Aspidosperma oblongum, alkaloids

Alkaloids 3,4,5,6-tetradehydrositsirikine (44) and 10-methoxysitsirikine (45) have recently been isolated from Aspidosperma oblongum by Robert et al. (24) and characterized in full spectral detail. 

The typical fragmentations pattern of the alkaloid type (199) was very useful for the structural elucidation of some minor alkaloids occurring in the bark of Aspidosperma oblongum A. DC. They were shown to be methoxyl and dehydro derivatives of the parent molecule.95, 96... 

In addition to olivacine and guatambuine (Section VII, C), an unnamed alkaloid, mp 186°-188°, resembling uleine in its color reactions, has been isolated from Aspidosperma australe (147)3. A glycosidic alkaloid, quebrachacidine, C26H28N2O11, has been found in A. quebracho-bianco (195), and its aglycone has been prepared. Several alkaloids have been reported in A. oblongum and A. album (196), notably kromantine, mp 176°, [a]D+ 159° (in chloroform), from the latter species (196a). 

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