Rapid Determination of Theophylline, Theobromine and Caffeine in Dietary Supplements Containing Guarana by Ultra-Performance Liquid Chromatography

Abstract

A rapid and simple method for determination of theophylline, theobromine and ca#eine in dietary supplements containing guarana by ultra-performance liquid chromatography (UPLC) has been developed. Theophylline, theobromine and ca#eine were extracted from finely powdered samples with water in a boiling water bath for 20 min, then the extracts were filtered and the filtrates were subjected to UPLC. Liquid samples were diluted with water and filteres, and the filtrates were subjected to UPLC. UPLC separation was performed on an AQUITY UPLC BEH C 18 column (2.1 mm i.d.ῒ50 mm, 1.7 mm, Waters) with 10 mmol/L ammonium acetate bu#er (pH 4.0)ῌacetonitrile gradient and eluates were monitored at 275 nm. .4ΐ, respectively. The quantitation limits of theophylline, theobromine and ca#eine were 10 mg/g (seed, seed powder, tablet and capsule) and 2.0 mg/mL (liquid) each. When this analytical method was applied to commercial dietary supplements, theophylline, theobromine and ca#eine were found at concentrations of 4.45 mg/tablet, 5.48 mg/tablet, 139 mg/tablet, respectively. Taking 4 tablets of this product according to the directions on the package could be dangerous to consumers because of possible overdosing of these ingredients.

Structure-Bioactivity Relationships of Methylxanthines: Trying to Make Sense of All the Promises and the Drawbacks

“…In the case of liquid samples (like tea) direct sample application is sometimes an option [50,78,79]. In the case of solid samples (powders, chocolate, leaves), a small amount (in the gram range) is sometimes simply added and extracted in heated (sometimes boiling) stirred water, with posterior filtration [50,71,79,80].…”

Φαρμακοκινητικές Αλληλεπιδράσεις Φαρμάκων Με Φυτοθεραπευτικά Σκευάσματα

“…των κλινικών μελετών υπάρχουν αρκετά άρθρα ανασκόπηση̋ όσον αφορά τι̋ παρατηρήσει̋ για τη χρήση των σκευασμάτων του Ginseng ω̋ βελτιωτικό τη̋ ψυχική̋ και σωματική̋ κατάσταση̋ και τη̋ ποιότητα̋ διαβίωση̋(Coleman et al 2003;Kennedy and Scholey 2003). 8%) και άλλε̋ μεθυλοξανθίνε̋ όπω̋ θεοφυλλίνη και θεοβρωμίνη.Δευτερεύουσε̋ ενώσει̋ που βρίσκονται στη δρόγη είναι οι ταννίνε̋ και οι σαπωνίνε̋(ESCOP 2009;Hasegawa et al 2009;Williamson et al 2009). Τυποποιημένα σκευάσματα Guarana χρησιμοποιούνται ω̋ τονωτικά σε περιπτώσει̋ κούραση̋ ή εξάντληση̋.…”