Nonchromatographic cyclodextrin assays: evaluation of sensitivity, specificity, and conversion mixture applications

Abstract

Methods based on various clathrate-forming molecules, siigar analyses in combination with glucoamylase treatment, or catalytic properties of cyclodextrins were evaluated as cyclodextrin assays. Optimum conditions for the assays were determined and, when necessary, appropriate modifications were made. The tests were made by using pure cyclodextrin standards, supplemented standards, and conversion mixtures obtained by the action of cyclodextrin glycosyltransferase on starch. The optimized methods varied considerably with respect to measurement range, relative sensitivity toward CY-, p-, and 7-cyclodextrin, and susceptibility to interferences. On the basis of data from these experiments, typical applications of individual methods or their combinations are suggested. The specificity differences of assays based on methylorange, bromocresol green, and phenolphthalein were found especially useful in the analysis of individual CDs out of their mixtures. An example of the usage of this method combination is given.

Immobilization of Cyclodextrin Glucanotransferase fromPaenibacillus MaceransATCC 8244 on Magnetic Carriers and Production of Cyclodextrins

“…The β-enzyme activity was assayed by modification of the Vikmon (63) method described by Mäkelä (31,32). In this method, negative colorimetric adsorption of phenolphthalein in alkaline pH was measured.…”

Studies on alkalophilic CGTase-producing bacteria and effect of starch on cyclodextrin-glycosyltransferase activity

“…The concentration of β-CD was analyzed by decrease in absorbance at 550 nm due to phenolphtalein-CD complex (Makela et al, 1988, modified from Vikmon, 1981. The concentration of γ-CD was analyzed by absorption increase at 620 nm due to bromocresol-CD complex (Kato and Horikoshi, 1984).…”

Cyclodextrin production by Bacillus lehensis isolated from cassava starch: Characterisation of a novel enzyme

“…Enzyme activity was determined after 72 h of fermentation as well as after each purification step using the method described by Makela et al (1988). Total protein was determined using bovine serum albumin as the standard, following Lowry's method (Lowry et al 1951).…”