Preparation and supramolecular properties of unadulterated glycosyl liposomes from a bis(alpha-D-mannopyranosyl)-[60]fullerene conjugate.
The bis(alpha-D-mannopyranosyl)-[60]fullerene conjugate 3 was prepared by thermal coupling of C60 and either 2-azidoethyl 2,3,4,6-tetra-O-acetyl- or 2,3;4,6-di-O-isopropylidene-alpha-D-mannopyranoside (Scheme). Compound 3 was found to readily self-assemble. Dynamic-light-scattering (DLS) and atomic-force microscopy (AFM) experiments supported that the amphiphilic compound gives rise to nano-sized supramolecular structures during sugar deprotection (Ac-group removal) performed in MeOH/CH2Cl2 solution. Encapsulation studies with an aqueous suspension of 3 showed that the self-assembling structure envelopes Ba2+ and the fluorescent dye Acridine Red during its formation, which indicates that it resembles a bilayer vesicle or an unadulterated liposome with an inner hollow space. In addition to this notable property, the unique molecular geometry of the spatially arranged mannosyl surface residues of 3 gives rise to strong binding of the carbohydrate-recognizing lectin Con A. Hence, the polar amphiphilic end of 3 mimics the structure of 3,6-branched tri-alpha-D-mannoside (6; Fig. 3), a natural ligand of the Con A protein.
Kato
Haruhito
H
Molecular Design & Engineering, Graduate School of Engineering, Nagoya University Chikusa-ku, Nagoya 464-8603, Japan.
Kaneta
Noboru
N
Nii
Susumu
S
Kobayashi
Kazukiyo
K
Fukui
Nobuyuki
N
Shinohara
Hisanori
H
Nishida
Yoshihiro
Y
D001464:Barium / Q000737:chemistry; D003208:Concanavalin A / Q000737:chemistry; D037741:Fullerenes / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D012235:Rhodamines / Q000737:chemistry
D037741:Fullerenes; D008081:Liposomes; D012235:Rhodamines; C032527:acridine red; D003208:Concanavalin A; D001464:Barium