Posted by A rapid test was worked out to identify single isomer heptakis(2,6-di-O-methyl) β-cyclodextrin (2,6-DIMEB), an isomer with distinct methylation pattern compared to various commercially available methylated cyclodextrins. It has been used in the production of acellular pertussis vaccine as an auxiliary material improving toxin secretion since the 1980s. 2,6-DIMEB has since gained significance in other biotechnological processes, too. Characterization of the isomeric purity and differentiation of 2,6-DIMEB from other methylated cyclodextrin types having different degree and pattern of substitution has therefore a critical relevance. A rapid test by hot crystallization is proposed here based on the peculiar behavior of this compound upon heating in aqueous solution. The temperature at the onset of crystallization is informative on the 2,6-DIMEB content of a mixture of methylated β-cyclodextrins. The test was validated by using HPLC and NMR studies. Comparing the samples from different manufacturers we show that industrially produced methylated cyclodextrins labeled as “DIMEB” contains usually at least 40% of the desired 2,6-DIMEB isomer. Using these techniques, we demonstrated an example of such “DIMEB” labeled products that do not even contain detectable amount of 2,6-DIMEB.
Szente, L., Tuza, K., Herr, D.M. . Rapid test for identification of heptakis (2,6-di-O-methyl) β-cyclodextrin in isomeric mixtures. J Incl Phenom Macrocycl Chem (2025). https://doi.org/10.1007/s10847-025-01304-1