Ravesilone,a quinolone alkaloid from Ravenia spectabilis

A new quinolone alkaloid designated ravesilone has been isolated from the leaves of Ravenia spectabilis. From spectral evidence the structure of the compound has been established as 3,4,5,6-tetrahydro-7-hydroxy-2,2,6-trimethyl-5-oxo-2H-pyrano[3,2-c]quinoline.     

Glycolone,a quinolone alkaloid from Glycosmis pentaphylla

Glycolone, a quinolone alkaloid has been isolated from the leaves of Glycosmis pentaphylla. The structure of the compound has been established as 4,8-dimethoxy-3-(3-methyl but-2-enyl)-2-quinolone from physical and chemical evidences.     

A 2-Quinolone alkaloid from Almeidea guyanensis

From Almeidea guyanensis, besides N-methylatanine, N-methylflindersine, N-methylkhaplofoline and 4-demethyl-N-methylatanine, a new 2-quinolone, almeine, has been isolated and its structure elucidated as 4-isopropenyl-N-methyl-3,4-dihydrofuro-2-quinolone.     

Alcaloides d'Araliopsis soyauxii. Isolement d'un nouvel alcaloide,l'Araliopsine

Six alkaloids have been isolated from root bark of Araliopsis soyauxii. Five are known, maculine, flindersiamine, skimmianine, (?) ribalinine, (+) isoplatydesmine and the sixth, araliopsine is new; its structure has been established as hydroxyisopropyldihydrofuro-2-quinolone. From the trunk bark four alkaloids have been isolated: flindersiamine, kokusaginine (?) ribalinine, (+) isoplatydesmine.     

New prenylated isoflavones and a prenylated dihydroflavonol from Millettia pachycarpa

Extraction of Millettia pachycarpa Benth. gave 5,7,4′-trihydroxy-6,8-diprenylisoflavone (1a), 5,7,4′-trihydroxy-6,3′-diprenylisoflavone (2a), 5,7,3′,4′-tetrahydroxy-6,8-diprenylisoflavone (3a) and (2R, 3R)-5,4′-dihydroxy-8-prenyl-6″,6″-dimethylpyrano[2″,3″: 7,6]-dihydroflavonol (4a) whose structures were established by chemical transformations and spectroscopic means. Pectolinarigenin and salvigenin were isolated from Buddleia macrostachya Benth.     

Amorinin,A prenylated chromenoflavanone from Amorpha fruticosa

A diprenylated chromenoflavanone has been characterized from the root bark of Amorpha fruticosa.     

Mukonal,a probable biogenetic intermediate of pyranocarbazole alkaloids from murraya koenigii

Mukonal, a carbazole alkaloid has been isolated from Murraya koenigii. The structure of the compound has been established as 2-hydroxy-3-formyl carbazole based on physical (UV, IR, ¹H NMR, ¹³C NMR and mass spectrometry) and chemical transformations.     

Tirumalin,a new prenylated dihydroflavonol from Rhynchosia cyanosperma

A new dihydroflavonol has been isolated together with the known flavonol-O- glycosides, rutin and kaempferol-3-rutinoside, and (+)-pinitol from the leaves of R. cyanosperma Benth. The dihydroflavonol was identified as (+)-(2R, 3R)-8-C-prenyltaxifolin-7, 4′-dimethyl ether on the basis of spectroscopic studies and the compound given the trivial name tirumalin.     

Glycozolidol,an antibacterial carbazole alkaloid from Glycosmis pentaphylla

Glycozolidol, a new carbazole alkaloid, has been isolated from the roots of Glycosmis pentaphylla. Its structure has been established as 6-hydroxy-2-methoxy-3-methylcarbazole on the basis of physical and chemical evidence. The compound has been found to be active at some Gram-positive and Gram-negative bacteria.     

An azole, an amide and a limonoid from Vepris uguenensis (Rutaceae)

The limonoid derivative, methyl uguenenoate, the azole, uguenenazole, and the amide, uguenenonamide, together with the known furoquinoline alkaloids flindersiamine and maculosidine, and syringaldehyde have been isolated from the root of the East African Rutaceae Vepris uguenensis. While methyl uguenenoate and the furoquinoline alkaloids displayed mild antimalarial activity, the azole and amide were completely inactive.     

Mixtecacin,a prenylated flavanone and oaxacacin its chalcone from the roots of Tephrosia woodii

From the roots of Tephrosia woodii, a new Mexican Tephrosia species, a new prenylated flavanone, oaxacacin, and its chalcone, mixtecacin, have been isolated and their structures elucidated from their chemical properties and spectral data.     

Oriciopsin,a new ring-D cleaved tetranortriterpenoid,and flindersiamine from Oriciopsis glaberrima

A novel ring-D cleaved tetranortriterpenoid, oriciopsin and flindersiamine have been isolated from the whole plant extracts of Oriciopsis glaberrima. The structure of the new limonoid was determined from its ¹H NMR and ¹³C NMR spectra and by mass spectrometry.     

Heptazolicine,a carbazole alkaloid from Clausena heptaphylla

A new carbazole alkaloid designated as heptazolicine has been isolated from the roots of Clausena heptaphylla. On the basis of spectral and chemical evidence it has been identified as [2,2-dimethyl-3,4-dihydropyrano-(5, 6-a)]-3-formyl-8-hydroxy-carbazole.     

Angustifolin,a coumarin from Ruta angustifolia

From the aerial parts of Ruta angustifolia, a new natural coumarin, angustifolin, was obtained. Two other coumarins (scoparone and 6,7,8-trimethoxycoumarin) and the alkaloid graveolin were also isolated.     

Flavanones and xanthones from Maclura pomifera

(+-)Euchrestaflavanones B and C and 8-prenyltoxyloxanthone C have been isolated from the root bark of Maclura pomifera. A study of the cyclization of alvaxanthone under varying conditions is reported.