Research Abstract |
1.2A, 6X-Bis (O-mesitylenesulfonyl)-beta-cyclodextrins (X=A-G) 1-7 were prepared by the selective reaction. The numbers of the compounds are given in the order of increasing retention time in reverse-phase HPLC. They were isolated and determined to be 2A, 6D-, 2A, 6E-, 2A, 6C-, 2A, 6F-, 2A, 6B-, 2A, 6A-, and 2A, 6G-isomers, respectively, by combination of selective hydrolyses with Taka amylase A (or bacterial saccharifying amylase) and selective conversion to the 2, 3-oxirane and the 3, 6-anhydride. 2.6A, 6X-Bis (2'-aminoethylamino) -6A, 6X-dideoxy-o-cyclodextrins (X=B : -D) were prepared by the reaction of 6A, 6X-bis (O-p-tosyl) -p-cyclodextrins with ethylenediamine. -Other bifunctional cyclodextrins having a sulfonate group and an amino group on the 6A, 6X- position were prepared by the reaction of the ditosylates with sodium mercaptoethanesulfonate followed by the reaction with ethylenediamine. 3. Rhodopsin models, Schiff bases 8-10, were prepared respectively by the reaction of 6A, 6X-bis (2'-aminoethylamino) -6A, 6X-dideoxy-beta-cyclodextrins (X=B-D) with retinal in ethylenegycol and their spectra were measured in 0.1 N HCI. The observed wavelength of maximum absorption were 470 nm, 468 nm, and 452 nm for 8-10, respectively, were shorter than that (497 nm) for the reported model which was prepared from 6- (2'-aminoethylamino) -6deoxy-beta-cyclodextrins and retinal. This shows the importance of the presence and the position of the ionic group in the absorption spectrum of rhodopsin.
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