Abstract
Sorbus decora and Sorbus americana are used traditionally as medicine by the Eeyou Istchee Cree First Nation of the James Bay region of Quebec, Canada. Because the ethanol extracts of the bark and the isolated terpenes of these plants have shown promising in vivo
antidiabetic effects, an analytical method was developed and validated
by RP-HPLC-ELSD for the identification and quantification of eight
lupane- and ursane-type terpenes. The extraction method reproducibly
recovered the compounds above 70 % and the chromatographic separation of
betulin, 23-hydroxy-betulin, 23,28-dihydroxylupan-20(29)-ene-3β-caffeate, betulinic acid, α-amyrin, uvaol, 3β,23,28-trihydroxy-12-ursene, and 23,28-dihydroxyursan-12-ene-3β-caffeate
was achieved within 27 min by linear gradient. The method produced
highly reproducible quantitative data at interday and intraday levels.
The limits of detection were in the ng level on-column with remarkable
range and linearity. The target compounds were present at mg levels in
the populations, collected from inland (Mistissini and Nemaska) and
costal (Waskagnish and Chisasibi) Cree communities of northern Quebec. A
triterpene, 23-hydroxybetulin, was the most abundant, while betulinic
acid and uvaol were minor constituents. Overall, HPLC-ELSD analyses
produced very similar profiles and contents of the eight compounds in
the plants collected from four geographic locations. The developed
HPLC-ELSD method can be used as a targeted analysis of triterpenes in
these medicinal plants.
Georg Thieme Verlag KG Stuttgart · New York.
