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Praziquantel is the only available drug to treat schistosomiasis, and therefore, urgent studies must be performed to identify new anthelmintic agents. This study reports the anthelmintic evaluation of two related ent-kaurane diterpenes isolated from aerial parts of Baccharis lateralis (Asteraceae), entkaur-16-en-19-oic acid (1) and 15β-senecioyl-oxy-ent-kaur-16-en-19oic acid (2) against Schistosoma mansoni in vitro and in a murine model of schistosomiasis. Both compounds exhibited in vitro activity with lethal concentration 50% (LC 50 ) values of 26.1 μM (1) and 11.6 μM (2) as well as reduced toxicity against human cell lines, revealing a good selectivity profile, mainly with compound 2 (selectivity index > 10). Compound 2 also decreased egg production and caused morphological alterations in the parasite reproductive system. In mice infected with S. mansoni, oral treatment with compound 2 at 400 mg/kg, the standard dose used in this model of schistosomiasis, caused a significant reduction in a total worm burden of 61.9% (P < 0.01). S. mansoni egg production, a key mechanism for both transmission and pathogenesis, was also markedly reduced. In addition, compound 2 achieved a significant reduction in hepatosplenomegaly. Therefore, the diterpene 15β-senecioyl-oxy-ent-kaur-16-en-19-oic acid (2) has an acceptable cytotoxicity profile and is orally active in a murine schistosomiasis model.

Open habitats such as grasslands occupy &lt; 5% of the Amazon and are currently grouped under the broad term Amazonian savanna, covering an area of c. 267 000 km2, mostly in Brazil and Bolivia. These habitats are found isolated within an extensive rainforest matrix, having a distinct flora from the latter. The lower Amazon River is home to several patches of savanna that occupy both south and north banks of the river, in Santarém, Alenquer and Monte Alegre. Although having an abundance of herbaceous plants, most studies on these open areas focus only on tree species, ignoring the relevant non-woody component of the vegetation. Our objectives were to provide new surveys of seed plants for two Amazonian savanna sites and to take the opportunity to revisit the biogeographical links between Amazonian savanna, Amazonian canga vegetation and the central Brazilian cerrado (CBC) and caatinga, analysing woody and herbaceous plants. We created a floristic database that includes sites of Amazonian savannas, including campinarana, coastal scrub (restinga), CBC and Amazonian campos rupestres (on canga or other substrate). We compared those sites using multivariate analyses to find out the degree of floristic resemblance between sites. We prepared a new list of 406 species of seed plants [336 in Parque Estadual de Monte Alegre (PEMA) and 117 in Serra do Itauajuri (SI)], including 23 new records for the state of Pará and some putative new species for science. The Amazonian savannas form three loosely arranged groups, whereas the Amazonian canga formed a cohesive assemblage. Both groups were contrasted against cerrado and caatinga sites and had a distinctive flora from both. Sites from north-western Pará (Alter do Chão, PEMA and SI) were grouped with their northern counterparts in Roraima. An improved representation of the flora of these sites is provided, with more insight into the relationship between the Amazonian savanna sites and other vegetation types. It is worrying that recent changes of the Brazilian legislation place open environments, such as PEMA, in the path of vulnerability to disturbance and destruction.

The shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora.

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The hexane extract from aerial parts Baccharis sphenophylla Dusén ex Malme (Asteraceae) displayed activity against amastigote forms of Trypanossoma cruzi and was subjected to chromatographic steps to afford one unreported – 7α‐hydroxy‐ent‐abieta‐8(14),13(15)‐dien‐16,12β‐olide (1) and three known diterpenes – ent‐kaur‐16‐en‐19‐oic acid, (2), grandifloric acid (3), and 15β‐tiglinoyloxy‐ent‐kaur‐16‐en‐19‐oic acid (4), two sesquiterpenes – spathulenol (5) and oplopanone (6) – as well as hexacosyl p‐coumarate (7). Isolated compounds were characterized by NMR and ESI‐HR‐MS spectra and were evaluated in vitro for activity against amastigote forms of the parasite T. cruzi – the relevant clinical form in the chronic phase of Chagas disease. In addition, the activity of compounds 1–7 against NCTC cells was evaluated. Compounds 1 and 7 showed effectiveness with EC50 values of 21.3 and 16.9 μM, respectively. Both compounds also exhibited reduced toxicity against NCTC cells (CC50>200 μM) with SI values higher than 9.4 and 11.9. Obtained results suggest that the new ent‐abietane diterpene 1 and alkyl coumarate 7 could be used as prototypes for the development of novel and selective semisynthetic derivatives against intracellular forms of T. cruzi.