Triterpenoid Constituents in the Outer Bark of Betula alleghaniensis (Yellow Birch)

Abstract

Yellow birch, Betula alleghaniensis, is a dark-barked birch species that is widely utilized in the northeastern region of the United States for pulp and solid wood products. Currently, the bark is used only as a low value fuel source. In this study, the triterpenoid composition of the outer bark of B. alleghaniensis was investigated in order to evaluate potential for use as a resource for specialty chemicals. Seventeen triterpenoids, including four new compounds, were isolated and identified. Previously known compounds included lupeol, lupenone, betulone, betulin, betulonic acid, lupenyl formate, lup-20(29)-ene-30-ol-3-one, lup-20(29)-ene-3β,30-diol, lup-20(29)-ene-28-ol-30-al, 29-norlupan-3β-ol-20-one, lupan-20-ol-3-one, lupan-3β,20-diol, and lupan-3β-ol-29-oic acid. The four new compounds isolated from yellow birch were lup-20(29)-ene-28-ol-3-one-30-al, 29-norlupan-3,20-dione, 29-norlupan-28-ol-3,20-dione, and lupan-20,28-diol-3-one.