Discovery of new pesticide candidates from nature: design, synthesis and bioactivity research of rutaecarpine derivatives.

Background: The invasion of viruses and fungi can cause pathological changes in the normal growth of plants and is an important factor in causing plant infectious diseases. These pathogenic microorganisms can also secrete toxic metabolites, affecting crop quality and posing a threat to human health. In this work, we selected the natural product rutaecarpine as the lead compound to achieve the total synthesis and structural derivation.

Design, synthesis, and insecticidal and fungicidal activities of quaternary ammonium salt derivatives of a triazolyphenyl isoxazoline insecticide.

Background: Insect pests seriously decrease the yield and quality of agricultural crops. Resistance to commonly used insecticides is increasingly undermining their effectiveness, and therefore the development of agents with novel modes of action is desirable. Isoxazolines are a new class of insecticides that act on γ-aminobutyric acid (GABA) gated chloride channels.

Discovery of glyantrypine-family alkaloids as novel antiviral and antiphytopathogenic-fungus agents.

Background: Plant diseases caused by viruses and fungi have caused great losses to crop quality and yield. The discovery of novel and efficient antiviral and antiphytopathogenic-fungus agents is urgently needed. It is the most important pesticide innovation strategy to find active compounds from natural products.

Pityriacitrin marine alkaloids as novel antiviral and anti-phytopathogenic-fungus agents.

Background: Plant diseases have been gripping agricultural production, seriously affecting the growth and yields of crops. Marine natural products are an important source for novel drugs discovery. In this work, pityriacitrin marine alkaloids were selected as the parent structures.

Rhodium(III)-Catalyzed Direct Coupling of Quinoline-8-Carbaldehydes with (Het)Arylboronic Acids for the Synthesis of 8-Aryloylquinolines.

Herein, we describe a method for the synthesis of aryl-(het)aryl ketones by Rh(III)-catalyzed direct coupling between quinoline-8-carbaldehydes and (het)arylboronic acids. The method has a broad substrate scope, a high functional group tolerance, and uses commercially available starting materials. Scale-up of the reaction and subsequent synthesis of tubulin polymerization inhibitor demonstrated its utilities.

Transfer learning radiomics based on multimodal ultrasound imaging for staging liver fibrosis.

Objectives: To propose a transfer learning (TL) radiomics model that efficiently combines the information from gray scale and elastogram ultrasound images for accurate liver fibrosis grading.

Methods: Totally 466 patients undergoing partial hepatectomy were enrolled, including 401 with chronic hepatitis B and 65 without fibrosis pathologically. All patients received elastography and got liver stiffness measurement (LSM) 2-3 days before surgery.

Preoperative Prediction of Microvascular Invasion of Hepatocellular Carcinoma: Radiomics Algorithm Based on Ultrasound Original Radio Frequency Signals.

To evaluate the accuracy of radiomics algorithm based on original radio frequency (ORF) signals for prospective prediction of microvascular invasion (MVI) in hepatocellular carcinoma (HCC) lesions. In this prospective study, we enrolled 42 inpatients diagnosed with HCC from January 2018 to December 2018. All HCC lesions were proved by surgical resection and histopathology results, including 21 lesions with MVI.

Marine-natural-products for biocides development: first discovery of meridianin alkaloids as antiviral and anti-phytopathogenic-fungus agents.

Background: Food is an important strategic material related to national economy and people's livelihood. Plant diseases seriously affect crop yield and quality. Marine natural products are an important source for novel drugs discovery.

Blue light photoredox-catalysed acetalation of alkynyl bromides.

Herein, we report an organo-photoredox-based protocol using 2,2-diethoxyacetic acid as the acetal source to achieve acetalation of alkynyl bromides to afford various alkynyl acetal products. In addition to arylethynyl bromides, substrates bearing heteroaryl rings (thiophene, pyridine, and indole) smoothly gave the corresponding acetalation products. This mild protocol has potential utility for the synthesis of aldehydes by further protonization.

Visible-Light-Induced Copper-Catalyzed Decarboxylative Coupling of Redox-Active Esters with -Heteroarenes.

Herein we report a protocol for visible-light-induced copper-catalyzed decarboxylative coupling reactions between -heteroarenes and redox-active esters. Various -hydroxyphthalimide esters reacted with isoquinoline, quinoline, pyridine, pyrimidine, quinazoline, phthalazine, phenanthridine, and pyridazine to give the corresponding products in modest to excellent yields. The reactions proceed under mild conditions and have a broad scope and high functional group tolerance.

Publisher Correction: Total synthesis of the reported structure of 13a-hydroxytylophorine.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Dehydrogenation of N-Heterocycles by Superoxide Ion Generated through Single-Electron Transfer.

Nitrogen-containing heteroarene motifs are found in numerous pharmaceuticals, natural products, and synthetic materials. Although several elegant methods for synthesis of these compounds through dehydrogenation of the corresponding saturated heterocycles have been reported, some of the methods are hampered by long reaction times, harsh conditions, and the need for catalysts that are not readily available. This work reports a novel method for dehydrogenation of N-heterocycles.

Total synthesis of the reported structure of 13a-hydroxytylophorine.

The first total synthesis of the reported structure of 13a-hydroxytylophorine was accomplished. The key step was an unprecedented NaBH-promoted one-pot reductive cyclization cascade that efficiently yielded a hydroxyl azonane intermediate. The indolizidine framework was obtained by means of oxidation and a subsequent unexpected protecting-group migration.

Noninvasive evaluation of corneal viscoelasticity based on displacement in response to acoustic radiation force.

Noninvasive assessment of corneal mechanical properties in vivo will help to the understanding of the pathogenesis and early diagnosis of ectatic corneal disorders. This study presented a noninvasive method that assesses the corneal biomechanical properties by exciting the cornea with acoustic radiation force and monitoring its displacement using a dual-frequency confocal transducer. A 3.

Monitor Polyimide Production from Diamine and Dianhydride Reactions Using a Combination of In Situ Infrared and Raman Spectroscopy.

A two-step synthesis of polyimide reaction from dianhydride and diamine was followed by both infrared (IR) and Raman spectroscopy in situ in this case study. In the first step, the two reactants form poly(amide acid), which resulted in substantial spectral changes easily detected by both spectroscopic techniques. The reaction was found to occur rapidly and reached completion within tens of minutes at room temperature.

Design, synthesis, anti-TMV, fungicidal, and insecticidal activity evaluation of 1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid derivatives based on virus inhibitors of plant sources.

By drawing the creation ideas of botanical pesticides, a series of tetrahydro-β-carboline-3-carboxylic acid derivatives were designed and synthesized, and first evaluated for their anti-TMV, fungicidal and insecticidal activities. Most of these derivatives exhibited good antiviral activity against TMV both in vitro and in vivo. Especially, the activities of compounds 8 and 15 in vivo were higher than that of ribavirin.

Design, synthesis, and biological evaluation of 2-benzylpyrroles and 2-benzoylpyrroles based on structures of insecticidal chlorfenapyr and natural pyrrolomycins.

Based on structures of insecticidal chlorfenapyr and antibiotic natural pyrrolomycins, a series of new 2-benzylpyrroles and 2-benzoylpyrroles (with or without ethoxymethyl group on the nitrogen of pyrrole) were designed and synthesized. These compounds or their parent compounds possess weak acidity and high lipophilicity, the two characteristic properties for uncouplers of oxidative phosphorylation; therefore, they are expected to have insecticidal and acaricidal activity. The bioassay result verified that both 2-benzylpyrroles 17 and 2-benzoylpyrroles 19 had varied degrees of insecticidal activity against oriental armyworm depending on the substituents on the benzene ring, but they did not give any acaricidal activity.

The discovery of 3-(1-aminoethylidene)quinoline-2, 4(1H,3H)-dione derivatives as novel PSII electron transport inhibitors.

Based on the structures of the 4-hydroxyphenylpyruvate dioxygenase inhibitor mesotrione and natural product fischerellin A, a series of imine derivatives of (E)-3-acyl-quinoline-2,4(1H,3H)-dione (6, 12 and 16) were designed, synthesized and systematically evaluated for their herbicidal activity. The bioassay results indicated that most of the synthesized compounds displayed good to excellent herbicidal activity, of which 6e, 6g, 6h, 6q and 6t exhibited more than 50 % inhibition against Brassica napus L., Amaranthus retroflexu or Digitaria adscendens at a dosage of 94 g ha−1 or lower.

First total synthesis of papilistatin.

Papilistatin has been isolated recently and found to have good anticancer and antibacterial activity. Papilistatin is a unique phenanthrene-1,10-dicarboxylic acid. The first total synthesis of papilistatin is described here with radical cyclisation as the key step.

Improved cellular immune response elicited by a ubiquitin-fused ESAT-6 DNA vaccine against Mycobacterium tuberculosis.

The present study evaluated the immune response elicited by a ubiquitin-fused ESAT-6 DNA vaccine against Mycobacterium tuberculosis. BALB/c mice were vaccinated with plasmid DNA encoding ESAT-6 protein, ubiquitin-fused ESAT-6 DNA vaccine (UbGR-ESAT-6), pcDNA3-ubiquitin and blank vector, respectively. ESAT-6 DNA vaccine immunization induced a Thl-polarized immune response.

N'-Benzoyl-N-tert-butyl-2-chloro-N'-{[3-(6-chloro-3-pyrid-ylmethyl)-2-nitrimino-imidazolidin-1-yl]sulfan-yl}benzo-hydrazide.

In the title compound, C(27)H(27)Cl(2)N(7)O(4)S, the amide groups bearing the N-S group and the tert-butyl group have s-trans conformations. The steric size of the tert-butyl and [(6-chloro-3-pyrid-yl)meth-yl]imidazolidin-2-yl-idene groups cause the 2-chloro-benzoyl group and the benzyol group to be directed away from one another, forming a dihedral angle of 60.62 (17)°.

Synthesis, herbicidal activities, and 3D-QSAR of 2-cyanoacrylates containing aromatic methylamine moieties.

A series of novel 2-cyanoacrylates containing different aromatic rings were synthesized, and their structures were characterized by (1)H NMR, elemental analysis, and single-crystal X-ray diffraction analysis. Their herbicidal activities against four weeds and inhibition of photosynthetic electron transport against isolated chloroplasts (the Hill reaction) were evaluated. Both in vivo and in vitro data showed that the compounds containing benzene, pyridine, and thiazole moieties gave higher activities than those containing pyrimidine, pyridazine, furan, and tetrahedronfuran moieties.

Synthesis and insecticidal evaluation of novel N'-tert-butyl-N'-substitutedbenzoyl-N-5-chloro-6-chromanecarbohydrazide derivatives.

A series of novel N'-tert-butyl- N'-substitutedbenzoyl-N-5-chloro-6-chromanecarbohydrazide derivatives were synthesized, and their larvicidal activities against Oriental armyworm were evaluated. The results of bioassays indicated that most of these title compounds exhibit higher larvicidal activities than RH-5849, and several of them somewhat lower than the commercial insecticide tebufenozide. The larvicidal activities are strongly associated with the types and patterns of substitution on the benzene, and 3,5-dimethyl, 2-nitro-4-chloro and 3-methyl derivatives are most prominent in increasing activity.

Synthesis and bioassay evaluation of 1-(4-substitutedideneaminooxymethyl)-phenyl-3-(2,6-difluorobenzoyl)ureas.

A variety of novel 1-(4-substitutedideneaminooxymethyl)-phenyl-3-(2,6-difluorobenzoyl)ureas were designed and synthesized by the reaction of 4-substitutedideneaminooxymethyl aniline with 2,6-difluorobenzoyl isocyanates in good yields. The title compounds were soluble in most organic solvents, which should make them easier to use. The preliminary bioassay showed that some of the title compounds show excellent insecticidal activity against Mythimna separata at the dosage of 25 mg kg(-1) and moderate insecticidal activity against Nephotettix cincticeps at the dosage of 500 mg kg(-1).

Iptakalim alleviated the increase of extracellular dopamine and glutamate induced by 1-methyl-4-phenylpyridinium ion in rat striatum.

The present study examined the effect of iptakalim (Ipt), a novel ATP-sensitive potassium (K(ATP)) channel opener (KCO), on 1-methyl-4-phenylpyridinium ion (MPP(+))-induced dopamine (DA) and glutamate efflux in extracellular fluid of rat striatum, using microdialysis technique. Rats were implanted guide cannula in the striatum and artificial cerebrospinal fluid was infused through a microdialysis probe to detect the level of DA and glutamate in the striatum. MPP(+) significantly enhanced the extracellular levels of DA and its metabolites, DOPAC and HVA, as well as glutamate.