Synthesis of a single-isomer sulfated β-cyclodextrin carrying nonidentical substituents at all of the C2, C3, and C6 positions and its use for the electrophoretic separation of enantiomers in acidic aqueous and methanolic background electrolytes, Part 2: Heptakis(2-O-methyl-6-O-sulfo) cyclomaltoheptaose

Abstract

The sodium salt of heptakis(2-O-methyl-6-O-sulfo)cyclomaltoheptaose (HMS), the second single-isomer, sulfated beta-CD carrying nonidentical substituents at all of the C2, C3, and C6 positions, has been synthesized, analytically characterized, and used for the capillary electrophoretic separation of the enantiomers of a group of 23 weak base analytes in acidic aqueous and methanolic BGEs. HMS interacted strongly with only about half of the analytes studied. The good separation selectivities and favorable normalized EOF mobilities allowed for rapid, efficient separation of the enantiomers of 19 of the 23 weak base analytes in the aqueous BGEs, often with separation selectivity values complimentary to those obtained with other single-isomer sulfated CDs. HMS did not prove to be as good a resolving agent in acidic methanolic BGEs as its counterpart, heptakis(2-O-methyl-3-O-acetyl-6-O-sulfo)cyclomaltoheptaose.

Review of aqueous chiral electrokinetic chromatography (EKC) with an emphasis on chiral microemulsion EKC

“…For some analytes, the nonaqueous buffer produced sharper peaks (less electromigration dispersion). The same group prepared another single isomer anionic CD: heptakis(2-O-methyl-6-Osulfo)cyclomaltoheptaose (HMS-b-CD) [130]. As with their previous report, basic pharmaceutical enantiomers were used to investigate the selectivity of the new CD in both aqueous and nonaqueous acidic buffers.…”

The role of cyclodextrins in chiral capillary electrophoresis

“…The ratio of success has been further improved up to 89% using dual mixtures of CDs [14]. Another publication refers to separation of 19 from 23 weak basic chiral pharmaceuticals using single-isomer heptakis(2-O-methyl-3-Oacetyl-6-O-sulfo)-b-CD [55]. CDs can separate not only enantiomers, but regio isomers (e.g.…”

“…The statistical substitution, however, causes moderate batch-to-batch reproducibility, which does not meet the strict requirement of good laboratory practice. A significant trend is the introduction and application of well reproducible single-isomer CD derivatives [3,5,10,13,14,20,32,53,55,58]. The single isomers, however, have less broad spectra and smaller selectivity values in several instances [36,43].…”

“…Their fully derivatized new members are used in NACE, because they show good solubility in organic BGE [13,15,20,55,58,69,71]. The NACE gives a good opportunity for their ion-pair applications.…”

Electrodriven methods for the enantioseparation of second‐generation antidepressant drugs: An update

“…Two related papers report the synthesis and use of the new selectors heptakis(2-O-methyl-6-O-sulfo)cyclomaltoheptaose [32] and heptakis(2-O-methyl-3-O-acetyl-6-O-sulfo)-cyclomaltoheptaose [33], however, in this case the only tried antidepressant was bupropion. Good enantiomeric separations of this compound were obtained in an acidic aqueous medium at selector concentrations ranging from 2.5 to 10 mM; on the other hand, in a nonaqueous medium (acidic methanol) a good separation was obtained with the latter selector and not with the former.…”