The Biological Actions of 1,10‐phenanthroline and 2,2′‐bipyridine Hydrochlorides, Quaternary Salts and Metal Chelates and Related Compounds

Abstract

Summary. The bacteriostatic activities of stable, inert, coordinately-satnratetl Rn(II) tholates of .suhstitiite;] l.in-phenanthrolin<! anti 2.2'-bipyrkline bases are reported together with tliosc of the Lorrespondirij^ chelates of Ni(II). Fe(II}. Co(Il). CH(II). Zn(ll). C(1(II) ami Mii(II). tlie hydrorhlorides and .inatornary salts of the bases and miscellaneou.'i conipoiinds; the principal test orgiiiiisiiis, in order of decreasing gentTal sensitivity, were M. iubercitlnsh. Slaph. anrvus. Strep, pneumoniae, Cl. parfrlngcm, E. coli and Pr. t:idnaris. The active Lomponent of the Rii(II) ehelates is the cation as a wholp which can only exert antibacterial action by weak Coulomhic ard short-range forces and possibly by interference iji biological redox reactions. However, metal chelates which are labile or have low stability may act by other mechanisms.Metal chelates generally were more active than corresponding base hydrochlorides and {juaternury salts and phennntliroline derivates more active than the correspondirg hipyridines. While the Rii(ll) chelate of 5-NO.,-l.lO-pIienanllirolinc was nn:ch les,s active thun [he oulstaiidin^ily antitiihcrcnlar chelates of the other seven transition metals, few other diHerenccs in bactfriostatif activity were detected by tlie present method between chdatt-s differing only in the metal ion. Since progressive methylation of each type of compound generally increased antibacterial activity, penetnition to or accunuTlation at vital sites are most likely important factors in determining activity.Whili-useful clinically as topical antimicrobials, selected compounds when adtninislered parenterally were foiird to hv chcmotheraptiitically ineffective against experimental infe^-tion due to Staph. ameua. Simp, pncitmaiiiaa or M. tiibercitliKus. Significant microbial resistance to selected metal chelates tioes not appear to develop.

The antimicrobial and antibiofilm activities of copper(II) complexes

“…2). Compared to the antibiotics vancomycin (12) and chloramphenicol (13), all of the copper compounds were more effective in removing biofilms. At 25 µg/mL, chloramphenicol only removed 26% of the biofilm, compared to 60-68% for the compounds 1, 2 and 3, and 35-42% for compounds 7, 8 and 9.…”

“…Early work by the group of Dwyer demonstrated that coordination complexes of Ru(II), Ni(II), Cu(II), Fe(II) or Co(II) with ligands such as 1,10-phenanthroline or 2,2'-bipyridine have activity against both Gram-positive and Gram-negative bacteria [12,13]. As recently reviewed by us, these complexes interact with DNA through intercalation [14].…”

Synthesis and X-ray crystal structure of [Ag(phendio)2]ClO4 (phendio = 1,10-phenanthroline-5,6-dione) and its effects on fungal and mammalian cells

“…1,10-Phenanthroline (phen) (Figure 1) and substituted derivatives, both in the metal-free state and as ligands co-ordinated to transition metals, disturb the functioning of a wide variety of biological systems (Butler et al 1969). Furthermore, when the metal-free N,N -chelating bases are found to be bioactive it is usually assumed that the sequestering of trace metals in situ is involved, and that the resulting metal complexes are the active species (MacLeod, 1952;Dwyer et al 1969). Previous work has demonstrated that in RPMI (Roswell Park memorial Institute) medium at 37 • C the metal-based drugs [Cu(phen) 2 (mal)] · 2H 2 O, [Mn(phen) 2 (mal)] · 2H 2 O and [Ag 2 (phen) 3 (mal)] · 2H 2 O (phen = 1,10-phenanthroline; malH 2 = malonic acid) inhibit the growth of C. albicans by around 95% at a concentration of 5 μg/ml Coyle et al 2003a).…”

Anti-tubercular Activity of Ruthenium (II) Complexes with Polypyridines

“…Since 1969, Dwyer et al [17] reported the bacteriostatic action of metal complexes of 2,2 0 -bipyridyl against selected Gram-positive, Gram-negative and acid-fast bacteria. With the same idea, we have prepared and wish to report some Ruthenium complexes bearing substituted polypyridyl ligands (2,2 0 -bipyridines or 2,2 0 -6 0 ,2 00 -terpyridines) bearing Ru(II)-X moieties where X ¼ Cl, CO, CH 3 CN or H 2 O.…”