Lupan-3beta,20-diol, and Lupan-3beta,20,28-triol in Bark from Birch, Betula verrucosa Erh..

Triterpenoid Extractives in the Outer Bark ofBetula lenta(Black Birch)

“…This compound was identified earlier in Betula verrucosa Ehrh. (Lindgren and Svahn 1966;Ekman 1983b) and in B. maximowicziana (Pokhilo et al 1986). It has been found in other species äs well (Dantanarayama et al 1981;Hui and Li 1977).…”

“…It is well known that the outer barks of white-barked birches are rieh in pentacyclic triterpenoid compounds, such äs lupeol (I) and betulin (II). The relative abundance of these unutilized natural products has prompted several researchers, particularly in Finland, where birch wood is used widely, to isolate, identify, and quantify the triterpenoid components in birch barks and to investigate their utilization (Lindgren and Svahn 1966;Chari et al 1968;Ukkonen and Era 1979;Jääskeläinen 1981;Ekman 1983a;Ekman and Sjöholm 1983;Ohara et al 1986). In these studies, most of which focused on European and Japanese species, it was found that the outer bark of white-barked species contained up to 40% total triterpenoids (Ekman 1983b).…”

The Suberin Monomers and Triterpenoids from the Outer Bark ofBetula verrucosaEhrh.

“…The mass spectra of peaks 45 and 46 were almost identical to those of lupeol and betulinol, respectively. Similarly, the acetylation products of lupane-3ß,20-diol (monogynol A) and lupane-3/3,20,28-triol, previously identified in birch bark (Lindgren and Svahn 1966) give mass spectra that were almost indistinguishable from corresponding derivatives of lupeol and betulinol. High-intensity mass spectra of peaks 45 and 46 further revealed molecular ions at mass numbers consistent with the assumption that the peaks arise from monogynol A and lupane-3ß,20,28-triol, respectively.…”

“…Several minor triterpenoids have been identified in birch bark extracts (Hejno et aL 1965;Rimpler et aL 1966;Lindgren and Svahn 1966). Recent review on birch bark chemistry have dealt with the extractives (Ukkonen and Erä, 1979) and the possibilities for utilizing betulinol (Jääskeläinen 1981).…”

The molecular structure of 3β-acetoxy-20-hydroxylupane, C32H54O3

“…(Lindgren & Svahn, 1966). Lewis (1959) reported that only the monoacetate derivative of lupane-3fl,20-diol could be prepared by acetylation, and the melting point of the monoacetate was reported as 248-250°C.…”