Artificial enzymes: synthesis of imidazole substituted at C(2) of β-cyclodextrin as an efficient enzyme model of chymotrypsin

Abstract

lmidazole has been attached at C(2) on the more open face of P-cyclodextrin to mimic the enzyme chymotrypsin; this chemical model is shown to be catalytically far superior to that with an imidazole on the primary side [C(6)] of cyclodextri n.

Urea bonded cyclodextrin derivatives onto silica for chiral HPLC

“…The secondary rim of CDs is reported to be catalytically very important [45,46] and modifications of this face are believed to produce valuable derivatives for catalysis, enzyme mimics, etc. However, the secondary hydroxyl groups on the secondary rim of CD are relatively less reactive/accessible in comparison to the primary hydroxyl groups.…”

Thermodynamics of Molecular Recognition of Bile Salts by 3,6- (Oligoethylenediamino-Bridged) β-Cyclodextrin Dimers

“…Subsequently, the nucleophiles 6-oligoethylenediamino--CDs reacted with manno-2,3-epoxy--CD to give the target products 1-3. Generally, the 13 C NMR spectra of N-or S-substituted sugar derivatives are known to show a larger upfield shift of the -carbon and smaller upfield shifts of the -carbon and -carbon relative to the parent sugar [23,24]. In the 13 C NMR spectra of 1-3, both C-3 (as a -carbon of 3-substituted) and C-6 carbon (as acarbon of 6-substituted) showed the appreciable upfield shifts (1.5-2.7 ppm for C-3, 0.3-2.8 ppm for C-6), while C-1 (as a -carbon of 3-substituted), C-2 (as a -carbon of 3-substituted), C-4 (as a -carbon of 3-substituted and a - Ref.…”

Cyclodextrin derivatives that display Enzyme Catalysis

“…Some of the simplest compounds to prepare, the N-alkylated derivatives 1, 2 and 3, are obtained by substitution of the b-cyclodextrin 6-or 2-monotosylate (Fig. 2), and for the latter two compounds through intermediacy of an 2,3-epoxide resulting in 3 having the D-altro stereochemistry at the imidazoyl substituted monosaccharide (5,6). The imidazoyl groups in these derivatives are presumably nucleophilic, since N-methyl imidazole has a pKa of 7.4 and thus is 100 times more basic than pyridine.…”