A1 Journal article (refereed)
Water soluble organometallic small molecules as promising antibacterial agents : synthesis, physical–chemical properties and biological evaluation to tackle bacterial infections (2022)

Bennour, I., Núria Ramos, M., Nuez-Martínez, M., Xavier, J. A. M., Buades, A. B., Sillanpää, R., Teixidor, F., Choquesillo-Lazarte, D., Romero, I., Martinez-Medina, M., & Viñas, C. (2022). Water soluble organometallic small molecules as promising antibacterial agents : synthesis, physical–chemical properties and biological evaluation to tackle bacterial infections. Dalton Transactions, 51(18), 7188-7209. https://doi.org/10.1039/D2DT01015A

JYU authors or editors

Publication details

All authors or editors: Bennour, Ines; Núria Ramos, M.; Nuez-Martínez, Miquel; Xavier, Jewel Ann Maria; Buades, Ana B.; Sillanpää, Reijo; Teixidor, Francesc; Choquesillo-Lazarte, Duane; Romero, Isabel; Martinez-Medina, Margarita; et al.

Journal or series: Dalton Transactions

ISSN: 1477-9226

eISSN: 1477-9234

Publication year: 2022

Publication date: 06/04/2022

Volume: 51

Issue number: 18

Pages range: 7188-7209

Publisher: Royal Society of Chemistry (RSC)

Publication country: United Kingdom

Publication language: English

DOI: https://doi.org/10.1039/D2DT01015A

Publication open access: Openly available

Publication channel open access: Partially open access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/81983


The Na[3,3′-Fe(8-I-1,2-C2B9H10)2] and Na[2,2′-M(1,7-C2B9H11)] (M = Co3+, Fe3+) small molecules are synthesized and the X-ray structures of [(H3O)(H2O)5][2,2′-Co(1,7-C2B9H11)2] and [Cs(MeCN)][8,8′-I2-Fe(1,2 C2B9H10)2], both displaying a transoid conformation of the [M(C2B9)2]− framework, are reported. Importantly, the supramolecular structure of [(H3O)(H2O)5][2,2′-Co(1,7-C2B9H11)2] presents 2D layers leading to a lamellar arrangement of the anions while the cation layers form polymeric water rings made of six- and four-membered rings of water molecules connected via OH⋯H hydrogen bonds; B–H⋯O contacts connect the cationic and anionic layers. Herein, we highlight the influence of the ligand isomers (ortho-/meta-), the metal effect (Co3+/Fe3+) on the same isomer, as well as the influence of the presence of the iodine atoms on the physical–chemical and biological properties of these molecules as antimicrobial agents to tackle antibiotic-resistant bacteria, which were tested with four Gram-positive bacteria, five Gram-negative bacteria, and three Candida albicans strains that have been responsible for human infections. We have demonstrated an antimicrobial effect against Candida species (MIC of 2 and 3 nM for Na[3,3′-Co(8-I-1,2-C2B9H10)2] and Na[2,2′-Co(1,7-C2B9H11)2], respectively), and against Gram-positive and Gram-negative bacteria, including multiresistant MRSA strains (MIC of 6 nM for Na[3,3′-Co(8-I-1,2-C2B9H10)2]). The selectivity index for antimicrobial activity of Na[3,3′-Co(1,2-C2B9H11)2] and Na[3,3′-Co(8-I-1,2-C2B9H10)2] compounds is very high (165 and 1180, respectively), which reveals that these small anionic metallacarborane molecules may be useful to tackle antibiotic-resistant bacteria. Moreover, we have demonstrated that the outer membrane of Gram-negative bacteria constitutes an impermeable barrier for the majority of these compounds. Nonetheless, the addition of two iodine groups in the structure of the parent Na[3,3′-Co(1,2-C2B9H11)2] had an improved effect (3–7 times) against Gram-negative bacteria. Possibly the changes in their physical–chemical properties make the meta-isomers and the ortho-di-iodinated small molecules more permeable for crossing this barrier. It should be emphasized that the most active metallabis(dicarbollide) small molecules are both transoid conformers in contrast to the ortho- [3,3′-Co(1,2-C2B9H11)2]− that is cisoid. The fact that these small molecules cross the mammalian membrane and have antimicrobial properties but low toxicity for mammalian cells (high selectivity index, SI) represents a promising tool to treat infectious intracellular bacteria. Since there is an urgent need for antibiotic discovery and development, this study represents a relevant advance in the field.

Keywords: organometallic compounds; bioactive compounds; antimicrobial compounds; chemical synthesis

Contributing organizations

Ministry reporting: Yes

Reporting Year: 2022

JUFO rating: 1

Last updated on 2023-30-08 at 09:09