The triterpenes
of Lantana camara
vary widely between taxa. In taxa
toxic to livestock 22β-angeloyloxy-3-oxoolean-12-en-28-oic acid (lantadene A) and 22β-dimethylacryloyloxy-3-oxoolean-12-en-28-
oic acid (lantadene B) are
present, usually as major constituents, although 3-oxolup-20(29)-en-28-oic acid
(betulonic acid) predominates in the taxon Helidon White. 22β-Angeloyloxy-3β-hydroxyolean-
12-en-28-oic acid, 22β -dimethylacryloyloxy-3β -hydroxyolean-12-en-28-oic
acid and 22β-hydroxy-3-oxoolean-12-en-28-oic acid, not previously known to
occur in L. camara,
have been isolated as well as a number of other well-known triterpenes.
The non-toxic Townsville Prickly Orange contains small amounts of lantadenes A and B, and is the only taxon
found to contain 228-angeloyloxy-23- hydroxy-3-oxoo1ean-12-en-28-oic acid (icterogenin). Another constituent is the new triterpene
24-hydroxy-3-oxoolean-12-en-28-oic acid. Common Pink, which is non-toxic and
does not contain lantadenes A and B, is characterized
by triterpene acids which have a C3, C25 oxide-bridge. It contains lantanolic acid, lantic acid, and
a new acid, lantabetulic acid, considered to be
3,25-epoxy- 3a-hydroxylup-20(29)-en-28-oic acid. A mixture of the 22β-angeloyloxy
and 22β-dimethylacryloyloxy derivatives of lantanolic
acid from Common Pink has been converted into 22P-hydroxylantanolic acid.
Wolff-Kishner reduction of 22~-hydroxy-3-oxoolean-12-en-28-oic acid gives a low
yield of 22β-hydroxyolean-12-en-28-oic acid, and the major product is the
C22-epimer, 22a-hydroxyolean- 12-en-28-oic acid. Corresponding products are
obtained from Wolff-Kishner reduction of 22β- hydroxylantanolic
acid.
A comparative study of thermal- and electrocatalytic conversion of furfural: methylfuran as a primary and major product
