Synthesis and in Vitro Study of Antibacterial, Antifungal Activities of some Novel Bisquinolines

Efficient syntheses of a series of novel bisquinolines have been accomplished from8-hydroxy quinolines under phase transfer catalyzed conditions using tetrabutylamoniumbromide as phase transfer catalyst. In vitro antibacterial and antifungal study of the synthesized analogues revealed six of them to show significant antibacterial and four to show significant antifungal activity. Among them 3c and 6c show most significant antibacterial activities with minimum inhibitory concentration value 32 lg/mL against four bacterial strains. Ultra structural studies of the microbes treated with 6c demonstrated deformation of cell wall and cell agglomeration. The bisquinolines exhibiting bacteriostatic or fungistatic activity may be developed as newer antimicrobial agents

Spatial variability of chlorophyll-a and abiotic variables in a river–floodplain system during different hydrological phases

Chlorophyll-a (Chl-a) and abiotic variables were measured in the main channel and floodplain waterbodies of the Middle Paraná River to analyse the system dynamics and to assess their spatial variability during different hydrological phases, including an extreme flood. We wanted to test that the flood does not always have a homogenising effect in a river-floodplain system. An explanatory model for Chl-a was performed according to Akaike?s Information Criterion (AIC), and the relation of water level with the coefficient of variation (CV) among sites for each variable was explored. The model explained 64% of Chl-a variability. Water level, depth:euphotic zone ratio (Zd:Zeu) (inverse correlation) and conductivity (direct correlation) were the significant explicative variables. The CV of Chl-a decreased with flood from the main channel to the floodplain, but for turbidity, Zd:Zeu, pH, dissolved oxygen, soluble reactive phosphorus and Chl-a:pheophytin-a ratio, it increased. However, within the floodplain, CV of turbidity, Zd:Zeu and pH decreased during flood. These suggest that the homogenising effect frequently observed during inundation cannot be generalised and that the floodplain may maintain its identity even during flood. The extreme flood and its overlap with the warm season and sedimentological pulse probably contributed to the heterogenity in the spatial gradient.Fil: Mayora, Gisela Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Devercelli, Melina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Giri, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentin