Cai Y et. al. (1993) “”Biological and Chemical Investigations of Dragon’s Blood from Croton Species of South America” Part 2. Diterpenes from Croton lecheri.” Phytochemistry 32(3), 755-760.
Abstract: The chloroform extract of
Croton
lechleri sap was
chemically examined, and the major constituents characterized by mass and NMR
spectroscopy. In addition to a number of known compounds, such as 1,3,5-
trimethoxybenzene, 2,4,6-trimethoxyphenol, 3,4-dimethoxyphenol,
3,4-dimethoxybenzyl alcohol, 4-hydroxyphenethyl alcohol and its acetate,
sitosterol, sitosterol-
-
-glucopyranoside
and -sitostenone,
four diterpenoids were isolated from
Croton lechleri
bark, and two of them were found to be novel compounds possessing a clerodane
skeleton. Their structures were unequivocally elucidated by extensive use of NMR
spectroscopy. They were termed as crolechinol and crolechinic acid,
respectively. The presence of these diterpenoids as minor constituents in the
sap was confirmed by TLC profiles and NMR spectra.