The genus Alstonia found in Africa and Asia comprises about
60 species, 8 of which are distributed in China. Four species
of this genus have been found in the Yunnan province.1 The
phytochemical constituents of the Alstonia sp. have been
investigated intensively. Until now, more than 300 compounds
have been reported from this genus. Most of them
are monoterpenoid indole alkaloids, which originate from
the condensation of tryptophan with secologanin to give
strictosidine and then elaborate to give an impressive array
of structural variants.2 This type of Alstonia alkaloid possesses
19 (or 18) carbon atoms in the skeleton and reportedly
has anticancer, antibacterial, antifertility, and antitussive
activity.3 Alstonia scholaris is widely distributed in South
and Southeast Asia, where it is used as a medicinal plant by
local ethnic people. For example, the bark is used in
traditional medicines throughout the region to treat dysentery