Synthesis and solvent driven self-aggregation studies of meso-“C-glycoside”-porphyrin derivatives

Abstract

New types of porphyrin derivatives bearing "C-glycoside" moieties, either in 5,10,15,20- or in 5,15-meso-positions, were prepared and fully characterized. The presence of the glycosidic groups imparts to the title macrocycles, besides an amphiphilic character, a clear tendency to form chiral suprastructures upon solvent-driven self-aggregation in different aqueous-organic solvent mixtures. Supra-assembly phenomena, in terms of the size and morphology of the resulting structures, as well as their kinetics of aggregation, were studied by UV-visible, fluorescence, resonance light scattering (RLS), and CD spectroscopy, indicating that the morphology of the aggregates depends strongly on the structure of the porphyrin rings, and on the bulk conditions of aggregation.

Chemical Synthesis and Medicinal Applications of Glycoporphyrins

“…Debenzylation was achieved by hydrogenation over Pd/C giving the hydroxylated derivative 177 in 63 % yield. Note, these structures form chiral super-structures due to selfaggregation in aqueous-organic solvent mixtures with the morphology of the aggregates depending on the porphyrin structure and the bulk conditions of aggregation [170] .…”

“…Several other examples were reported. These include the benzyl protected derivatives 66 and 67 [170] and condensation products of commercially available di-aldose and pyrrole [171] . Metallation and deprotection of the glycosyl units provided compounds 68 and 69 in yields ranging from 63-90 %.…”

“…The carbonyl of these residues were deprotected and subsequently reacted via pyrrole condensation to afford 375-379 in an overall yield of 22-49 % [219] . In extension of the A 4 C-glycosyl porphyrins 66 and 67 diglycosylated porphyrins were synthesized to investigate their ability to form chiral supramolecular structures in different aqueous-organic solvent mixtures [170] . The 5,15-substitution pattern was achieved using the [2+2] MacDonald type procedure where the dipyrryl derivatives were prepared by condensing the respective aldehydes with pyrrole affording 373 and 374 in 49 and 84 % yield, respectively.…”

The kinetic studies of the solvent-promoted aggregation of a steroid-porphyrin derivative

“…Within these topics we focused on the aggregation properties of porphyrin derivatives characterised by the presence of chiral polar functionalities, with the aim to build up mesoscopic structures featuring supramolecular chirality [3]. In particular, we devoted our interest in (L)-proline [4], glucosides [5], or steroid derivatives [6] as structural chiral effectors, which, besides inferring to the macrocycle amphiphilic properties, drive the stereochemical evolution toward the formation of specific architectures. These latter structures are also of importance in the study of their interaction with liposomes as cell-membrane mimics [7], for the development of drug carriers in photodynamic treatment of cancer and related diseases (PDT) [8].…”

Design and studies of novel polyoxysterol-based porphyrin conjugates

“…For a number of years, we have been interested in various aspects of pyrrole-steroid conjugates [5,13,[23][24][25][26][27][28][29][30] having in mind their expected value as new fluorescent probes for biochemical studies and immunoanalysis [31], and as possible sensing elements in special analytical devices [32] for recognizing the corresponding hormones perception. The main purposes of the present work were (1) to synthesize new steroid-porphyrin conjugates based on oxygenated sterols belonging to BS and ES and (2) to investigate physicochemical properties of the newly prepared compounds.…”