Synthesis and Antibacterial Activity of New Poly-<i>S</i>-lysine−Porphyrin Conjugates

Tomé, João P. C.; Neves, Maria G. P. M. S.; Tomé, Augusto C.; Cavaleiro, José A. S.; Soncin, Marina; Magaraggia, Michela; Ferro, Stefania; Jori, Giulio

doi:10.1021/jm040802v

Cited by 142 publications

(109 citation statements)

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Section: Methodsmentioning

confidence: 99%

“…The key neutral porphyrin derivatives were obtained from crossed-Rothemund reactions using the appropriate benzaldehydes and pyrrole in refluxing acetic acid and nitrobenzene [22][23][24]. The alkylation with methyl iodide in dry DMF (dimethylformamide) gave the expected tris(N-methylpyridinium)porphyrin salts 1-5 in roughly 95% yield (Scheme 1) [23].…”

Section: Methodsmentioning

confidence: 99%

“…The alkylation with methyl iodide in dry DMF (dimethylformamide) gave the expected tris(N-methylpyridinium)porphyrin salts 1-5 in roughly 95% yield (Scheme 1) [23].…”

Section: Methodsmentioning

confidence: 99%

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Reduction of cationic free-base meso-tris-N-methylpyridinium-4-yl porphyrins in positive mode electrospray ionization mass spectrometry

Ramos

Marques

Correia

et al. 2007

J. Am. Soc. Mass Spectrom.

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Reductions involving more than one electron with formation of the M ϩ and [Mϩ2H] ϩ ions were observed for electrosprayed meso-tris (N-methylpyridinium-4-yl)porphyrin iodides, MI 3 . These reductions were studied by using different solvents and flow rates. Formation of the [Mϩ2H] ϩ ions occurred only for protic solvents and to a larger extent at lower flow rates. The type of the fourth substituent does not seem to affect the reduction processes. , it is generally accepted that redox reactions do occur in the capillary sprayers and that they are responsible for charge balance [1,2]. Redox processes in electrospray mass spectrometry were comprehensively investigated by and, more recently, electrochemical aspects and applications of electrospray ionization were the focus of reviews [9,10].Ions formed by one electron reduction from nonmetallated dicationic species in solution were previously observed in positive-mode electrospray mass spectrometry for ionic compounds such as diquaternary pyridinium salts [11-13] and free-base N-alkylpyridiniumyl porphyrin salts [14]. One-and two-electron reductions of the cations of metallated N-alkylpyridiniumyl porphyrin salts were also reported, when electrospray was used in the positive mode [15][16][17].When acquiring the electrospray mass spectra of 5,10,15-tris(N-methyl-pyridinium-4-yl)-20-phenylporphyrin iodide, MI 3 , we observed, besides the expected M 3ϩ ion, ions such as M 2ϩ , M ϩ , and [Mϩ2H] ϩ , which may be the result of reductive processes. Reductions involving more than one electron were never reported before for electrosprayed free-base cationic porphyrins and, although formation of [MϩnH] ϩ ions (n Ͼ 1) in desorption ionization (fast atom or ion bombardment) [18 -20] and matrix assisted laser desorption (MALDI) [21] has been described, it was never reported as occurring in electrospray mass spectrometry (ESI-MS) until now. These facts prompted us to use ESI-MS to investigate a group of meso-tris(N-methylpyridinium-4-yl)porphyrin iodides, MI 3 , with a different fourth meso substituent (see Scheme 1) to gather more information on the species formed with respect to their formation reactions and to their relation with the ionization processes occurring in the electrospray interface. ExperimentalThe key neutral porphyrin derivatives were obtained from crossed-Rothemund reactions using the appropriate benzaldehydes and pyrrole in refluxing acetic acid and nitrobenzene [22][23][24]. The alkylation with methyl

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Reduction of cationic free-base meso-tris-N-methylpyridinium-4-yl porphyrins in positive mode electrospray ionization mass spectrometry

Ramos

Marques

Correia

et al. 2007

J. Am. Soc. Mass Spectrom.

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“…As the NHS ester was non-sulphonated, causing it to be water insoluble, the reaction was performed in the water miscible organic solvent DMSO. To produce a pH of pH 9, provide a base in the non-aqueous DMSO solution and catalyse the reaction be-tween NHS and lysine trimethylamine (TEA) was added [50]. In addition to the reaction conditions used the structure of duramycin means it is reasonable to presume the desired location for conjugation was achieved.…”

Section: Discussionmentioning

confidence: 99%

“…The conjugation of the porphyrin to duramycin at this chosen location should minimise interference with the PE binding site [3]. A number of biological molecules conjugated to porphyrin through lysine residues have been shown to retain their antimicrobial function [50,52,53]. The scFv antibody fragment LAG-3 when conjugated through its ly-sine residues to a porphyrin PS was shown to bind to the colorectal cancer cell line Caco-2 and effectively induce cell death following 15 J/cm 2 light treatment [26].…”

Section: Discussionmentioning

confidence: 99%