Synthesis and biological activity of 1,3,4-oxa(thia)diazole, 1,2,4-triazole-5-(thio)one and S-substituted derivatives of 3-((2-carboxyethyl)phenylamino)propanoic acid

Article abstract of DOI:10.1007/s11164-015-2290-0

Abstract: A series of novel derivatives of 3-((2-carboxyethyl)phenylamino)propanoic acid bearing two identical substituted 1,3,4-oxadiazole, 1,3,4-thiadiazole, or 1,2,4-triazole moieties were synthesized and their molecular structures were confirmed by IR, ¹H, ¹³C NMR spectroscopy, and elemental analysis data. The synthesized compounds were screened for their reducing power, free radical scavenging, plant growth regulating, and antimicrobial properties. 5,5′-((Phenylazanediyl)bis(ethane-2,1-diyl))bis(4-phenyl-2,4-dihydro-3H-1,2,4-triazole-3-thione) showed excellent antioxidant activity, three times higher than that of the antibiotic control (cefazolin). 2,2′-((((Phenylazanediyl)bis(ethane-2,1-diyl))bis(4-phenyl-4H-1,2,4-triazole-5,3-diyl))bis(sulfanediyl))diacetate exhibited notable bactericidal activity against Pseudomonas aeruginosa with MBC and MIC values 7.3?μg/ml, whereas 12 compounds displayed significant fungicidal activity against Candida albicans with MIC value 3.9?μg/ml. Graphical Abstract: Synthesis of compounds 2–27. R: 2, 5, 7, 10, 13, 15-27 C₆H₅–; 3, 8, 11 4-Cl-C₆H₄–; 4, 9, 12 CH₃–; 6, 14 2.6-(CH₃)₂-C₆H₃–; R′: 15 CH₃CH₂–; 16 (CH₃)₂CH–; 17 (CH₃)₂CHCH₂–; 18 CH₃CH₂CH₂CH₂–; 19 (CH₃)₂CHCH₂CH₂–; 20 CH₃CH₂CH₂CH₂CH₂–; 21 NH₂COCH₂–; 22 C₆H₅CH₂–; 23 C₆H₅COCH₂–; 24 4-ClC₆H₄COCH₂–; 25 4-NO₂C₆H₄COCH₂–; 26 C₂H₅OCOCH₂–.[Figure not available: see fulltext.]