en عمومى General پژوهشي Research Article <span style="font-size:12pt"><span style="line-height:16.0pt"><span new="" roman="" style="font-family:" times=""><b><i><span style="font-size:9.0pt">Background & Aims</span></i></b><b><span style="font-size:9.0pt">: </span></b><span lang="EN-GB" style="font-size:9.0pt">In this research, a novel series of heterocyclic compounds containing pyrazoline nuclei was synthesized in two steps.</span> <span style="font-size:9.0pt"></span></span></span></span><br> <span style="font-size:12pt"><span style="line-height:16.0pt"><span new="" roman="" style="font-family:" times=""><b><i><span style="font-size:9.0pt">Materials & Methods</span></i></b><b><span style="font-size:9.0pt">:</span></b> <span lang="EN-GB" style="font-size:9.0pt">I</span><span lang="TR" style="font-size:9.0pt">n the first step, chalcones were prepared using the Claisen-Schmidt reaction between substituted benzaldehydes and acetophenone derivatives. In the second step, t</span><span lang="EN-GB" style="font-size:9.0pt">he chalcones were cyclized under acidic conditions with hydrazine derivatives to produce pyrazolines. </span><span lang="TR" style="font-size:9.0pt">All compounds were characterized through </span><span lang="EN-GB" style="font-size:9.0pt">physical, chromatographic, spectroscopic, and elemental analyses, and their antibacterial properties were tested using seven microorganisms. The minimum inhibitory concentrations of all compounds were determined using the broth dilution method.</span> <b><span style="font-size:9.0pt"></span></b></span></span></span><br> <span style="font-size:12pt"><span style="line-height:16.0pt"><span new="" roman="" style="font-family:" times=""><b><i><span style="font-size:9.0pt">Results</span></i></b><b><span style="font-size:9.0pt">:</span></b> <span lang="EN-GB" style="font-size:9.0pt">Among them, compound 2f (4-(1, 5-diphenyl-4, 5-dihydro-1<i>H</i>-pyrazol-3-yl) phenol)</span> <span lang="EN-GB" style="font-size:9.0pt">exhibited the highest antibacterial and antifungal activity, making it the </span><span lang="TR" style="font-size:9.0pt">most potent compound in the series.</span> <b><span style="font-size:9.0pt"></span></b></span></span></span><br> <span style="font-size:12pt"><span style="line-height:16.0pt"><span new="" roman="" style="font-family:" times=""><b><i><span style="font-size:9.0pt">Conclusion</span></i></b><b><span style="font-size:9.0pt">: </span></b>&nbsp;<span lang="EN-GB" style="font-size:9.0pt">These results indicate that increasing the polarity of the compounds enhanced their efficacy against Gram-positive strains, whereas derivatives containing at least one methoxy group in their structure suppressed Gram-negative growth.</span></span></span></span> Antibiotic resistance, Antimicrobial activity, Phenylhydrazine, Pyrazolines, Synthesis 131 139 http://hsm.umsu.ac.ir/browse.php?a_code=A-10-305-1&slc_lang=en&sid=1 Sevda Afzal-Ahangaran sevdaafzal@gmail.com 10031947532846003780 10031947532846003780 No Department of Medicinal Chemistry, School of Pharmacy, Urmia University of Medical Sciences, Urmia, Iran Yaeghob Sharifi ya.sharifi@gmail.com 10031947532846003781 10031947532846003781 No Department of Microbiology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran Maryam Allahyari-Devin alahyaree@gmail.com 10031947532846003782 10031947532846003782 Yes Department of Medicinal Chemistry, School of Pharmacy, Urmia University of Medical Sciences, Urmia, Iran