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Published on: April 5, 2015
An experimental implementation of chemical subtraction
Shao-Nong Chen1, Allison Turner, Birgit U Jaki
1UIC/NIH Center for Botanical Dietary Supplements Research, Department of Medicinal Chemistry and Pharmacognosy & PCRPS, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, USA.
Journal of Pharmaceutical and Biomedical Analysis
|February 1, 2008
Summary
A new method selectively removes benzoic acid (BA) from cranberry extracts, enhancing anti-adhesion activity against E. coli. This countercurrent chromatography technique preserves compound integrity for accurate bioassays.
Area of Science:
- Phytochemistry
- Analytical Chemistry
- Natural Products
Background:
- Cranberry extracts show anti-adhesion effects against uropathogenic Escherichia coli.
- Benzoic acid (BA) is a major constituent that may interfere with bioassays.
- Accurate assessment of cranberry's anti-adherence properties requires removal of interfering compounds.
Purpose of the Study:
- To develop a preparative analytical method for selective removal of a single compound from complex mixtures.
- To demonstrate the method's efficacy by removing benzoic acid from cranberry juice fractions.
- To evaluate the impact of benzoic acid removal on the anti-adherence activity of cranberry fractions.
Main Methods:
- Development of a single-step preparative analytical method using countercurrent chromatography (CCC).
- Selective chemical subtraction of benzoic acid (BA) from cranberry (Vaccinium macrocarpon Ait.) juice fractions.
- Quantitative (1)H NMR and HR-ESI-MS for purity determination and impurity identification.
Main Results:
- Benzoic acid was selectively removed with 97.47% purity.
- Anti-adherent activity increased from 36% inhibition to 58% inhibition after BA removal.
- Scopoletin, a coumarin, was identified as a minor impurity, marking its first report in cranberries.
Conclusions:
- The developed CCC method enables selective and loss-free removal of compounds from complex mixtures.
- Chemical subtraction of BA enhances the accuracy of bioassays by eliminating interference.
- The method has broad applicability for evaluating medicinal plant extracts and pharmaceutical preparations.
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