Okada Y, Koizumi K
School of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Japan.
Chem Pharm Bull (Tokyo). 1998 Feb;46(2):319-23. doi: 10.1248/cpb.46.319.
Three positional isomers of 6(1),6n-di-O-alpha-D-glucosyl-cyclomaltoheptaose [1,n-(G)2-beta CDs; n = 2-4] which existed in the digests with glucoamylase of the products from cyclomaltoheptaose (beta-cyclodextrin, beta CD) and maltose with Klebsiella pneumoniae pullulanase, were purified by HPLC. The solubilities of two isomers of those doubly branched beta CDs, 1,2- and 1,3-(G)2-beta CDs, in water were much higher than those of parent non-branched beta CD and mono-branched beta CD, 6-O-alpha-D-glucosyl-beta CD (G-beta CD), while the solubility of another isomer, 1,4-(G)2-beta CD, was significantly lower than these two isomers, though it was higher than that of beta CD. On the other hand, the solubilities of 1,2- and 1,3-isomers in 10, 30, and 50% (v/v) aqueous methanol at 25 degrees C were independent of methanol concentrations and their solubilities were the same as those in water at 25 degrees C. However, that of 1,4-isomer increased with increasing methanol concentrations. The hemolytic activities of 1,n-(G)2-beta CDs on human erythrocytes in isotonic solution were lower than those of G-beta CD and beta CD, and became weaker in the order of 1,4- > 1,2- > 1,3-isomers. The complex-forming abilities of 1,n-(G)2-beta CDs for digitoxin, digoxin, fluorometholone, flurbiprofen, hydrocortisone acetate, and norfloxacin were about the same as those of beta CD and G-beta CD, whereas reserpine was more difficult to include within 1,n-(G)2-beta CDs than beta CD and G-beta CD. Nevertheless, the solubilities of those guest compounds were much more enhanced by 1,n-(G)2-beta CDs and G-beta CD than by beta CD.
6(1),6n - 二 - O - α - D - 葡萄糖基 - 环麦芽七糖[1,n - (G)2 - β - 环糊精；n = 2 - 4]的三种位置异构体存在于环麦芽七糖（β - 环糊精，β - CD）与麦芽糖的产物经肺炎克雷伯菌支链淀粉酶和葡糖淀粉酶消化后的产物中，通过高效液相色谱法（HPLC）进行了纯化。这些双分支β - 环糊精的两种异构体，即1,2 - 和1,3 - (G)2 - β - 环糊精，在水中的溶解度远高于母体非分支β - 环糊精和单分支β - 环糊精6 - O - α - D - 葡萄糖基 - β - 环糊精（G - β - CD），而另一种异构体1,4 - (G)2 - β - 环糊精的溶解度虽高于β - CD，但显著低于这两种异构体。另一方面，1,2 - 和1,3 - 异构体在25℃下于10%、30%和50%（v/v）甲醇水溶液中的溶解度与甲醇浓度无关，且与它们在25℃水中的溶解度相同。然而，1,4 - 异构体的溶解度随甲醇浓度的增加而增大。1,n - (G)2 - β - 环糊精在等渗溶液中对人红细胞的溶血活性低于G - β - CD和β - CD，且按1,4 - > 1,2 - > 1,3 - 异构体的顺序减弱。1,n - (G)2 - β - 环糊精对洋地黄毒苷、地高辛、氟米龙、氟比洛芬、醋酸氢化可的松和诺氟沙星的络合能力与β - CD和G - β - CD大致相同，而利血平比β - CD和G - β - CD更难被1,n - (G)2 - β - 环糊精包合。尽管如此，这些客体化合物被1,n - (G)2 - β - 环糊精和G - β - CD提高的溶解度比被β - CD提高的溶解度要大得多。
