Browsing by Author "Mbago, Frank M."
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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.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.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.Item Correspondence in Forest Species Composition Between The Vegetation Map of Africa And Higher Resolution Maps For Seven African Countries(Wiley, 2013-12) Kindt, Roeland; Lillesø, J. P. B.; van Breugel, Paulo; Bingham, M.; Demissew, Sebsebe; Dudley, C.; Gachathi, Francis; Kalema, James; Mbago, Frank M.Item Ecological features and ranging patterns at a chimpanzee release site on Rubondo Island, Tanzania(Elsevier, 2010-10) Moscovice, Liza R.; Mbago, Frank M.; Snowdon, Charles T.; Huffman, Michael A.This study examines the behavioral ecology of a chimpanzee population on Rubondo Island in Lake Victoria, Tanzania, over 40 years after chimpanzees were first introduced to the island from captivity. Despite little pre-release habitat assessment, rehabilitation, or post-release monitoring, these chimpanzees are one of the only released populations to survive over decades without provisioning. We surveyed habitat structure and plant composition to gain insights into ecological features that have supported this self-sufficient chimpanzee population for over 40 years. We also examined possible ecological sources of chimpanzee ranging patterns on the island. We surveyed woody plant composition, and quantified densities of species producing large fleshy fruits and confirmed chimpanzee fruit foods across three chimpanzee ranging areas, each separated by several kilometers. We used non-metric multidimensional scaling (NMS) ordination to compare community-level patterns of plant composition across regions. The densities of trees and lianas producing fleshy fruits were high in comparison with similar measures at endemic chimpanzee study sites. There were major differences in the composition of tree species, including species of chimpanzee fruit foods, across the three regions. In contrast, liana species composition was similar across regions, and was characterized by a few super-abundant species, including one chimpanzee fallback food. The wide-ranging patterns of chimpanzees do not appear to be influenced by localized tree fruiting patterns, but may be facilitated by the wide-spread distribution of an important fallback food. In comparison with other endemic and release sites, the relatively low ecological population density of chimpanzees, the high density of both trees and lianas producing large fleshy fruits and the presence of a high-quality, widely-distributed fallback food are factors that likely contributed to the success of Rubondo chimpanzees in reverting to natural foraging behaviors after their release.Item Increasing Carbon Storage in Intact African Tropical Forests(2009-03) Lewis, Simon L.; Gonzalez, Gabriela L.; Sonke, Bonaventure; Baffoe, Kofi A.; Baker, Timothy R.; Ojo, Lucas O.; Phillips, Oliver L.; Reitsma, Jan M.; White, Lee; Comiskey, James A.; Djuikouo, Marie N. K.; Ewango, Corneille E. N.; Feldpausch, Ted R.; Hamilton, Alan C.; Gloor, Manuel; Hart, Terese; Hladik, Annette; Lloyd, Jon; Lovett, Jon C.; Makana, Jean R.; Malhi, Yadvinder; Mbago, Frank M.; Ndangalasi, Henry J.; Peacock, Julie; Peh, Kelvin S. H.; Sheil, Douglas; Sunderland, Terry; Swaine, Michael D.; Taplin, James; Taylor, David; Thomas, Sean C.; Votere, Raymond; Woll, HannsjorgThe response of terrestrial vegetation to a globally changing environment is central to predictions of future levels of atmospheric carbon dioxide. The role of tropical forests is critical because they are carbon-dense and highly productive. Inventory plots across Amazonia show that old-growth forests have increased in carbon storage over recent decades, but the response of one-third of the world's tropical forests in Africa is largely unknown owing to an absence of spatially extensive observation networks. Here we report data from a ten-country network of long-term monitoring plots in African tropical forests. We find that across 79 plots (163 ha) above-ground carbon storage in live trees increased by 0.63 Mg C ha(-1) yr(-1) between 1968 and 2007 (95% confidence interval (CI), 0.22-0.94; mean interval, 1987-96). Extrapolation to unmeasured forest components (live roots, small trees, necromass) and scaling to the continent implies a total increase in carbon storage in African tropical forest trees of 0.34 Pg C yr(-1) (CI, 0.15-0.43). These reported changes in carbon storage are similar to those reported for Amazonian forests per unit area, providing evidence that increasing carbon storage in old-growth forests is a pan-tropical phenomenon. Indeed, combining all standardized inventory data from this study and from tropical America and Asia together yields a comparable figure of 0.49 Mg C ha(-1) yr(-1) (n = 156; 562 ha; CI, 0.29-0.66; mean interval, 1987-97). This indicates a carbon sink of 1.3 Pg C yr(-1) (CI, 0.8-1.6) across all tropical forests during recent decades. Taxon-specific analyses of African inventory and other data suggest that widespread changes in resource availability, such as increasing atmospheric carbon dioxide concentrations, may be the cause of the increase in carbon stocks, as some theory and models predict.Item Potential Natural Vegetation Of Eastern Africa (Ethiopia, Kenya, Malawi, Rwanda, Tanzania, Uganda And Zambia) : Volume 3: Description And Tree Species Composition For Woodland And Wooded Grassland Potential Natural Vegetation Types.(2010-12) Kindt, Roeland; van Breugel, Paulo; Lillesø, J. P. B; Demissew, Sebsebe; Dudley, C.; Friis, I.; Gachathi, F.; Kalema, J.; Mbago, Frank M.; Minani, V.; Moshi, H.N.; Mulumba, J.; Namaganda, M.; Ndangalasi, H.J.Item Potential Natural Vegetation of Eastern Africa (Ethiopia, Kenya, Malawi, Rwanda, Tanzania, Uganda And Zambia) : Volume 4: Description and Tree Species Composition For Bushland and Thicket Potential Natural Vegetation Types(2010-12) Kindt, Roeland; van Breugel, Paulo; Lillesø, J.P. B.; Bingham, M.; Demissew, Sebsebe; Friis, I.; Mbago, Frank M.; Minani, V.; Moshi, H.N.; Mulumba, J.; Namaganda, M.; Ndangalasi, H.J.; Ruffo, C.K.; Jamnadass, R.This book represents Volume 4 in a seven-volume series that documents the potential natural vegetation map that was developed by the VECEA (Vegetation and Climate change in East Africa) project. The VECEA map was developed as a collaborative effort that included partners from each of the seven VECEA countries (Ethiopia, Kenya, Malawi, Rwanda, Tanzania, Uganda and Zambia). • In Volume 1, we present the potential natural vegetation map that we developed for seven countries in eastern Africa. In Volume 1, we also introduce the concept of potential natural vegetation and give an overview of different application domains of the VECEA map. • Volumes 2 to 5 describe potential natural vegetation types, also including lists of the “useful tree species” that are expected to naturally occur in each vegetation type – and therefore also expected to be adapted to the environmental conditions where the vegetation types are depicted to occur on the map. Volume 2 focuses on forest and scrub forest vegetation types. Volume 3 focuses on woodland and wooded grassland vegetation types. Volume 4 focuses on bushland and thicket vegetation types. In Volume 5, information is given for vegetation types that did not feature in Volumes 2 to 4Item Potential Natural Vegetation Of Eastern Africa (Ethiopia, Kenya, Malawi, Rwanda, Tanzania, Uganda And Zambia) : Volume 5: Description And Tree Species Composition For Other Potential Natural Vegetation(2010-12) Kindt, Roeland; Lillesø, J.P. B.; van Breugel, Paulo; Bingham, M.; Demissew, Sebsebe; Dudley, C.; Friis, I.; Gachathi, F.; Kalema, J.; Mbago, Frank M.; Minani, V.; Moshi, H. N.; Mulumba, J.; Namaganda, M.Item Potential natural vegetation of Eastern Africa (Ethiopia, Kenya, Malawi, Rwanda, Tanzania, Uganda and Zambia) : Volume 6: An overview of the methods and material used to develop the map(2010-12) van Breugel, Paulo; Kindt, Roeland; Lillesø, Jens-Peter B.; Bingham, M.; Demissew, Sebsebe; Dudley, C.; Friis, I.; Gachathi, F.; Kalema, J.; Mbago, Frank M.; Minani, V.; Mulumba, J.This book represents Volume 6 in a seven-volume series that documents the potential natural vegetation map that was developed by the VECEA (Vegetation and Climate change in East Africa) project. The VECEA map was developed as a collaborative effort that included partners from each of the seven VECEA countries (Ethiopia, Kenya, Malawi, Rwanda, Tanzania, Uganda and Zambia). • In Volume 1, we present the potential natural vegetation map that we developed for seven countries in eastern Africa. In Volume 1, we also introduce the concept of potential natural vegetation and give an overview of different application domains of the VECEA map. • Volumes 2 to 5 describe potential natural vegetation types, also including lists of the “useful tree species” that are expected to naturally occur in each vegetation type – and therefore also expected to be adapted to the environmental conditions where the vegetation typesItem Potential Natural Vegetation of Eastern Africa (Ethiopia, Kenya, Malawi, Rwanda, Tanzania, Uganda And Zambia) : Volume 7: Projected Distributions of Potential Natural Vegetation Types and Two Important Agroforestry Species (Prunus Africana And Warbur(2010-12) van Breugel, Paulo; Kindt, Roeland; Lillesø, J. P. B; Mbago, Frank M.; Minani, V.; Moshi, H. N.; Mulumba, J.; Namaganda, M.; Ndangalasi, H.JThis book represents Volume 7 in a seven-volume series that documents the potential natural vegetation map that was developed by the VECEA (Vegetation and Climate change in East Africa) project. The VECEA map was developed as a collaborative effort that included partners from each of the seven VECEA countries (Ethiopia, Kenya, Malawi, Rwanda, Tanzania, Uganda and Zambia).Item Potential Natural Vegetation Of Eastern Africa (Ethiopia, Kenya, Malawi, Rwanda, Tanzania, Uganda And Zambia). Volume 10. Atlas And Tree Species Composition For Tanzania(2013-12) Lillesø, Jens-Peter B.; Breugel, Paulo V.; Kindt, Roeland; Mbago, Frank M.; Moshi, Heriel N.; Ndangalasi, Henry J.; Jamnadass, Ramni H.; Graudal, LarsThis book represents Volume 10 in a eleven-volume series that documents the potential natural vegetation map that was developed by the VECEA (Vegetation and Climate change in East Africa) project. The VECEA map was developed as a collaborative effort that included partners from each of the seven VECEA countries (Ethiopia, Kenya, Malawi, Rwanda, Tanzania, Uganda and Zambia).Item Two ‘Extinct’ Trees Rediscovered Near Kilwa, Tanzania(2011) Clarke, Philip G.; Burgess, Neil D.; Mbago, Frank M.; Mligo, Cosmas; Mackinder, Barbara; Gereau, Roy E.Preliminary botanical explorations in the little-known Namatimbili-Ngarama forest block located some 35 km inland of Kilwa in south-east Tanzania have rediscovered and further confirmed the presence of two tree species, Erythrina schliebenii Harms and Karomia gigas (Faden) Verde., that were previously thought to have become extinct. Both trees are endemic to the Coastal Forests of Eastern Africa hotspot and to the Swahilian Regional Centre of Endemism.