Synthesis of haptens and protein conjugates for the development of immunoassays for the insect growth regulator fenoxycarb.

Sensitive and selective enzyme-linked immunosorbent assays (ELISAs) in the immobilized antigen format were developed for fenoxycarb (1), an insect growth regulator (IGR). The parent molecule [ethyl 2-(4-phenoxyphenoxy)ethylcarbamate] was derivatized at several positions to obtain haptens (2-5) that were used to produce protein conjugates and rabbit polyclonal antisera. Amino derivatives of fenoxycarb at the terminal and internal rings (2 and 3, respectively) were linked to carrier proteins by azo coupling. Carboxyalkyl-spacer groups were attached to the ethyl group and the nitrogen atom of the target compound (1) to obtain haptens 4 and 5, respectively. Hapten-homologous ELISAs based on protein conjugates of compounds 2 and 4 determined fenoxycarb in the mid-ppb range (IC(50), 102 and 95 ppb, respectively). A more sensitive hapten-heterologous ELISA (IC(50), 17 ppb; detection limit 0.5 ppb) involved the antiserum raised against a conjugate of hapten 2 and the plate-coating antigen obtained from compound 3. These assays displayed no significant interferences with photodegradation products of fenoxycarb, the IGRs methoprene and pyriproxyfen, and a variety of pesticides including the pyrethroids fenvalerate and cypermethryn, the phenoxyacetic acid herbicide 2,4-D, DDT, and the nitrodiphenyl ether herbicides acifluorfen and fluorodifen.     

Controlled-release systems for the delivery of cyromazine into water surface

Controlled-release systems (CRSs) for the insect growth regulator cyromazine (Neporex), as a larvicide against Culex pipiens (Culicidae) mosquitoes, are under development. Despite promising results obtained previously for both in vitro (dissolution tests) and in vivo systems (mosquito larvae floating on water surfaces), it was evident that the CRSs did not remain afloat for sufficiently long times. The present study was thus conducted to determine the relationship between the process parameters and the potential contact time of the active ingredient with the mosquito larvae. A series of CRSs were prepared by an extrusion process, alone or in combination with a supplementary coating. The active ingredient was incorporated into the matrix or the coating. The matrix comprised low-density polyethylene 600 and perlite, and the coating, a polyurea with or without the addition of paraffin wax. The study showed that the cumulative release of the active ingredient into water could be controlled by manipulating the preparation techniques, the types and concentrations of inert materials, and the concentration of the active ingredient.     

Determination of altosid insect growth regulator in waters, soils, plants, and animals by gas-liquid chromatography.

Residues of isopropyl (2E,4E)-11-methoxy-3,7,11-trimethyl-2,4-dodecadienoate (Altosid) insect growth regulator are determined in waters, soils, plants, milk, eggs, fish, shellfish, poultry and cattle tissues, blood, urine, and feces. Acetonitrile is the primary extraction solvent for all samples. Residues are extracted by high-speed blending followed by vacuum filtration. Fatty extracts are subjected to cold-temperature precipitation and filtration. Samples are cleaned up by petroleum ether partitioning and Florisil and neutral alumina chromatography. The concentrated eluants are analyzed by gas-liquid chromatography (GLC) on columns of differing polarity, using hydrogen flame ionization detectors. The identity of suspected residues is confirmed by additional GLC and by mass fragmentography. The lower limits of detection were: water samples, 0.0004-0.001 ppm; soils, blood, and urine, 0.001 ppm; forage grasses, forage legumes, and rice foliage, 0.005 ppm; and milk, eggs, fish, shellfish, poultry and cattle tissues, and feces, 0.010 ppm.     

Concise synthesis of the plant growth regulator theobroxide

A plant growth regulator, theobroxide, which produces potato tubers under noninduced long-day conditions, was synthesized in four steps from dihydrotoluene.     

湘西植烟土壤交换性钙含量及空间分布研究

  目的  交换性钙含量是衡量土壤钙丰缺状况的重要指标,剖析耕地土壤交换性钙的空间分布特征及影响因子,可为耕地土壤钙肥管理提供重要参考依据。  方法  本研究以福建省耕地土壤为研究对象,收集了2016 ~ 2019年期间1900个土壤监测点数据,量化不同自然条件（海拔、年平均降水量）、土壤性质（土壤交换性镁、速效钾、pH、有机质、土壤类型和质地）以及作物类型对土壤交换性钙的影响,并通过随机森林模型分析这些影响因子对土壤交换性钙的相对重要性。  结果  福建省耕地土壤交换性钙平均含量为519 mg kg⁻¹,49.3%的地区低于400 mg kg⁻¹,31.6%的地区在400 ~ 800 mg kg⁻¹之间。随着土壤交换性镁、pH和有机质的增加,显著提高了土壤交换性钙含量;海拔高度的增加显著降低了土壤交换性钙含量。水稻土和砖红壤交换性钙含量分别为650 mg kg⁻¹和632 mg kg⁻¹,显著高于黄壤。稻-菜轮作和蔬菜种植体系土壤交换性钙含量显著高于其他作物种植体系。随机森林分析结果显示,土壤交换性镁是影响交换性钙含量的最重要的因素,其次是海拔、土壤pH和作物类型,而年均降雨量、土壤质地、土壤速效钾、土壤有机质和土壤类型影响较小。  结论  福建省土壤交换性钙含量总体较低,建议通过增施钙肥提高土壤交换性钙含量。在钙肥施肥中,应充分考虑当地气候条件、土壤性质、作物类型等因素,提高钙利用效率,促进作物产量和品质提升。     

生长调节剂对玉米氮代谢的影响

采用田间小区试验,研究了植物生长调节剂不同配方对玉米光合特性、氮素代谢以及玉米子粒产量与蛋白质含量的影响。结果表明,调节剂不同配方处理能明显提高子粒灌浆期玉米功能叶叶绿素的含量和净光合速率,功能叶与茎秆中的全氮和蛋白氮的减少量,功能叶的硝酸还原酶、谷氨酰胺合成酶与转化酶活性及子粒谷氨酰胺合成酶与转化酶活性;灌浆中、后期玉米功能叶蛋白水解酶活性和玉米子粒产量、子粒蛋白质含量及蛋白质产量。在生长调节剂中,PGR4处理玉米子粒的蛋白氮含量比对照提高1.35.g/kg,子粒产量比对照增加9.5%,子粒蛋白质产量比对照增加19.6%;PGR3处理玉米子粒的蛋白氮含量比对照提高0.78.g/kg,子粒产量比对照增加11.4%,子粒蛋白质产量比对照增加17.4%,是较合理的配方。     

Sublethal effects of insect growth regulators upon crab larval behavior

Both swimming speeds and phototaxis by the four larval stages of the crab Rhithropanopeus harrisii were monitored upon chronic exposure to sublethal concentrations of the insect growth regulators methroprene (Altosid^R: ZR-515), hydroprene (Altozar^R: ZR-512) and dimiline (TH-6040). Larvae were reared under conditions of salinity (20orbo) and temperature (25°C) which produce the greatest developmental success. Sublethal concentrations of methroprene had no effect on swimming rates or phototaxis as compared to the acetone control larvae. For hydroprene, swimming rates by stage I, II and III zoeae were unaffected while a significant increase in swimming speeds occurred in Stage IV zoeae exposed to concentrations of 0.05 and 0.1 ppm. Only Stage III zoeae exposed to 0.l ppm showed a significant decrease in the level of positive phototaxis. Dimilin was much more potent, as significant increases in swimming speeds occurred in Stage I, II and III zoeae, with 0.3 ppb being the lowest effective concentration. Although swimming by Stage IV zoeae was unaffected, phototaxis was altered at concentrations as low as 0.1 ppb. Concentrations, which alter behavior, are related to levels which are reported to control mosquitoe larvae.     

Effect of a commercial plant growth regulator on the elemental content of tea plants

Abstract

Response of field grown mature tea to the foliar application of Biozyme Crop Plus, a commercial plant growth regulator, applied at different concentrations ranging from 250 to 1000 ppm was evaluated. Tea shoots were analysed to determine their N, P, K, Ca, and Mg contents. The treated tea plant shoots contained significantly higher contents of N and K followed by Ca and Mg than the untreated control plant shoots. The total chlorophyll content of Biozyme treated tea shoots was also increased significantly. Yield response to Biozyme applied to tea bushes were also determined.     

植物生长剂和固沙剂对民勤沙区植被生长的影响

 为探讨植物生长调节剂、固沙剂的保水、增产及其固沙效果,挽救濒临死亡的地表植被,修复地区生态平衡,在民勤干旱沙区开展了有关应用技术研究。结果表明:1)植物生长调节剂及固沙剂具有一定的保水能力,可使农田作物含水率（耕作层）提高1.0～1.5百分点,使梭梭林分100cm内土壤层平均含水率提高2.3百分点,流动沙丘80cm内土壤层平均含水率提高3.5～3.9百分点。2)种子包衣制剂处理对小麦、玉米生长发育具有滞后作用,但均存在增产效果,能使小麦增产12.2%,玉米增产2.0%。3)利用液体试剂进行籽瓜灌根处理可促使植株较对照的主根增长9.1cm,主蔓增长33.0 cm,平均增产率为11.5%。4)用植物生长调节剂对退化植被梭梭、唐古特白刺进行根部追施后,梭梭新梢增长0.6～3.0 cm,唐古特白刺冠幅增大45.1～96.2 cm。5)固沙剂固定流动沙丘后,使沙丘结皮厚度增加0.2～0.3cm,风蚀减小50%～80%,沙丘植被盖度增加1.9%～2.7%。     

Development of a compound-specific ELISA for flufenoxuron and an improved class-specific assay for benzoylphenylurea insect growth regulators.

This study describes immunochemical approaches for the compound-specific detection of flufenoxuron and class-specific detection of benzoylphenylurea (BPU) insecticides. With the aim of developing a highly specific immunoassay for flufenoxuron, a hapten was synthesized by introducing a spacer arm at the 2,6-difluoro substituent aromatic ring of a flufenoxuron derivative. An IC(50) value of 2.4 ppb was obtained for flufenoxuron, with detection of the other four BPUs being more than 4000-fold less sensitive. For the development of class-specific ELISA for five BPUs, a new approach was used for the hapten preparation in which a butanoic acid linkage was introduced into the 3,5-dichloro-substituted aniline ring of chlorfluazuron analogue. Although the resultant ELISA still exhibited slightly differing cross-reactions for these five BPUs, this method had broader specificity than the previously reported polyclonal antibody-based ELISA. Spike and recovery studies for five BPUs in soil and water indicated that both the compound- and class-specific ELISAs were able to quantitatively detect BPU residues in soil and water. This study also provided additional insights into the influence of the immunizing hapten structure on the specificities of the antibodies obtained.     

Design and synthesis of benzoylphenylureas with fluorinated substituents on the aniline ring as insect growth regulators

Enormous numbers of synthetic fluorine-containing compounds have been widely used in a variety of fields, especially in drug and pesticide design. To find novel insect growth regulators, a series of benzoylphenylureas with fluorinated substituents were designed and synthesized. The results of larvicidal activities of those novel fluoro-substituted benzoylphenylureas against oriental armyworm and mosquito revealed that most compounds exhibited excellent activities. It is worth mentioning that compounds 3 and 6 exhibited higher activities against oriental armyworm and mosquito than commercial Hexaflumuron. It can be further seen that the insecticidal activities would increase significantly by introducing fluorinated substituents into the structure of the designed benzoylphenylureas.     

Microparticle dispensers for the controlled release of insect pheromones

The potential utility of micrometer-sized particles as controlled-release devices for the volatilization of insect pheromones for mating disruption applications is evaluated in this study for two pheromone/model compound systems (codlemone/1-dodecanol and disparlure/1,2-epoxyoctadecane). To expedite the measurement of release rates from these particle devices, two techniques based on thermogravimetric analysis (TGA) have been exploited: isothermal TGA (I-TGA) at elevated temperatures (40-80 degrees C) with N(2) convection and volatilization temperature (VT) by dynamic TGA. A correlation between these two methods has been established. Samples that exhibit a higher VT provide a lower release rate from a particle substrate. Using these techniques, it has been demonstrated that chemical interactions between adsorbed liquids and particle surfaces may play a small role in defining release characteristics under conditions of low surface area, whereas parameters associated with total surface area and micropore structure appear to be much more significant in retarding evaporation for uncoated particles containing an adsorbed liquid. Additional regulation of release rates was achieved by coating the particle systems with water-soluble or water-dispersible polymers. By careful selection of particle porosity and coating composition, it is envisioned that the evaporation rate of pheromones can be tailored to specific insect control applications.