Amazon plant diversity revealed by a taxonomically verified species list.

Recent debates on the number of plant species in the vast lowland rain forests of the Amazon have been based largely on model estimates, neglecting published checklists based on verified voucher data. Here we collate taxonomically verified checklists to present a list of seed plant species from lowland Amazon rain forests. Our list comprises 14,003 species, of which 6,727 are trees. These figures are similar to estimates derived from nonparametric ecological models, but they contrast strongly with predictions of much higher tree diversity derived from parametric models. Based on the known proportion of tree species in neotropical lowland rain forest communities as measured in complete plot censuses, and on overall estimates of seed plant diversity in Brazil and in the neotropics in general, it is more likely that tree diversity in the Amazon is closer to the lower estimates derived from nonparametric models. Much remains unknown about Amazonian plant diversity, but this taxonomically verified dataset provides a valid starting point for macroecological and evolutionary studies aimed at understanding the origin, evolution, and ecology of the exceptional biodiversity of Amazonian forests.

Chemical constituents of apolar fractions from fruit latex of twelve Clusia species (Clusiaceae).

The apolar fractions components of fruit latex of twelve species of Clusia belonging to four different taxonomic sections were examined by GC-MS. The latex of Clusia is characterised by large amounts of sesquiterpene hydrocarbons as major constituents like germacrene D: C. paralicola (44.28 %), C. criuva subsp. criuva (29.03 %); ß-caryophyllene: C. fluminensis (35.61 %), C. lanceolata (36.39 %), C. hilariana (58.10 %); α-trans-bergamontene: C. spirictus-sanctensis (36.30 %); α-bulnesene: C. weddelliana (25.61 %); bicyclogermacrene: C. panapanari (25.93 %) and trans-ß-farnesene: C. nemorosa (24.63 %), while C. grandiflora is composed of 42.16 % monoterpene hydrocarbons. Verbenone (31.91 %) was the major component. In contrast, C. rosea, C. grandiflora, C. lanceolata and C. criuva subsp. parviflora are rich in 3-methylcyclohexanone (19.56 %), hexadecanol (22.72 %), p-anisaldehyde (23.39 %) and octadecanol (26.81 %), respectively. This study suggests considerable chemical variation among the non-polar fractions of fruit latex of the twelve Clusia species.

Phenology, floral and reproductive biology of Dichorisandra rhizantha Aona (Commelinaceae), an endemic endangered species in an Atlantic Forest fragment.

Commelinaceae is an important component of the Atlantic Forest and its analysis can provide information on the conservation of that species. This study had the objective of analyzing the phenology and floral and reproductive biology of Dichorisandra rhizantha, growing in an Atlantic Forest fragment, to obtain data related to the form of reproduction and pollination mechanism of this species. We monitored the phenophases and reproductive biology of the D. rhizantha in the area studied using different methodologies and microscopy techniques (LM, SEM and FM). The flowering period occurs during the dry season. The species is andromonoecious and has daytime anthesis (4:30 a.m.-1:30 p.m.). It has purple zygomorphic flowers and rimose but functionally poricidal anthers. The pollen viability was 97.6% and the two floral morphs investigated contained a large quantity of pollen grains. The time of greatest stigma receptivity (anthesis) coincided with the pollen viability. Cross-pollination was the only efficient reproductive system of the species, with observation of gametophytic self-incompatibility and pollen tubes growth only as far as the middle or lower third of the pistil. We observed bee species of the genera Xylocopa and Euglossa visiting the flowers and acting as effective pollinators. The immature fruits were formed after about 3.25 ± 1 days, and the presence was noted of ants of the genus Cephalotes acting as dispersers of the seeds, with aril serving as the reward. Although the natural reproductive system is efficient, D. rhizantha is endangered, mainly due to fragmentation of habitat caused by deforestation and urban encroachment.

Phylogeny of the clusioid clade (Malpighiales): evidence from the plastid and mitochondrial genomes.

PREMISE OF THE STUDY: The clusioid clade includes five families (i.e., Bonnetiaceae, Calophyllaceae, Clusiaceae s.s., Hypericaceae, and Podostemaceae) represented by 94 genera and ≈1900 species. Species in this clade form a conspicuous element of tropical forests worldwide and are important in horticulture, timber production, and pharmacology. We conducted a taxon-rich multigene phylogenetic analysis of the clusioids to clarify phylogenetic relationships in this clade. METHODS: We analyzed plastid (matK, ndhF, and rbcL) and mitochondrial (matR) nucleotide sequence data using parsimony, maximum likelihood, and Bayesian inference. Our combined data set included 194 species representing all major clusioid subclades, plus numerous species spanning the taxonomic, morphological, and biogeographic breadth of the clusioid clade. KEY RESULTS: Our results indicate that Tovomita (Clusiaceae s.s.), Harungana and Hypericum (Hypericaceae), and Ledermanniella s.s. and Zeylanidium (Podostemaceae) are not monophyletic. In addition, we place four genera that have not been included in any previous molecular study: Ceratolacis, Diamantina, and Griffithella (Podostemaceae), and Santomasia (Hypericaceae). Finally, our results indicate that Lianthus, Santomasia, Thornea, and Triadenum can be safely merged into Hypericum (Hypericaceae). CONCLUSIONS: We present the first well-resolved, taxon-rich phylogeny of the clusioid clade. Taxon sampling and resolution within the clade are greatly improved compared to previous studies and provide a strong basis for improving the classification of the group. In addition, our phylogeny will form the foundation for our future work investigating the biogeography of tropical angiosperms that exhibit Gondwanan distributions.

Clarifying the nomenclatural history of Tovomitopsis, a Brazilian endemic genus of Clusiaceae.

Tovomitopsis Planch. & Triana is a Brazilian Atlantic Forest endemic genus composed of two species: T.paniculata (Spreng.) Planch. & Triana and T.saldanhae Engl. An investigation was conducted to clarify the nomenclatural history of Tovomitopsis. We report the results of this investigation, provide an updated description of the genus, and propose lectotypes for T.paniculata and its synonyms: Tovomitafoliosa C.Presl and Tovomitapaniculata Cambess. We also propose lectotypes for T.saldanhae and for the new synonym Clusiaangustifolia Engl.

Calophyllaceae plastomes, their structure and insights in relationships within the clusioids.

A complete chloroplast genome is not yet available for numerous species of plants. Among the groups that lack plastome information is the clusioid clade (Malpighiales), which includes five families: Bonnetiaceae, Calophyllaceae, Clusiaceae, Hypericaceae, and Podostemaceae. With around 2200 species, it has few published plastomes and most of them are from Podostemaceae. Here we assembled and compared six plastomes from members of the clusioids: five from Calophyllaceae (newly sequenced) and one from Clusiaceae. Putative regions for evolutionary studies were identified and the newly assembled chloroplasts were analyzed with other available chloroplasts for the group, focusing on Calophyllaceae. Our results mostly agree with recent studies which found a general conserved structure, except for the two Podostemaceae species that have a large inversion (trnK-UUU-rbcL) and lack one intron from ycf3. Within Calophyllaceae we observed a longer LSC and reduced IRs in Mahurea exstipulata, resulting in some genic rearrangement, and a short inversion (psbJ-psbE) in Kielmeyera coriacea. Phylogenetic analyses recovered the clusioids and the five families as monophyletic and revealed that conflicts in relationships reported in the literature for the group agree with nodes concentrating uninformative or conflicting gene trees. Our study brings new insights about clusioid plastome architecture and its evolution.

Floristic survey of herbaceous and subshrubby aquatic and palustrine angiosperms of Viruá National Park, Roraima, Brazil.

We provide and discuss a floristic survey of herbaceous and subshrubby aquatic and palustrine angiosperms of Viruá National Park (VNP). The VNP is located in the northern Amazon basin and displays phytophysiognomies distributed in a mosaic where these plants occur, as flooded forests, hydromorphic white-sand savannas, "buritizais" and waterbodies. After expeditions between February/2010 and January/2015 and the analysis of specimens from regional herbaria, we list 207 species of herbaceous and subshrubby aquatic and palustrine angiosperms for the VNP, distributed in 85 genera in 37 families. We recorded six new occurrences for Brazil, two for the northern Brazilian region and 21 for Roraima state. These new occurrences, added to the other species listed here, highlight the floristic similarity between the study site and the Guiana Shield, an adjacent phytogeographical unit and geologically related to the origin of white-sand savannas.

Resumo(Lista Florística de angiospermas herbáceas e subarbustivas aquáticas e palustres do Parque Nacional do Viruá, Roraima, Brasil) Esse estudo foi realizado objetivando a elaboração de uma lista florística das angiospermas herbáceas e subarbustivas aquáticas e palustres do Parque Nacional do Viruá (PNV). O PNV está localizado na região norte da Bacia Amazônica e apresenta fitofisionomias distribuídas em mosaico onde esse grupo de plantas ocorre, como florestas inundáveis, savanas sobre solos de areia branca hidromórficas, buritizais e corpos d'água. Após coletas entre Fevereiro/2010 e Janeiro/2015 e a análise de espécimes depositados em herbários regionais, foram listadas 207 espécies de angiospermas herbáceas e subarbustivas aquáticas e palustres no PNV, distribuídas em 85 gêneros e 37 famílias. Foram registradas seis novas ocorrências para o Brasil, duas para a região norte do Brasil e 21 para o estado de Roraima. Essas novas ocorrências, juntamente com as demais espécies listadas, evidenciam a similaridade florística entre a área de estudo e o Escudo das Guianas, uma unidade fitogeográfica adjacente e geologicamente relacionada com a origem das savanas sobre solos de areia branca.

Floral resin of Tovomitopsis saldanhae (Guttiferae) and 7-epi-nemorosone: structural revision.

The floral resin of Tovomitopsis saldanhae (Guttiferae) is composed of poliisoprenylated benzophenone and the major constituent is 7-epi-nemorosone which has now been revised.

Antiproliferative properties of polyketides isolated from Virola sebifera leaves.

An activity-guided fractionation of Virola sebifera Aubl. methylene chloride-soluble fraction provided novel 3,5-dihydro-2-(1'-oxo-3'-hexadecenyl)-2-cyclohexen-1-one (3), two known lignans (1, 2) and dehydro hexadecanoyl resorcinol (4). Isolation and purification were conducted with the application of column chromatography and structures were assigned by spetral analysis (1D and 2D NMR, HREIMS). Compounds 1-4 were evaluated for cytotoxic activities against human tumour cell lines UACC62 (melanoma), MCF-7 (breast), NCI 460 (lung, non-small cells), OVCAR03 (ovarian), PC-03 (prostate), HT-29 (colon), 786-0 (renal) and NCI-ADR (breast expressing phenotype multiple drugs resistance) in vitro. The new polyketide (3) showed selectivity against human OVCAR03 and NCI-ADR cell lines, ranging from 2 to 4 microg/mL.

Antiproliferative activity, isolation and identification of active compound from Gaylussacia brasiliensis

Gaylussacia brasiliensis (Spreng.) Meissn., Ericaceae, is used in folk medicine for treatment of several inflammatory processes and as healing agent. The scope of this work was to evaluate the in vitro antiproliferative activity of crude dichloromethane extract (CHD) and to identify the compound(s) responsible for this activity. CHD was evaluated and showed a concentration dependent inhibition on all cells lines. Therefore CHD was submitted to several classical columns chromatography providing the most active fraction (FC), inhibiting all cells line at 25 µg/mL. FC was further fractionated affording isolated compound 2β, 3β-dihydroxy-urs-12-ene-28-oic acid , identified on basis of 2D-NMR experiments and showed concentration-dependent activity and selectivity for kidney and breast cell lines.