On-column esterification and N-methylation of carbetamide with N,N,N-trimethylanilinium hydroxide

Transesterification and N-methylation of carbetamide was carried out using N,N,N-trimethylanilinium hydroxide as an alkylation reagent. The final product of the on-column methylation appeared as the dimethyl derivative of carbetamide which was qualitatively identified and quantitatively determined by means of gas-liquid chromatography. The standard methyl N-methylcarbanilate was analytically identified by a mass spectrometric method.     

Insecticidal activity of N,N-diethyl-, N,N-dipropyl-, N,n-di-isopropyl-, and n,n-di-isobutylalkanamides against mosquito larvae

N,N-Diethyl-, N,N-dipropyl-, N,N-di-isopropyl, and N,N-di-isobutylalkanamides in which the acyl moiety ranged from C₈ to C₂₁ were synthesised, and their larvicidal activity was determined against the first-instar larvae of the southern house mosquito Culex quinquefasciatus Say. The four homologous series of amides generally showed an increase in their larvicidal activity as the carbon number in the acyl moiety of the amides increased, until the activity reached a maximum. Subsequently, an increment of carbon number resulted in declining activity in the higher homologues, until the activity disappeared. N,N-Diethyltetradecanamide, N,N-dipropylundecanamide, N,N-di-isopropylundecanamide, and N,N-di-isobutlynonanamide or -dodecanamide were the most active compounds in their respective homologous series of amides; however, they were less active than their analogous N,N-dimethylalkanamides previously studied.     

Novel acetylcholinesterase inhibitors: Synthesis and structure–activity relationships of phthalimide alkyloxyphenyl N,N-dimethylcarbamate derivatives

Based on the multiple binding sites of acetylcholinesterase (AChE), a series of AChE inhibitors: phthalimide alkyloxyphenyl N,N-dimethylcarbamate were designed and synthesized. AChE inhibitory activity and structure–activity relationship of the compounds were researched also. The influence of structural variations on the inhibitory potency was carefully investigated by modifying different alkyloxy chain length and position between phthalimide and phenyl N,N-dimethylcarbamate (PDM). The biological properties of the series were investigated by considering the activity on isolated enzyme. Some of the newly synthesized derivatives, when tested on isolated AChE from head of housefly (Musca domestica), were more active than PDM. The compounds J1, J2 and K1–K8 demonstrated higher inhibitory activity (5- to 404-fold) for AChE than that of PDM. In particular, compound K1 displayed the best AChE inhibition (404-fold higher than PDM), which suggested that phthalimide group of K1 strongly bound at the residues lining the gorge while phenyl N,N-dimethylcarbamate bound at the catalytic site.     

Design, synthesis, insecticidal activity and structure-activity relationship of 3,3-dichloro-2-propenyloxy-containing phthalic acid diamide structures

BACKGROUND: Phthalic acid diamide derivatives are among the most important classes of synthetic insecticides. In this study, a 3,3‐dichloro‐2‐propenyloxy group, the essential active group of pyridalyl derivatives, was incorporated into phthalic acid diamide derivatives with the aim of combining the active groups to generate more potent insecticides. RESULTS: Thirty‐one new phthalic acid diamides were obtained, and these were characterised by ¹H and ¹³C NMR. The structure of N²‐[1,1‐dimethyl‐2‐(methoxy)ethyl]‐3‐iodo‐N¹‐[4‐(3,3‐dichloro‐2‐propenyloxy)‐3‐(trifluoromethyl)phenyl]‐1,2‐benzenedicarboxamide was determined by X‐ray diffraction crystallography. The insecticidal activities of the compounds against Plutella xylostella were evaluated. The title compounds exhibited excellent larvicidal activities against P. xylostella. Structure‐activity relationships revealed that varying the combination of aliphatic amide and aromatic amide moieties, or the nature and position of substituent Y on the aniline ring, could aid the design of structures with superior performance. CONCLUSION: A series of novel phthalic acid diamides containing a 3,3‐dichloro‐2‐propenyloxy group at the 4‐position of the aniline ring were designed and synthesised. Structure‐activity relationships with the parent structure provided information that could direct further investigation on structure modification. Copyright © 2012 Society of Chemical Industry     

Adsorption and bioactivity of di-allate,tri-allate and trifluralin*

Studies were conducled to cstmiate the adsorption parameter k and the bioactivity (in terms of G R₅₀) of di-allate [S-2,3-dichloroallyl N, N-di-isopropyl (thiocar bamate)], iri-allate [S-2,3,3-trichloroallyl N, N -di-isopropyl (thiocar bamate], and [trifiuralin (2,6-dinitro N, N-dlpropyl-4-trifluoromelhylaniline) in a number of Saskatchewan soil. The k values ratiged from 5 for di-allate adsorption m Asquilh loamy sand to 315 for trifluralin adsorption on Melfort loam and were closely related to the soil organic matter content. The relative degree of adsorption was irifluralin > tri-allate >di-allaie. For each herbicide, the G R₅₀ values were positively correlated wich organic matter conienl atid wilh k. It was suggested that these nonionic herbicides may be amenable to a predictive approach for field application rates in different soils. Among herbicides for any one soil, however, there was not the same relationship between G R₅₀andk. since the G R₅₀ was least for trifluralin and there was no significant difference between di-allate and tri-allate.     

Rapid nitrogen and phosphorus homeostasis transformation in Eupatorium adenophorum during invasion

Exotic plants can compete well with native species because many invasive species are considered better nutrient users in both low‐ and high‐resource environments. However, whether invasive plants can outperform native plants at all stages of invasion is not very clear. We investigated the nitrogen (N), phosphorus (P) and N:P homeostasis of an invasive Eupatorium adenophorum and a co‐occurring native plant Artemisia argyi in an area across the five invasion stages of E. adenophorum. The N homeostasis (H_N) of E. adenophorum was higher than that of A. argyi, whereas the P and N:P homeostasis (H_P and H_N/P) were higher for A. argyi. For E. adenophorum, H_N decreased, but H_P and H_N/P increased with the invasion time. For A. argyi, H_N/P increased, H_P and H_N remained stable with the invasion time. The results demonstrated that E. adenophorum could maintain higher H_N during invasion stages when N was limited and could maintain higher H_N and H_P at invasion stages when P was more limited. This rapid nitrogen and phosphorus homeostasis transformation of invasive E. adenophorum during its invasion stages guarantees its stronger competitive ability over native species and promotes its invasion success.     

新饲玉11号氮磷钾最佳施肥量及肥效模型拟合研究

为了解决新疆地区青贮玉米高产施肥配比问题,本试验以青贮玉米品种“新饲玉11号”为材料,采用3414试验方法,设计了不同的氮磷钾配比,在新疆农垦科学院试验地田间试验研究玉米的氮、磷、钾肥料效应并配置相应的肥效函数,以筛选出适合当地青贮玉米高产的最佳氮磷钾配比.结果表明:供试土壤中有效养分含量丰缺程度为N含量为低水平,K20、P205含量为中水平.14个处理中以N2P2K2处理的产量最高,产量为8066.79 kg·667m-2；用二次回归分析,得出氮磷钾的肥料效应函数方程为:Y=4659.93+ 79.56N-5.06N2+ 101.7P-33.81P2+286.4K-10.28K2+ 24.87NP+ 2.66NK-12.97PK;通过模型寻优得出“新饲玉11号”的最佳施肥量为667m2施N 21kg,P2O5 5 kg,K2O 22 kg,在此配方组合下能够获得最佳产量7692.96 kg·667m-2.     

Synthesis and insecticidal activity of new 3-benzylfuran-2-yl N,N,N',N'-tetraethyldiamidophosphate derivatives

BACKGROUND: A series of 3-benzylfuran-2-yl N,N,N',N'-tetraethyldiamidophosphate derivatives were synthesized as potential new agents to control insects. Their structures were confirmed on the basis of IR, NMR and MS analyses. RESULTS: Ten 3-benzylfuran-2-ylN,N,N',N'-tetraethyl derivatives were prepared from the compound furan-2-yl N' (N,N,N',N'-tetraethyldiamidophosphate). The contact toxicity of all derivatives, at a dose of 10 microg mg(-1) insect, was evaluated against four insect species, Ascia monuste orseis Latr. (Lepidoptera: Pyralidae), Diaphania hyalinata (L.) (Lepidoptera: Pyralidae), Sitophilus zeamais Mots. (Coleoptera: Bruchidae) and Solenopsis saevissima (Smith) (Hymenoptera: Formicidae). The mortality range observed for some derivatives, such as 3-(3-methylbenzyl)furan-2-yl N,N,N',N'-tetraethyldiamidophosphate (82.5% mortality against D. hyalinata; 100% mortality against S. saevissima), was comparable with that of the commercial insecticide chlorpyrifos-methyl. The biological activity of the derivatives depended on the substitution pattern of the benzylic ring. Furan-2-yl N,N,N',N'-tetraethyldiamidophosphate, furan-2-yl N,N-diethylamidochlorophosphate and difuran-2-yl N,N-diethylamidophosphate were also evaluated, displaying, in some cases, activity comparable with that of chlorpyrifos-methyl (90%, 100% and 97.5% respectively against A. monuste orseis). Considerable activity was observed for some furan-2(5H)-ones evaluated. CONCLUSION: Ten 3-benzylfuran-2-yl N,N,N',N'-tetraethyldiamidophosphate derivatives were synthesized and fully characterized from a chemical point of view. The results obtained from the biological assays indicate that this class of compounds can be utilized for the design of new substances endowed with insecticidal activity.     

Mode of action of new diethylamines in lycopene cyclase inhibition and in photosystem II turnover

The new bleaching herbicidal compound N,N‐diethyl‐N‐(2‐undecynyl)amine (NDUA) is identified here as an inhibitor of lycopene cyclase and is compared with the known cyclase inhibitors N,N‐diethyl‐N‐[2‐(4‐chlorophenylthio)ethyl]amine (CPTA) and N,N‐diethyl‐N‐[2‐(4‐methylphenoxy)ethyl]amine (MTPA). HPLC separation of chloroplast pigments shows lycopene accumulation in NDUA treated tissue. Variation in chain length of the undecynylamine moeity of NDUA from 7 to 21 C atoms reveals an optimum of 11 to 14 C atoms for herbicidal activity. A series of seven further analogues of NDUA and CPTA reveals the structural elements necessary for inhibition of lycopene cyclase. The effect of NDUA derivatives on photosynthesis has been studied in Chlamydomonas reinhardtii. Photosynthesis is highly sensitive, particularly towards the C14 and longer chain length analogues at nanomolar concentrations. It is shown that the breakdown of photosynthesis by NDUA is due to interference with the turnover of the D1 protein of the photosystem II reaction centre that requires the continous biosynthesis of the two reaction‐centre β‐carotene moieties in the reassembly phase. The D1 protein disappearance is most marked under strong light conditions. The depletion of photosystem II occurs before total pigment bleaching. This newly recognized mechanism in herbicidal activity is also the basis for the mode of action of other lycopene cyclase inhibitors as well as phytoene desaturase inhibitors. © 2001 Society of Chemical Industry     

Phototransformation of napropamide [N,N-diethyl-2-(1-naphthyloxy)propionamide] in aqueous solution: influence on the toxicity of solutions

The main photoproducts formed in an aqueous solution of napropamide irradiated in UV light are N,N-diethyl-2-(1-hydroxynaphthalen-2-yl)propionamide, N,N-diethyl-2-(4-hydroxynaphthalen-1-yl)propionamide and 1-naphthol. These account for c.60%, 15% and 10% of napropamide converted respectively. No influence of the irradiation wavelength or of oxygen was observed. The same products were obtained by irradiation of methanolic solutions. The three identified products result from the cleavage of naphthoxy–carbon bond. The first two products imply a photo-Fries rearrangement. The influence of irradiation on the toxicity of the solutions was studied by the Microtox™ test. The significant increase observed may be attributed partly to the formation of 1-naphthol. © 1998 Society of Chemical Industry     

Short-term Cover Crop Decomposition in Organic and Conventional Soils: Characterization of Soil C, N, Microbial and Plant Pathogen Dynamics

Stages of oat–vetch cover crop decomposition were characterized over time in terms of carbon and nitrogen cycling, microbial activity and damping-off pathogen dynamics in organically and conventionally managed soils in a field and a controlled incubation experiment. A measurement of relative growth consisting of radial growth of a fungal colony over non-sterilized soil divided by that over sterilized soil was used as an assay of suppressiveness. No differences in relative growth of Pythium aphanidermatum and Rhizoctonia solani were detected between organic and conventionally managed soils amended with cover crop residue. Significant effects of cover crop decomposition stage on the relative growth of both pathogens were obtained. Relative growth of P. aphanidermatum was highest just after incorporation and decreased 3 weeks after incorporation. Relative growth of R. solani was highest about 20 days after incorporation, and decreased 2 weeks later in the organic system, but continued to increase in the conventional system. In both experiments, the N or C content, C:N ratio or dry weight of retrieved debris were significantly correlated with relative growth of P. aphanidermatum. Relative growth of R. solani was significantly correlated with the C:N ratio of soil or the C or N content of debris. Microbial activity was not consistently associated with relative growth of either pathogen.     

Determination of the sulfonylurea herbicides chlorsulfuron and metsulfuron-methyl in soil,water and plant material by gas chromatography of their pentafluorobenzyl derivatives

The measurement of the sulfonyl urea herbicides, chlorsulfuron and metsulfuron-methyl as pentafluorobenzyl derivatives has been investigated and the kinetics of reaction optimised. The reaction product was identified by mass spectroscopy as N,N-bis(pentafluorobenzyl)-2-chlorobenzenesulfonamide. Amounts of herbicide derivative as low as 0·1 pg per injection can be detected. Suitable conditions for both packed and capillary chromatography are given. Application of the method to residue determination is discussed and the method is shown to be suitable for residues in soil and water but less so for plant material.     

Development of isolate‐specific markers for Neofusicoccum parvum and N. luteum and their use to study rainwater splash dispersal in the vineyard

Unique bands were identified in single isolates of Neofusicoccum parvum and Neofusicoccum luteum using universally primed polymerase chain reaction (UP‐PCR) analysis of isolates obtained from grapevines and non‐grapevine hosts in New Zealand, Australia, South Africa and the USA. Primers were designed to amplify a 1550 bp portion of the 1573 bp marker band from N. parvum isolate B2141 and a 510 bp portion of the 524 bp marker band from N. luteum isolate G51a2. A PCR‐RFLP assay was developed to distinguish the N. parvum isolate B2141 from other N. parvum isolates, based on a polymorphism found in the marker band using the TaqI restriction endonuclease. For N. luteum isolate G51a2, the designed primers were specific at an annealing temperature of 63°C in the PCR. The sensitivity threshold of the N. parvum and N. luteum isolate‐specific markers was 50 pg and 5 pg, respectively, when used in standard PCR with purified genomic DNA. The sensitivity of the N. parvum isolate‐specific marker was increased to 0·5 pg by nested PCR. The specificity test of both isolate‐specific markers with six other Botryosphaeriaceae spp. showed that they were specific to their respective species and isolates. Both markers were able to detect the conidia of N. parvum and N. luteum marker isolates in rainwater samples collected at different distances from an inoculation point in the vineyard. The results showed that rain splash could disperse the conidia of both of these species up to 2 m from the inoculum point in a single rainfall event.     

Effects of N, P and K on Striga asiatica (L.) Kuntze seed germination and infestation of sorghum

Sorghum (Sorghum bicolor (L.) Moench) plants were grown in pots with 12.5 and 50 mg applied N kg^?1 soil. With an increase of soil N, the Striga asiatica (L.) Kuntze infestation, as well as the sorghum shoot dry matter losses due to infestation, decreased. The relative differences in stimulant capacity to induce Striga seed germination among the four sorghum genotypes were not consistent over the 0 to 150 mg N 1^?1 range. The sorghum root exudate was considerably more active at 0 mg N 1^?1, than at 30 mg N 1^?1, and the stimulant produced at 150 mg N 1^?1 failed to induce Striga seed germination. Presence of N in the growth medium considerably reduced the effectiveness of the stimulating substance produced by sorghum roots, whereas K promoted stimulant activity only in the absence of N. The presence or absence of P in the growth medium did not affect Striga seed germinability, probably due to the inability of this element to interfere with the production or activity of the stimulating substance from the host plants. It can be concluded, therefore, that sorghum plants seem to produce active root exudate only in conditions of N deficiency.     

Identification,potential inoculum sources and pathogenicity of botryosphaeriaceous species associated with grapevine dieback disease in New Zealand

This study investigated the prevalence and identity of botryosphaeriaceous dieback pathogens in necrotic grapevines tissues in New Zealand vineyards, and other woody hosts growing nearby. The presumptive identities of the isolates by conidial and cultural morphology were confirmed with ITS sequence data as Neofusicoccum australe, N. luteum, N. parvum and Diplodia seriata. They were isolated predominantly from necrotic stems of grapevine and other hosts, but also from leaves, flowers and wood debris of grapevines. Inoculation with conidia and mycelium of multiple isolates of each species onto excised and attached green shoots and trunks of five grapevine varieties, Cabernet sauvignon, Chardonnay, Pinot noir, Riesling, and Sauvignon blanc, showed that all varieties became infected to a similar extent. All species except D. seriata were pathogenic, irrespective of the host source, with N. luteum being the most and D. mutila the least pathogenic (P < 0.05). On trunks, N. parvum caused cankers and the other pathogenic species caused die-back when the inoculated vines became winter-dormant. Conidia were produced from green shoot lesions and die-back wood, which indicates potential inoculum sources for vineyard infection.     

Synthesis and characterisation of some 4‐keto derivatives of 1,3,4(2H)‐isoquinolinetrione redox mediator herbicides

Derivatives of 2‐ethyl‐1,3,4(2H)‐isoquinolinetrione in which the 4‐keto group has been modified to (Z)‐oxime, (E)‐ and (Z)‐O‐methyl oxime, (Z)‐N,N‐dimethyl hydrazone, cyano‐imine and dicyanomethylene moieties have been prepared and evaluated as redox mediator herbicides. All of the compounds have the free‐radical properties required to function as redox mediators, as determined by cyclic voltammetry, though only the O‐methyl oximes, the N,N‐dimethyl hydrazone and the cyano‐imine have reduction potentials in the range required to stimulate the light‐dependent consumption of oxygen at photosystem I in isolated chloroplasts. The O‐methyl oximes and the cyano‐imine are fast‐acting post‐emergence herbicides, producing symptoms of rapid desiccation; the (E)‐O‐methyl oxime is the most active herbicide, being somewhat more potent than the parent isoquinolinetrione. Hydrolysis studies indicate that it is unlikely that any compound generates the parent isoquinolinetrione in vivo. Attempts to explain differences between in vitro and in vivo activities using hydrolytic stabilities and physical properties were unsuccessful, and it was concluded that these factors probably play a less significant role in moderating the herbicidal activity of isoquinolinetrione derivatives than originally thought. © 2000 Society of Chemical Industry     

Production of phytotoxic metabolites by five species of Botryosphaeriaceae causing decline on grapevines, with special interest in the species Neofusicoccum luteum and N. parvum

In recent years an increasing number of species of Botryosphaeriaceae have been associated with grapevine decline worldwide. Five species isolated from declining grapevines in Spain (Botryosphaeria dothidea, Diplodia seriata, Dothiorella viticola, Neofusicoccum luteum and N. parvum) were checked for toxin production in liquid cultures. Cultural conditions for all fungi were adjusted to obtain optimal production of phytotoxic culture filtrates, by growing the fungi in steady liquid cultures of Czapek–Dox broth for different time intervals. Phytotoxicity of D. seriata and N. parvum reached a maximum after 14 days while the remaining species showed the highest phytotoxicity levels after 21 days in culture. All fungi produced hydrophilic high-molecular weight compounds with phytotoxic properties. In addition, N. luteum and N. parvum produced lipophilic low-molecular weight phytotoxins, not detected consistently among the remaining species. This led to a more exhaustive study on the phytotoxicity of N. luteum and N. parvum. Culture filtrates and corresponding extracts of both species were consistently highly phytotoxic in different assays. The gas-chromatography analysis of the acetylated O-methyl glycosides of the phytotoxic exopolysaccharides produced by N. parvum showed these substances to be composed mainly of glucose, mannose and galactose. Results suggest that phytotoxic metabolites could be involved in the virulence of both species in planta.     

Conversion of [14C]buturon in soil and leaching water under outdoor conditions

[¹⁴C]Buturon, a urea herbicide, was sprayed on soil and winter wheat as an aqueous formulation (2.98 kg/ha) under outdoor conditions. Three months after application, a total of 49.2% of the applied radiocarbon was recovered: 46.9% in the soil, 0.3% in the leaching water (depth > 50 cm), and 2.0% in the plants. Radioactive residues in the soil were distributed to a depth of 50 cm and decreased with increasing depth of the soil. An average of 47% of the radioactivity present in the soil could be extracted with cold chloroform; by this extraction method, the formation of artefacts was avoided. Between one and two thirds of the extracted radioactivity was unchanged buturon. In the soil extracts, the following eight conversion products were isolated and identified by combined gas chromatography/mass spectrometry: N-(p-chlorophenyl)-N-methyl-O-methyl carbamate; N-(p-chlorophenyl)-O-methyl carbamate; N-(p-chlorophenyl)-N′-methyl-N′-isobutenyl-urea; N-(p-chlorophenyl)-N′-methyl-urea, N-(p-chlorophenyl)-N′-methyl-N′-isobutenylol-urea; p-chloroaniline in “biologically bound” form; N-(p-chlorophenyl)-N′-methyl-N′-methoxyisobutenyl-urea; and N-(p-chlorophenyl)-N′-methyl-N′-ethoxyisobutenyl-urea. In the leaching water, which contained only 0.005–0.006 mg/liter of radioactive substances, the following three conversion products were isolated and identified by gas chromatography/mass spectrometry: p-chloroformanilide; N-(p-chlorophenyl)-N-methyl-O-methyl carbamate; and an N-hydroxyphenyl-N′-methyl-N′-isobutinyl-urea. The results are discussed in relation to the factors responsible for the formation of these products.     

Interaction of formamidines with octopamine-, dopamine-and 5-hydroxytryptamine-sensitive adenylate cyclase in the nerve cord of Periplaneta americana

The interaction of chlordimeform, N¹-demethylchlordimeform [N²-(4-chloro-o-tolyl)-N¹-methylformamidine], BTS-27271 [N¹-methyl-N²-(2,4-xylyl)formamidine, the 2,4-xylyl analogue of N¹-demethylformamidine], and amitraz with octopamine-, dopamine-, and 5-hydroxytryptamine-mediated enhancement of cyclic-AMP production was investigated in nerve cord homogenates of the American cockroach Periplaneta americana. N¹-Demethylchlordimeform, BTS-27271 and amitraz simulated the actions of the monoamines in enhancing cyclic-AMP production, whereas chlordimeform showed no such agonism. Additivity studies indicated that these formamidine derivatives were interacting with dopamine- and 5-hydroxytryptamine-sensitive sites, in addition to their known interaction with octopamine-sensitive adenylate cyclase. N¹-Demethylchlordimeform (Ki= 0.2μM) and amitraz (Ki=0.5μM) inhibited the dopamine-mediated response, but only N¹-demethylchlordimeform (Ki=2μM) effected appreciable inhibition of the octopamine-response. Pharmacological characterisation of the formamidineinduced elevation of cyclic-AMP production indicated that the agonistic effects of formamidines are expressed primarily through the octopamine-sensitive adenylate cyclase, rather than the dopamine- or 5-hydroxytryptamine-sensitive sites. The results are discussed in the light of the proposal that the behavioural changes, associated with formamidine poisoning, reflect the cumulative effects of octopamine-agonism, and antagonism of the dopamine- and 5-hydroxytryptaminemediated processes.