Skimmia japonica

Slfinrnnianini , C14H13O4N. This alkaloid was first isolated from the leaves oi Skimmia japonica Thunb. by Honda, and later from S, laureola Hook by Chopra et It has also been recorded from Fagara spp. 

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. ... 

Skimmtn. 7-(0-D-Glucopyrano ytoxy -2H-I-ben-zopyran-2-ane 7-(glucosyloxy)coumarin 7 -hydroxycouma-rin -7 -glucoside umbelliferone glucoside. C,sH]403 mo] wt 324.28. C 55.55%, H 4.97%, O 39,47%. In bark and wood of Skimmia japonica Thunb., Rutaceae. lsoln, structure and synthesis Spath. Neufeld, Rec. Trav. Chim. ST, 535 (1938). 

A quaternary alkaloid extracted by Boyd and Grundon (37) from leaves of Skimmia japonica Thunb. was shown to be the (+)-A/-methyl-platydesminium salt (51) by comparison with the racemate that had been synthesized earlier (27). The alkaloid has subsequently been isolated from Ruta graveolens (39) and from Araliopsis tabouensis (66). 

Earlier theories of the biosynthesis of quinoline alkaloids found in the Rutaceae have been discussed in Volume IX of this treatise, and the first experimental results using radioactive tracers were also reviewed. Spenser and his collaborators showed that anthranilic acid is incorporated intact into dictamnine in Dictamnus albus and that C-10 and C-ll (cf. 328) are derived from C-l and C-2 of acetate, respectively (220). Matsuo et al. (221) demonstrated almost simultaneously that the quinoline ring of skimmianine in Skimmia japonica was formed similarly. Since then, the biosynthesis of furo- and isopropyldihydrofuroquinoline alkaloids has been studied intensively, with particular interest in the origin of the C2 and C5 side chains present at the 3-position of the quinoline ring of these alkaloids. 

Quinoline Alkaloids.—An efficient and specific conversion of (-f)-platydesmine (156), C-labelled as shown, into dictamnine (157) has been demonstrated in Skimmia japonica, as has its presence in this plant. Its role as an intermediate between the dimethylallylquinoline (155) and the furanoquinoline dictamnine is thus established. Platydesmine was also incorporated into platydesminium metho-salt (159) and skimmianine (158), but into the latter with low efficiency. The metho-salt (159) was poorly incorporated into dictamnine. 

Dictamnine (7, R = Me) was a specific precursor of skimmianine (7, R = Me, 7,8-diOMe) and other furoquinoline alkaloids oxygenate in the aromatic ring in Skimmia japonica and Choisya ternate [41] similar results were obtained with cell cultures of Ruta graveolens [104]. Dihydro- (5) and furoquinolin-4-ones (8) are also known. 

Eduline 1-Me, 6-OMe Casimiroa edulis [41], Esenbeckiapentaphylla [41], Orixa japonica [41], Skimmia japonica [41]... 

Constit. of Skimmia japonica. Shows insect antifeedant activity. Cryst. (EtOH). Mp 164.5-165.5°. [a] —22.7°... 

Related alkaloids have been obtained from other sources Lunasia amara, Ptelea trifoliata, Orixa japonica, Skimmia japonica, etc. 

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