In view of the isosterism of sulfonyl group (-SO2-) and phosphoryl group [-P(O)(OR)-,R=H, CH3, C2H5, etc], a new type of ureas, that is, N-phosphoryl-N'-(4,6-dimethoxypyrimidin-2yl) ureas 2 were synthesized and sh...In view of the isosterism of sulfonyl group (-SO2-) and phosphoryl group [-P(O)(OR)-,R=H, CH3, C2H5, etc], a new type of ureas, that is, N-phosphoryl-N'-(4,6-dimethoxypyrimidin-2yl) ureas 2 were synthesized and shown to be a new class of acetolactate synthase (ALS) inhibitors.展开更多
In view of the isosterism of the sulfonyl (-SO2-) and phosphoryl groups [-P(O)(OR)-,R=H, CH3, C2H5, etc], two new types of ureas, N-(N-aryl-O-alkyl phosphoryl)-N'-(4, 6-dimethoxypyrinddin-2-yl) ureas 2 and N-(N-ar...In view of the isosterism of the sulfonyl (-SO2-) and phosphoryl groups [-P(O)(OR)-,R=H, CH3, C2H5, etc], two new types of ureas, N-(N-aryl-O-alkyl phosphoryl)-N'-(4, 6-dimethoxypyrinddin-2-yl) ureas 2 and N-(N-aryl-N-alkyl phosphoryl)-N'-(4, 6-dimethoxy pyrimidin-2-yl)ureas 3, were synthesized by treating N- (arylandnochlorophosphoryl ) - N'- (4, 6-dimethoxypyriAndinyl-2-) ureas 4 with alcohols or amines. Compounds 4 were obtained by reactingdichlorophosphoryl isocyanate with 4,6 - di meth oxy- 2-aminopyrimidine, and then with aromaticamines. The enzyme tests (in vitro) indicated that compounds 2 and 3 were two novel classes ofacetolactate synthase (ALS) inhibitors, which showed that the phosphoryl group, [-P(O)(OR)-], or[-P(O)(NHR)-], was a good bioisostere of the sulfonyl group (-SO2-) in sulfonylurea.展开更多
Extensive acceptance of glyphosate-resistant (GR) row crops coupled with the simultaneous increase in glyphosate usage has sped the evolution of glyphosate resistance in economically important weeds. GR </span>&...Extensive acceptance of glyphosate-resistant (GR) row crops coupled with the simultaneous increase in glyphosate usage has sped the evolution of glyphosate resistance in economically important weeds. GR </span><i><span style="font-family:Verdana;">Amaranthus</span></i><span style="font-family:Verdana;"> <i>palmeri</i></span><span style="font-family:Verdana;"> populations are widespread across the state with some exhibiting multiple resistance to acetolactate synthase (ALS) inhibiting herbicides such as pyrithiobac. A GR and ALS inhibitor-resistant accession was also resistant to the protoporphyrinogen oxidase (PPO) inhibiting herbicide fomesafen. The PPO inhibitor resistance profile and multiple herbicide resistance mechanisms in </span><span style="font-family:Verdana;">this accession were investigated. In addition to fomesafen, resistance to</span><span style="font-family:Verdana;"> postemergence applications of acifluorfen, lactofen, carfentrazone, and sulfentrazone was confirmed. There was no resistance to preemergence application of fomesafen, flumioxazin, or oxyfluorfen. Molecular analysis of the </span><span style="font-family:Verdana;">ALS</span><span style="font-family:Verdana;"> gene indicated the presence of point mutations leading to single nucleotide substitutions at codons 197, 377, 574, and 653, resulting in proline-to-serine, arginine-to-glutamine, tryptophan-to-leucine, and serine-to-asparagine replacements, respectively. The resistant accession contained up to 87-fold more copies of the </span><span style="font-family:Verdana;">EPSPS</span><span style="font-family:Verdana;"> gene compared to a susceptible accession. A mutation leading to a deletion of glycine at codon 210 (ΔG210) of </span><span style="font-family:Verdana;">PPO2</span><span style="font-family:Verdana;"> gene was also detected. These results indicate that the mechanism of resistance in the Palmer amaranth accession is target-site based, </span><i><span style="font-family:Verdana;">i</span></i><span style="font-family:Verdana;">.</span><i><span style="font-family:Verdana;">e</span></i><span style="font-family:Verdana;">., altered target site for ALS and PPO inhibitor resistance and gene amplification for glyphosate resistance.展开更多
Corrosion inhibition of Al and Al-3.5Mg alloy by organic compounds, namely chalcones in hydrochloric acid solutions has been investigated by rapid polarization technique and weight loss method. Polarization measuremen...Corrosion inhibition of Al and Al-3.5Mg alloy by organic compounds, namely chalcones in hydrochloric acid solutions has been investigated by rapid polarization technique and weight loss method. Polarization measurements show that, the inhibitors act cathodically both in case of Al and Al-3.5Mg alloy. It was found from the weight loss measurements that, the inhibition efficiency depends on the substituent in the chalcone compound. The relative inhibitive efficiency of these compounds has been explained on the basis of structure dependent electron donor properties of the inhibitors and the metal inhibitor interaction on the surface. The inhibition efficiency ranges from 16 to 64% for Al and from 30% to 91% for Al-3.5Mg alloy展开更多
文摘In view of the isosterism of sulfonyl group (-SO2-) and phosphoryl group [-P(O)(OR)-,R=H, CH3, C2H5, etc], a new type of ureas, that is, N-phosphoryl-N'-(4,6-dimethoxypyrimidin-2yl) ureas 2 were synthesized and shown to be a new class of acetolactate synthase (ALS) inhibitors.
文摘In view of the isosterism of the sulfonyl (-SO2-) and phosphoryl groups [-P(O)(OR)-,R=H, CH3, C2H5, etc], two new types of ureas, N-(N-aryl-O-alkyl phosphoryl)-N'-(4, 6-dimethoxypyrinddin-2-yl) ureas 2 and N-(N-aryl-N-alkyl phosphoryl)-N'-(4, 6-dimethoxy pyrimidin-2-yl)ureas 3, were synthesized by treating N- (arylandnochlorophosphoryl ) - N'- (4, 6-dimethoxypyriAndinyl-2-) ureas 4 with alcohols or amines. Compounds 4 were obtained by reactingdichlorophosphoryl isocyanate with 4,6 - di meth oxy- 2-aminopyrimidine, and then with aromaticamines. The enzyme tests (in vitro) indicated that compounds 2 and 3 were two novel classes ofacetolactate synthase (ALS) inhibitors, which showed that the phosphoryl group, [-P(O)(OR)-], or[-P(O)(NHR)-], was a good bioisostere of the sulfonyl group (-SO2-) in sulfonylurea.
文摘Extensive acceptance of glyphosate-resistant (GR) row crops coupled with the simultaneous increase in glyphosate usage has sped the evolution of glyphosate resistance in economically important weeds. GR </span><i><span style="font-family:Verdana;">Amaranthus</span></i><span style="font-family:Verdana;"> <i>palmeri</i></span><span style="font-family:Verdana;"> populations are widespread across the state with some exhibiting multiple resistance to acetolactate synthase (ALS) inhibiting herbicides such as pyrithiobac. A GR and ALS inhibitor-resistant accession was also resistant to the protoporphyrinogen oxidase (PPO) inhibiting herbicide fomesafen. The PPO inhibitor resistance profile and multiple herbicide resistance mechanisms in </span><span style="font-family:Verdana;">this accession were investigated. In addition to fomesafen, resistance to</span><span style="font-family:Verdana;"> postemergence applications of acifluorfen, lactofen, carfentrazone, and sulfentrazone was confirmed. There was no resistance to preemergence application of fomesafen, flumioxazin, or oxyfluorfen. Molecular analysis of the </span><span style="font-family:Verdana;">ALS</span><span style="font-family:Verdana;"> gene indicated the presence of point mutations leading to single nucleotide substitutions at codons 197, 377, 574, and 653, resulting in proline-to-serine, arginine-to-glutamine, tryptophan-to-leucine, and serine-to-asparagine replacements, respectively. The resistant accession contained up to 87-fold more copies of the </span><span style="font-family:Verdana;">EPSPS</span><span style="font-family:Verdana;"> gene compared to a susceptible accession. A mutation leading to a deletion of glycine at codon 210 (ΔG210) of </span><span style="font-family:Verdana;">PPO2</span><span style="font-family:Verdana;"> gene was also detected. These results indicate that the mechanism of resistance in the Palmer amaranth accession is target-site based, </span><i><span style="font-family:Verdana;">i</span></i><span style="font-family:Verdana;">.</span><i><span style="font-family:Verdana;">e</span></i><span style="font-family:Verdana;">., altered target site for ALS and PPO inhibitor resistance and gene amplification for glyphosate resistance.
文摘Corrosion inhibition of Al and Al-3.5Mg alloy by organic compounds, namely chalcones in hydrochloric acid solutions has been investigated by rapid polarization technique and weight loss method. Polarization measurements show that, the inhibitors act cathodically both in case of Al and Al-3.5Mg alloy. It was found from the weight loss measurements that, the inhibition efficiency depends on the substituent in the chalcone compound. The relative inhibitive efficiency of these compounds has been explained on the basis of structure dependent electron donor properties of the inhibitors and the metal inhibitor interaction on the surface. The inhibition efficiency ranges from 16 to 64% for Al and from 30% to 91% for Al-3.5Mg alloy