Yuzurine

Quite recently, three new alkaloids were isolated as minor components from the fruits of the plant Daphniphyllum teijsmanni Zollinger and their structures also determined on the basis of their physical and chemical data (43). In addition, the structure of yuzurine,9 one of the alkaloids of undetermined structure (see Section II, F), was also elucidated by means of an X-ray crystallographic analysis of its methiodide (44). 

Nine alkaloids belonging to the yuzurine group were isolated from D. macropodum and D. gracile distributed in New Guinea. The structure of yuzurine (27) was... 

Daphnigracine (137), C24H37NO4, a viscous liquid, and daphnigraciline (138), C23H35NO4, m.p. 76—78 °C, were found to differ only by the alkyl group at C-16. On treatment of daphnigraciline methiodide with acetic acid in methanol, yuzurine methiodide (139) was obtained. The n.m.r. spectra of (137) and (138) indicated... 

Yuzurine.—From the bark and leaves of Daphniphyllum macropodum Miquel, a new alkaloid, yuzurine, C24H37NO4, has been isolated as a colourless viscous liquid.This base was previously identified as the Alkaloid-A2. °... 

The structure of yuzurine was determined to be (88) by an X-ray crystallographic study of the methiodide derivative, employing a heavy-atom method. This structure accounts for the observed chemical and physical data. The proposed biosynthetic pathway from yuzurimine-B (89) is indicated in Scheme 2. Yuzurine, which may be included in the yuzurimine class, differs from the previously isolated Daphniphyllum alkaloids in that it has no 2-azabicyclo-[3,3,l]nonane system. 

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