Synthesis and Insecticidal Activity of Novel N‐Pyridylpyrazole Carbonyl Thioureas

A series of novel N‐pyridylpyrazole carbonyl thioureas were designed and synthesized. Their structures were characterized by melting points, ¹H NMR, IR and elemental analysis or HRMS. The bioassay tests indicated that some of these compounds exhibited moderate insecticidal activity against Mythimna separata Walker and Culex pipiens pallens. Among 17 compounds, 5n and 5p showed 100% larvicidal activity against Mythimna separata Walker at the test concentration of 100 mg/L.     

Synthesis and Insecticidal Evaluation of Novel N‐pyridylpyrazole Derivatives Containing Diacylhydrazine/1,3,4‐Oxadiazole Moieties

Two series of novel N‐pyridylpyrazole derivatives containing diacylhydrazine/1,3,4‐oxadiazole moieties were designed and synthesized based on the structure of chlorantraniliprole and characterized via ¹H‐NMR, ¹³C‐NMR, IR, MS, and elemental analysis. The preliminary bioassay indicated that some of the title compounds I and II exhibited larvicidal activities against Mythimna separata with 90–100% death rates at 500 mg/L. The further test showed that these compounds had weak insecticidal activity against Mythimna separata and Plutella xylostella at 200 mg/L and might be not suitable as insecticide lead compound for further optimization.     

Structure-Based Bioisosterism Design,Synthesis, Biological Activity and Toxicity of 1,2,4-Oxadiazole Substituted Benzamides Analogues Containing Pyrazole Rings

In order to discover pesticidal lead compounds with high activity and low toxicity, a series of novel benzamides substituted with pyrazole-linked 1,2,4-oxadiazole were designed via bioisosterism. The chemical structures of the target compounds were confirmed via ¹H NMR, ¹³C NMR and HRMS analysis. The preliminary bioassay showed that most compounds exhibited good lethal activities against Mythimna separate, Helicoverpa armigera, Ostrinia nubilalis and Spodoptera frugiperda at 500 mg/L. Particularly in the case of Mythimna separate, compound 14q (70%) exhibited obvious insecticidal activity. In addition, compound 14h demonstrated good fungicidal activity against Pyricularia oryae with an inhibition rate of 77.8%, and compounds 14e, 14k, 14n and 14r also showed certain antifungal activities (55.6–66.7%). The zebrafish toxicity test showed that the LC₅₀ of compound 14h was 14.01 mg/L, which indicated that it may be used as a potential leading compound for further structural optimization.     

含呋喃环双酰肼类化合物的合成及杀虫活性研究

为发现新的昆虫生长调节剂, 经邻、间、对氯单取代苯基呋喃甲酰氯与取代苯甲酰肼反应得到15个未见文献报道的含呋喃环双酰肼类化合物, 其结构均通过了IR, ¹H NMR和元素分析确认. 初步生测结果表明R²为对氯取代的目标化合物对3龄粘虫(Mythimna separate)表现出较好或中等的杀幼虫活性. 其中化合物Io和Ij在药剂浓度为0.1%时, 对粘虫幼虫的死亡抑制率分别为85%和55%, 并对幼虫蜕皮有一定的抑制作用. 而大部分目标化合物在药剂浓度为0.05%时, 对豆蚜(Aphis fabae)和棉红蜘蛛(Tetranchus urticae)杀虫活性不明显.     

Synthesis, crystal structure and biological activity of a novel anthranilic diamide insecticide containing allyl ether

In search of environmentally benign insecticides with high activity, low toxicity and low residue, a series of novel anthranilic diamides containing allyl ether were designed and synthesized. All the compounds were characterized by ¹H NMR spectroscopy, HRMS or elemental analysis. The single crystal structure of 18e was determined by X-ray diffraction. The insecticidal activities of the new compounds were evaluated. The results showed that some compounds exhibited excellent insecticidal activities against Lepidoptera pests. Among this series compounds, 18l showed 100 % larvicidal activity against Mythimna separate Walker and Plutella xylostella Linnaeus at the test concentration.     

Synthesis and insecticidal activities of O,O-dialkyl-2-[3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carbonyloxy] (aryl) methylphosphonates

A series of novel O,O-Dialkyl-2-[3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carbonyloxy](aryl) methy-lphosphonates I-1–14 were designed and synthesized. The structures of all the title compounds were confirmed by ¹H-NMR, ¹³C-NMR, ³¹P-NMR, IR and elemental analysis. Their insecticidal activities against Mythimna separata and Plutella xylostella were evaluated. The results of bioassays indicated that the title compounds exhibited 20–80% larvicidal activity against Mythimna separata at 1000 mg/L.     

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.     

The Antimicrobial Activity,Mosquito Larvicidal Activity,Antioxidant Property and Tyrosinase Inhibition of Piper Betle

The essential oil and methanolic and aqueous extracts of Piper betle L. were assayed for their antimicrobial activity, mosquito larvicidal activity, antioxidant property and mushroom tyrosinase inhibition. The methanolic and aquaous extracts showed strong activity against the yeasts: C. albicans, and M. pachydermatis. The crude essential oil exhibited a broad‐spectrum strong antimicrobial activity against all test organisms. The strongest activity was observed against C. albicans, followed by S. aureus and M. pachydermatis. The chemical composition of the essential oil and its fractions was analyzed by GC/MS analysis. Eugenol (36.2%), chavibetol acetate (16.9%), 4‐allylphenyl acetate (9.4%) and 4‐allylphenol (7.2%) were the main components, comprising 69.7% of the oil. The fractionation of the essential oil gave two fractions. Fraction I was rich in eugenol (71.3%) and fraction II in eugenol (46.4%), chavibetol acetate (19.4%) and 4‐allylphenyl acetate (11.8%). The essential oil exhibited the mosquito larvicidal activity with 2 h and 24 h LD₅₀ value of 86 and 48 ppm, respectively. The methanolic extract of P. betle showed larvicidal activity with 2 h and 24 h LD₅₀ value of 153 and 125 ppm, respectively, whereas the aqueous extract showed slight active. The individual antioxidant assays such as DPPH scavenging activity, chelating effect of ferrous ions and reducing power have been used. P. betle showed remarkable antioxidant activity in DPPH and reducing power assays. The activity observed can be attributed to the presence of the phenolic compounds. The essential oil exhibited concentration‐dependent inhibition of mushroom tyrosinase, giving an IC₅₀ value of 126 ppm. The fraction I showed a strong inhibition of tyrosinase activity, giving an IC₅₀ value of 115 ppm. The presence of 4‐allylphenolic components in the essential oil may play an important role in the inhibition of tyrosinase. In conclusion, the results presented here show that Piper betle essential oil could be considered as a natural antimicrobial, mosquito larvicidal, antioxidant and tyrosinase inhibition source.     

Synthesis and Antifungal Activity Evaluation of Novel Substituted Pyrimidine‐5‐Carboxamides Bearing the Pyridine Moiety

A series of novel N‐(substituted phenyl/benzyl)‐2‐methylthio‐4‐((pyridin‐3‐ylmethyl)amino)pyrimidine‐5‐carboxamides were synthesized by multistep reactions. The structures of the target compounds were characterized by IR, ¹H NMR, ¹³C NMR, and elemental analysis. Their in vitro antifungal activities against two kinds of plant pathogenic fungi were evaluated by the mycelial growth rate method. The result showed that at the dosage of 100 μg/mL, several of these compounds exhibited moderate activity against Botrytis cinerea with inhibition rates of ~70%, and most compounds (e.g., 5a , 5c , 5e , 5f, and 5h ) possessed excellent activity against Sclerotinia Sclerotiorum with more than 90% inhibition rate.     

Synthesis and Herbicidal Activity of Muti‐Substituted Pyrido[4,3‐d]pyrimidin‐4‐ones

A series of novel muti‐substituted pyrido[4,3‐d]pyrimidin‐4‐one derivatives 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j , 5k , 5l were designed and synthesized by the muti‐step reaction. N,S‐acetal 1 reacted with acetyl acetamide in the presence of zinc nitrate to obtain muti‐substituted pyridine 2 , which reacted with triethyl orthoformate to give 8‐cyano‐5‐methyl‐7‐methylthio‐pyrido[4,3‐d]pyrimidin‐4‐one 3 ; the target compounds 5 were obtained in good yields by the oxidation of 3 with H₂O₂ in a catalytic amount of sodium tungstate then by the substitution with various substituted phenols. Their structures were confirmed by IR, ¹H NMR, EI‐MS, and elemental analyses. The preliminary bioassay indicated that some of them displayed moderate herbicidal activity against dicotyledonous weed Brassica campestris L. at the concentration of 100 mg/L. For example, compounds 5a , 5f , and 5g possessed 76.0%, 62.7%, and 60.2% inhibition against B. campestris at the concentration of 100 mg/L. Moreover, 5a exhibited 58.2% inhibition against B. campestris at the concentration of 10 mg/L.     

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.     

Synthesis and Bioactivity of Novel N,N'-Diacylhydrazine Derivatives Containing Furan (Ⅱ)

Diacylhydrazines have been found as molting hormone analogs since RH‐5849 was reported as the first nonsteroidal ecdysone agonist in 1988. Optimizations on diacylhydrizines with benzoheterocycle containing oxygen were widely explored in recent years. In order to find novel compounds with high bioactivity, a series of mono‐ ( I ) and di‐acylhydrazine ( II ) derivatives containing furan were designed and synthesized. Their structures were confirmed by ¹H NMR, IR, elemental analyses and single crystal X‐ray diffraction analyses ( II ₇). The bioassay results showed that some of the mono‐acylhydrazine ( I ) derivatives exhibited good larvicidal activity against Culex pipiens pallens at 10 mg/L and better than those of di‐acylhydrazines ( II ). Generally, the anti‐tumor activity of di‐acylhydrazines ( II ) was better than that of mono‐acylhydrazines ( I ).     

Design,Synthesis and Insecticidal Activity of Novel Anthranilic Diamides Containing Oxime Ester and Diacylhydrazine Moieties

Two series of novel anthranilic diamides containing oxime ester and diacylhydrazine moieties were designed and synthesized.Their structures were characterized by melting points,1H NMR,13C NMR and high resolution mass spectrometry（HRMS）.The single crystal structure of compound 7e was determined by X-ray diffraction and their evaluated insecticidal activity against oriental armyworm（Mythimna separata） indicates that some of the compounds exhibited moderate insecticidal activities.Among the 20 compounds,6a and 6b show 100％ larvicidal activity against Mythimna separate Walker at the test concentration of 100 mg/L.     

Synthesis and Antibacterial Evaluation of Some Semicarbazides and 1,2,4‐Triazol‐5‐Ones Containing Thiophene Moieties

In this study, some 3‐(thiophen‐2‐ylmethyl)‐4‐substituted‐4,5‐dihydro‐1H‐1,2,4‐triazol‐5‐one derivatives were synthesized by the cyclization reaction of 1‐(thiophen‐2‐ylacetyl)‐4‐substituted semicarbazide derivatives in alkaline medium or in the immediate reaction of thiophen‐2‐yl‐acetic acid hydrazide with isocyanates. The structures of all new compounds were confirmed by analytical and spectroscopic methods. Selected derivatives were evaluated in vitro against several species of aerobic bacteria. Some of them showed activity against S. pyogenes, P. aeruginosa and S. aureus.     

Synthesis and Herbicidal Activity of Acylpyrazole Derivatives Containing 1,2,3‐Thiadiazole Moiety

A series of novel acylpyrazole derivatives containing 1,2,3‐thiadiazole ring 3a – 3m were synthesized by the condensations of 1‐phenyl‐3‐methyl‐4‐(substituted benzal or 4‐methyl‐1,2,3‐thiadiazole‐5‐carbonyl)‐5‐hydroxypyrazole 2 with 4‐methyl‐1,2,3‐thiadiazole‐5‐carbonyl chloride or substituted benzoyl chloride. Their structures were confirmed by IR, ¹H‐NMR, mass spectroscopy, and elemental analyses. The results of preliminary bioassays showed that some of the title compounds 3 exhibited moderate to good herbicidal activities against dicotyledonous plants (Brassica campestris L.) at the concentration of 100 mg/L. For example, compounds 3e , 3f , 3g , and 3k possessed 74.6%, 72.2%, 70.3%, and 84.5% inhibition against B. campestris L., respectively, whereas commercially available herbicide Sulcotrione showed only 35.0% inhibition at the same concentration. Moreover, these compounds displayed higher herbicidal activity against B. campestris L. than Echinochloa crus‐galli. However, these compounds showed weak activities at the concentration of 10 mg/L.     

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.     

Synthesis of 3,5-Dichloro-4-(1,1,2,2-tetrafluoroethoxy)phenyl Containing 1,2,3-Thiadiazole Derivatives via Ugi Reaction and Their Biological Activities

A series of novel 3,5‐dichloro‐4‐(1,1,2,2‐tetrafluoroethoxy)phenyl containing 4‐methyl‐1,2,3‐thiadiazole derivatives were designed and synthesized via Ugi reaction. Their structures were confirmed by IR, ¹H NMR, ¹³C NMR and high‐resolution mass spectroscopy. The preliminary bioassay results indicated that some title compounds had good fungicide activity at 50 µg/mL; most of the compounds presented a certain degree of direct inhibition activity, good inactivation and curative activity against tobacco mosaic virus at 500 µg/mL and 100 µg/mL; some compounds showed good larvicidal activity against Plutella xylostella L. at 200 µg/mL and excellent larvicidal activities against Culex pipiens pallens at 2 µg/mL.     

Design, Syntheses and Biological Activities of Novel Anthranilic Diamide Insecticides Containing N-Pyridylpyrazole

In search of environmentally benign insecticides with high activity, low toxicity and low residue, a series of novel anthranilic diamide derivatives containing N-pyridylpyrazole was designed and synthesized. All the compounds were characterized by ¹H NMR spectroscopy and elemental analysis. The single crystal structure of compound 8j was determined by X-ray diffraction. The insecticidal activities of the new compounds were evaluated. The results show that some compounds exhibited moderate insecticidal activities against Lepidoptera pests. Among this series of compounds, compounds 8o and 8p showed 100% larvicidal activity against Mythimna separate Walker, Plutella xylostella Linnaeus and Laphygma exigua Hubner at a test concentration of 200 mg/kg, which is equal to the commercial chlorantraniliprole.     

新型含N-吡啶基吡唑杂环的邻氨基苯甲酸酯类化合物合成，结构及生物活性研究

设计,合成了8个新的含N-吡啶基吡唑杂环的邻氨基苯甲酸酯类化合物,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14d的结构。并且对这些化合物进行了杀虫活性测试,结果表明目标化合物在200 µg·mL-1对粘虫 (Mythimna separata Walker)具有一定的杀虫活性,其中14d,14f,14h在1 µg·mL-1对淡色库蚊（Culex pipiens pallens）具有很好的杀幼虫活性。     

Antimicrobial,Mosquito Larvicidal and Antioxidant Properties of the Leaf and Rhizome of Hedychium coronarium

The essential oil, methanolic and aqueous extracts of the leaves and rhizomes of Hedychium coronarium Koen. (Zingiberaceae) were assayed for their antimicrobial, mosquito larvicidal and antioxidant properties. The chemical composition of the essential oil of two organs was analyzed by GC/MS analysis. β‐Pinene (33.9%), α‐pinene (14.7%), 1,8‐cineole (13.3%), r‐elemene (11.0%) and carotol (9.1%) were the main components in the leaf oil, including 82.0% terpenoid compounds. The major constituents of the rhizome oil were 1,8‐cineole (37.3%), β‐pinene (23.0%), α‐terpineol (10.4%) and α‐pinene (9.9%), comprising 80.6% of the oil. The leaf and rhizome essential oil displayed significant antimicrobial activity, as determined by the disc‐diffusion method, inhibiting the growth of all five fungal and four bacterial strains tested. The antimicrobial nature of the essential oil is related to high terpenoid contents. The leaf oil exhibited the mosquito larvicidal activity with 2 h and 24 h LC₅₀ values of 111 and 90 ppm, respectively, while the rhizome oil showed the larvicidal activity with 2 h and 24 h LC₅₀ values of 86 and 47 ppm, respectively. β‐Pinene, α‐pinene and 1,8‐cineol in H. coronarium serve as the principal larvicidal components of both oils. The individual antioxidant assays such as DPPH scavenging activity, chelating effect of ferrous ions and reducing power have been used. The present study demonstrated that the polar extracts of H. coronarium possessed anti‐oxidant. Appreciable total phenolic content (18.5‐26.3 mg/g) was also detected by Folin‐Ciocalteu test.