1. A new alkaloid, viroallosecurinine, C13H15O2N, m.p. 136-138°, was isolated from the leaves of Securinega virosa PAX. et HOFFM., and was proved to be enantiomorphous with allosecurinine, with absolute stereochemistry as shown in structure (IV).
2. Another new alkaloid, virosine, C12H15O2N, m.p. 134-135°, was isolated from the roots of the same plant. This molecular formula is to be revised from what was reported in the previous communication.
3. Separatory determination of securinine, its stereoisomeric alkaloid and their dihydroderivatives in plants of the genus Securinega were carried out by means of both chemical separation and gas chromatography. The results are summarized in Tables II and III. The following findings were obtained.
i) From the leaves of S. suffruticosa REHD. were obtained securinine (I) as a major alkaloid and allosecurinine (III) as a minor alkaloid, while from the roots allosecurinine (III) in majority and securinine (I) in minority were reversely obtained.
ii) From the leaves of S. virosa were obtained virosecurinine (II) dominantly and viroallosecurinine (IV) as a minor quantity.
iii) As to the alkaloids of S. suff. REHD. var. amamiensis FURUSAWA, the female plant is similar to S. suff. R., while the male plant contained nearly equal amounts of securinine (I) and virosecurinine (II) as major alkaloids.
