Design,Synthesis, and Insecticidal Activity of 1,5‐Diphenyl‐1‐pentanone Analogues

Three series of novel 1,5‐diphenyl‐1‐pentanone derivatives were designed and synthesized. Their structures were characterized by IR, ¹H NMR techniques, and elemental analysis. The insecticidal activities of the new compounds were preliminarily evaluated. The bioassay results indicated that the compounds X11 – X30 displayed better aphicidal activity against Aphis gossypii than compounds X1 – X10 and the lead compound (E)‐1,5‐diphenyl‐1‐penten‐1‐one ( A ). The inhibitory rates of compounds X6 and X29 were 100% against Plutella xylostella (L.) at 600 mg·L^?1. Compounds X12 , X13, X19 , X24, X25 , X26 and X27 showed higher insecticidal activity against Tetranychus cinnabarinus (Boisduval) at 600 mg·L^?1 than the lead compound ( A ).     

Design,Synthesis and Biological Activities of Novel Benzoyl Hydrazines Containing Pyrazole

In search of environmentally benign compounds with high biological activity, low toxicity and low resistance, 8 novel benzoyl hydrazines containing pyrazole were designed and synthesized. All compounds were characterized by ¹H NMR spectra and HRMS. The preliminary results of biological activity assessment indicated that most of title compounds exhibited certain insecticidal activities against Mythimna separata Walker at 200 mg·L^?1 but excellent fungicidal activities against six fungus at 50 mg·L^?1, which were better than the control.     

Synthesis and Insecticidal Evaluation of Novel Anthranilic Diamides Derivatives Containing 4‐Chlorine Substituted N‐Pyridylpyrazole

To search for potent insecticides targeting at ryanodine receptors (RyRs), a series of novel anthranilic diamides analogs containing 4‐chlorine N‐pyridylpyrazole were designed and synthesized. Their insecticidal activities were evaluated and the preliminary structure‐activity relationships (SARs) were discussed. The insecticidal results showed that some of the compounds (8a—8h, 8m, 8n) exhibited good larvicidal activities against oriental armyworm at 2.5 mg·L^–1, and compound 8m possessed 60% insecticidal activity at 0.5 mg·L^–1. For diamondback moth, 8m exhibited better activity than Chlorantraniliprole at a hundred fold preference. The calcium imaging technique experiment results suggested that compound 8m could increase the intracellular [Ca²⁺]_i. With the neurons preincubated experiment, the results confirmed that the target of this series of compounds could be RyRs in the central larvae neurons of oriental armyworm. The results indicated that compound 8m could respond as a potential modulator of the insect ryanodine receptor.     

Design,synthesis, and insecticidal activities of novel diamide derivatives with alpha-amino acid subunits

A series of diamide derivatives containing α-amino acids were designed and synthesized. These compounds were evaluated for their insecticidal activities against Plutella xylostella, Mythimna separate, Myzus persicae, and Tetranychus cinnabarinus. Most of the title compounds containing an l -phenylglycine skeleton were endowed with good activities at the concentration of 500 mg·L⁻¹. Compounds ( R)-A6 showed a potential value for further optimization as an insecticidal lead with the LC₅₀ value of 86.8 mg·L⁻¹.     

Synthesis,Bioactivities and Structure Activity Relationship of N‐4‐Methyl‐1,2,3‐thiadiazole‐5‐carbonyl‐N′‐phenyl Ureas

Twenty nine novel N‐4‐methyl‐1,2,3‐thiadiazole‐5‐carbonyl‐N′‐phenyl ureas were designed and synthesized, and their structures were confirmed by proton nuclear magnetic resonance (¹H NMR), infra red spectroscopy (IR) and high‐resolution mass spectroscopy (HRMS). Compounds V‐9 , V‐11 , V‐12 , V‐15 , V‐19 , V‐21 , V‐22 and V‐24 exhibit excellent activity against Culex pipiens pallens. Compounds V‐12 and V‐22 present good insecticidal activity against Plutella xylostella L. Their median lethal concentrations (LC₅₀) are 164.15 and 89.69 mg·L^?1, respectively. Compound V‐11 also has potential wide spectrum of fungicide activity. Its median effective concentrations (EC₅₀) detected from 3.82 µg·mL^?1 against Physalospora piricola to 31.60 µg·mL^?1 against Cercospora arachidicola. Compounds V‐15 and V‐24 show outstanding induction activities as same as positive controls TDL and ningnanmycin, furthermore V‐24 has the highest induction activity of 41.85%±4.43%. To elucidate the structure activity relationship in these compounds, a 3D‐QSAR model has been built. The established model showed a reliable predicting ability with q² values of 0.643 and r² values of 0.982.     

Synthesis and Bioactivities Evaluation of Novel Anthranilic Diamides Containing N‐(tert‐Butyl)benzohydrazide Moiety as Potent Ryanodine Receptor Activator

Anthranilic diamides have been proven to be a class of efficacious and safe insecticides targeting ryanodine receptors (RyRs) during the last decade. In order to develop innovative scaffolds with high insecticidal activity, two series of N‐pyridylpyrazole derivatives containing N‐(tert‐butyl)benzohydrazide substructures were designed and synthesized. Their insecticidal activities against oriental armyworm (Mythimna separata) and diamondback moth (Plutella xylostella) were evaluated. Preliminary bioassay results revealed that some of the new compounds exhibited good insecticidal activity against the oriental armyworm and diamondback moth. The mode of action of these compounds were verified using calcium‐imaging technique and the results showed that some new compounds could effectively modulate the insect cytosolic Ca²⁺ level, and break the cellular calcium homeostasis, indicating some of these compounds were potent activators of the RyRs.     

Design,Synthesis and Insecticidal Evaluation of Anthranilic Diamides Containing Optically Pure Amino Acid Moiety

Two series of N‐pyridylpyrazolecarboxamide derivatives were designed and synthesized by introducing D‐alanine acid esters and D‐serine acid esters into the skelecton of chlorantraniliprole. The obtained structures were characterized by ¹H NMR, ¹³C NMR, elemental analysis and specific optical rotation analysis. Preliminary bioassays indicated that some compounds displayed excellent insecticidal activities against Mythimna separate and Plutella xylostella in comparison with chlorantraniliprole. In particular, IIq showed excellent insecticidal activity against Plutella xylostella with a mortality rate of 90% at 0.01 mg·L^?1. A 3D‐QSAR (CoMSIA) study was performed in order to disclose the insecticidal structure‐activity relationship and indicate the future work. The CoMSIA study demonstrated that large substitutes and electron deficient groups at the 3‐position of pyrazole ring are favorable, the same as a small group near the ester groups of amino acid.     

Synthesis and Insecticidal Activity of Nitenpyram Analogs with Tetrahydropyrimidine Fixed (Z)‐Configuration

Two series of novel (Z)‐nitenpyram analogs 2a , 2b , 2c , 2d , 2e , 2f , 2g , 2h , 3a , 3b , 3c , 3d were synthesized by introducing various amino acids benzyl ester or amino acids tetrahydrofurfur‐2‐yl ester into nitenpyram and forming a tetrahydropyrimidine ring to fix (Z)‐configuration. The structures of the target compounds were characterized by ¹HNMR, MS, IR, and elemental analysis. Preliminary bioassays against Nilaparvata lugens indicated that all the nitenpyram analogs exhibited good insecticidal activity at 100 mg/L, whereas the compounds 3b and 3d afforded the best in vitro inhibitory activities that had ≥ 90% mortality at 20 mg/L.     

Synthesis,Insecticidal Assay and Molecular Docking Study of Novel Neonicotinoids N‐Oxide Analogues

Eight novel neonicotinoids N‐oxide analogues were designed and synthesized. All the compounds have been identified by ¹H NMR and HRMS. The N‐oxide analogues exhibit high insecticidal activity against cowpea aphids (Aphis craccivora) at 250 mg·L^?1. The influence of N‐oxide formation on the biological activity was elucidated by computational chemical study, and it indicated that the water bridge hydrogen bonding network was broken due to the influence of the O atom connected with the pyridine ring.     

Synthesis,Crystal Structure,and Biological Activity of Novel Anthranilic Diamide Insecticide Containing Propargyl Ether Group

In search of environmentally benign insecticides with high activity, low toxicity, and low residue, a series of novel anthranilic diamide containing propargyl ether were designed and synthesized. All compounds were characterized by ¹H NMR spectroscopy, high‐resolution mass spectrometry, or elemental analysis. The single crystal structure of 18g was determined by X‐ray diffraction. The insecticidal activities against Lepidoptera pests of the new compounds were evaluated. Their insecticidal activities against oriental armyworm (Mythimna separata) and diamondback moth (Plutella xylostella) indicated that most of the compounds showed moderate to high activities at the tested concentration.     

Design,Synthesis and Herbicidal Activities of Tetrahydroisoindoline‐1,3‐dione Derivatives Containing Alkoxycarbonyl Substituted 2‐Benzoxazolinone

Several different alkoxycarbonyl‐substituted 2‐benzoxazolinone moieties have been incorporated into a tetrahydroisoindoline‐1,3‐dione scaffold to provide 25 compounds ( 1a – 1u and 2a – 2d ). The structures of these compounds were confirmed by ¹H and ¹³C NMR, HRMS and X‐ray single‐crystal diffraction. Some of these compounds ( 1g , 1h , 1j , 1k ) exhibited excellent herbicidal activities against Abutilon theophrasti, Amaranthus retroflexus and Echinochloa crus‐galli at a rate of 375 g AI·ha^?1. Among them, compounds 1h and 1j displayed the best post‐emergence herbicidal effect against Abutilon theophrasti with ED₅₀ values of 1.8 and 5.3 g AI·ha^?1, respectively, which are superior to that of the commercial acifluorfen (44.3 g AI·ha^?1). Field trials demonstrated that compound 1h exhibited similar herbicidal activity to a high concentration atrazine, and found to be safer for maize than atrazine. The results of this study therefore show that compound 1h could potentially be used as a post‐emergence herbicide for maize fields.     

Synthesis and Insecticidal Evaluation of Novel N‐Pyridylpyrazolecarboxamides Containing Different Substituents in the ortho‐Position

In order to look for novel insecticides containing N‐pyridylpyrazole, ten novel pyrazolecarboxamides containing different ortho‐substituents in the aniline part were synthesized, and their structures were characterized by ¹H NMR, ¹³C NMR and HRMS. The single crystal structure of 10b was determined by X‐ray diffraction. Their evaluated insecticidal activity against oriental armyworm (Mythimna separata) indicated that all the compounds exhibited moderate insecticidal activities.     

新型N-（4，6-双取代嘧啶-2-基）-N’-（三氟甲基苯基）胍的合成，结构及生物活性研究

设计,合成了10种新型的胍衍生物,结构经FTIR, MS, 1H NMR 和元素分析确证,并且采用X-射线衍射分析方法确证了具有较好生物活性的化合物11a的结构。并且对这些化合物进行了除草活性测试,结果表明化合物11a,11b,11c在100µg·mL-1 对油菜具有较好的抑制作用,初步的KARI活性结果表明这些化合物对KARI的活性很弱。     

Synthesis and Insecticidal Activities of cis‐Configuration Nitenpyram Analogues with Benzoyl Hydrazines

To research on the structure–activity relationships of our designed neonicotinoid compounds, a series of novel cis‐configuration nitenpyram analogues with benzoyl hydrazines were designed and synthesized. The structures of all compounds were confirmed by IR, ¹H NMR, MS, and elemental analysis. Preliminary bioassays indicated that all the analogues exhibited good insecticidal activities against Nilaparvata legen and Aphis medicagini at 500 mg L^?1.     

Design,Synthesis, Structure‐Activity Relationship and Insecticidal Activities of Trifluoromethyl‐Containing Sulfiliminyl and Sulfoximinyl Phthalic Acid Diamide Structure

Due to a novel mode action, low toxicity to mammals and low residue characteristics, phthalic acid diamides have aroused considerable interests in agricultural chemistry. With introduction of N‐cyano, N‐trifluoroacetyl, N‐carbamoylsulfiliminyl and sulfoximinyl substituents into phthalamides, 12 novel derivatives containing trifluoromethyl moiety were designed and synthesized. All title compounds were characterized by ¹H NMR and high‐resolution mass spectrometry. The preliminary results of biological activity assessment indicated that some title compounds exhibited moderate to good insecticidal activities against oriental armyworm (Pseudaletia separata Walker). In particular, Va gave higher activity against oriental armyworm and diamondback moth. The present work reported that the new trifluoromethylated diamides incorporating N‐trifluoroacetylsulfoximinyl moieties are potential lead compounds for further structure optimization, providing some insight into the relating structure‐activity relationship.     

Cadmium Distribution in a Timberline Forest in the Hengduan Mountains in the Eastern Tibetan Plateau

In order to study the regional distribution, characterization, and possible source of Cadmium in the eastern Tibetan Plateau, samples of leaves, xylem, twigs, bark, and roots of timberline forest trees (fir or spruce) and soils at depths from 0 to 40 cm were collected in eight sites in Hengduan Mountains. According to Cd contents, organs and tissues were divided into three groups: the highest-level organ (roots: 0.237 mg · kg^?1), the high-level organ/tissue (bark: 0.183 mg · kg^?1 and twigs: 0.159 mg · kg^?1), and the low-level organ/tissue (xylem: 0.054 mg · kg^?1and leaves: 0.048 mg · kg^?1). Cd contents in Transect A were a little higher than Transect B. Sites near pollutant sources and high-levels are more sensitive to Cd pollution and accumulated more Cd, while Cd contents in sites far away from pollutant sources and low-level organ/tissue were relatively low. It is suggested that the eastern Tibetan Plateau has already been polluted by the influence of general circulation to some extent. Nevertheless, low Cd contents in some sites prove that high mountains may barricade Cd pollutants from monsoon.     

Synthesis,Structure and Biological Activities of Novel 2‐(Trifluoromethyl)‐ 6‐arylimidazo[2,1‐b][1,3,4]‐thiadiazole (bis‐)Mannich Base Derivatives Containing Substitutedpiperazine Moiety

A convenient and practicable method for the synthesis of the novel 2‐(trifluoromethyl)‐6‐arylimidazo[2,1‐b][1,3,4]‐thiadiazole (bis‐)Mannich base derivatives containing various substitutedpiperazine motif has been developed based on the fused‐heterocycle intermediate. The new structures were identified through melting points, ¹H NMR, ¹³C NMR, ¹⁹F NMR, elemental analysis (or HRMS) and X‐ray single‐crystal diffraction. The pesticidal bioassays showed that some of compounds exhibited good fungicidal activities against Cercospora arachidicola, Physalospora piricola and Rhizoctonia cereali at 50 mg/L; some of them displayed favourable insecticidal activities against oriental armyworm (Mythimna separata Walker) at 200 mg/L, particularly, Vk and Vm with mortality rate of 75% and 80% respectively, could be considered as new insecticidal lead compounds for further structural optimization.     

Design,Synthesis, Biological Evaluation and SARs of Novel N‐Substituted Sulfoximines as Potential Ryanodine Receptor Modulators

The sulfoximine group has been evaluated as a pharmacophore. Introducing the sulfoximine structure into medicinal compounds as exciting motifs has brought opportunities in drug discovery. In order to develop new ryanodine receptor (RyR) modulators, a series of phthalamides containing sulfoximine derivatives were designed, synthesized, and evaluated against oriental armyworm and diamondback moth for their insecticidal activities. These studies helped to elucidate the electronic and structural requirements around the sulfoximine motif for insecticidal activity. All new structures were synthesized and characterized by ¹H NMR, ¹³C NMR, HRMS and bioassay and a preliminary structure − activity relationship (SAR) was discussed. The biological assessment indicated that most title compounds showed good to excellent larvicidal activities. Compounds Ia , Ie , and If gave excellent insecticidal activity against oriental armyworm, which showed 100% larvicidal activity at 0.5 mg/L. All compounds showed 100% larvicidal activity at 0.1 mg/L against diamondback moth. In particular, the larvicidal activities of Ie , If , and Ih at 0.0001 mg/L were 50%, 20%, and 40%, respectively, reaching an activity as high as that of the commercial flubendiamide (40%, 0.0001 mg/L). Therefore, Ia , Ie , If and Ih could be considered as new lead structures for the development of new ryanodine receptor (RyR) modulators.     

Influence of Culture Medium Composition and Light Conditions on the Accumulation of Bioactive Compounds in Shoot Cultures of <Emphasis Type="Italic">Scutellaria lateriflora</Emphasis> L. (American Skullcap) Grown In Vitro

Methanolic extracts from in vitro grown Scutellaria lateriflora shoots cultured on five Murashige and Skoog (MS) medium variants supplemented with different combinations of 6-benzylaminopurine (BAP) and α-naphthaleneacetic acid (NAA) under different light conditions (monochromatic light, white light and no light) were analysed by HPLC for three groups of metabolites: flavonoids (26 compounds), phenolic acids and their precursors (19+2) and phenylethanoid glycosides (2). The analyses revealed the presence of baicalein, baicalin, wogonin, wogonoside, 3,4-dihydroxyphenylacetic acid and verbascoside. There was clear evidence of the influence of plant growth regulators and light conditions on the accumulation of the analysed groups of secondary metabolites. The amounts of the compounds changed within a wide range—for the total flavonoid content, 30.2-fold (max. 1204.3 mg·100 g^?1 dry weight (DW)); for 3,4-dihydroxyphenylacetic acid, 5.5-fold (max. 33.56 mg·100 g^?1 DW); and for verbascoside, 1.5-fold (169.15 max. mg·100 g^?1 DW). The best medium for the production of most of the compounds was the Murashige and Skoog variant with 1 mg l^?1 BAP and 1 mg l^?1 NAA. For verbascoside, the best ‘productive’ medium was the MS variant supplemented with 0.5 mg l^?1 BAP and 2 mg l^?1 NAA. The accumulation of the metabolites was stimulated to the greatest extent by blue light, under which the extracts were found to contain the highest total amount of flavonoids and the highest amounts of flavonoid glucuronides, baicalin and wogonoside, as well as of verbascoside. Their amounts were, respectively, 1.54-, 1.49-, 2.05- and 1.86-fold higher than under the control white light.     

Design,Synthesis, and Insecticidal Activities of Novel Pyranoside Derivatives Targeting at Potential Second Calcium Channel IP3 Receptor

In order to search for potent and environmental friendly insecticides with new modes of action, a series of pyranoside derivatives mimicking D‐myo‐inositol 1,4,5‐trisphosphate (IP₃) were designed and synthesized according to the bioisosteric approach. The biological assay indicated that most of the new compounds showed moderate to good insecticidal activities against oriental armyworm (Mythimna separata) and diamondback moth (Plutella xylostella). Especially, compound 5g displayed 80% larvicidal activity against oriental armyworm at 50 mg/L. Meanwhile, 5a showed 100% and 70% larvicidal activities against diamondback moth at 50 and 25 mg/L, respectively. To further explore the mode of action, calcium imaging technique was applied to study the effects of 5a , 5g , and 5i on the intracellular calcium ion concentration ([Ca²⁺]_i) in central neurons isolated from Spodoptera exigua. The results indicated that the tested compounds released stored calcium ions from endoplasmic reticulum.