Improved In Vitro Antimycobacterial Activity of Trinuclear Complexes Cobalt(II,III) and Iron(III) with 2‐Furoic Acid againstMycolicibacterium smegmatis

Abstract

The reaction of cobalt(II) and iron(III) pivalates with anions of 2furancarboxylic acid (pyromucic acid, Hfur) yielded trinuclear homometallic complexes with linear ([Co 3 (fur) 6 (phen) 2 ] (1, phen = 1,10-phenanthroline)) and triangular ([Co 3 O(fur) 6 (H 2 O) 3 ] (3), [Fe 3 O(fur) 6 (THF) 3 ] ⋅ 3THF (4)) structures of the metal moiety. The hexanuclear mixed carboxylate cobalt complex [Co 6 (piv) 8 (Hpiv) 4 (fur) 2 (OH) 2 ] (2, piv À = (CH 3) 3 COO À) was isolated as an intermediate in the synthesis of 3. According to CVA data, complex 3 contains bivalent and trivalent cobalt ions. According to Mossbauer spectroscopy data, all the iron(III) atoms in 4, which is an isostructural analogue of 3, are solely in the highspin state. The antibacterial activity of compounds 1-4, K(fur) (5) and Na(fur) (6) was determined in vitro against a nonpathogenic Mycolicibacterium smegmatis strain. The results of in vitro biological tests against Mycolicibacterium smegmatis showed a high bioactivity of complexes 1 and 4.

What are the prospects for using complexes of copper(ii) and zinc(ii) to suppress the vital activity ofMycolicibacterium smegmatis?

“…57–59 Moreover, it was noted that pyridine, aminopyridine, and phenylpyridine (in the case of copper complexes) could hinder the biological efficiency of compounds with respect to the strain. 31–34 In contrast, 1,10-phenanthroline and its methylated derivative, neoc, show a synergistic effect: they increase bioactivity by almost an order of magnitude (534 μg per disk for 1 and 50 for 3 ). If the fur anion is replaced by Ac − , the biological activity of 4 towards M. smegmatis increases more than twofold (21 μg per disk).…”

“…[57][58][59] Moreover, it was noted that pyridine, aminopyridine, and phenylpyridine (in the case of copper complexes) could hinder the biological efficiency of compounds with respect to the strain. [31][32][33][34] In contrast, 1,10-phenanthroline and Fig. 8 The comparison of a mixture and complex 3 ( 1 H) NMR spectra.…”

“…Further studies of furoate complexes with various cations (Ni 2+ , Fe 3+ , Co 2+/3+ , Zn 2+ , Cu 2+ ) showed that the mycobacterium was most sensitive to Zn 2+ and Cu 2+ . [30][31][32][33][34][35] In continuation of the "structure activity relationship (SAR)" studies, Zn(II) complexes were synthesized, namely, polymeric [Zn 2 (fur) 4 ] n (1), bi-[Zn 2 (fur) 4 (NH 2 py) 2 ] (2, NH 2 py ¼ 3-aminopyridine) and mononuclear [Zn(fur) 2 (neoc)] (3, neoc ¼ 2,9-dimethyl-1,10-phenantroline), [Zn(OAc) 2 (neoc)] ( 4) and [Cu(fur) 2 (neoc)(H 2 O)] ( 5). The structures of all the compounds obtained were resolved by direct single-crystal X-ray diffraction analysis.…”

Binuclear Complexes of Cu(II) and Mg(II) with 2-Furancarboxylic Acid: Synthesis, Structure, EPR Spectroscopy, and Results of In Vitro Biological Activity against Mycolicibacterium Smegmatis and SCOV3

“…In contrast to I, complex II barely exhibits biological activity (Table 4). Its MIC value is among the lowest ones in the investigated series of furancarboxylate complexes of Fe(III), Co(II), Cu(II), and Zn(II) (Table 4) [29][30][31][32][33][34]. Thus, the following dependence of the sensitivity of the mycobacterial wall to cations can be drawn: For complexes I and II, cytotoxicity against human ovarian adenocarcinoma cells SCOV3 and normal human fibroblast cells of the HDF line was determined.…”

“…For example, magnesium often tends to be surrounded by water molecules rather than carboxylate anions when interacting with carboxylate anions (this fact was additionally confirmed by quantum chemical calculations [28]). Our earlier studies [29][30][31][32][33][34] on the in vitro biological activity of furoate complexes of Fe(III), Co(II), Ni(II), Cu(II), and Zn(II) with various N,Odonor ligands showed their effectiveness against nonpathogenic mycobacterial strain Mycolicibacterium smegmatis. In this connection, the aims of this study were developing a procedure for the synthesis of Cu(II) and Mg(II) complexes with 2-furancarboxylic acid anions (HFur), i.e., [Cu 2 (Fur) 4 (MeCN) 2 ] (I) and [Mg 2 (Fur) 4 (H 2 O) 5 ]•MeCN•H 2 O (II), elucidating the structure of the obtained compounds and the nature of electronic interactions from the EPR spectroscopy data for I, and determining the in vitro biological activity against model nonpathogenic strain Mycolicibacterium smegmatis and human ovarian adenocarcinoma cells (SCOV3) for complexes I and II.…”