1H NMR and electronic absorption spectroscopy of paramagnetic water-soluble Meso-tetraarylsubstituted cationic and anionic metalloporphyrins

Yushmanov, Victor E.; Imasato, Hidetake; Tominaga, Tânia Toyomi; Tabak, Marcel

doi:10.1016/0162-0134(95)00071-2

Cited by 60 publications

(50 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Furthermore, as shown in Table 2, Fe(III)TSP exhibits therapeutic activity in mice, whereas under the same conditions Mn(III)TSP does not. Others have shown that Mn(III)TSP is essentially monomeric in aqueous media at physiological pH, whereas Fe(III)TSP exists predominantly as dimers or larger aggregates (23). Furthermore, we have seen less inhibition of PrP-res accumulation in vitro by Mn(III) than Fe(III) complexes of deuteroporphyrinIX-2,4-disulfonate, a sulfonated cyclic tetrapyrrole structure related to hemin (data not shown).…”

Section: Discussionsupporting

confidence: 45%

Cyclic Tetrapyrrole Sulfonation, Metals, and Oligomerization in Antiprion Activity

Caughey¹,

Priola²,

Kocisko³

et al. 2007

Antimicrob Agents Chemother

View full text Add to dashboard Cite

Cyclic tetrapyrroles are among the most potent compounds with activity against transmissible spongiform encephalopathies (TSEs; or prion diseases). Here the effects of differential sulfonation and metal binding to cyclic tetrapyrroles were investigated. Their potencies in inhibiting disease-associated protease-resistant prion protein were compared in several types of TSE-infected cell cultures. In addition, prophylactic antiscrapie activities were determined in scrapie-infected mice. The activity of phthalocyanine was relatively insensitive to the number of peripheral sulfonate groups but varied with the type of metal bound at the center of the molecule. The tendency of the various phthalocyanine sulfonates to oligomerize (i.e., stack) correlated with anti-TSE activity. Notably, aluminum(III) phthalocyanine tetrasulfonate was both the poorest anti-TSE compound and the least prone to oligomerization in aqueous media. Similar comparisons of iron-and manganese-bound porphyrin sulfonates confirmed that stacking ability correlates with anti-TSE activity among cyclic tetrapyrroles.

show abstract

Section: Discussionsupporting

confidence: 45%

Cyclic Tetrapyrrole Sulfonation, Metals, and Oligomerization in Antiprion Activity

Caughey¹,

Priola²,

Kocisko³

et al. 2007

Antimicrob Agents Chemother

View full text Add to dashboard Cite

show abstract

“…For Fe(III)TMPyP, analysis of optical absorption, EPR and 1 H NMR spectra allowed to conclude that at acidic pH in the range 2.0-6.0 there is an equilibrium between monomeric species, pentacoordinated monoaqueous and hexacoordinated diaqueous Fe(III)-porphyrin; in the pH range 6.0-10 there is a predominance of the loxo dimeric species [18]. An equilibrium between monomeric and dimeric species was also found for Fe(III)TPPS 4 in the pH range 5-8 [34]. The l-oxygen bridged FeTPPS 4 is supposed to be pentacoordinated but hexacoordinated FeTMPyP was proposed to occur [35].…”

Section: Ph Titration Of the Fe-porphyrins In Buffer And In Micellar mentioning

confidence: 76%

Nitric oxide transfer from the NO-donor S-nitroso-N-acetylpenicillamine to monomers and dimers of water-soluble iron-porphyrins

Vilhena

Louro

2004

Journal of Inorganic Biochemistry

View full text Add to dashboard Cite

“…4 + 10Na] 6− signal corresponds to the small leading peak in the ATD of m/z = 701. The main peak is [(MTPPS) 2 + 5Na] 3− , see Figure 2 and Supporting Information.)…”

Section: ■ Computational Methodsmentioning

confidence: 99%

Structures of Metalloporphyrin–Oligomer Multianions: Cofacial versus Coplanar Motifs as Resolved by Ion Mobility Spectrometry

et al. 2016

View full text Add to dashboard Cite

ABSTRACT:We have combined ion mobility mass spectrometry with quantum chemical calculations to investigate the gasphase structures of multiply negatively charged oligomers of mesotetra(4-sulfonatophenyl)metalloporphyrins comprising the divalent metal centers Zn II , Cu II , and Pd II . Sets of candidate structures were obtained by geometry optimizations based on calculations at both the semiempirical PM7 and density functional theory (DFT) levels. The corresponding theoretical cross sections were calculated with the projection approximation and also with the trajectory method. By comparing these collision cross sections with the respective experimental values we were able to assign oligomer structures up to the tetramer. In most cases the cross sections of the lowest energy isomers predicted by theory were found to agree with the measurements to within the experimental uncertainty (2%). Specifically, we find that for a given oligomer size the structures are independent of the metal center but depend strongly on the charge state. Oligomers in low charge states with a correspondingly larger number of sodium counterions tend to form stacked, cofacial structures reminiscent of H-aggregate motifs observed in solution. By contrast, in higher charge states, the stack opens to form coplanar structures. ■ INTRODUCTIONMetalloporphyrins constitute the reactive centers in a large number of biochemical systems such as hemoglobin, myoglobin, and chlorophyll. As a consequence, they are wellstudied in condensed phase. 1 It is also well-known that porphyrins and metalloporphyrins can self-assemble into larger oligomers in solution. This aggregation has attracted considerable interest, especially for porphyrins functionalized with highly polar groups such as sulfonic acids. 2−9 Much of this effort has been focused on water-soluble meso-tetra(4-sulfonatophenyl)porphyrin (TPPS). Ribóet al. 6 investigated aqueous solutions thereof spectroscopically. In studies performed at various concentrations and pH values, they found evidence for the formation of small J (edge-to-edge) and H (face-to-face) aggregates. The light scattering measurements of Micali et al. 10 have in fact suggested that even larger mesoscopicself-similar clusters of TPPS J-aggregates may form in solution. More recently, Hollingsworth et al. 9 have investigated the aggregation of TPPS in aqueous solution using UV−vis and fluorescence spectroscopy, small-angle X-ray scattering, analytical ultracentrifugation, and transmission electron microscopy. They inferred stacks of ring structures containing typically 25 monomeric units.TPPS oligomers as well as aggregates of the corresponding metalloporphyrins, MTPPS, can also be prepared and studied in gas phase, i.e., in the absence of solvent molecules. For example, multiply negatively charged aggregates of MTPPS (also containing sodium counterions) can be generated by electrospray ionization (ESI) and detected with mass spectrometry. To what extent such isolated aggregates can also provide an indirect measure of aggregatio...

show abstract

1H NMR and electronic absorption spectroscopy of paramagnetic water-soluble Meso-tetraarylsubstituted cationic and anionic metalloporphyrins

Cited by 60 publications

References 44 publications

Cyclic Tetrapyrrole Sulfonation, Metals, and Oligomerization in Antiprion Activity

Cyclic Tetrapyrrole Sulfonation, Metals, and Oligomerization in Antiprion Activity

Nitric oxide transfer from the NO-donor S-nitroso-N-acetylpenicillamine to monomers and dimers of water-soluble iron-porphyrins

Structures of Metalloporphyrin–Oligomer Multianions: Cofacial versus Coplanar Motifs as Resolved by Ion Mobility Spectrometry

Contact Info

Product

Resources

About