Synthesis, crystal structures and ab initio studies of some heptaaza manganese(II) macrocyclic Schiff-base complexes with two 2-aminoethyl pendant arms

Fluorinated tetrapodal anion transporters

Synthetic anion transporters show potential in treating life-threatening diseases like cystic fibrosis and cancer. However, with increasingly complex transporter architectures designed to control anion binding and transport, it is important to consider solubility and deliverability during transporter design. The fluorination of synthetic anion transporters has been shown to tune the transporter lipophilicity, transport rates, and binding strength. In this work, we expand on our previously reported tetrapodal (thio)urea transporters with a series of fluorinated tetrapodal anion transporters. The effects of fluorination on tuning the lipophilicity, solubility, deliverability, and anion transport selectivity of the tetrapodal scaffold were investigated using anion-binding and transport assays. The primary mode of anion transport was H⁺/X^- cotransport, with the most fluorinated tetrathiourea (8) displaying the highest transport activity in the 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) assay. Intriguingly, inversion of the transmembrane Cl^- vs NO₃ ^- transport selectivity compared with previously reported tripodal (thio)urea transporters was observed under a modified HPTS assay.

Tetrapodal Anion Transporters

Synthetic anion transporters that facilitate chloride transport are promising candidates for channelopathy treatments. However, most anion transporters exhibit an undesired side effect of facilitating proton transport via interacting with fatty acids present in the membrane. To address the limitation, we here report the use of a new tetrapodal scaffold to maximize the selective interaction with spherical chloride over binding the carboxylate headgroup of fatty acids. One of the new transporters demonstrated a high selectivity for chloride uniport over fatty acid-induced proton transport while being >10 times more active in chloride uniport than strapped calixpyrroles that were previously the only class of compounds known to possess similar selectivity properties.

New asymmetric heptaaza Schiff base macrocyclic complex of Mn(II): Crystal structure, biological and DFT studies

A new asymmetric heptaaza Schiff base macrocyclic bis(pendant donor) manganese(II) complex, [MnL(1)](ClO(4))(2).CH(3)CN (1), has been prepared and characterized by X-ray diffraction and spectroscopic methods. The antimicrobial activity of 1 and a series of its familiar symmetric heptaaza [15]pydieneN(5), [16]pydieneN(5), and [17]pydieneN(5)-based bis-(2-aminoethyl) pendant armed Schiff base macrocyclic complexes of Mn(II) were tested against Escherichia coli, Staphylococcus aureus and Candida albicans. The results showed that the symmetric heptaaza [16]pydieneN(5), and [17]pydieneN(5)-based Schiff base macrocyclic complexes of Mn(II) had remarkable inhibition zone on the culture of S. aureus and E. coli as compared with standard drugs. The optimized geometry of the prepared complex has been obtained from density functional method, DFT, using B3LYP/6-31G* basis set.