ABSTRACT
In this research, a new urea-rich porous organic polymer (urea-rich POP) as a hydrogen bond catalyst was synthesized via a solvothermal method. The physiochemical properties of the synthesized urea-rich POP were investigated by using different analyses like Fourier transform infrared (FT-IR) spectroscopy, field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), derivative thermogravimetry (DTG), energy-dispersive X-ray spectroscopy (EDS), elemental mapping analysis, X-ray diffraction analysis (XRD) and Brunauer-Emmett-Teller (BET) techniques. The preparation of urea-rich POP provides an efficacious platform for designing unique hydrogen bond catalytic systems. Accordingly, urea-rich POP, due to the existence of several urea moieties as hydrogen bond sites, has excellent performance as a catalyst for the Knoevenagel condensation reaction and multi-component synthesis of 2,3-dihydroquinazolin-4(1H)-ones.
ABSTRACT
Herein, a new heterogeneous catalytic system through modification of urea functionalized magnetic nanoparticles with choline chloride [Fe3O4@SiO2@urea-riched ligand/Ch-Cl] was designed and synthesized. Then, the synthesized Fe3O4@SiO2@urea-riched ligand/Ch-Cl was characterized by using FT-IR spectroscopy, FESEM, TEM, EDS-Mapping, TGA/DTG and VSM techniques. After that, the catalytic usage of Fe3O4@SiO2@urea-riched ligand/Ch-Cl was investigated for the synthesis of hybrid pyridines with sulfonate and/or indole moieties. Delightfully, the outcome was satisfactory and the applied strategy represents several advantages such as short reaction times, convenience of operation and relatively good yields of obtained products. Moreover, the catalytic behavior of several formal homogeneous DESs was investigated for the synthesis of target product. In addition, a cooperative vinylogous anomeric-based oxidation pathway was suggested as rational mechanism for the synthesis of new hybrid pyridines.
Subject(s)
Magnetics , Silicon Dioxide , Silicon Dioxide/chemistry , Spectroscopy, Fourier Transform Infrared , Ligands , CatalysisABSTRACT
Background: Oral candidiasis (OC) has been noticed as a common mucous membrane infection in immunocompromised patients such as that diabetes. This study, focused on the genotyping of Candida albicans and enzymatic activities of Candida species recovered from oral mucosa among diabetes patients and healthy individuals. Materials and Methods: Specimens were obtained from oral mucosa of One-hundred and sixty patients with type 2 diabetic and 108 healthy individuals. All isolates were definitely identified by ribosomal DNA (rDNA) gene sequencinghHydrophobicity, hemolytic activities of Candida species and genotypes of C. albicans were determined through polymerase chain reaction (CA-INT). Results: , Eighty eight (55%) samples out of 160, were positive for Candida species in diabetic patients. Moreover, 79.5% (70/88) and 20.5% (18/88) isolates belonged to the C. albicans and non-albicans Candida species respectively. Three genotypes of C. albicans have recovered in diabetic patients: genotype A (71.42%), B (21.42%), and C (7.14%). In healthy individuals, 42.6% (46/102) Candida species recovered from oral cavity, with the highest prevalence of genotype A (76.6% of C. albicans). Additionally, hydrophobicity and hemolytic activities from Candida species were significantly greater in diabetes patients than healthy nondiabetic subjects. Conclusion: Collectively, C. albicans was the most causative agent isolated from diabetes patients and non-diabetes healthy individuals. Genotype A, as the most remarkable genotype, should be mentioned in both groups. Higher potential hydrophobicity and hemolytic activities of Candida species in diabetic patients compared to healthy cases suggest these features triggering pathogenicity of OC in diabetes patients.
