共查询到18条相似文献，搜索用时 218 毫秒
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用相转移催化法标记合成了植物生长延缓剂1-对氯苯基-2-[(5-(14)~C)-1,2,4-三唑-1-基]4,4-二甲戊-3-醇((14)~C-多效唑)。其步骤包括在相转移催化剂PEG800的存在下,(5-(14)~C)-1,2,4-三唑与一氯片呐酮在乙酸乙酯溶液中反应,生成(5-(14)~C)-α-三唑基片呐酮,后者在苯溶液中再与对氯氯苄反应,生成(14)~C-三唑酮,最后在甲醇溶液中用硼氢化钠还原得到(14)~C-多效唑。其总放化收率为20.9％(以(14)~C-三唑计),放化纯度大于99％。 相似文献
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(35)~S-多噻烷,即(35)~S-7-二甲氨基-1,2,3,4,5-五硫环辛烷,是由Na_2~(35)SO_4制备Na_2~(35)S,进而制备Na_2~(35)SS_x,再与氯化物缩合而成,放化收率33.6％,放化纯度97％。 相似文献
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水稻对~(14)CO_3~(2-)的吸收和积累动态 总被引：5，自引：3，他引：5
用同位素示踪技术研究水稻对14CO32-的吸收和积累动态,及其在水稻田中的行为特性。结果表明:通过水稻根系和浸于水中的茎杆下部吸收的14CO32-离子会向上部组织输送并形成积累趋势;在上部组织中,叶和茎杆上部的14C比活度随时间呈逐渐上升的趋势,而穗中的比活度于14d达最大值(271.9Bq/g)后又呈下降趋势;茎杆下部由于直接浸于水中,表现出对14CO32-离子的快速吸收、吸附,此后随时间呈下降趋势,根部表现出上升过程迟后于茎杆下部,其14C比活度也低于茎杆下部。上部组织(穗、叶和茎杆上部)中14C的百分含量随时间上升,而下部组织(茎杆下部和根)则相反,至试验后期(21~35d),其百分含量基本持平(约各占50%),14C从下部组织向上部组织输送的特征非常明显。 相似文献
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本文应用~(14)C-示踪技术研究了大麦叶片~(14)C-同化物在不同时空状态下输出的变化。结果发现,在不同空间序列的叶片,随叶位上升,~(14)C-同化物的输出量逐渐增加,同化~(14)CO_2后不同时间观察,趋势相同;1天内不同时间同化的~(14)C产物的输出量表现不同,8:00同化的~(14)C产物的输出量高于12:00和18:00同化的~(14)C产物输出量;随叶位上升,不同时间同化的~(14)C产物输出量增多,叶位间差异还表现为随叶位上升,早、中、晚3个时间同化的~(14)C产物输出量差异逐渐变小。 相似文献
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用同位素示踪技术研究了14 C 丁草胺、14 C 毒死蜱和14 C DDT在日本林蛙 (RanajaponicajaponicaGuenther)中的生物学行为。结果发现 ,14 C 丁草胺、14 C 毒死蜱和14 C DDT在 2 4h后分布到青蛙的各个器官组织 ,并分别以胆囊、小肠、小肠为它们的特异性浓集器官。与胆囊或小肠的14 C放射性活度比较 ,其它器官组织中的要小得多。14C DDT在日本林蛙中较难降解 ,2 4h后DDT母体在肝和脂肪组织中占DDT代谢物的54 6%和 88 4%。青蛙中的14 C 丁草胺、14 C 毒死蜱和14 C DDT可被丙酮提取 ,但三者之间以及在青蛙的器官之间有差异 相似文献
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实验室培养条件下 ,研究了14 C 甲磺隆在 7种不同类型土壤中形成结合残留( 14 C BR)的规律、主要影响因子及14 C BR在腐殖质中的动态分布规律等。结果表明 :( 1 ) 14 C 甲磺隆在 7种土壤中形成的14 C BR含量在培养初期的 2 0d内与土壤pH呈显著负相关且与土壤粘粒含量呈显著正相关 ;而 2 0d后 ,14 C BR含量只与土壤pH呈显著负相关。土壤pH是14 C 甲磺隆在土壤中形成BR的主要影响因子。14 C -甲磺隆在各类土壤中的14 C BR的最大值分别占引入量的 48 5%、46 5%、52 6%、1 9 3 %、49 7%、42 0 %和 46 5% ;( 2 )在整个培养试验过程中 ,14 C 甲磺隆在 7种不同类型土壤中的14 C BR ,主要分布在富啡酸和胡敏素中 ,前者中的相对百分比大于后者 ,而在胡敏酸中的相对百分比较小。土壤中14 C 甲磺隆BR的形成过程中 ,富啡酸的作用 >胡敏素 胡敏酸 相似文献
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本文对14 C 绿磺隆在 7种不同类型土壤中形成结合残留 ( 14 C ER)、可提态残留( 14 C ER)以及矿化为14 C CO2 的规律、影响14 C BR的主要因子及其在腐殖质中的分布规律等进行了研究。结果表明 :( 1 ) 14 C 绿磺隆在土壤中形成的14 C ER含量与土壤pH呈显著正相关 ,与土壤粘粒和有机质含量呈显著负相关 ,14 C ER中的绿磺隆母体化合物的消减满足一级反应动力学方程 ,其在 7种土壤中的半减期分别为 1 3 0～ 1 3 3 3d。pH是影响绿磺隆母体化合物降解的主要因子 ;( 2 ) 14 C 绿磺隆在 7种土壤中的14 C BR含量与土壤pH呈显著负相关 ,并与土壤粘粒含量呈显著正相关 ,土壤pH是14 C 绿磺隆在土壤中形成BR的主要影响因子 ;( 3 ) 14 C 绿磺隆形成的14 C BR主要分布在富啡酸和胡敏素中 ;14 C BR分布在胡敏酸中的相对百分比约为 2 % ,在14 C 绿磺隆BR的形成过程中 ,富啡酸的作用 >胡敏素 胡敏酸 ;( 4) 14 C 绿磺隆在 7种土壤中的14 C BR含量 ,在培养 2 0d内均随时间而快速增加 ,2 0d后变化量较小。 7种土壤中的14 C BR含量最大值分别占引入量的 53 5%、40 9%、3 7 8%、1 6 4%、42 5%、41 0 %和 3 1 3 % ;( 5)培养 90d内 ,14 C 绿磺隆通过三嗪杂环开环矿化为14 CO2 的量约占引入量的 4%～9% ,而土壤 1表明14 C 相似文献
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Celis R Koskinen WC Hermosin MC Cornejo J 《Journal of agricultural and food chemistry》1999,47(2):776-781
Sorption-desorption of the azole fungicide triadimefon [1-(4-chlorophenoxy)-3,3-dimethyl-1-(1H-1,2, 4-triazol-1-yl)-2-butanone] on eight soils and a series of single, binary, and ternary model soil colloids was determined using the batch equilibration technique. Regression analysis between Freundlich sorption coefficients (K(f)) and soil properties suggested that both clay and organic C (OC) were important in triadimefon sorption by soils, with increasing importance of clay for soils with high clay and relatively low OC contents. Triadimefon sorption coefficients on soil were not significantly affected by the concentration of electrolyte or the presence of soluble soil material in solution, but they were highly dependent on the soil:solution ratio due to the nonlinearity of triadimefon sorption on soil. Freundlich sorption isotherms slopes were very similar for all soils (0.75 +/- 0.02). Desorption did not greatly depend on the concentration at which it was determined and showed higher hysteresis for more sorptive soils. Results of triadimefon sorption on model sorbents supported that both humic acid and montmorillonite-type clay constituents contribute to triadimefon retention by soil colloids. 相似文献
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Tomigahara Y Onogi M Kaneko H Nakatsuka I Yamane S 《Journal of agricultural and food chemistry》1999,47(6):2429-2438
On single oral administration of (14)C-S-53482 [7-fluoro-6-(3,4,5, 6-tetrahydrophthalimido)-4-(2-propynyl)-2H-1,4-benzoxazin-3( 4H)-one, Flumioxazin] labeled at the 1- and 2-positions of tetrahydrophthaloyl group to rats at 1 (low dose) or 100 (high dose) mg/kg, the radiocarbon was almost completely eliminated within 7 days after administration in both groups with generally very low residual (14)C tissue levels. The predominant excretion route was via the feces. The major fecal and urinary metabolites involved reduction or sulfonic acid addition reactions at the 1,2-double bond of the 3,4,5,6-tetrahydrophthalimide moiety and hydroxylation of the cyclohexene or cyclohexane ring. One urinary and four fecal metabolites were identified using chromatographic techniques and spectroanalyses (NMR and MS). Three of five identified metabolites were unique forms, reduced at the 1,2-double bond of the 3,4,5, 6-tetrahydrophthalimide moiety. On the basis of the metabolites identified in this study, the metabolic pathways of S-53482 in rats are proposed. To specify tissues forming reduced metabolites, an in vitro study was conducted. Reduction was found to take place in red blood cells. 相似文献
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Banijamali AR Xu Y DeMatteo V Strunk RJ Sumner SJ 《Journal of agricultural and food chemistry》2000,48(10):4693-4710
Species differences in the metabolism of acetylenic compounds commonly used in the formulation of pharmaceuticals and pesticides have not been investigated. To better understand the in vivo reactivity of this bond, the metabolism of propargyl alcohol (PA), 2-propyn-1-ol, was examined in rats and mice. An earlier study (Banijamali, A. R.; Xu, Y.; Strunk, R. J.; Gay, M. H.; Ellis, M. C.; Putterman, G. J. J. Agric. Food Chem. 1999, 47, 1717-1729) in rats revealed that PA undergoes extensive metabolism primarily via glutathione conjugation. The current research describes the metabolism of PA in CD-1 mice and compares results for the mice to those obtained for rats. [1,2,3-(13)C;2,3-(14)C]PA was administered orally to the mice. Approximately 60% of the dose was excreted in urine by 96 h. Metabolites were identified, directly, in whole urine by 1- and 2-D (13)C NMR and HPLC/MS and by comparison with the available reference compounds. The proposed metabolic pathway involves glucuronide conjugation of PA to form 2-propyn-1-ol-glucuronide as well as oxidation of PA to the proposed intermediate 2-propynal. The aldehyde undergoes conjugation with glutathione followed by further metabolism to yield as final products 3,3-bis[(2-acetylamino-2-carboxyethyl)thio]-1-propanol, 3-[(2-acetylamino-2-carboxyethyl)thio]-3-[(2-amino-2-carboxyethyl)thi o]-1-propanol, 3,3-bis[(2-amino-2-carboxyethyl)thio]-1-propanol, 3-[(2-amino-2-carboxyethyl)thio]-2-propenoic acid, and 3-[(2-formylamino-2-carboxyethyl)thio]-2-propenoic acid. A small portion of 2-propynal is also oxidized to result in the excretion of 2-propynoic acid. On the basis of urinary metabolite data, qualitative and quantitative differences are noted between rats and mice in the formation of the glucuronide conjugate of PA and in the formation of 2-propynoic acid and metabolites derived from glutathione. These metabolites represent further variation on glutathione metabolism following its addition to the carbon-carbon triple bond compared to those described for the rat. 相似文献
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Tomigahara Y Isobe N Kaneko H Nakatsuka I 《Journal of agricultural and food chemistry》2006,54(12):4333-4342
Rats were orally dosed with a 1:1 diastereomixture of N-[(R)-1-(2,4-dichlorophenyl)ethyl]-2-cyano-3,3-dimethylbutanamide (Delaus, S-2900) and N-[(S)-1-(2,4-dichlorophenyl)ethyl]-2-cyano-3,3-dimethylbutanamide (S-2900S), both labeled with 14C, at 200 mg/kg/day for 5 consecutive days, and 16 metabolites in urine and feces were purified by a combination of several chromatographic techniques. The chemical structures of all isolated metabolites were identified by spectroanalyses (NMR and MS). Several of them were unique decyanated and/or cyclic compounds (lactone, imide, cyclic amide, cyclic imino ether forms). Major biotransformation reactions of the mixture of S-2900 and S-2900S in rats are proposed on the basis of the metabolites identified in this study. 相似文献
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Nagahori H Yoshino H Tomigahara Y Isobe N Kaneko H Nakatsuka I 《Journal of agricultural and food chemistry》2000,48(11):5760-5767
14C-Labeled furametpyr [N-(1,3-dihydro-1,1, 3-trimethylisobenzofuran-4-yl)-5-chloro-1, 3-dimethylpyrazole-4-carboxamide, Limber] was dosed to male and female rats at 1 (low dose) and 200 or 300 mg/kg (high dose). Elimination of furametpyr was rapid, and the dosed (14)C was substantially excreted within 7 days (45.5-53.3% in feces, 44.1-53. 8% in urine, and 0.01% in expired air). However, (14)C excretion rate showed sex- and dose-related differences, more rapid in males at low dose. (14)C concentrations in tissues decreased rapidly to generally low levels at 7 days (<0.004 ppm with the low dose and <1. 1 ppm with the high dose). Forty metabolites were detected, and 13 metabolites and 4 glucuronides were identified. A small amount of unchanged furametpyr was detected in feces (0.1-0.5% of the dose). The major metabolites in tissues were N-demethylated metabolites. In a bile study, 52.5-54.2% of the dosed (14)C was rapidly excreted into bile within 2 days. The absorption ratio was estimated to be >93.7% for the low dose (1 mg/kg). Major metabolites in bile were glucuronic acid conjugates of furametpyr hydroxides. On the basis of the results, furametpyr is substantially absorbed from the gastrointestinal tract after oral administration, rapidly distributed to tissues, extensively metabolized, and excreted into urine and bile or feces. 相似文献
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Engel W 《Journal of agricultural and food chemistry》2001,49(8):4069-4075
The major in vivo metabolites of S-(+)- and R-(-)-carvone in a metabolism of ingestion correlated amounts (MICA) experiment were newly identified as alpha,4-dimethyl-5-oxo-3-cyclohexene-1-acetic acid (dihydrocarvonic acid), alpha-methylene-4-methyl-5-oxo-3-cyclohexene-1-acetic acid (carvonic acid), and 5-(1,2-dihydroxy-1-methylethyl)-2-methyl-2-cyclohexen-1-one (uroterpenolone) on the basis of mass spectral analysis in combination with syntheses and NMR experiments. Minor metabolites were identified as reduction products of carvone, namely, the alcohols carveol and dihydrocarveol. The previously identified major in vivo metabolite in rabbits, 10-hydroxycarvone, could not be detected, indicating either concentration effects or interspecies differences. Metabolic pathways for carvone in humans including oxidation of the double bond in the side chain and, to a minor extent 1,2- and 1,4 + 1,2-reduction of carvone, are discussed. No differences in metabolism between S-(+)- and R-(-)-carvone were detected. 相似文献
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An isotopic exchange method for the characterization of the irreversibility of pesticide sorption-desorption in soil 总被引：1，自引：0，他引：1
An isotopic exchange method is presented that characterizes the irreversibility of pesticide sorption-desorption by soil observed in batch equilibration experiments. The isotopic exchange of (12)C- and (14)C-labeled triadimefon [(1-(4-chlorophenoxy)-3,3-dimethyl-1-(1H-1, 2,4-triazol-1-yl)-2-butanone] and imidacloprid-guanidine [1-[(6-chloro-3-pyridinyl)methyl]-4,5-dihydro-1H-imidazol-2-amine] in Hanford sandy loam soil indicated that these systems can be described by a two-compartment model in which about 90% of sorption occurs on reversible, easily desorbable sites, whereas 10% of the sorbed molecules are irreversibly sorbed on soil and do not participate in the sorption-desorption equilibrium. This model closely predicted the hysteresis observed in the desorption isotherms from batch equilibration experiments. The isotopic exchange of triadimefon and imidacloprid-guanidine in Drummer silty clay loam soil indicated that there was a fraction of the sorbed (14)C-labeled pesticide that was resistant to desorption, which increased as pesticide concentration decreased and was higher for triadimefon than for imidacloprid-guanidine. In contrast, the batch equilibration method resulted in ill-defined desorption isotherms for the Drummer soil, which made accurate desorption characterization problematic. 相似文献
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[Phenyl(U)-(14)C] and [triazole(3)-(14)C]flusilazole ([(bis 4-fluorophenyl)]methyl(1H-1,2,4-triazole-1-ylmethyl)silane; I) were extensively metabolized when fed to lactating goats (Capra hircus). The primary metabolites identified in goat tissues and milk were bis(4-fluorophenyl)(methyl)silanol (II) and 1H-1,2,4-triazole (III). Concentrations of total radiolabeled residues in the milk ranged from 0.09 to 0.74 microg/mL. Concentrations of radiolabeled residues found in tissues when the [(14)C] label was in the phenyl or triazole position, respectively, were 13.5 and 3.54 microg/g (liver), 8.74 and 0.75 microg/g (kidney), 0.41 and 0.52 microg/g (leg muscle), and 4.07 and 0.94 microg/g (back fat). Urine contained an additional major metabolite identified as [bis(4-fluorophenyl)](methyl)silylmethanol (IV) and its glucuronic acid conjugate (V). With either labeled form of flusilazole, the majority of the recovered radiolabel was excreted in urine or feces. 相似文献