title: Synthesis and antimicrobial evaluation of new pyrano[4,3-b]pyran and Pyrano[3,2-c]chromene derivatives bearing a 2-thiophenoxyquinoline nucleus.
abstract: A new series of pyrano[4,3-b]pyran 4a-i and pyrano[3,2-c]chromene 6a-r derivatives bearing a 2-thiophenoxyquinoline nucleus were synthesized by reaction of 2-(4-(un)-substituted thiophenoxy)quinoline-3-carbaldehydes 2a-i with 6-methyl-4-hydroxypyran-2-one 3 and 4-hydroxy-6-(un)-substituted-2H-chromen-2-one 5a-b respectively and malononitrile at room temperature in the presence of KOH as a basic catalyst. All the compounds were screened against three Gram-positive bacteria (Streptococcus pneumoniae, Bacillus subtilis, Clostridium tetani), three Gram-negative bacteria (Salmonella typhi, Escherichia coli, Vibrio cholerae) and two fungi (Candida albicans, Aspergillus fumigatus) using the broth microdilution MIC (minimum inhibitory concentration) method. Upon antimicrobial screening, it was observed that the majority of the compounds were found to be active against Bacillus subtilis, Clostridium tetani and Candida albicans as compared to standard drugs.
authors: Department of Chemistry, Sardar Patel University, Vallabh Vidyanagar, Gujarat, India.
authors: Jigar A
authors: JA
authors: Makawana
authors: Manish P
authors: MP
authors: Patel
authors: Ranjan G
authors: RG
authors: Patel
mesh_terms: D000890:Anti-Infective Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D001578:Benzopyrans / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests / Q000379:methods / Q000706:statistics & numerical data; D015394:Molecular Structure; D015125:Oxyquinoline / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D011714:Pyrans / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D013329:Structure-Activity Relationship
chemical_list: D000890:Anti-Infective Agents; D001578:Benzopyrans; D011714:Pyrans; D015125:Oxyquinoline