Monoterpene alkaloids, iridoids and phenylpropanoid glycosides from Osmanthus austrocaledonica

Six monoterpene alkaloids have been isolated from the aerial parts of Osmanthus austrocaledonica. Two of these, dihydrojasminine and austrodimerine, are novel compounds. Their structures have been elucidated on the basis of their spectral data and molecular modeling. Seven iridoids and six phenolic compounds have been also isolated from the same plant. Two of these, austrosmoside and 6'-O-β-(E)-cinnamoylverbascoside, are novel compounds. Their structures have been deduced from their spectral data and confirmed by chemical correlations

Molluscicidal activity of Hammada scoparia (Pomel) Iljin leaf extracts and the principal alkaloids isolated from them against Galba truncatula

The molluscicidal activity of Hammada scoparia leaf extracts and the principal alkaloids isolated from them (carnegine and N-methylisosalsoline) were tested against the mollusc gastropod, Galba truncatula, the intermediate host of Fasciola hepatica in Tunisia. The results indicated that the molluscicidal activity was correlated with the presence of alkaloids. A significant molluscicidal value, according to the World Health Organization, was found with the methanol extract (LC50 = 28.93 ppm). Further fractionation of the methanolic extract led to the isolation of two principal alkaloids: carnegine and N-methylisosalsoline. These alkaloids are isoquinolines that have not previously been characterised for their molluscicidal activity. The N-methylisosalsoline possesses the highest molluscicidal activity (LC50 = 0.47 μM against G. truncatula)

Gold(I)-Catalyzed Enantioselective Carboalkoxylation of Alkynes

A highly enantioselective carboalkoxylation of alkynes catalyzed by cationic (DTBM-MeO-Biphep) gold(I) complexes is reported. Various optically active beta-alkoxy indanone derivatives were obtained in good yields and high enantioselectivities. Furthermore, this methodology was extended to enantioselective syntheses 3-methoxycyclopentenones. The reaction is proposed to proceed through an enantioselective cyclization of intermediates containing vinylgold(I) and prochiral oxocarbenium moieties