You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Synthesis and evaluation of antibacterial activity of 7-alkyloxy-4,5-dihydro-imidazo[1,2-a]quinoline derivatives. In this study, a series of 7-alkyloxy-4,5-dihydro-imidazo[1,2-a]quinoline derivatives was synthesized and tested for their antibacterial activity against various bacterial strains. Most of the compounds exhibited potential antibacterial activity against gram-negative and gram-positive bacteria. Compound 7p (7-heptyloxy-4,5-dihydro-imidazo[1,2-a]quinoline) was found to be the most potent inhibitor. The minimum inhibitory concentration (MIC) of compound 7p against Escherichia coli was 0.5 μg/mL, better than that of reference agent ciprofloxacin and amoxicillin. Furthermore, compound 7p exhibited a modest activity against several gram-negative bacterial strains at a dose range of 2-64 μg/mL.
{"Chemical": ["7-alkyloxy-4,5-dihydro-imidazo[1,2-a]quinoline", "ciprofloxacin", "amoxicillin", "7-heptyloxy-4,5-dihydro-imidazo[1,2-a]quinoline"]}