Evodia alata

Seitdem die Bildung der Acridinbasen (z.B. 1,2,3-Trimethoxy-N-methylacridon (CCLXVI) aus Evodia alata) unter. .zellmoglichen" Be-dingungen (s. Schema 48) gelungen ist (146), muB man annehmen, daB dieser Alkaloidtyp auch in der Pflanze aus Anthranilsaure entsprechend Schema 48 aufgebaut werden kann. 

Five acridone alkaloids were obtained previously from the bark of Teclea boiviniana cf. Vol. 6, p. 108) a recent investigation showed that the constituents of the leaves are similar, and resulted in the isolation of arborinine (37 R = H), tecleanthine (38 R = H, R = OMe), evoxanthine (38 R = R = H), 6-methoxytecleanthine (38 R = R = OMe), and 1,3,4-trimethoxy-iV-methyl-acridone (39 R = Me, R = OMe). The latter compound has not been obtained previously from a natural source. The n.m.r. and mass spectra indicated that the new alkaloid was a trimethoxy-iV-methylacridone and that ring A was unsubstituted. The three possible acridones had been synthesized earlier, and from melting-point data the alkaloid appeared to be the 1,3,4-trimethoxy-derivative this was confirmed by synthesis using a modification of the published procedures. 1,2,3-Trimethoxy-iV-methylacridone (37 R = Me), previously isolated from Evodia alata, has now been obtained from Melicope leratii. The known alkaloids melicopidine (40 R = Me, R = OMe) and xanthovedine (40 R = R = H) were also shown to be constituents of M. leratii. Arborinine (37 R = H) has been obtained from Vepris pilosa and from Ruta chalapensis. Other known acridone alkaloids isolated from a new source include the l-hydroxy-3-methoxy-deriva-tive (39 R = R = H) and its methyl ether (39 R = Me, R = H), from Vepris pilosa. ... 

---