Coordination features of difunctionalized beta-cyclodextrins with carnosine: ESI-MS and spectroscopic investigations on 6A,6D-di-(beta-alanyl-L-histidine)-6A,6D-dideoxy-beta-cyclodextrin and 6A,6C-di-(beta-alanyl-L-histidine)-6A,6C-dideoxy-beta-cyclodextrin and their copper(II) complexes.
The synthesis and characterization of two beta-cyclodextrins (beta-CD) functionalized with two units of carnosine (beta-alanyl-L-histidine) through the amino group, 6A,6C-(beta-alanyl-L-histidine)-6A,6C-dideoxy-beta-cyclodextrin (ACCDAH) and 6A,6D-(beta-alanyl-L-histidine)-6A,6D-dideoxy-beta-cyclodextrin (ADCDAH), are reported. NMR and C.D. data of the ligands indicate a different interaction of dipeptide chains with upper rim and cavity of beta-CD. Analogously, spectroscopic and electrospray ionization mass spectrometry data show different copper(II) complex species formed by the two regioisomers. The ability of carnosine-cyclodextrin derivatives to bind copper ions in a head-to-tail fashion induces the formation of oligomeric species (up to hexamers) in the case of ACCDAH, where the two carnosine moieties are adjacent, while in the ADCDAH case the mutual interaction between the peptidic chains of two ADCDAH molecules allows the almost exclusive formation of a copper-assisted self-assembled dimeric species.
Mineo
Placido
P
Istituto di Chimica e Tecnologia dei Polimeri, CNR-Sezione di Catania, Catania, Viale A. Doria, 6, Catania 95125, Italy.
Vitalini
Daniele
D
La Mendola
Diego
D
Rizzarelli
Enrico
E
Scamporrino
Emilio
E
Vecchio
Graziella
G
D002336:Carnosine / Q000737:chemistry* / Q000378:metabolism; D003300:Copper / Q000737:chemistry* / Q000378:metabolism; D003505:Cyclodextrins / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D004151:Dipeptides / Q000737:chemistry / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D021241:Spectrometry, Mass, Electrospray Ionization; D047392:beta-Cyclodextrins
D003505:Cyclodextrins; D004151:Dipeptides; D047392:beta-Cyclodextrins; C061116:alanylhistidine; D003300:Copper; D002336:Carnosine; C031215:betadex