Design, synthesis, insecticidal evaluation and molecular docking studies of cis-nitenpyram analogues bearing diglycine esters

Based on the strategies of receptor structure-guided neonicotinoid design, a series of novel cis-nitenpyram analogues bearing diglycine esters were designed and synthesized. Preliminary bioassays indicated that the insecticidal spectra of the target compounds were expanded compared with our previous work, while all the target compounds presented excellent insecticidal activities against Nilaparvata lugens and Aphis medicagini at 100 mg/L. Among these analogues, 6b showed 100% mortality against Nilaparvata lugens (LC 50 = 0.163 mg/L) and 90% against Aphis medicagini at 4 mg/L. SARs suggested that the insecticidal potency of our designed cis-nitenpyram analogues was dual-controlled by the size and species of the ester groups. The molecular docking simulations revealed that the structural uniqueness of these analogues may lead to a unique molecular recognition and binding mode compared with the previously designed compounds. Introduction of the peptide bond gave rise to more significant hydrogen bonds between the nitenpyram analogues bonding with the amino acid residues of insect nAChRs. The docking results explained the SARs observed in vitro, and shed light on the novel insecticidal mechanism of these cis-nitenpyram analogues.     

cis‐Nitenpyram Analogues Containing 1,4‐Dihydropyridine: Synthesis,Insecticidal Activities,and Molecular Docking Studies

A novel series of cis‐nitenpyram analogues ( 2a – 2p ) were designed and prepared by introducing the 1,4‐dihydropyridine, with their cis‐configuration confirmed by X‐ray diffraction. Preliminary bioassays showed that most compounds exhibited good insecticidal activities at 20 mg/L against Aphis medicagini, and analogues 2a and 2d afforded the best activity, and both of them had 100% mortality at 4 mg/L. In addition, molecular docking studies were also performed to model the ligand‐receptor complexes, and the results explained the structure‐activity relationships observed in vitro, which may provide some useful information for future design of new insecticides.     

Synthesis,Insecticidal Activities and Molecular Docking Studies on cis-Nitenpyram Analogues with a Flexible Amido Segment Anchored on Tetrahydropyrimidine Ring

To make further studies on the difference of cis-nitenpyram analogues, a series of cis-nitenpyram com- pounds containing a flexible amido segment anchored on tetrahydropyrimidine ring was designed and synthesized. Preliminary bioassays indicate that all the analogues exhibit a mortality of 100% at 100 rag/L, and the analogue 4d shows the best activity against Nilaparvata lugens and Myzus persicae, with a mortality of 100% at 4 mg/L （LCs0=0.172 rag/L）. The structure activity relationship studies show that insecticidal activities of the analogues are affected by the kinds and size of substituent R. In addition, the molecular docking simulations reveal that compouds 4 with a flexible amido segment on tetrahydropyrimidine ring show their different binding affinities for the nicotinic acetyleholine receptor（nAChR） of insect and compoud 4d shows stronger hydrogen-bonding with nAChR, which may provide the structure-activity relationship observed in vitro.     

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.     

Synthesis and Biological Activities of Novel Anthranilic Diamides Analogues Containing Benzo[b]thiophene

A series of novel anthranilic diamides analogues containing benzo[b]thiophenyl ring was designed and synthesized. Their structures were characterized by melting points, ¹H nuclear magnetic resonance(¹H NMR) and high-resolution mass spectrometry(HRMS). The bioassay tests indicate that their insecticidal activities were weak to moderate. Antibacterial tests indicate that some of the compounds showed favourable activity in vitro against Physalospora piricola, Alternaria solani, Cercospora arachidicola, Gibberella sanbinetti and Phytophthora infestans at a dosage of 50 mg/L.     

Synthesis and Biological Evaluation of Novel Anthranilic Diamides Containing N-H/CH3-1H-Pyrazole

In order to systematically study the structure-activity relationship of anthranilic diamides and develop insecticides with simple structure and high efficiency, a series of novel anthranilic diamides containing N-H/CH₃-1H-pyrazole was designed and synthesized. Their chemical structures were characterized by ¹H NMR spectra, high resolution mass spectrometry(HRMS) or ¹³C NMR spectra. The preliminary bioassay results indicated that all title compounds displayed moderate insecticidal activity against oriental armyworm(Mythimna separata) at 200 mg/L and fungicidal activities against six kinds of fungi at 50 mg/L, especially compound 5i showed 50% insecticidal activity at 25 mg/L. In addition, some compounds exhibited certain antitumor activities. It was demonstrated that the introduction of CH₃ group into pyrazole ring was superior to H for the insecticidal activity.     

Synthesis,bioactivity, action mode and 3D-QSAR of novel anthranilic diamide derivatives

Several newly synthesized anthranilic diamide derivatives were found to exhibit excellent bioactivity. The action mode test and 3D-QSAR analysis provided valuable information for evaluation and future design of anthranilic diamide insecticides.     

Design,synthesis, insecticidal,and acaricidal activities of novel pyrimidinamine derivatives containing a biphenyl ether

A series of original pyrimidinamine derivatives containing a biphenyl ether moiety were designed and synthesized. Their structures were confirmed by ¹H NMR, MS, and elemental analyses. Their insecticidal activities against lepidopteran and hemiptera insects and acaricidal activities were tested. The results of bioassay demonstrated that 9k showed the best activity (LC₅₀ = 2.08 mg/L) against Tetranychus urticae, which is comparable with the positive control, spirotetramat (LC₅₀ = 2.27 mg/L), and 9g showed better activity (LC₅₀ = 0.52 mg/L) against Aphis fabae than the positive control, imidacloprid (LC₅₀ = 1.02 mg/L), and relatively good activity (LC₅₀ = 2.49 mg/L) against T urticae. Their structure‐activity relationships indicated that both an ethyl group on the 4‐position of the pyrimidine ring and alkyl chain as a para‐substituent group of the benzene ring showed good biological activity.     

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.     

Cytotoxic and insecticidal activities of derivatives of harmine, a natural insecticidal component isolated from Peganum harmala

In a continuing effort to develop novel β-carbolines endowed with better insecticidal activity, a simple high-yielding method for the synthesis of harmine compounds starting from L-tryptophan has been developed and a series of 1,3-substituted β-carboline derivatives have been synthesized and evaluated for their cytotoxicity against insect cultured Sf9 cell line in vitro and insecticidal activities against 4th instar larvae of mosquitos, Culex pipiens quinquefasciatus and mustard aphid, Lipaphis erysimi. The results demonstrated that 1-phenyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (compound 2) and methyl 1-phenyl-β-carboline-3-carboxylate (compound 13) represented the best potential compounds, with Sf9 cells inhibition rates of 71.55% and 60.21% after 24 h treatment at concentrations of 50-200 mg/L, respectively. Both compounds 2 and 13 also showed strong insecticidal activity towards 4th instar larvae of mosquitos with LC(50) values of 20.82 mg/L and 23.98 mg/L, and their LC(90) values were 88.29 mg/L and 295.13 mg/L, respectively. Furthermore, the LC(50) values of compounds 2 and 13 against mustard aphids were 53.16 mg/L and 68.05 mg/L, and their LC(90) values were 240.10 mg/L and 418.63 mg/L after 48 h treatment. The in vitro cytotoxicity of these compounds was consistent with the insecticidal activity in vivo. The results indicated that the 1- and 3-positions of the β-carboline ring deserve further investigation to develop biorational insecticides based on the natural compound harmine as a lead compound.     

大黄酸-缬氨酸加合物的合成及初步抗肿瘤活性

以大黄酸为原料,经酯化、烷基化、水解及缩合等反应步骤合成了12个大黄酸-缬氨酸加合物.目标化合物经1H NMR,~(13)C NMR和HRMS进行了结构确证.以顺铂和阿霉素为阳性对照药,采用四甲基偶氮唑盐(MTT)法考察了目标化合物的体外抗肿瘤(Hela,MCF-7,HepG2,KB和HEK293T等5株细胞)活性.结果表明,化合物5l显示出较好的抗肿瘤活性,其IC50值在1.6~9.4μmol/L之间.作用机制研究结果表明,化合物5l能够与DNA发生较强的结合作用.     

含N-吡啶联吡唑杂环的(磺)酰胺类化合物的设计、合成及生物活性

以氯虫酰胺结构为基础, 设计合成了一系列含N-吡啶联吡唑杂环的酰胺及磺酰胺类化合物. 所有化合物的结构均通过元素分析和 ¹H NMR确证. 生物活性测试结果表明, 部分化合物对东方粘虫(4龄幼虫)和尖音库蚊(幼虫)表现出较好的杀灭活性. 化合物4a, 4k和5b在浓度为100 mg/L时对东方粘虫(4龄幼虫)的致死率均高于50%, 化合物4g 在浓度为2 mg/L时对尖音库蚊(幼虫)的致死率达100%.     

Design,synthesis and insecticidal activities of novel anthranilic diamides containing polyfluoroalkyl pyrazole moiety

In order to discover new molecules with good insecticidal activities, a series of anthranilic diamides containing polyfluoroalkyl pyrazole were designed and synthesized, and their structures were characterized by ¹H NMR and HRMS. Bioassays demonstrated that some of the title compound exhibited excellent insecticidal activities. The larvicidal activities of compound 8a, 8c, 8g, 8k and 8l against Mythimna separata Walker were 100% at 0.8 mg/L. The insecticidal activities of compound 8a, 8c, 8e, 8g, 8k and 8l against Plutella xylostella Linnaeus were 100% at 0.4 mg/L. Surprisingly compounds 8a and 8c still showed 100% larvicidal activities against Plutella xylostella Linnaeus at 0.08 mg/L comparable to the commercialized Chlorantraniliprole. The LC₅₀ of compound 8a and 8c against M. separata is 0.048 and 0.043 mg/L respectively.     

Novel Symmetrical trans‐Bis‐Schiff Bases of N‐Substituted‐4‐ piperidones: Synthesis,Characterization, and Preliminary Antileukemia Activity Mensurations

A series of novel symmetrical trans‐bis‐Schiff bases ( 11a , 11b , 11c , 11d , 11e , 11f , 11g , 11h , 11i , 11j , 11k , 11l , 11m ) were designed and prepared as novel anticancer analogues, with the trans‐configuration confirmed by X‐ray diffraction. Preliminary inhibitory effects of these compounds on CML K562 cell growth were investigated, and the potential analogue 11e showed an excellent anti‐leukemia activity (IC₅₀=6.35 μg/mL), which is higher than that of the clinical drug 5‐fluorouracil (IC₅₀=8.48 μg/mL). Complete assignments had been achieved for the title compounds by spectroscopic techniques, and their structure–activity relationships have been studied.     

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.     

Chemical synthesis and biological evaluation of palmerolide A analogues

Molecular design and chemical synthesis of several palmerolide A analogues allowed the first structure activity relationships (SARs) of this newly discovered marine antitumor agent. From several analogues synthesized and tested (ent- 1, 5- 14, 21- 26, 50, 51), compounds 25 (with a phenyl substituent on the side chain) and 51 (lacking the C-7 hydroxyl group) were the most interesting, exhibiting approximately a 10-fold increase in potency and equipotency, respectively, to the natural product. These findings point the way to more focused structure activity relationship studies.     

Regiospecific Isomerization of 2‐Benzoxazinon‐2‐yl Benzoic Acid Toward Some Nitrogen Nucleophiles as Environmental Insecticide

Based on the strategies of receptor structure‐guided benzoxazinone design, a series of nitrogen nucleophiles such as benzyl amine, sodium azide, 4,4‐bis o‐toluidine, 4‐butanolamine, glucosamine, 2‐amino pyridine, 2‐picolinyl amine, hydroxyl amine, and hydrazine derivatives, for example, hydrazine hydrate, semicarbazide, thiosemicarbazide, methylhydrazide, phenylhydrazide, could be reacted with 2‐benzoxazine‐2‐yl benzoic acid 1 . According the basicity of nucleophiles, regiospecific isomerization of benzoxazinone has been considered through formation of the spiro derivatives. Organic reagents can be controlled on the course of reaction of benzoxazinonyl benzoic acid 1 . Preliminary bioassays indicated that the insecticidal spectra of the synthesized compounds were ecofriendly biodegradable materials due to isomerization. Among these analogues, the quinazoline 2 – 4 showed 100% mortality against Nilaparvata lugens (LC₅₀ = 0.087 mg/L). The insecticidal potency of our designed analogues was dual‐controlled by isomerization to quinazolinone and spiro derivatives that observed in vitro and shed light on the novel insecticidal mechanism. The chemical structure of the products can be confirmed by microanalytical, spectral data, optimized and stimulated by quantum chemical parameters.     

Synthesis and Insecticidal Activities of Novel Analogues of Chlorantraniliprole Containing Nitro Group

Twelve novel analogues of chlorantraniliprole containing nitro group were synthesized,and their structures were characterized by 1H NMR and high-resolution mass spectrometry(HRMS).Their evaluated insecticidal activities against oriental armyworm(Mythimna separata) indicate that the nitro-containing analogues showed favorable insecticidal activities,while the activity of compounds 5g at 0.25mg/L was 40%,but still lower than chlorantraniliprole.     

Design,Synthesis, Biological Evaluation and SARs of Anthranilic Diamide Derivatives Containing Pyrrole Moieties

In order to find a new variety of ryanodine receptor(RyR) regulator with greater biological activity, a series of anthranilic diamide derivatives possessing pyrrole structure was designed and synthesized in this study. The pyrrole derivatives were evaluated for their insecticidal activity against Mythimna separata and Plutella xylostella. As indicated by the preliminary biological activities, compounds 12h-12j and 12l-12n exhibited a remarkable insecticidal activity against M. separata at 0.25 mg/L. Compared to control chlorantraniliprole, compound 12j exhibited more excellent insecticidal activity at 0.1 mg/L. Meanwhile, compounds 12c, 12h, 12i, 12j, 12l, and 12m were selected to test the insecticidal activity against P. xylostella, which led to the desirable insecticidal activity at 1×10^-3 mg/L. Notably, compound 12l demonstrated 47% insecticidal activity at 5×10^-6mg/L over the control. In addition, the biological mechanism of action of compound 12j was investigated by means of insect electrophysiology experiment.