Synthesis and fungitoxicity of some pyrimidine derivatives
A series of 12 pyrimidine derivatives were prepared and testedin vitro against growth, sporulation and nucleic acid content ofFusarium oxysporum f. sp.lycopersici andHelminthosporium oryzae. Introduction of a thiazole ring together with two aryl groups into 2-aminopyrimidine brought about drastic toxicity for both fungi. Pyrimidine derivatives with aryl groups alone were less toxic. Nitro groups were found to enhance the toxicity of the pyrimidine derivatives especially when substituted in the ortho-position of the aryl groups. Inhibition of nucleic acid synthesis of both fungi was attributed mainly to the presence of the thiazole ring.
Design, Synthesis, and Antimicrobial Activity, of New 1,4-disubstituted Octahydroquinoxaline-2,3-dione Derivatives
E-mail: mostafa1705@yahoo.comReceived November 15, 2010, Accepted March 7, 2011A series of 1,4-disubstituted octahydroquinoxaline-2,3-dione derivatives was prepared through two stepsreaction. The latter involves the formation of N,N-disubstituted cyclohexane-1,2-diamine derivatives (la-j)through reductive alkylation of 1,2-cyclohexanediamine with different aldehydes in presence of sodiumcyanoborohydride. Fusion of compounds (1a-j) with diethyl oxalate affording the target compounds (2a-j).Elucidation of structures of compounds (2a-j) was based upon different spectral data as well as the elementalmethods of analyses. In addition, mass spectrometry and X-ray diffraction analyses were carried out.Moreover, the lipophilicity of the target compounds as expressed from the Clog P. Most of the test compounds(2a-j) showed weak to moderate antibacterial and antifungal activities against most of the used bacterial andfungal strains in comparison to chloramphenicol and clotrimazole as reference drugs respectively. Key Words : Antimicrobial, Activity, Octahydroquinoxaline-2,3-dione, Diffraction, SynthesisIntroductionThe emergence of microbial resistance is an evolutionaryprocess based on selection for organisms that have enhancedability to survive doses of antibiotics that would havepreviously been lethal. Survival of bacteria often resultsfrom an inheritable resistance.
Distribution-free monitoring of univariate processes
We consider statistical process control (SPC) of univariate processes when observed data are not normally distributed. Most existing SPC procedures are based on the normality assumption. In the literature, it has been demonstrated that their performance is unreliable in cases when they are used for monitoring non-normal processes. To overcome this limitation, we propose two SPC control charts for applications when the process data are not normal, and compare them with the traditional CUSUM chart and two recent distribution-free control charts. Some empirical guidelines are provided for practitioners to choose a proper control chart for a specific application with non-normal data.