Synthesis, Structural Aspects, Antimicrobial Activity, and Ion Transport Investigations of Four New [1 + 1] Condensed 12‐Membered Cyclophane Amides

Abstract

Two new diamines (a, b) and their four [1 + 1] condensed macrocyclic peptides (c–f) were synthesized via dilution method affording the expected dilactams in reasonably high‐yield yields. The compounds were characterized by elemental analyses, mass, FT‐IR, 1H, and 13C NMR spectral data. Mass spectra reveal their [1 + 1] cyclic condensation. The macrocycles having two peptide units in the ring would constitute three configurational isomers: cisoid–cisoid, transoid–transoid, and cisoid–transoid. Their 1H and 13C NMR show one signal for each chemically equivalent SCH2 and CONH and could be assigned symmetrical structures lacking any configurational isomerism. The ion transport activity of the compounds (c) and (d) on Na+ and K+ ions were evaluated by CH2Cl2 liquid–liquid membrane method using a U tube system. Slightly higher affinity for potassium than sodium was also observed, which is undoubtedly related to the matching size of the cavity between K+ and cyclic peptides. The antimicrobial and antifungal activities of four macrocyclic amides (c, d, e, and f) were illuminated using disk diffusion method in dimethyl sulfoxide as well as the minimal inhibitory concentration dilution method, against several bacteria and yeast cultures. Comparing all methods, in most cases, the (e) and (f) compound seems to show slightly higher biological activity than the (c) and (d) macrocycles. This may be because of the presence of extra chlorine atoms on the exterior part of the molecules.

Synthesis, antimicrobial activity, and ion transportation investigation of four new [1 + 1] condensed furan and thiophene‐based cycloheterophane amides

“…[35][36][37][38][39] In our recent studies, we have achieved the synthesis of macrocyclic tetra-amides bearing nitrogen, sulphur, and oxygen and investigated pharmacological and iontransporting properties of these compounds. [37,[40][41][42] As a continuation of our previous work, the macrocyclic amides that have furan or thiophene ring were synthesized by following the same experimental procedure, and also, antimicrobial activities of these compounds were explored. These compounds have been named according to the IUPAC Phane Nomenclature System.…”