Bioactivity-directed fractionation of extracts of two Diospyros maritima bark samples from Indonesia,one collected at sea level in a beach forest in Java and the other collected at a slight elevation away from the sea shore on the island of Lombok, yielded a diverse set of secondary metabolites. The naphthoquinone plumbagin (1), although found in extracts of both specimens, constituted a much larger percentage of the former sample, which also yielded a series of plumbagin dimers, maritinone (2), chitranone (3), and zeylanone (4). The latter sample yielded a new naphthoquinone derivative, (4S)-shinanolone (5), and a new natural product coumarin, 7,8-dimethoxy-6-hydroxycoumarin (6), along with three other analogues of plumbagin, 2-methoxy-7-methyljuglone (7), 3-methoxy-7-methyljuglone (8), and 7-methyljuglone (9). The structures of compounds 5 and 6 were elaborated by physical, spectral, and chemical methods. All of the isolates were evaluated in both cytotoxicity and antimicrobial assays, and structure-activity relationships of these naphthoquinones are proposed. Plumbagin (1) and maritinone (2) were evaluated also for in vivo antitumor activity in the hollow fiber assay, but both were found to be inactive.

The previously known potent cytotoxic agent silvestrol (1) (0.002% w/w yield) and five new flavagline derivatives (2-6) were isolated from the leaves of Aglaia foveolata collected in Indonesia. The new compound 5 has an unprecedented cyclic amide moiety in its cyclopenta [b]benzopyran skeleton, while compound 6 is a novel benzo [b]oxepine derivative in which the oxepine ring is cleaved. Pyramidatine (7), a biogenetic precursor of the new flavaglines 2-6, was isolated from the leaf extract investigated. Silvestrol was also isolated from the stem bark of A. foveolata (yield of 0.02% w/w) along with a new baccharane-type triterpenoid (8). The structures of the new compounds were elucidated on the basis of their NMR and mass spectrometric data. All new compounds isolated were tested against a panel of cancer cell lines, but only compound 2 was cytotoxic (IC 50 range = 1.4-1.8 μM), and is the first member of the cyclopenta[b]benzopyran class found to exhibit this type of activity. Compound 2 also showed significant NF-κB inhibitory activity in an Elisa assay (IC 50 = 0.37 μM).

Cytotoxicity-guided fractionation of the stems of Helicteres hirsuta, of Indonesian origin, led to the isolation and identification of six lignans, namely, (+/-)-pinoresinol, (+/-)-medioresinol, (+/-)-syringaresinol, (-)-boehmenan, (-)-boehmenan H and (+/-)-trans-dihydrodiconiferyl alcohol. Of these isolates, (+/-)-pinoresinol exhibited potent cytotoxic effects when evaluated against a small panel of cancer cell lines.

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We describe the vegetation of Kwerba, in the foothills of the Foja Mountains in the Mamberamo Basin of West Papua, Indonesia. Few surveys have been carried out in this remote area of Western New Guinea. Working in collaboration with local people we made 15 plots, 10 in primary forest, 3 in secondary forest and 2 in gardens. A total of 487 morpho-species were distinguished, of which 32 % (156) did not match any herbarium specimens or published reference. Tree densities (598 ± 136/ha) are similar to lowland forests elsewhere, but mean stem sizes (22 ± 1 cm dbh and 21 ± 2 m height for trees over 10 cm dbh) appear small. Numbers of tree species per plot (22 ± 4, of 40 stems recorded) are unremarkable, but levels of endemism are potentially high with many of the unidentified species being rare (seldom collected) or undescribed. This is the first quantitative description of vegetation in Kwerba, Foja and Mamberamo, and joins only a handful of such studies in Papua. Additional botanical and ecological survey effort is greatly needed in Mamberamo, and in New Guinea generally.

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New Guinea is the world’s largest, most speciose, and most culturally rich tropical island, and the little-studied Mamberamo Basin of Papua (Indonesian New Guinea) is recognised among the region’s most-important areas for biological diversity. Here, we examined the floodplain forests in the indigenous territory of Papasena, within the Mamberamo-Foja Wildlife Reserve in the Mamberamo Basin. As part of a training activity with local researchers, students, and civil servants, and with the permission and assistance of the local people, we employed various methods including the field surveys detailed here. We used variable-area tree plots, transects for non-trees and soil sampling, and local informants to document 17 plots: four in old-growth dryland forest, five in old-growth swamp forests (two seasonally flooded and three permanently wet including one dominated by sago, Metroxylon sagu Rottb.), five in secondary forest (fallows), and three in gardens (two in swamps and one on dryland). In total, we measured 475 trees over 10 cm in diameter at 1.3 m (dbh). The swamp forests had high local basal areas (highest value 45.1 m2 ha−1) but relatively low statures (20 m but with emergent trees over 40 m). In total, 422 morphospecies from 247 genera and 89 different families were distinguished. These included 138 tree species and 284 non-tree plant species. A quarter (105) of the morphospecies lacked species-level identifications. The woody families Rubiaceae, Araceae, Moraceae, and Euphorbiaceae were especially diverse, with 20 or more morphospecies each. Tree richness was highest in dryland forest (plot 7 having 28 species in 40 stems over 10 cm dbh) with more variation in the flooded forests. Non-tree vegetation showed similar patterns ranging from 65 species in one 40-by-5 m primary forest plot to just 5 in one seasonally flooded forest plot. The local people identified many plants as useful. Among trees, at least 59 species were useful for construction (the most common use), while, for non-trees, medicinal uses were most frequent. Inceptisols dominated (12 plots), followed by Ultisols and Entisols (3 and 2 plots, respectively). Drainage appeared poor and nutrient availability low, while land-suitability criteria implied little potential for crops aside from sago. We discuss the implication of local practises and more recent developments that may threaten the conservation of these floodplain systems. We underline the key role of local people in the oversight and protection of these ecosystems.

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