[化] 桦木脑; 桦木醇

[医] 桦木醇, 桦木脑

Betulin \Bet"u*lin\, n. [L. betula birch tree.] (Chem.)
a term originally applied to a substance obtained as a resin
or tar by extraction from the outer bark of the common
European white birch ({Betula alba}); now referring to the
chemical compound ({C30H50O2}) having a
cyclopentanophenanthrene ring system, which is the main
constituent of that extract, and which may be obtained
crystalline; -- called also {birch camphor}. --Watts.
[1913 Webster +PJC]