Antiprotozoal potential of Vismia species (Hypericaceae), medicinal plants used to fight cutaneous leishmaniasis.

ETHNOPHARMACOLOGICAL RELEVANCE: Species of Vismia (Hypericaceae), known in Brazil as "lacre", are commonly used in traditional Amazonian medicine for the treatment of skin lesions, including those caused by Leishmania infection. AIM OF THE STUDY: Hexane extracts from the leaves of Vismia cayennensis, V. gracilis, V. sandwithii and V. guianensis, as well as from the fruits of the latter, in addition to the anthraquinones vismiaquinone, physcion and chrysophanol isolated from these species were explored for their anti-promastigote and anti-amastigote activity on Leishmania amazonensis. MATERIALS AND METHODS: Extracts were prepared by static maceration with n-hexane. The compounds, isolated by chromatographic techniques, were identified by spectroscopic methods (1H and 13C NMR). Promastigotes of L.amazonensis were incubated with hexane extracts (1-50 µg/mL) or anthraquinones (1-50 µM) and the parasite survival analyzed. The action of compounds on reactive oxygen species (ROS) production, mitochondrial membrane potential, and membrane integrity of promastigotes were evaluated by flow cytometer, and the cytotoxicity on mammalian cells using MTT assay. Furthermore, the activity of compounds against amastigotes and nitric oxide production were also investigated. RESULTS: Vismiaquinone and physcion were obtained from the leaves of V. guianensis. Physcion, as well as chrysophanol, were isolated from V. sandwithii. Vismia cayennensis and V. gracilis also showed vismiaquinone, compound detected in lower quantity in the fruits of V. guianensis. All extracts were active against the parasite, corroborating the popular use. The greatest activity against promastigotes was achieved with V. guianensis extract (IC50 4.3 µg/mL), precisely the most used Vismia species for treating cutaneous leishmaniasis. Vismiaquinone and physcion exhibited relevant activity with IC50 12.6 and 2.6 µM, respectively. Moreover, all extracts and anthraquinones tested induced ROS production, mitochondrial dysfunction, membrane disruption and were able to kill intracellular amastigote forms, being worthy of further in vivo studies as potential antileishmanial drugs. CONCLUSIONS: The overall data achieved in the current investigation scientifically validate the traditional use of Vismia species, mainly V. guianensis, as an anti-Leishmania agent. Furthermore, the promising results presented here indicate species of Vismia as potentially useful resources of Brazilian flora for the discovery of therapeutic solutions for neglected diseases.

Deciphering the Heteropterys pannosa species complex (Malpighiaceae).

We describe three new species of Malpighiaceae that are endemic to central Brazil and related to the Heteropterys pannosa complex, a group of xylopodiferous, unbranched subshrubs with fruit in mericarps that have a strongly reduced or no dorsal wing. Heteropterys tocantinensis is more common in eastern Tocantins State and on the border with Bahia State, and there are a few records from Mato Grosso State. Heteropterys veadeirensis is restricted to northern Goiás State and H. walteri has a wider distribution, occurring in some municipalities in northern Goiás and southern Tocantins. Additionally, we also provide detailed redescriptions of H. pannosa and H. rosmarinifolia, the two previously known species in this complex. All species are considered Endangered (EN) based on IUCN criteria, especially due to the low area of occupancy. Illustrations, distribution maps, and information about phenology and habitat are also provided for all taxa.

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.

Tovomita nebulosa (Clusiaceae), a new species from Cerro de la Neblina, Venezuela

Although the number of recently described Tovomita species is relatively high, much more remains to be done, given that each new survey of representative Amazonian collections reveals many potentially undescribed taxa. In the treatment for Tovomita published in Flora of the Venezuelan Guayana, at least six distinct morphotypes did not match any previously described species. Here we recognize morphotype "D" as a new endemic species from Cerro de la Neblina. Additionally, we provide an identification key to the Tovomita species in Venezuela. (AU)

How phantom databases could contribute to conservation assessments.

Reliable data are needed to produce representative and useful conservation assessments for species. To this end, taxonomists and their unpublished, archived and unused databases-here called phantom databases-have great relevance for assessing the conservation status of species. Taxonomist's phantom databases are usually the result of a review work, and, if made available, they could be used to assess a species conservation status with greater accuracy, allowing for more effective conservation planning. Here we characterise these databases, provide examples of their relevance and recommend solutions to make these phantom databases available for conservation use. Databases of taxonomic and geographic information need not be phantom and could be made openly accessible to encourage their use in conservation activities.

Plastomes resolve generic limits within tribe Clusieae (Clusiaceae) and reveal the new genus Arawakia.

Clusieae is an exclusively Neotropical tribe in the family Clusiaceae sensu stricto. Although tribes within Clusiaceae are morphologically and phylogenetically well-delimited, resolution among genera within these tribes remains elusive. The tribe Clusieae includes an estimated ∼500 species distributed among five genera: Chrysochlamys, Clusia, Dystovomita, Tovomita, and Tovomitopsis. In this study, we used nearly complete plastid genomes from 30 exemplar Clusieae species representing all genera recognized, plus two outgroups to infer the phylogeny of the tribe using Maximum Likelihood and Bayesian Inference. For comparison, we also inferred a phylogeny from the nuclear Internal Transcribed Spacer (ITS) region using the same methods. Our study corroborates earlier findings that Clusia is monophyletic while Tovomita is not. It also provides additional support to the hypothesis that Chrysochlamys and Tovomitopsis are not closely related despite gross morphological similarity. Tovomita is divided into three distantly related clades: (i) core Tovomita (including the type T. guianensis), (ii) T. croatii, and (iii) the T. weddelliana species complex. Members of the T. weddelliana complex are isolated from the core Tovomita, and placed in a well-supported clade that is sister to a clade composed of Chrysochlamys plus Clusia. Tovomita croatii is nested within Chrysochlamys. We propose taxonomic revisions to accommodate our phylogenetic findings, including the description of the new genus Arawakia, which includes the 18 species formerly recognized in the T. weddelliana species complex. Lectotypes are also designated for nine species (i.e., Arawakia angustata, A. lanceolata, A. lingulata, A. longicuneata, A. macrocarpa, A. oblanceolata, A. pithecobia, A. rhizophoroides, and A. weddelliana), and a taxonomic key for the identification of the six genera of Clusieae recognized is presented.