron dioxygenases, and that proper substrate chelation to Fe appears to be critical for S-oxygenation.
CONDENSED HETEROCYCLIC COMPOUND HAVING CYCLOALKYLPYRIDYL GROUP OR SALT THEREOF, AGRICULTURAL AND HORTICULTURAL INSECTICIDE COMPRISING THE COMPOUND, AND METHOD FOR USING THE INSECTICIDE
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, (2018/09/24)
An object of the present invention is to provide and develop novel agricultural and horticultural insecticides in view of the still immense damage caused by insect pests etc. and the emergence of insect pests resistant to existing insecticides in crop production in the fields of agriculture, horticulture and the like. Provided are a condensed heterocyclic compound represented by the general formula (1): {wherein R1 represents an ethyl group, R2 represents a cycloalkyl group, R3 represents a haloalkyl group, A, A2 and A3 each represent a nitrogen atom or a CH group, A1 represents N-Me, m represents 0 or 2, and n represents 1} or a salt thereof; an agricultural and horticultural insecticide comprising the compound or a salt thereof as an active ingredient; and a method for using the insecticide.
Synthesis and properties of arsenic(III)-reactive coumarin-appended benzothiazolines: A new approach for inorganic arsenic detection
Ezeh, Vivian C.,Harrop, Todd C.
, p. 2323 - 2334 (2013/04/10)
The EPA has established a maximum contaminant level (MCL) of 10 ppb for arsenic (As) in drinking water requiring sensitive and selective detection methodologies. To tackle this challenge, we have been active in constructing small molecules that react specifically with As3+ to furnish a new fluorescent species (termed a chemodosimeter). We report in this contribution, the synthesis and spectroscopy of two small-molecule fluorescent probes that we term ArsenoFluors (or AFs) as As-specific chemodosimeters. The AFs (AF1 and AF2) incorporate a coumarin fluorescent reporter coupled with an As-reactive benzothiazoline functional group. AFs react with As3+ to yield the highly fluorescent coumarin-6 dye (C6) resulting in a 20-25-fold fluorescence enhancement at λem ～ 500 nm with detection limits of 0.14-0.23 ppb in tetrahydrofuran (THF) at 298 K. The AFs also react with common environmental As3+ sources such as sodium arsenite in a THF/CHES (N-cyclohexyl-2-aminoethanesulfonic acid) (1:1, pH 9, 298 K) mixture resulting in a modest fluorescence turn-ON (1.5- to 3-fold) due to the quenched nature of coumarin-6 derivatives in high polarity solvents. Bulk analysis of the reaction of the AFs with As3+ revealed that the C6 derivatives and the Schiff-base disulfide of the AFs (SB1 and SB2) are the ultimate end-products of this chemistry with the formation of C6 being the principle photoproduct responsible for the As3+-specific turn-ON. It appears that a likely species that is traversed in the reaction path is an As-hydride-ligand complex that is a putative intermediate in the proposed reaction path.
