Browsing by Author "Faber, Johan H."

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Ancistrotanzanine A, the First 5,3‘-Coupled Naphthylisoquinoline Alkaloid, and Two Further, 5,8‘-Linked Related Compounds from the Newly Described Species Ancistrocladus tanzaniensis # ,1
    (2003-09) Bringmann, Gerhard; Dreyer, Michael; Faber, Johan H.; Dalsgaard, Petur W.; Staerk, Dan; Jaroszewski, Jerzy W.; Ndangalasi, Henry J.; Mbago, Frank M.; Brun, Reto; Reichert, Matthias; Maksimenka, Katja; Christensen, Søren B.
    The first phytochemical investigation of the recently discovered East African liana Ancistrocladus tanzaniensis is described, resulting in the isolation and structural elucidation of two new naphthylisoquinoline alkaloids, ancistrotanzanines A (5) and B (6), and the known compound ancistrotectoriline A (7). Ancistrotazanine A (5) represents a hitherto unprecedented 5,3'-coupling type between the naphthalene and isoquinoline portions, while 6 and 7 are 5,8'-coupled. The structures of the compounds were determined by spectroscopic, chemical, and chiroptical methods. Compounds 5 and 6 showed good activities against the pathogens of leishmaniasis and Chagas' disease, Leishmania donovani and Trypanosoma cruzi, while 5-7 displayed moderately potent antiplasmodial activities against Plasmodium falciparum parasites.
  • Thumbnail Image
    Item
    Ancistrotanzanine A, the First 5,3‘-Coupled Naphthylisoquinoline Alkaloid, and Two Further, 5,8‘-Linked Related Compounds from the Newly Described Species Ancistrocladus tanzaniensis # ,1
    (2003-10) Bringmann, Gerhard; Dreyer, Michael; Faber, Johan H.; Dalsgaard, Petur W.; Staerk, Dan; Jaroszewski, Jerzy W.; Ndangalasi, Henry J.; Mbago, Frank M.; Brun, Reto; Reichert, Matthias; Maksimenka, Katja; Christensen, Søren B.
    The first phytochemical investigation of the recently discovered East African liana Ancistrocladus tanzaniensis is described, resulting in the isolation and structural elucidation of two new naphthylisoquinoline alkaloids, ancistrotanzanines A (5) and B (6), and the known compound ancistrotectoriline A (7). Ancistrotazanine A (5) represents a hitherto unprecedented 5,3'-coupling type between the naphthalene and isoquinoline portions, while 6 and 7 are 5,8'-coupled. The structures of the compounds were determined by spectroscopic, chemical, and chiroptical methods. Compounds 5 and 6 showed good activities against the pathogens of leishmaniasis and Chagas' disease, Leishmania donovani and Trypanosoma cruzi, while 5-7 displayed moderately potent antiplasmodial activities against Plasmodium falciparum parasites.
  • Thumbnail Image
    Item
    Ancistrotanzanine C and Related 5,1‘- And 7,3‘-Coupled Naphthylisoquinoline Alkaloids From Ancistrocladus T Anzaniensis 1
    (2004-05) Bringmann, Gerhard; Dreyer, Michael; Faber, Johan H.; Dalsgaard, Petur W.; Staerk, Dan; Jaroszewski, Jerzy W.; Ndangalasi, Henry J.; Mbago, Frank M.; Brun, Reto; Christensen, Søren B.
    Three new naphthylisoquinoline alkaloids, the 7,3'-coupled ancistrotanzanine C (6), the 5,1'-coupled O-methylancistrocladinine (7), and the likewise 5,1'-coupled O,N-dimethylancistrocladine (8, previously known only as a partial-synthetic compound), have been isolated from the highland liana Ancistrocladus tanzaniensis, along with the two known 7,3'-coupled naphthylisoquinoline alkaloids ancistrocladidine (4) and ancistrotectorine (5). All of the compounds are S-configured at C-3 and bear an oxygen at C-6, and thus belong to the so-called Ancistrocladaceae type, similar to 1-3 previously isolated from this newly discovered plant species. The structural elucidation was achieved by chemical, spectroscopic, and chiroptical methods. The biological activities of the alkaloids against the pathogens causing malaria tropica, leishmaniasis, Chagas' disease, and African sleeping sickness were evaluated.