DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane), a contact insecticide with rich and controversial history since its activity was discovered in 1939, has long been thought to be monomorphic. Herein we report the discovery characterization of second polymorph, designated Form II, which can isolated as single crystals, but converts very slowly at room temperature form reported previously, now I. Computations based on an evolutionary algorithm for crystal structure prediction revealed that...

Pyrethroid contact insecticides are mainstays of malaria control, but their efficacies declining due to widespread insecticide resistance in Anopheles mosquito populations, a major public health challenge. Several strategies have been proposed overcome this challenge, including with new modes action. New insecticides, however, can be expensive implement low-income countries. Here, we report simple and inexpensive method improve the efficacy deltamethrin, most active commonly used pyrethroid,...

Imidacloprid, the world's leading insecticide, has been approved recently for controlling infectious disease vectors; yet, in agricultural settings, it implicated frightening decline of pollinators. This argues strategies that sharply reduce environmental impact imidacloprid. When used as a contact effectiveness imidacloprid relies on physical between its crystal surfaces and insect tarsi. Herein, seven new polymorphs are reported, adding to two known forms. Anticipating uptake molecules...

The first example of a copper(I)-catalyzed intramolecular aminotrifluoromethylation unactivated alkenes using (TMS)CF3 (trimethyl(trifluoromethyl)silane) as the CF3 source is described. A broad range electronically and structurally varied substrates undergo convenient step-economical transformations for concurrent construction five- or six-membered ring C-CF3 bond toward different types trifluoromethyl azaheterocycles. methodology not only circumvents use expensive electrophilic reagents...

The asymmetric inverse-electron-demand hetero-Diels–Alder (IEHDA) reactions of imines and dienophiles have emerged as an attractive tool for derivatizing optically active complex azaheterocycles. In comparison, such involving iminium ions remain great challenges because low association with neutral catalytic centers. To overcome this, we report a metal-phosphate-catalyzed tandem hydroamination/formal Povarov reaction secondary aminoalkynes via chiral counteranion-controlled ion intermediate...

Malaria control is under threat by the development of vector resistance to pyrethroids in long-lasting insecticidal nets, which has prompted calls for a return notorious crystalline contact insecticide DDT. A faster acting difluoro congener, DFDT, was developed Germany during World War II, but 1945 Allied inspectors dismissed its superior performance and reduced toxicity mammals. It vanished from public health considerations. Herein, we report discovery amorphous forms DFDT mono-fluorinated...

Two books that describe the forms of thin films many molecular crystals grown from melt in polarized light, "Gedrillte" Kristalle (1929) by Ferdinand Bernauer and Thermomicroscopy Analysis Pharmaceuticals (1971) Maria Kuhnert-Brandstätter, are analyzed. Their descriptions, especially curious morphologies consistent with helicoidal twisting crystalline fibrils or narrow lamellae, compared aggregate observations our laboratory collected during past 10 years. According to Bernauer, 27% adopt...

We have developed a new copper-based photocatalyst, [(binap)(tpy)Cu]Cl, and applied it in the visible-light promoted Sonogashira coupling reactions.

A metal-free organic photoredox-catalyzed alkylation of heteroarenes using alkylsulfonium salts as reagents has been developed.

A copper-catalyzed decarboxylative C–H alkylation of heteroarenes with alkyl carboxylic acids has been realized.

Islatravir, a highly potent nucleoside reverse transcriptase translocation inhibitor (NRTTI) for the treatment of HIV, has great potential to be formulated as ethylene-vinyl acetate (EVA) copolymer-based implants via hot melt extrusion. The crystallinity EVA determines its physical and rheological properties may impact drug-eluting implant performance. Herein, we describe systematic analysis factors affecting in islatravir implants. Differential scanning calorimetry (DSC) on solid-state NMR...

Abstract DDT (1,1,1‐trichloro‐2,2‐bis(4‐chlorophenyl)ethane), a contact insecticide with rich and controversial history since its activity was discovered in 1939, has long been thought to be monomorphic. Herein we report the discovery characterization of second polymorph, designated Form II, which can isolated as single crystals, but converts very slowly at room temperature form reported previously, now I. Computations based on an evolutionary algorithm for crystal structure prediction...

Contact insecticides often involve the interaction of whole organisms and toxicant crystal surfaces. The crystalline phase these compounds has not, however, been considered for optimization insecticide performance. Lindane (1R,2r,3S,4R,5r,6S-hexachlorocyclohexane) one most widely used insecticides, but other (inactive) stereoisomers accompanying its manufacture have led to massive chemical waste remediation problems. Crystalline polymorphs are also isomers in broadest sense, yet only...

Crystal polymorphism, characterized by different packing arrangements of the same compound, strongly ties to physical properties a molecule. Determining polymorphic landscape is complex and time-consuming, with number experimentally observed polymorphs varying widely from molecule Furthermore, disappearing polymorphs, phenomenon whereby forms cannot be reproduced, pose significant challenge for pharmaceutical industry. Herein, we focused on oxindole (OX), small rigid four known including...

Subretinal fibrosis is an important cause of visual loss in age-related macular degeneration, but its mechanism remains unclear. This study aims to investigate the role macrophage-to-myofibroblast transition (MMT) formation subretinal and assess whether circ_0001103 can regulate by regulating MMT. was induced C57BL/6J mice laser induction. The expression profiles circRNAs a choroidal neovascularization (CNV) model were accessed via microarray analysis. MMT TGF-β1 (2.5 ng/ml, 48 h)....

Abstract In this manuscript, we report a radical type ring‐opening of sulfonium salts with heteroarenes under visible light conditions. This developed method does not require noble metal photocatalysts, or stoichiometric amount external oxidants, and has application prospect in the synthesis organosulfur compounds bioactive molecules. photocatalytic system could inspire further applications C( sp 3 )−C( 2 ) bond forming reactions. magnified image

The Au-catalyzed tandem reaction provided simple and efficient access to spiro-dipyrroloquinolines incargranine B aglycone (±)-seneciobipyrrolidine (<bold>I</bold>).

Ion-mediated interaction is important for the properties of polyelectrolytes such as colloids and nucleic acids. The effective pair interactions between two have been investigated extensively, but many-body effect multiple still remains elusive. In this work, in potential mean force (PMF) like-charged nanoparticles various salt solutions has comprehensively examined by Monte Carlo simulation nonlinear Poisson-Boltzmann theory. Our calculations show that, at high 1:1 salt, PMF weakly...

Abstract A convenient platinum‐catalyzed tandem cyclization reaction from readily available aminoalkynes and enones has been developed to efficiently prepare multiply substituted indolines in good yields under microwave irradiation within a short time. This efficient is presumed proceed via process involving intramolecular hydroamination of aminoalkynes, Michael addition enones, aldol condensation intermolecular transfer hydrogenation. magnified image

The activity of crystalline contact insecticides relies on the extraction surface molecules by insect tarsi upon contact. Most crystals are inherently anisotropic, and symmetry independent faces expected to have different free energies. facet-dependent bioavailability associated efficacy lethality not been investigated, however. We discriminate bioactivity various facets single DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane), a well-known insecticide. Our findings reveal differences...

The active forms of contact insecticides used for combatting mosquito-borne infectious diseases are typically crystalline solids. Numerous molecular crystals polymorphic, crystallizing in several solid characterized by different physicochemical properties, including bioavailability. Our laboratory recently found that the activity is inversely dependent on thermodynamic stability their polymorphs, suggesting efficacy can be enhanced manipulation solid-state structure. This paper argues...

The development of safe and potent insecticides remains an integral part a multifaceted strategy to effectively control human-disease-transmitting insect vectors. Incorporating fluorine can dramatically alter the physiochemical properties bioavailability insecticides. For example, 1,1,1-trichloro-2,2-bis(4-fluorophenyl)ethane (DFDT)─a difluoro congener trichloro-2,2-bis(4-chlorophenyl)ethane (DDT)─was demonstrated previously be 10-fold less toxic mosquitoes than DDT in terms LD50 values, but...