Lunasia

A number of simple quinolines and quinolones have been isolated from various rutaceous plants, e.g., from angostura bark (Volume III, p. 80) and from Lunasia amara Blanco (Volume VII, p. 241 this chapter Section IV,A). The leaves of Haplophyllum dubium Eug. Kor (15, 16) contain dubamine (mp 96°-97°) which has been identified (17) as 2-(3,4-methylenedioxyphenyl)quinoline (I). Ruta graveolens L. contains, in addition to furoquinolines, the alkaloids graveoline (mp 205°) (18,19), and graveolinine (mp 115°-116°) (20), the latter (II) is also found in L. amara, and the former is the related l-methyl-4-quinolone (III). 

H. robustum Hortia arborea Lunasia amara Blanco Melicope fareana Engl. 

Although the presence of alkaloids in Lunasia amara Blanco has been long recognized and several bases were isolated and characterized during the first half of this century (Volume V, p. 316) the structures of only two had been elucidated by 1957 (Volume VII, p. 241) both of these being simple 2-arylquinoline derivatives (XXVII and XXVIII). Shortly... 

Alkaloids Isolated from Lunasia amara and Balfourodendron riedelianum ... 

Lunacrinol, isolated in very small amount from L. amara leaves (12), is identical with Lunasia II obtained from the bark (122). Beyerman and Rooda (122) have shown this to be a dihydropyranoquinoline... 

Rearrangement also occurs when balfourodine is treated with methyl sulfate, isobalfourodine methosulfate being formed. When the alkaloids or the methosulfate are treated with strong alkali, angular dihydrofuro-and dihydropyrano-2-quinolones (LIU, LIV) are formed because of the occurrence of stereochemical inversions in some of these transformations both (-f-)- and (— )-forms of the rearrangement products can be obtained IS). Similarly, Beyerman and Rooda 122) have shown that Lunasia II is isomerized by alkali to LIV. The structures of these i/i-alkaloids were assigned by correlation of the UV-spectra with those of model compounds. 

Hydroxylunidonlne (41 ) occurs both in the stems and flowers of Lunasia amara, whereas 6-methoxylunidonine (42), 6-methoxylunidine (43) and 6-methoxyhydroxylunidine (44) have only been found in the stem of this plant (L.A. Mitscher et al., Lloydla, 1975, 28, 117 J.A. Reisch et ai., Phytochem., 1975, 14, 1678). 

Lunasia quercifolia K. Schum. Lauterb. (Androcephalium querci-folium Warb.) Euphorbiaceae (Vol. IX, p. 225). 

Hydroxy-l-methyl-2-phenyl-4-quinolone (3), obtained previously from Lunasia quercifolia, now has been isolated from Skimmia japonica. Details have been published of the Italian synthesis of halfordamine (6) (see Vol. 4 and Vol. 5 of these Reports) and related 2-quinolones. ... 

A further study of the constituents of Ptelea trifoliata resulted in the isolation of lunidonine (2 R = Me), previously obtained from Lunasia amara, and of the new alkaloid, N-desmethyl-lunidonine (2 R = H). ... 

During the last decade, new alkaloids of this type have been isolated, methods of asymmetric synthesis have been developed, the absolute stereochemistry of a number of alkaloids has been established, and the mechanisms of certain rearrangement reactions of furo- and pyrano-quinoline alkaloids of the group have been studied. Additional pyrano-quinolines of the flindersine type have been discovered, and new methods of synthesis have been developed. Isopropyldihydrofuroquinoline alkaloids without a hydroxy group in the side chain are characteristic components of Lunasia species, but not much new work on this group has appeared recently. 

The 7,8-methylenedioxyhydroxyisopropyldihydrofuroquinolone alkaloid, (-)-hydroxylunine (55), was isolated from Lunasia amara (Volume IX, p. 245), and the (+) enantiomer has now been shown to be a constituent of Ptelea trifoliata (55). Mitscher et al. (54) obtained the corresponding quaternary salt, O-methylhydroxyluninium salt (56), from the stems of... 

Isopropyldihydrofuroquinoline alkaloids, such as (—)-lunasine (63) and (-)-lunine (64), are constituents of Lunasia species (Volume IX, p. 239)... 

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