Large-ring cyclodextrins (CD) are cyclic glucans composed of 9o rm ore a-1,4-linked glucose units.T hey are minor side products of bacterial glucanotransferases (CGTases,E C2.4.1.19) and have previously been available only in very small amounts for studies of their properties in supramolecular complex formation reactions.W ee ngineered aCGTase to synthesizemainly large-ring CD facilitating their preparation in larger amounts.B yr eversed phase chromatography,w eo btained single CD samples composed of 10 to 12 glucose units (CD10, CD11, and CD12) with ap urity of > 90 %. Their identity was confirmed by high resolution mass spectrometry and fragmentation analysis.Wedemonstrated the non-toxicity of CD10-CD12 for human cell lines by ac ell proliferation assaya nd impedimetric monitoring.W et hen showed that CD10 and CD11 are efficient chiral selectors for the capillary electrophoretic separation of the enantiomeric pharmaceuticals fluvastatin, mefloquine,c arvedilol, and primaquine.CDa re a-1,4-linked cyclic glucans with ad egree of polymerization (DP) between 6t o> 100. Branched a-1,6-CD have also been described. [1] In contrast to larger CD,CD6, CD7, and CD8 (a-, b-, g-CD) have been studied extensively and are produced commercially. [2] They form cone-shaped structures with ahydrophobic cavity and an outer hydrophilic area, enabling the reversible binding of hydrophobic mole-Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.