A Versatile Synthesis of Linked Cyclodextrins

Abstract

Reactions of amino-substituted cyclodextrins with bis(3-nitrophenyl) oxalate, malonate, succinate and glutarate, and with diphenyl carbonate, afford a range of linked cyclodextrins. These include α- and β-cyclodextrin dimers, joined by substitution at either C6 or C3, and asymmetric species with a β-cyclodextrin bonded to an a-cyclodextrin and a C3-substituted cyclodextrin attached to a C6-substituted moiety.

Preparation, physicochemical analysis and molecular modeling investigation of 2,2′-Bipyridine: β-Cyclodextrin inclusion complex in solution and solid state

“…For example CDs have been used in the pharmaceutical industry as solubilizers, diluents and tablet ingredients which improve the stability, bio availability and pharmacokinetic properties of drugs [27][28][29][30]. In cosmetic field, the interaction of the guest with CDs produces a higher energy barrier to overcome to volatilize, thus producing long-lasting fragrance [31].…”

Complexation of dodecyl-substituted poly(acrylate) by linked β-cyclodextrin dimers and trimers in aqueous solution

“…Poly(acrylic acid) ( M w = 250,000, M w / M n ≈ 2) was purchased from Aldrich as a 35 wt % aqueous solution and freeze‐dried to a constant weight. The linked β‐CD dimers, N , N ′‐ bis (6 A ‐deoxy‐6 A ‐β‐cyclodextrin)urea, β‐CD 2 ur, N , N ′‐ bis (6 A ‐deoxy‐6 A ‐β‐cyclodextrin)succinamide, β‐CD 2 su, the linked β‐CD trimers, 1,3,5‐ N , N , N‐tris (6 A ‐deoxy‐6 A ‐β‐cyclodextrin)benzene, β‐CD 3 bz, and 1,3,5‐ N , N , N‐tris (6 A ‐(2‐aminoethyl)amino‐6 A ‐deoxy‐6 A ‐β‐cyclodextrin)benzene, β‐CDen 3 bz, and the sodium salt of 3% dodecyl‐substituted poly(acrylate), PAAC12, were prepared and characterized as previously described. The extent of substitution of PAAC12 was determined to be 3.0 ± 0.1% by 1 H NMR spectroscopy from the ratio of the areas of the resonances of the methyl proton of the dodecyl substituent and that of the poly(acrylate) methine proton.…”

“…), has been selected for study, and two‐dimensional NOESY 1 H NMR spectroscopic, isothermal titration calorimetric, ITC, and rheological techniques have been used to characterize the host–guest complexation of the C12 substituents of PAAC12 in aqueous solution by the two β‐cyclodextrin (β‐CD) trimers, 1,3,5‐ N , N , N‐tris ‐(6 A ‐deoxy‐6 A ‐β‐cyclodextrin)‐benzene, β‐CD 3 bz, and 1,3,5‐ N , N , N‐tris (6 A ‐(2‐aminoethyl)amino‐6 A ‐deoxy‐6 A ‐β‐cyclodextrin)‐benzene, β‐CDen 3 bz, which are unusual because of their tritopic nature . Comparisons are made with the analogous host–guest interactions of the linked β‐CD dimers, N , N ′‐ bis (6 A ‐deoxy‐6 A ‐β‐cyclodextrin)urea, β‐CD 2 ur, and N , N ′‐ bis (6 A ‐deoxy‐6 A ‐β‐cyclodextrin)succinamide, β‐CD 2 su, and β‐CD with PAAC12 (Fig. ).…”

An H.P.L.C. Study of Cooperative Guest Binding by a Covalently Linked b-Cyclodextrin Dimer

“…Under these circumstances, depletion of the guest concentration resulted in a negative peak at the retention time of the guest, and the area of the peak was calibrated as described by Sébille et al, 7 to give the guest-host binding ratio, r. The variation in the ratio r as a function of concentration of the guest was interpreted by use of Scatchard plots (r/[guest] against r), 8 according to equation (1), where n is the number of binding sites and K is the association constant for the complex. From these plots, the number of binding sites, n, is given by the x -intercept, while the y-intercept equals K n.…”