Intelligent Sugar Complexes

Abstract

The structure of [Co(&-Rha)3-mn)]Br2.2CH30H, where (Rhah-tren is tris(N-rhamnosyl-2-aminoethyl)amine, was elucidated by X-ray crystallography, which confirmed the unprecedented configurational inversion of [Co((Rha)3-tren)]2+, around the metal center reversibly by an addition and a removal of sulfate. INTRODUCTIO N

Peroxo-Bridged Dinuclear Cobalt(III) Complexes Containing N-Glycoside Ligands from Tris(2-aminoethyl)amine and d-Glucose or Maltose

“…‡ Osaka City University. in hoping to arrange a highly assembled sugar domain around metal centers, [28][29][30][31][32][33][34][35] which might lead to a minimal model for so-called sugar clusters of glycoproteins playing crucial roles in cell-cell adhesion and recognition. [36][37][38][39][40][41] We have previously reported the mononuclear cobalt(II) complexes ligated by a heptadentate N-glycoside formed from tren and mannose-type aldohexoses, [Co(aldose 3 -tren)]X 2 (1), where aldose 3 -tren ) tris-(N-aldosyl-2-aminoethyl)amine, aldose ) D-mannose (D-Man), L-rhamnose (L-Rha), and X ) Cl, Br, 1 / 2 SO 4 .…”

“…We have systematically studied the synthesis, characterization, and reactions of sugar−transition metal complexes in which carbohydrate moieties are anchored onto metal centers as N -glycosides with diamines. − A polyamine, tris(2-aminoethyl)amine (tren), has recently been used instead of diamines in hoping to arrange a highly assembled sugar domain around metal centers, − which might lead to a minimal model for so-called sugar clusters of glycoproteins playing crucial roles in cell−cell adhesion and recognition. − We have previously reported the mononuclear cobalt(II) complexes ligated by a heptadentate N -glycoside formed from tren and mannose-type aldohexoses, [Co(aldose 3 -tren)]X 2 ( 1 ), where aldose 3 -tren = tris( N -aldosyl-2-aminoethyl)amine, aldose = d -mannose ( d -Man), l -rhamnose ( l -Rha), and X = Cl, Br, 1 / 2 SO 4 . ,, Complex 1 showed a dynamic chiral inversion around the metal center (Δ↔Λ) induced by the interaction of the trivalent sugar domain with sulfate anion, which could be regarded as a basic synthetic model for biological induced-fit molecular recognition by a sugar receptor. In general, mannose-type aldoses such as d -Man and l -Rha have 2,3-cis configuration and the sugar ring is axially oriented with respect to the chelate ring upon coordination through the 1,2-functional groups with β-anomeric form (Scheme 1).…”

“…We have systematically studied the synthesis, characterization, and reactions of sugar-transition metal complexes in which carbohydrate moieties are anchored onto metal centers as N-glycosides with diamines. [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] A polyamine, tris(2-aminoethyl)amine (tren), has recently been used instead of diamines in hoping to arrange a highly assembled sugar domain around metal centers, [28][29][30][31][32][33][34][35] which might lead to a minimal model for so-called sugar clusters of glycoproteins playing crucial roles in cell-cell adhesion and recognition. [36][37][38][39][40][41] We have previously reported the mononuclear cobalt(II) complexes ligated by a heptadentate N-glycoside formed from tren and mannose-type aldohexoses, [Co(aldose 3 -tren)]X 2 (1), where aldose 3 -tren ) tris-(N-aldosyl-2-aminoethyl)amine, aldose ) D-mannose (D-Man), L-rhamnose (L-Rha), and X ) Cl, Br, 1 / 2 SO 4 .…”

“…[36][37][38][39][40][41] We have previously reported the mononuclear cobalt(II) complexes ligated by a heptadentate N-glycoside formed from tren and mannose-type aldohexoses, [Co(aldose 3 -tren)]X 2 (1), where aldose 3 -tren ) tris-(N-aldosyl-2-aminoethyl)amine, aldose ) D-mannose (D-Man), L-rhamnose (L-Rha), and X ) Cl, Br, 1 / 2 SO 4 . 29,31,33 Complex 1 showed a dynamic chiral inversion around the metal center (∆TΛ) induced by the interaction of the trivalent sugar domain with sulfate anion, which could be regarded as a basic synthetic model for biological induced-fit molecular recognition by a sugar receptor. In general, mannose-type aldoses such as D-Man and L-Rha have 2,3-cis configuration and the sugar ring is axially oriented with respect to the chelate ring upon coordination through the 1,2-functional groups with β-anomeric form (Scheme 1).…”