Synthesis of some novel 5-substituted benzamido-6-arylamino-pyrazolo[3,4-D]pyrimidin-4-one derivatives for herbicidal activity

Abstract

Sixteen novel 3-methylthio-5-substituted benzamido-6-arylamino-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4 (5H)-one derivatives (4a–p) were successfully synthesized from iminophosphoranes, aryl isocyanate, and substituted benzoylhydrazine. The structures of the title compounds were elucidated by FT-IR, ¹H NMR, ¹³C NMR, and HRMS. Herbicidal activity of the compounds 4a–p against Brassica napus (rape), Echinochloa crusgalli (barnyard grass), Cucumis sativus (cucumber), and Triticum aestivum (wheat) were determined. The results showed that 5-(2-chlorobenzamido)-6-phenylamino-3-methylthio-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4 (5H)-one (4c) displayed remarkable inhibition activity against the stalk and root of rape with 100% inhibition rate at the dosages of 10?mg/L and 100?mg/L, and 5-(4-nitrobenzamido)-6-phenylamino-3-methylthio-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4 (5H) -one (4d) exhibited excellent activity against the stalk and root of barnyard grass with 100% inhibition rate at the same dosages.     

Silver Nanoparticles in Polyacrylamide and Hyperbranched Polyamine Matrix

Silver nanoparticles have been prepared in a polyacrylamide (PA) matrix, as well as in the presence of a hyperbranched polyamine/polyacrylamide combined system (HB‐PA) by using a reductive technique. The stability of colloidal solution of silver nanoparticles is higher (5 months) in combined matrix compared to PA alone (4 months). The prepared silver nanoparticles were characterized by different spectroscopic and analytical techniques such as FTIR, UV‐visible, X‐ray diffraction, TEM etc. TEM and XRD studies confirmed the formation of well‐dispersed nanoparticles with an average size of 9.91 nm and 8.5 nm for PA and HB‐PA matrices, respectively. The antibacterial activity of silver nanoparticles in both the matrices was tested against Bacillus Subtilis bacteria by using the diffusion disc technique. The result shows that the antibacterial activity of the active agent, Ag(0) is a little higher in the case of HB‐PA system. The dielectric constant of the matrices decreases with an increase in frequency, but the values increase with an increase of concentration of silver nanoparticles in PA matrix.     

QSAR Correlations of the Algistatic Activity of 5-Amino-1-Aryl-1H-Tetrazoles

Abstract

The algistatic activity of 20 substituted 5-aminol-aryl-1H-tetrazoles was correlated with the second order Kier and Hall index, the XY shadow on the XY rectangle and the total hybridization component of the molecular dipole by the CODESSA program in a three parameter equation with r² = 0.9330.     

Asymmetric Synthesis, Antifungal Activity and Molecular Modeling of Iodiconazole Isomers

Iodiconazole is a novel antifungal agent that was developed in its racemic form. In order to investigate the ef- fects of the chiral center on the antifungal activity, R- and S-isomers of iodiconazole were prepared on the basis of the asymmetric Sharpless epoxidation. （S）-Iodiconazole was proved to have better antifungal activity than the （R）- isomer. The binding modes of the two isomers with lanosterol 14~z-demethylase were clarified by molecular dock- ing.     

The cytotoxic activities of imidazole derivatives prepared from various guanylhydrazone and phenylglyoxal monohydrate

Abstract

A series of imidazole derivatives were synthesized from two-component condensation reaction of phenylgloxal monohydrate with guanylhydrazone. They were characterized by spectroscopic and analytical techniques. The in vitro anticancer evaluation of these compounds was done on human breast cancer (MCF-7) and human liver cancer (HepG2) cell lines using the MTT assay method. Most of the newly synthesized compounds displayed cytotoxic activity against these cancerous cells. In fact, compounds 3a, 3e, and 3?h exhibited more cytotoxic activities than the positive control drugs, fluro-5, and irinocam, against the MCF-7 cell line. Almost all the compounds, except for three, 3b, 3d, and 3f, gave more cytotoxic results than cisplatin. Therefore, these compounds could be considered for further development as anticancer drug candidates.     

Silica Sulfuric Acid: An Efficient,Reusable, Heterogeneous Catalyst for the One-Pot,Five-Component Synthesis of Highly Functionalized Piperidine Derivatives

A series of highly functionalized piperidine derivatives was synthesized through one-pot, five-component reaction of aldehydes, amines, and β-ketoesters. Silica sulfuric acid efficiently catalyzes the reaction to afford the corresponding piperidine derivatives in good yields. As a representative example, heating of 4-methylaninle, 4-fluorobezaldehyde, and methyl-acetoacetate in methanol in the presence of silica sulfuric acid furnished the corresponding ethyl 2,6-bis(4-fluorophenyl)-1-p-tolyl-4-(p-tolylamino)-1,2,5,6-tetrahydropyridine-3-carboxylate in excellent yield (85%). Most of the synthesized compounds were screened in vitro for their antibacterial and antifungal activities. Most of compounds showed significant antibacterial activity.     

New Cytotoxic Triterpenoids from the Aerial Parts of Euphorbia sieboldiana

Phytochemical investigation of the EtOH extract of Euphorbia sieboldiana led to the isolation of four new oleanane‐type triterpenoids, (1β,2α,3β,19β)‐1,2,3,19‐tetrahydroxyolean‐12‐en‐28‐oic acid, (1β,3β,19β)‐1,3,19‐trihydroxyolean‐12‐en‐28‐oic acid, (1β,2α,3β,16β,19β)‐1,2,3,16,19‐pentahydroxyolean‐12‐en‐28‐oic acid, and (1β,2α,3β,19β,23)‐1,2,3,19,23‐pentahydroxyolean‐12‐en‐28‐oic acid, along with 16 known compounds. Their structures were established by extensive 1D‐ and 2D‐NMR, as well as other spectral analyses. Biological evaluation of the four new triterpenoids revealed potent cytotoxic activities against HeLa and Hep‐G2 cells.     

Mesomorphous Structure and Electrochemical Behavior of Polyelectrolyte-Ferrocenyl Surfactant Complexes

Redox-active polyelectrolyte-surfactant complexes (PSC) were prepared via the ionic self-assembly of sodium polyacrylate (PAAS) and ferrocenyl surfactant, n-alkyl (ferrocenylmethyl)ammonium bromide (Fcn, n = 8, 12, 16, where n is the carbon number of the alkyl chain), in solution. The obtained PAAS-Fcn complex exhibited crystalline and lamellar mesomorphous structure. Moreover, the ferrocenyl moieties formed H-aggregation in the solid complex as known from the blue shift in the ultraviolet-visible spectrum. Cyclic voltammogram (CV) measurements indicated that the reversibility of the electrode process became worse when the surfactant tail length increases because of the more ordered packing in the complex film formed by longer surfactant tails. The present results demonstrate that the electrochemical activity of the redox-active polyacrylate-ferrocenyl surfactant complex can be easily tuned by changing the surfactant tail length. Our work provides a simple and facile approach to the preparation of redox-active polymers with ordered mesomorphous structure by the ionic self-assembly.     

Crystal Structure of 2-（2-Carboxy-4-hydroxy-6- methoxyphenoxy）-3,5-dichloro-6-hydroxy- 4-methylbenzoic Acid 1-Methyl Ester

The title compound, neogeodin hydrate （C17H14C1208, CAS： 94540-50-8）, was derived from marine fungus Aspergilhts terreus CRIM301. It was unequivocally characterized by IR, NMR spectroscopies, and single-crystal X-ray crystallography and tested for various biological activities. Neogeodin hydrate crystallizes in the triclinic space group P1 with a = 8.1159（5） A, b = 8.2472（4） A, c= 14.1278（7） A, a = 81.448（2）°, β = 84.860（2）°, γ= 70.400（2）°, V = 880.13（8） A3; Z = 2. It comprises a diphenyl ether, asterric acid skeleton and dichloro substituents. The methoxyphenoxy rings of the inversely related molecules form a ribbon-like structure that is stabilized by O-H...O hydrogen bonds through the doubly disordered carboxyl groups and by C-H...O interactions, generating the same R22（8） ring motif. The chlorinated methylbenzoate rings, making mostly a right angle, link the parallel upper and lower ribbons via bifurcated O-H...O and C-H...O hydrogen bonds, yielding endless channels. The channels formed are further sustained by C-H...O and π...π interactions Neogeodin hydrate exhibits inhibition against superoxide anion radical formation in the xanthine/xanthine oxidase （XXO） assay, but has no aromatase inhibitory activity.