Synthesis and Crystal Structures of Axially Substituted Titaniumphthalocyanines and Preparation of PcTi@SBA‐15 and PcTi&TiOx@SBA‐15 Materials

Four axially substituted titanium(IV)phthalocyanines of formula trans‐[PcTi(OSiPh₃)₂], [PcTi{(NH)₂C₆H₄}], [PcTi(η²‐S₂)], and [PcTi=S] were prepared starting from the reactive species N,N′‐di‐4‐tolylureato(phthalocyaninato)titanium(IV). The prepared compounds were characterized by using UV/Vis‐spectroscopy, FT‐IR and raman spectroscopy, TGA, elementalanalysis and MALDI‐TOF measurements. The compound trans‐[PcTi(OSiPh₃)₂] crystallizes from chlorobenzene in the triclinic space group P with a = 10.4160(8) Å, b = 11.2160(8) Å, c = 13.1495(9) Å, α = 114.124(5)°, β = 99.452(6)°, γ = 96.174(6)°, and Z = 1. [PcTiS₂] crystallizes from chlorobenzene in the monoclinic space group P2₁/n with a = 13.114(3) Å, b = 9.752(2) Å, c = 20.975(5) Å, β = 100.46(2), and Z = 4. The crystal structures of both compounds are discussed. The reactive ureato complex could also successfully be anchored onto SBA‐15 and TiO_x@SBA‐15 materials using the apical ureato ligand as a good leaving group for the reaction with the silanol groups of the host material.     

Synthesis and antiviral evaluation of new 2,5-disubstituted 1,3,4-oxadiazole derivatives and their acyclic nucleoside analogues

Abstract  

A number of new 5-[(naphthalen-1-yloxy)-methyl]-1,3,4-oxadiazole derivatives were synthesized. Sugar 2-[5-[(naphthalen-1-yloxy)methyl]-1,3,4-oxadiazol-2-ylthio]acetohydrazones were prepared by condensation of the hydrazide with the corresponding monosaccharides. Cyclization of the sugar hydrazones with acetic anhydride afforded the substituted oxadiazoline derivatives. The synthesized compounds displayed different degrees of antiviral activities or inhibitory actions against HCV and HIV viruses.     

Solid and liquid green Ag nanoparticles based on banana peel extract as an eco-friendly remedy for ringworm in pets

Green chemistry-based biowaste has been taken attention toward new components for many applications especially in dermatophytes of animals and humans. The main goal of this study is to assist the synthetic pathways; clean and large-scale synthesis of silver nanoparticles is achieved as a promising alternative green technique with high efficiency, simplicity and less hazardous waste based on agro-waste of banana peels extract powder. The preparation of silver nanoparticles is directly via solid-state reaction and the liquid one based on the natural agro-waste of banana peels under specific conditions for treating ringworm in pets. Ultraviolet (UV)-visible spectroscopy, Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscope (TEM) were used to prove the prepared nanoparticles. A total of 30 samples from pets (dogs and cats) were subjected to mycological examination. Ten (33.3%) were culture positive, and 100% of the positive samples were Microsporum canis. In vitro antifungal activity against M. canis isolates using both the disc diffusion and the broth microdilution methods was evaluated. The significant results for solid silver nanoparticles (Ags1 and Ags2) than liquid Ag NPs (AgL) with p < 0.05 compared with itraconazole were observed. This biomaterial from waste could be used as a fast, simple, eco-friendly, and efficient method to prepare Ag NPs on solid that can be applied in the veterinary sector against ringworm.     

Synthesis of novel 5,6,7,8,9,10-hexahydropyrimido[4,5-b]quinoline derivatives for antimicrobial and anti-oxidant evaluation

Because of the well-known chemotherapeutic activity of pyrimidoquinolines, a new series of the title compounds were synthesized and biologically screened for their antimicrobial and anti-oxidant activities. The intermediate compound, 2-amino-1-cyclohexyl-4-(3,4-dimethoxyphenyl)-1,4,5,6,7,8-hexahydroquinoline-3-carbonitrile (2), was prepared and allowed to react with oxalyl chloride to give the corresponding strategic starting material, 10-cyclohexyl-5-(3,4-dimethoxyphenyl)-4-oxo-3,4,5,6,7,8,9,10-octahydropyrimido[4,5-b]quinoline-2-carbonyl chloride 3. Compound 3 underwent diverse reactions with amines to give the corresponding carboxylic amides 4, with alcohols to give the carboxylic esters 5 and with hydrazine to give the carbohydrazide 8. Compound 8 reacted with aldoses to give the corresponding polyhydroxy(-)alkyl Schiff bases 9, which upon reaction with thioglycolic acid afforded the thiazolidinone-C-acyclic nucleosides 10. Several other pyrimidoquinolines incorporated to oxadiazole, iminothiazolidinones and thiadiazoles were synthesized starting from the 2-carbohydrazide derivative 8. Most of the newly prepared derivatives showed considerable antimicrobial activity against Gram +ve and Gram ?ve bacteria and anti-oxidant activity.     

Spectrofluorometric determination of ketorolac tromethamine via its oxidation with cerium(IV) in pharmaceutical preparations and biological fluids

A simple and sensitive fluorometric method for determination of ketorolac tromethamine was studied. The method depends on oxidation of the drug with cerium(IV) and subsequent monitoring of the fluorescence of the induced cerium(III) at lambda(em) 365 nm after excitation at 255 nm. Different variables affecting the reaction conditions, such as the concentrations of cerium(IV), sulfuric acid concentration, reaction time, and temperature, were carefully studied and optimized. Under the optimum conditions, a linear relationship was found between the relative fluorescence intensity and the concentration of the investigated drug in the range of 0.1-0.8 microg/mL. No interferences could be observed from the excipients commonly present in dosage forms. The proposed method was successfully applied to the analysis of the investigated drug in its pure form, pharmaceutical preparations, and biological fluids with good accuracy and precision. The recoveries for pharmaceutical formulations ranged from 99.8-101.0 +/- 0.6% for tablets, 98.5-101.0 +/- 1.0% for ampoules, and 99.0-100.5 +/- 0.7% for eye drops. The results obtained by the proposed method were satisfactory compared with those obtained by the official method. The recoveries for biological fluids were 99.1-100.4 +/- 0.7 and 99.0-100.0 +/- 0.5% for plasma and urine, respectively.     

Synthesis of Novel Heterocycles Derived from 4‐Arylmethylene‐2‐phenyl‐1,3‐oxazole‐5(4H)‐ones

The acid hydrazide derivatives 2 were converted into pyrazolone, triazinone, and schiff bases. However, the reaction of Schiff base 12 with malononitrile or thioglycolic acid gives the pyrazolotriazinone or thiazolidinone derivative, respectively. The structures of the newly synthesized compounds were established on the basis of IR, ¹H‐NMR, mass spectral data, and elemental analyses. The antimicrobial activities of the synthesized compounds were examined against two types of bacteria and two types of fungi. Some of the tested compounds showed promising activities.     

Synthesis and X-ray crystal structures of imido and ureato derivatives of titanium(IV) phthalocyanine and their application in the catalytic formation of carbodiimides by metathesis from isocyanates

The imido titanium phthalocyanine complex [PcTi(NDip)] (Dip = 2,6-diisopropylphenyl) 2a was synthesized from [PcTiO] 1 and one eq. of DipNCO. Due to the steric demand of the Dip group, addition of another isocyanate molecule to the Ti = N functionality of 2a does not occur even at high molar ratios of DipNCO. However, 1 reacts with 2 eq. of arylisocyanates containing sterically less demanding aryl groups producing N,N'-diarylureatotitanium(iv)phthalocyanines [PcTi{κ(2)-(NR)C(O)(N'R)}] (R = p-tolyl (Tol) 3a or mesityl (Mes) 3b). The N,N' coordination (III) of the ureato ligand in 3a and 3b was proven by a single set of resonances for the aryl groups in their (1)H-NMR spectra. An N,O coordination (IV) can therefore be excluded. This is also confirmed by the X-ray crystal structure of 3a. Upon heating [PcTiO] and an excess of aryl isocyanates for 6 days, a steady evolution of CO(2) was observed and a white precipitate, identified as the corresponding diarylcarbodiimides (V), could be isolated. Therefore this reaction was applied in the metathetic conversion of two isocyanate molecules into diarylcarbodiimides (V) and CO(2). Additionally, imido titanium Pc's 2b (R = tBu) and 2c (R = Mes) were prepared by a more general synthetic strategy, reacting the potassium salt of the ligand PcK(2) with appropriate imido titanium precursors.     

X-ray scattering for the determination of fat content in dairy products

The scattering of X-rays from biological samples has been shown to produce characteristic profiles, which depend on their molecular structure. The highly ordered fat molecules in an adipose tissue result in a relatively sharp scattering peak at 1.1 nm^?1 with a scattering profile, which is considerably different from the scattering profile of a water-rich tissue. The latter is characterized by a broad scattering peak at about 1.6 nm^?1. A biological sample consisting of a mixture of both adipose and a water-rich tissue is expected to show a scattering profile, which is directly linked to the relative contribution of each component and would reflect the percentage by volume of each component in the mixture. In this work, X-ray scattering profiles of a number of dairy products and water are measured. The values of two selected X-ray scattering characterization parameters (I₁/I₂% and areas A₁/A₂% of the scattering peaks at 1.1 and 1.6 nm^?1, respectively) are plotted against the fat content of each of the measured dairy samples. Results show a strong linear dependence of each of the X-ray scattering parameters and the fat content of the investigated dairy products. These results suggest a possible use of such technique as a new, simple and straight forward method for determination of fat content of dairy products that would join and support the currently available techniques.     

On a Nirenberg-type problem involving the square root of the Laplacian

Through an Euler–Hopf-type formula, we establish existence result to a Nirenberg-type problem involving the square root of the Laplacian in sphere S²$S^2$.