title: Synthesis, structure optimization and antifungal screening of novel tetrazole ring bearing acyl-hydrazones.
abstract: Azoles are generally fungistatic, and resistance to fluconazole is emerging in several fungal pathogens. In an attempt to find novel azole antifungal agents with improved activity, a series of tetrazole ring bearing acylhydrazone derivatives were synthesized and screened for their in vitro antifungal activity. The mechanism of their antifungal activity was assessed by studying their effect on the plasma membrane using flow cytometry and determination of the levels of ergosterol, a fungal-specific sterol. Propidium iodide rapidly penetrated a majority of yeast cells when they were treated with the synthesized compounds at concentrations just above MIC, implying that fungicidal activity resulted from extensive lesions of the plasma membrane. Target compounds also caused a considerable reduction in the amount of ergosterol. The results also showed that the presence and position of different substituents on the phenyl ring of the acylhydrazone pendant seem to play a role on the antifungal activity as well as in deciding the fungistatic and fungicidal nature of the compounds.
authors.affiliation: Department of Chemistry, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21413, Saudi Arabia.
authors.forename: Maqsood Ahmad
authors.initials: MA
authors.lastname: Malik
authors.affiliation: Department of Chemistry, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21413, Saudi Arabia.
authors.forename: Shaeel Ahmed
authors.initials: SA
authors.lastname: Al-Thabaiti
authors.affiliation: Department of Chemistry, Jamia Millia Islamia (Central University), New Delhi, 110025, India.
authors.forename: Manzoor A
authors.initials: MA
authors.lastname: Malik
mesh_terms: D000215:Acylation; D000935:Antifungal Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects*; D002177:Candidiasis / Q000188:drug therapy; D006801:Humans; D006835:Hydrazones / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D013777:Tetrazoles / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: D000935:Antifungal Agents; D006835:Hydrazones; D013777:Tetrazoles; C045574:1H-tetrazole
keywords: Candida albicans; acylhydrazone; ergosterol; flow cytometry; tetrazole