Bauerella simplicifolia

Occurence and New Alkaloids.—Six acridone alkaloids have been isolated from the leaves of Bauerella simplicifolia subsp. neo-scotica. Four of the alkaloids, i.e. melicopine (27), melicopidine (28 R = Me), 1,3-dimethoxy-JV-methylacridone (29 R1 = Me, R2 — H), and xanthovodine (28 R = H), have been obtained from other sources, but the alkaloids (29 R1 = H, R2 = OMe) and (29 R1 — R2 = H) were known previously only as synthetic compounds. The new alkaloids were identified by spectroscopy, by chemical correlation, and by synthesis. 

The 5-hydroxy derivative (21, R=OH) of the known alkaloid arborinine (21, R=H) has been obtained for the first time from the leaves of Glycosmis bilocularis (I.H. Bowen, K.P.W. Perera and J.R. Lewis, Phytochem., 1978, 17, 2125). Two other acridones differing only in the presence or absence of methoxyl groups are the alkaloids (22 R=H) and (22 R=OMe) isolated from the leaves of Bauerella simplicifolia (F. Tillequin et al., J.nat.Prod., 1980, 43, 498). 

Acronycidine I 4,5,7,8-tetraOMe Acronychia baueri [42, 44], Bauerella simplicifolia ssp. neo-scotica [44], Medicosma subsessilis [38], Melicope foreana [42], Sarcomelicope leiocarpa [19], S. megistophylla [29]... 

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