A facile synthesis and antibacterial activity of novel pyrrolo[3,4-b]quinolin-2(3H)-yl)benzamides

<p>A new series of pyrrolo[3,4-b]quinolin-2(3H)-yl)benzamides were designed based on molecular hybridization approach and synthesized by reaction of benzohydrazide derivatives with 9-phenylfuro[3,4-b]quinoline-1,3-diones in the presence of an Et₃N catalyst. Simple reaction, excellent yield, simple separation process and eco-friendly approach by minimizing the chemical waste renders this protocol particularly attractive. The series <b>9a–g</b> was evaluated for <i>in vitro</i> antibacterial activity against (+ve bacteria) <i>Staphylococcus aureus</i> ATCC 25923 and <i>Enterococcus faecalis</i> ATCC 29212, (−ve bacterium) <i>Escherichia coli</i> ATCC 25922. <i>In vitro</i> minimum inhibitory concentration (MIC) evaluations showed that the compound <b>9a</b> was effective against <i>E. coli</i> (MIC: 0.25 mg/mL) <i>S. aureus</i> (MIC: 0.25 mg/mL) and <i>E. faecalis</i> (MIC: 0.5 mg/mL).</p

<i>S</i>. <i>pinnatifida</i> extracts are neuroprotective against paraquat and oligomeric α-SN toxicity on dopaminergic neurons in primary mesencephalic cell cultures.

<p>(<b>A</b>) Box-Plot Graphic showing the effect of 1, 10, 100 and 1000 μg/ml to determine the non-toxic concentration of DCMEx (DCM) and BuOHEx / EtOAcEx (BE) on dopaminergic TH⁺ neurons. (<b>B</b>) Box Plot Graphic showing the toxic effect of paraquat, rotenone and an α-SN oligomer/monomer mixture on TH⁺ neurons and the protective effect of 100 μg/mL BuOHEx / EtOAcEx (BE) or 1 μg/mL DCMEx (DCM) against this aggression. (<b>C</b>) Box-Plot Graphic showing the effect of α-SN oligomers on ROS production in mesencephalic cells and its reduction in the presence of DCMEx, and BuOHEx / EtOAcEx. Whiskers represent Max and Min values. * represents <i>P</i> < 0.05, ** represents <i>P</i> < 0.01, n.s. non-significant.</p

Assessment the cytotoxicity of α-SN on PC12 cells in the presence of the extracts.

<p>(<b>A</b>) Cell viability measuring by MTT assay. PC12 cells were treated with 7 h-aged incubated α-SN in the absence and presence of different extracts. (<b>B-D</b>) Analysis of the cell death type using Annexin V/PI method: Living cell (Annexin V−/PI−) populations were located in the lower-left quadrant, the apoptotic cells were in the lower-right quadrant, late apoptotic (Annexin V+/PI+) populations were located in the upper-right quadrant, and necrotic cell (Annexin V−/PI+) populations were presented in the upper-left quadrant.(<b>E</b>) ROS production assay. Fluorescence intensity was measured at 480nm excitation and 520nm emission. The significance was set at <i>P</i><0.05.* The data are the means of three independent experiments ± SEM.</p