Vepris louisii

Prenyl-quinolones and Related Tricyclic Alkaloids.—The l-methyI-3-prenyl-2-quinolone (6 R1 = H, R2 = OMe), already known as a synthetic compound, has been isolated from the roots of Glycosmis mauritiana it is converted into a mixture of the dihydropyrano-quinolones (8 R1 = H, R2 = OMe) and (9 R1 = H, R2 = OMe) by formic acid (Scheme 2).4 A new l-methyl-3-prenyl-2-quinolone, 7V-methylpreskimmianine (6 R1 = R2 = OMe), was obtained from the stem bark of Vepris louisii-, its structure was established by spectroscopy and by its preparation from preskimmianine (7) (Scheme 2).11 A second new alkaloid of Vepris louisii, named veprisine, was shown by spectroscopic studies and by its synthesis from A-methylpreskimmianine to be the pyrano-quinolone (10) (Scheme 2).11 Five furoquinoline alkaloids were found in the wood of Esenbeckia flava (see Table 1) and a non-crystalline bisprenyl compound (11) was also isolated from this source the new alkaloid, which was first obtained as a synthetic compound,17 is readily converted into the dihydropyrano-4-quinolone (9 R1 = R2 = H) (Scheme 2).1... 

New alkaloids obtained from the stem bark of Vepris louisii... 

Hydroxyrutaecarpine (64) is a constituent of the bark of Euxylophora paraensis Hub. (55) and was also found in Vepris louisii G. Gilbert (12 a). A bathochromic shift in the presence of base evidenced the phenolic nature of the hydroxyl group. The mass spectrum (m/z 169, 168, 167, 155, 115)... 

The structures of vepridimerines A-D, four new dimeric prenylated quinolone alkaloids from Vepris louisii and Oricia renieri (Rutaceae). Tetrahedron Lett., 2041-2044. 

N- Methylpreskimmianine 1-Me, 3-CH2CH = CMe2, 4,7,8-triOMe Aralipsis tabouensis [23], Vepris louisii [44]... 

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