Design and studies of novel polyoxysterol-based porphyrin conjugates

Abstract

a b s t r a c tNew types of steroid-porphyrin conjugates derived from 20-hydroxyecdysone (20E) and 24-epibrassinolide (EBl) were synthesized. An exceptional regioselectivity in the reaction of both steroids with porphyrin boronic acids was found to give side-chain-conjugated boronic esters as sole products. UV-Vis-, fluorescence and NMR spectroscopy yielded similar data for all the studied compounds confirming the solvent driven supramolecular assembly with formation of J-aggregates. CD measurements of water diluted solutions showed a clear difference between 20E and EBl conjugates. The latter showed a strong supramolecular chirality, whereas 20E J-aggregates did not.

Conjugates of Pyropheophorbide a with Androgen Receptor Ligands

“…[1][2][3] Synthesized earlier conjugates of macrocycles with polyamines, amino acids, peptides, peptidomimetics, antibiotics, nucleotides, carbohydrates, bile acids, lipids, steroids, etc., revealed prospective implications in biomedical studies and photodynamic therapy. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] In this study we have synthesized conjugates of pyropheophorbide a with androgen receptor ligandstestosterone and dihydrotestosterone. Аndrogen receptor is known to be an important drug target for treatment of prostate cancer.…”

Steroid-photosensitizer conjugates: Syntheses and applications

“…The reaction of porphyrins 88-90a with 20(E)-hydroxyecdysone and 24-epibrassinolide (EBl) in methanol gave the corresponding products 88-89b,c through the interaction of the 20,22-diol of the former, or the 22,23-diol of EBl, with the boronic acid moieties of the porphyrins. High regioselectivity of the reaction of both steroids with the porphyrin boronic acids gave the side-chain-conjugated boronic esters as sole products [75]. CD measurements provided evidence for the presence of supramolecular chirality in EBl J-aggregates which were absent in the hydroxyecdysone J-aggregates.…”

Synthetic Aspects of Brassinosteroids

“…To date, there have been several attempts to make use of BS for preparing supramolecular structures. A number of side-chain-conjugated boronic esters were obtained from the corresponding porphyrin boronic acids and epibrassinolide [155]. Almost 21% of the crystal total volume in (311) is void filled with solvent molecules.…”