Information on the knowledge, uses, and abundance of natural resources in local communities can provide insight on conservation status and conservation strategies in these locations. The aim of this research was to evaluate the uses, knowledge and conservation status of plants in two Quilombolas (descendants of slaves of African origin) communities in the Atlantic rainforest of Brazil, São Sebastião da Boa Vista (SSBV) and São Bento (SB). We used a combination of ethnobotanical and ecological survey methods to ask: 1) What ethnobotanical knowledge do the communities hold? 2) What native species are most valuable to them? 3) What is the conservation status of the native species used? Thirteen local experts described the names and uses of 212 species in SSBV (105 native species) and 221 in SB (96 native species). Shannon Wiener diversity and Pielou’s Equitability indices of ethnobotanical knowledge of species were very high (5.27/0.96 and 5.28/0.96, respectively). Species with the highest cultural significance and use-value indexes in SSBV were Dalbergia hortensis (26/2.14), Eremanthus erythropappus (6.88/1), and Tibouchina granulosa (6.02/1); while Piptadenia gonoacantha (3.32/1), Sparattosperma leucanthum (3.32/1) and Cecropia glaziovii (3.32/0.67) were the highest in SB. Thirty-three native species ranked in the highest conservation priority category at SSBV and 31 at SB. D. hortensis was noteworthy because of its extremely high cultural importance at SSBV, and its categorization as a conservation priority in both communities. This information can be used towards generating sustainable use and conservation plans that are appropriate for the local communities.

Resumo: Plantas do gênero Piper são frequentemente utilizadas comercialmente. A espécie Piper chimonanthifolium Kunth. apresenta poucos estudos em literatura quanto a sua composição química e atividades biológicas. Óleos essenciais de outras espécies deste gênero apresentam boas atividades biológicas, principalmente contra microrganismos. Este trabalho apresenta uma comparação da composição química de óleos essenciais e hidrolatos de folhas, inflorescências e caules desta espécie. As amostras foram obtidas por co-destilação e analisadas por cromatografia com fase gasosa acoplada à espectrometria de massas (CG-EM). As amostras mostraram presença de monoterpenos e sesquiterpenos, com predominância de monoterpenos. A piperitona, um monoterpeno com atividades biológicas anteriormente relatadas na literatura, foi a substância com maior destaque. Além desta substância, destacaram-se: L-linalol, cis-β-ocimeno, trans-β-cimeno, 1-felandreno, α-pineno, limoneno e espatulenol. Algumas dessas substâncias podem exibir variação na composição de acordo com fatores ambientais e podem ser agentes de controle biológico, demonstrando importância ecológica. As análises por CG-EM evidenciaram diferenças na composição química entre folhas, inflorescências e caules, além de demonstrarem potencial biológico para esta espécie. Palavras-chave:Atividade biológica; Óleo essencial; Monoterpeno; Piperaceae; Piperitona. AbstractPlants of the genus Piper are widely used commercially. Piper chimonanthifolium Kunth. is a species with few studies on chemistry and biological activities. Essential oils of other species of this genus show good biological activities, especially against microorganisms. This work presents a comparative analysis of chemical composition of essential oils and hydrolates of leaves, inflorescences and stems of this specie. Samples were obtained by co-distillation and analyzed by gas chromatography-mass spectrometry (GC-MS). The samples were composed of monoterpenes and sesquiterpenes, with predominance of monoterpenes. Piperitone, a monoterpene with important biological activities, was the most important substance and in addition to this compound, L-linalool, cis-β-ocimene, trans-β-ocimene, 1-phellandrene, α-pinene, limonene, and spathulenol stood out. Some of these substances can exhibit a variation in the composition according to environmental factors or may be biological control agents, demonstrating ecological importance. The chemical characterization showed chemical differences between leaves, stems and inflorescences and demonstrated biological potential for this species.

The Aedes aegypti mosquito is one of the major vectors of arboviruses. These diseases have re-emerged and the insecticides used nowadays are toxic to mammals and environment and have only been effective in the short-term. In this context, natural products are an alternative. The genus Piper has many active compounds against arthropods, including neolignans. The present study evaluated the larvicidal potential of the n-hexanic extract of Piper solmsianum and eupomatenoid-6, identified by GC-MS and NMR techniques, from this extract against Ae. aegypti. The crude extract (100 μg/mL) killed 80% and 98.3% of larvae in the first and third day, respectively. Eupomatenoid-6 exhibited LD of 19.33 μM and LD of 28.68 μM and was then assayed in human fibroblast cells (MRC5), showing an IC of 39.30 μM with estimated LD of 42.26 mmol/kg. Our results indicate eupomatenoid-6 as a potent insecticide with relatively low toxicity for mammals.

The present review aims to summarize extraction and isolation methods and biological activities of the different types of neolignans covering the period from 1968 to January 2016.

Oral squamous cell carcinoma (OSCC) is a worldwide public health problem, with high morbidity and mortality rates. The development of new drugs to treat OSCC is paramount. Piper plant species have shown many biological activities. In the present study, we show that dichloromethane partition of Piper cernuum (PCLd) is nontoxic in chronic treatment in mice, reduces the amount of atypia in tongues of chemically induced OSCC, and significantly increases animal survival. To identify the main active compounds, chromatographic purification of PCLd was performed, where fractions 09.07 and 14.05 were the most active and selective. These fractions promoted cell death by apoptosis characterized by phosphatidyl serine exposition, DNA fragmentation, and activation of effector caspase-3/7 and were nonhemolytic. LC–DAD–MS/MS analysis did not propose matching spectra for the 09.07 fraction, suggesting compounds not yet known. However, aporphine alkaloids were annotated in fraction 14.05, which are being described for the first time in P. cernuum and corroborate the observed cytotoxic activity. Putative molecular targets were determined for these alkaloids, in silico, where the androgen receptor (AR), CHK1, CK2, DYRK1A, EHMT2, LXRβ, and VEGFR2 were the most relevant. The results obtained from P. cernuum fractions point to promising compounds as new preclinical anticancer candidates.