Synthesis, structural aspects, antimicrobial activity and ion transport investigation of five new [1+1] condensed cycloheterophane peptides

Five novel [1+1] condensed cycloheterophane peptides were synthesized via reaction of pyridine-2,6-bis(2-aminothiophenoxymethyl) with several diacid chlorides: glutaryl dichloride, adipoyl dichloride, 2,2′-thiodiacetyl chloride, dithiodiglycoloyl chloride and 3,3′-thiodipropionoyl chloride combinations (L 1 –L 5 ). The compounds were characterized by elemental analyses, mass, FT-IR, 1H, and 13C NMR spectral data. The antimicrobial activities of the compounds were evaluated using the disk diffusion method in dimethyl sulfoxide as well as the minimal inhibitory concentration dilution method, against several bacteria and yeast cultures. The results were compared with those of commercial antibiotic and antifungal agents. Structure activity relationships were also discussed. Permeability of compound L 5 against Na+ and K+ were also investigated. Five novel cycoloheterophane amides were synthesized. Mass spectra reveal their [1+1] cyclic condensation. The compounds exert moderate microbial activity. Thia and aza groups seem to be a key element of microbial potency.