Revised Stereochemistry of So-Called Isoselagine and Spectroscopic Analysis of 6alpha-Hydroxylycopodine from Lycopodium serratum var. longipetiolatum.
The structure of isoselagine, isolated from the Chinese medicinal plant LYCOPODIUM SERRATUM Thunb. var. longipetiolatum Spring, was shown to be identical with huperzine A ( 1) and to have an exocyclic double bond in the E -configuration from NOE data. In the process of extraction of isoselagine, we also isolated and identified another alkaloid, 6alpha-hydroxylycopodine (L. 20) ( 2) that was found to occur in this plant for the first time. The structure of L. 20 was previously determined mainly by the chemical means, and this is the first report on the analysis of its structure by (1)H- and (13)C-NMR with more advanced 2D-NMR techniques. The X-ray crystallography revealed the stereochemistry of 2 and confirmed its structure. The hemostatic properties of the isolated alkaloids were studied, but they showed no platelet aggregation activity.
Sun
C M
CM
National Research Institute of Chinese Medicine, Taipei Hsien, 231 Taiwan, Republic of China.
Ho
L K
LK
Sun
M L
ML