New spiro (thio) barbiturates based on cyclohexanone and bicyclo [3.1.1]heptan-6-one by nonconcerted [1+5] cycloaddition reaction and their conformational structures

Crossed-aldol condensation reaction of aromatic aldehydes with ketones such as; acetone and cyclohexanone leads to the efficient formation of cross conjugated α,β-unsaturated ketones in excellent yield. The intermolecular and then intramolecular Michael addition reaction of α,β-unsaturated ketones derived from acetone and cyclohexanone with (thio)barbituric acids lead to synthesis new type of 7,11-diaryl-2,4-diazaspiro[5.5]undecane-1,3,5,9-tetraone and 2,4-diaryl-1'H-spiro[bicyclo[3.3.1]nonane-3,5'-pyrimidine]-2',4',6',9(3'H)-tetraone, respectively in good yield. Structure elucidation is carried out by 1H NMR, 13C NMR, FT-IR, UV-Visible, mass spectroscopy and X-ray crystallography techniques. A possible mechanism of the formation is discussed. The structural conformation also demonstrated by coupling constants derived from dihedral angles between vicinal and geminal protons. The 1H NMR spectra of NH protons of spiro compounds derived from barbituric acid show a broad singlet peak instead, these protons in the spiro compounds derived from thiobarbituric acid show two distinct peaks. KEY WORDS: Crossed-aldol condensation, Michael addition, [1+5] Cycloaddition, Barbituric acid, Conformation, Spiro barbiturate Bull. Chem. Soc. Ethiop. 2014, 28(3), 423-440.DOI: http://dx.doi.org/10.4314/bcse.v28i3.1

Detecting of Beta-lactamase Genes in Clinical Isolates of Escherichia Coli Isolated From Baqiyatallah Hospital of Bashagard and Evaluating Their Antibiotic Resistance and Biofilm Formation

Biofilm formation has been observed in different species of bacteria such as Escherichia coli and Pseudomonas aeruginosa. The formation of biofilms in the airways of pneumonia patients and chronic lung patients is one of the important factors in prolonging the treatment period, exacerbating clinical symptoms and even death of patients. The present study aimed to investigate beta-lactamase genes in clinical isolates of Escherichia coli isolated from Baqiyatallah Bashagard Hospital and to evaluate their antibiotic resistance and biofilm formation. In the present study, 60 isolates from fecal samples of patients with symptoms of diarrhea and suspected Escherichia coli infection were collected and selected from Baqiyatallah Hospital of Bashagard. After confirmation of Escherichia coli strains using microbial culture and biochemical tests, the presence of three beta-lactamase genes in these isolates was examined. The ability of isolates to form biofilms and their resistance to two different antibiotics were also measured. A phenotypic study of isolates based on optical absorbance measurements showed that among the clinical Escherichia coli isolated from Baqiyatallah Hospital of Bashagard, only 10 isolates could form a strong biofilm in the microtiter plate.&nbsp