{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,21]],"date-time":"2026-03-21T04:08:54Z","timestamp":1774066134093,"version":"3.50.1"},"reference-count":17,"publisher":"S. Karger AG","issue":"3","license":[{"start":{"date-parts":[[2017,1,1]],"date-time":"2017-01-01T00:00:00Z","timestamp":1483228800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.karger.com\/Services\/SiteLicenses"},{"start":{"date-parts":[[2017,1,1]],"date-time":"2017-01-01T00:00:00Z","timestamp":1483228800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/www.karger.com\/Services\/SiteLicenses"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Chemotherapy"],"published-print":{"date-parts":[[2017]]},"abstract":"<jats:p>&lt;b&gt;&lt;i&gt;Background:&lt;\/i&gt;&lt;\/b&gt; Fluoroquinolones are widely prescribed synthetic antimicrobial agents. Quinolones act by converting their targets, gyrase and topoisomerase IV, into toxic enzymes that fragment the bacterial chromosome; the irreversible DNA damage eventually causes the killing of bacteria. Thorough knowledge of the structure-activity relationship of quinolones is essential for the development of new drugs with improved activity against resistant strains. &lt;b&gt;&lt;i&gt;Methods:&lt;\/i&gt;&lt;\/b&gt; The compounds were screened for their antibacterial activity against 4 representing strains using the Kirby-Bauer disk diffusion method. Minimal inhibitory concentration (MIC) was determined by measuring the diameter of the inhibition zone using concentrations between 250 and 0.004 \u03bcg\/mL. &lt;b&gt;&lt;i&gt;Results:&lt;\/i&gt;&lt;\/b&gt; MIC of derivatives 2, 3, and 4 showed potent antimicrobial activity against gram-positive and gram-negative bacteria. The effective concentrations were 0.860 \u03bcg\/mL or lower. MIC for compounds 5-11 were between 120 and 515 \u03bcg\/mL against &lt;i&gt;Escherichia coli&lt;\/i&gt; and &lt;i&gt;Staphylococcus aureus&lt;\/i&gt;, and substituted hydrazinoquinolones 7-10 showed poor antibacterial activity against gram-positive and gram-negative bacteria compared with other quinolones. &lt;b&gt;&lt;i&gt;Conclusion:&lt;\/i&gt;&lt;\/b&gt; Compounds obtained by modifications on C-7 of norfloxacin with the acetylated piperazinyl, halogen atoms, and substituted hydrazinyl showed good in vitro activity - some even better than the original compound.<\/jats:p>","DOI":"10.1159\/000456533","type":"journal-article","created":{"date-parts":[[2017,3,23]],"date-time":"2017-03-23T22:22:38Z","timestamp":1490307758000},"page":"194-198","source":"Crossref","is-referenced-by-count":10,"title":["In vitro Antibacterial Activity of 7-Substituted-6-Fluoroquinolone and 7-Substituted-6,8-Difluoroquinolone Derivatives"],"prefix":"10.1159","volume":"62","author":[{"given":"Socorro","family":"Leyva-Ramos","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Denisse","family":"de Loera","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jaime","family":"Cardoso-Ortiz","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"127","published-online":{"date-parts":[[2017,3,24]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","DOI":"10.3390\/molecules21040268"},{"key":"ref2","doi-asserted-by":"publisher","DOI":"10.1021\/cr030101q"},{"key":"ref3","doi-asserted-by":"publisher","DOI":"10.1021\/bi5000564"},{"key":"ref4","doi-asserted-by":"publisher","DOI":"10.1086\/321846"},{"key":"ref5","doi-asserted-by":"publisher","DOI":"10.1016\/j.ejmech.2013.06.045"},{"key":"ref6","doi-asserted-by":"publisher","DOI":"10.1021\/jm00014a005"},{"key":"ref7","doi-asserted-by":"publisher","DOI":"10.1016\/j.bmc.2009.04.027"},{"key":"ref8","doi-asserted-by":"publisher","DOI":"10.1016\/j.ejmech.2011.09.011"},{"key":"ref9","doi-asserted-by":"publisher","DOI":"10.1016\/j.bmcl.2015.06.041"},{"key":"ref10","doi-asserted-by":"publisher","DOI":"10.1016\/j.bmcl.2012.07.064"},{"key":"ref11","doi-asserted-by":"publisher","DOI":"10.1021\/jm000153x"},{"key":"ref12","doi-asserted-by":"publisher","DOI":"10.1248\/cpb.c13-00040"},{"key":"ref13","doi-asserted-by":"publisher","DOI":"10.2174\/1568005043340920"},{"key":"ref14","doi-asserted-by":"publisher","DOI":"10.1021\/jm0600139"},{"key":"ref15","doi-asserted-by":"publisher","DOI":"10.1016\/j.bmcl.2010.11.068"},{"key":"ref16","doi-asserted-by":"publisher","DOI":"10.1086\/428052"},{"key":"ref17","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijantimicag.2005.04.002"}],"container-title":["Chemotherapy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/456533","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/456533","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/456533","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,4,23]],"date-time":"2025-04-23T17:18:05Z","timestamp":1745428685000},"score":1,"resource":{"primary":{"URL":"https:\/\/karger.com\/article\/doi\/10.1159\/000456533"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017]]},"references-count":17,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2017,4,20]]}},"URL":"https:\/\/doi.org\/10.1159\/000456533","archive":["Portico"],"relation":{},"ISSN":["0009-3157","1421-9794"],"issn-type":[{"value":"0009-3157","type":"print"},{"value":"1421-9794","type":"electronic"}],"subject":[],"published":{"date-parts":[[2017]]}}}