Electrospray ionization mass spectrometry with in-source collision-induced dissociation of monensin factors and related metabolites

Abstract

Monensins are a series of polyether ionophore antibiotic factors produced by Streptomyces cinnamonensis. Three monensin factors and four metabolites of monensin A isolated from cattle feces were investigated by electrospray ionization mass spectrometry (ESI-MS). In-source collision-induced dissociation (CID) of the alkali metal and ammonium molecular ion adducts of monensin produce strikingly different mass spectra, with the alkali metal complexes exhibiting little dissociation and the ammoniated forms characterized by extensive fragmentation of the polyether skeletal structure with the production of several structurally diagnostic ions. The observed fragmentation of ammoniated monensin primarily involves opening of the cyclic ether rings and consecutive H 2 O losses. The propensity of ammoniated monensin derivatives toward skeletal fragmentation may involve the complexation of the thermally labile NH 4 ion through multiple hydrogen-bonding interactions with the polyether complexing oxygens resulting in decreased stability of the resultant complex. Comparison of the in-source CID spectra associated with the structurally similar compounds evaluated provides for the proposal of a general scheme for the fragmentation of ammoniated monensins and related compounds, the consistency of which indicates the usefulness of ESI-MS with insource CID in ionophore structure elucidation. # 1998 John Wiley & Sons, Ltd. Received 8 May 1998; Accepted 20 May 1998 Monensin is a polyether monocarboxylic acid ionophore and refers to a group of factors comprising an antibiotic complex first isolated from Streptomyces cinnamonensis.

Sorption and Degradation in Soils of Veterinary Ionophore Antibiotics: Monensin and Lasalocid

“…1). In addition, the polar functionality of these compounds can orient toward the cation with the outer solvent accessible portion of the molecule being largely hydrophobic [44][45][46][47], resulting in some degree of metal encapsulation [6,46,48]. In addition, the polar functionality of these compounds can orient toward the cation with the outer solvent accessible portion of the molecule being largely hydrophobic [44][45][46][47], resulting in some degree of metal encapsulation [6,46,48].…”

“…These groups can undergo anion exchange for soils such as A1A2 that have a considerable anion-exchange capacity (Table 1), which likely is why the highly selective phosphate anion was needed to extract sorbed lasalocid. This coordination gives ionophores the unique ability to transport metal ions across cell membranes as either undissociated acids or neutral complexes and gives the molecule a largely hydrophobic exterior [12,46,[48][49][50]. This coordination gives ionophores the unique ability to transport metal ions across cell membranes as either undissociated acids or neutral complexes and gives the molecule a largely hydrophobic exterior [12,46,[48][49][50].…”

A comparison of data analysis methods for determining gas phase stabilities by cid: Alkali metal complexes of polyether ionophore antibiotics

“…In addition to the development of analytical methods, numerous studies have described fragmentation mechanisms of ionophores using collision induced dissociation (CID) spectra. The sodium complexes of lasalocid [38] and monensin [39][40][41][42][43] have received considerable attention, as have salinomycin [43,44] and tetronasin [45]. Furthermore, significant interest has been raised concerning the CID properties of different metal complexes with ionophores, including Group I, Group II, and several transition metals [46].…”

Avaliação de modelos químicos e microbiológicos para o estudo de (bio)transformações do antibiótico monensina A

“…Resultados e Discussão ________________________________________ 79 quantitativamente semelhantes entre as espécies estudadas (DAVISON, 1984;NEBBIA et al, 1999NEBBIA et al, , 2001 (DAVISON, 1984;KIEHL;JULIAN;KENNINGTON, 1998;NEBBIA et al, 1999NEBBIA et al, , 2001. Nebbia et al (1999), em um estudo empregando microssomas de fígado de ratos, mostrou que a principal família da citocromo P450 que participa do metabolismo oxidativo da MonA é a família 3A, grupo de enzimas responsáveis pelo metabolismo de cerca de 70% de fármacos, o que pode acarreta a possibilidade de interações medicamentosas da MonA com outros fármacos ou xenobióticos.…”

“…Os três metabólitos (metabólito 1, 2 e 3) obtidos neste trabalho foram descritos anteriormente em estudos que envolvem o metabolismo in vivo da MonA (DONOHO, 1978;DAVISON, 1984;KIEHL;JULIAN;KENNINGTON, 1998) (ROCHA et al, 2014;SOUSA-JUNIOR et al, 2013).…”