Diamide derivatives and cycloartanes from the leaves of Aglaia elliptica.
Chemical examination of the leaves of Aglaia elliptica led to the isolation of two new diamides, 10-O-acetylaglain B (1) and 4-epiaglain A (2), two known diamides, aglain A (3) and odorine (4), and three known cycloartanes (5-7). The structures of 1 and 2 were elucidated by interpretation of the spectral data. (+info
Cancer chemopreventive activity of odorine and odorinol from Aglaia odorata.
In the course of our continuing search for novel cancer chemo-preventive agents from natural sources, we have carried out a primary screening in vitro assay of the compounds isolated from Aglaia odorata. Consequently, aminopyrrolidine-diamides, odorine and odorinol, were obtained as active constituents. These compounds exhibited potent anti-carcinogenic effects in a two-stage carcinogenesis test of mouse skin induced by 7,12-dimethylbenz[a]anthracene (DMBA) as an initiator and 12-O-tetradecanoylphorbol-13-acetate (TPA) as a promoter. Further, both compounds showed remarkable inhibitory effects in two-stage mouse skin carcinogenesis models induced by nitric oxide (NO) donors such as (+/-)-(E)-methyl-2-[(E)-hydroxyimino]-5-nitro-6-methoxy-3-hexenamide (NOR-1) or peroxynitrite as an initiator and TPA as a promoter. From these results, it was concluded that odorine and odorinol inhibited both the initiation and promotion stages of two-stage skin carcinogenesis. (+info
Multiplexed systems of microsatellite markers for genetic analysis of mahogany, Swietenia macrophylla King (Meliaceae), a threatened neotropical timber species.
Mahogany (Swietenia macrophylla King [Meliaceae]) is the most valuable hardwood species in the neotropics. Its conservation status has been the subject of increasing concern due to overexploitation and habitat destruction. In this work we report the development and characterization of 10 highly variable microsatellite loci for S. macrophylla. Twenty-nine percent of the 126 sequenced mahogany clones yielded useful microsatellite loci. Three high-throughput genotyping systems were developed based on polymerase chain reaction (PCR) multiplexing of these mahogany loci. We identified a total of 158 alleles in 121 adult individuals of S. macrophylla, with an average of 15.8 alleles (range 11-25) per locus. All loci showed Mendelian inheritance in open-pollinated half-sib families. The mean expected heterozygosity was 0.84 and the mean observed heterozygosity was 0.73. The combined probability of identity-the probability that two individuals selected at random from a population would have identical genotypes--was 7.0 x 10(-15), and combined probability of paternity exclusion was 0.999998 overall loci. These microsatellite loci permit precise estimates of parameters such as gene flow, mating system, and paternity, thus providing important insights into the population genetics and conservation of S. macrophylla. (+info
Fine-scale genetic structure and gene flow within Costa Rican populations of mahogany (Swietenia macrophylla).
Fine-scale structure of genetic diversity and gene flow were analysed in three Costa Rican populations of mahogany, Swietenia macrophylla. Population differentiation estimated using AFLPs and SSRs was low (38.3 and 24%) and only slightly higher than previous estimates for Central American populations based on RAPD variation (20%). Significant fine-scale spatial structure was found in all of the surveyed mahogany populations and is probably strongly influenced by the limited seed dispersal range of the species. Furthermore, a survey of progeny arrays from selected mother trees in two of the plots indicated that most pollinations involved proximate trees. These data indicate that very little gene flow, via either pollen or seed, is occurring between blocks of mahogany within a continuous or disturbed forest landscape. Thus, once diversity is removed from a forest population of mahogany, these data suggest that recovery would be difficult via seed or pollen dispersal, and provides an explanation for mahogany's apparent susceptibility to the pressures of logging. Evidence is reviewed from other studies of gene flow and seedling regeneration to discuss alternative extraction strategies that may maintain diversity or allow recovery of genetic resources. (+info
Ichthyotoxic and anticarcinogenic effects of triterpenoids from Sandoricum koetjape bark.
After bioassay-guided fractionation of the extract from Sandoricum koetjape bark, which exhibited significant toxicity to killifish (Oryzias latipes), two ichthyotoxic triterpenoids were isolated and characterized as koetjapic acid and 3-oxo-olean-12-en-29-oic acid. These constituents, along with non-toxic katonic acid, had a remarkable inhibitory effect on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol 13-acetate (TPA), which is a preliminary in vitro screening method for possible anti-tumor-promoting agents. Of the triterpenoids active in vitro, koetjapic acid appears to be a promising cancer chemopreventive agent, since it significantly delayed tumor promotion in two-stage mouse skin carcinogenesis induced by 7,12-dimethylbenz(a)anthracene and promoted by TPA. (+info
Novel antimalarial compounds isolated in a survey of self-medicative behavior of wild chimpanzees in Uganda.
Following a veterinary and behavioral survey of chimpanzees from a natural population in Uganda, leaf samples of Trichilia rubescens were collected because of the unusual method of ingestion observed. The methanolic crude extract of T. rubescens leaves exhibited significant antimalarial activity in vitro. Bioassay-directed fractionation provided two new limonoids, trichirubines A and B. A greater understanding of the role of secondary compounds in the primate diet may be helpful in recovering naturally occurring compounds of medicinal significance for human medicine. (+info
Two new analogues of trijugin-type limonoids from the leaves of Sandoricum koetjape.
Two new additional trijugin-type limonoids, sandrapins D (4) and E (5), which are analogues of the previously reported sandrapins A-C (1-3), were isolated as minor components from the leaves of Sandoricum koetjape (Meliaceae), and their structures were elucidated on the basis of MS and NMR spectral data. (+info
Genotyping of mature trees of Entandrophragma cylindricum with microsatellites.
We have characterized 10 microsatellite loci for the tropical tree Entandrophragma cylindricum (Sprague) Sprague (sapelli) in order to genotype individuals in forest stands for estimation of the genetic diversity of the species. We used the technique of building a (GA)n microsatellite-enriched library by capture with streptavidin-coated magnetic beads. We assessed the polymorphism of seven microsatellites in 186 mature trees in a selectively logged stand (Dimako) and an unlogged stand (Ndama), both in Cameroon. All the loci were polymorphic, and the number of alleles was high, ranging from eight to 36, with a mean of 22.1. Both stands showed the same high level of genetic diversity (mean H(E) = 0.85) and a low genetic differentiation (FST = 0.007), indicating that genetic diversity was within rather than among populations. Five and three out seven loci in Dimako and Ndama, respectively, showed a deficit of heterozygotes. The seven loci enabled more than 97% of the mature trees in each stand to be identified. It was concluded that these markers can be efficiently used for gene flow studies. (+info