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SÃO PAULO. The essential oils from the leaves of six species of the Baccharis genus (B. dracunculifolia, B. microdonta, B. regnelli, B. schultzii, B. trimera, and B. uncinella), collected in the "Campos de Altitude" of the Atlantic Forest (SP), were extracted using hydrodistillation procedures and analyzed by GC and GC/MS. There was a predominance of sesquiterpenes in all studied oils as β-elemene in B. dracunculifolia and B. regnelli, α-humulene in B. trimera, γ-gurjunene in B. schultzii, bicyclogermacrene in B. regnelli, δ-cadinene in B. regnelli and B. uncinella, spathulenol in B. schultzii, caryophyllene oxide in B. microdonta and guaiol in B. uncinella. However, a high amount of monoterpenes was also observed in B. uncinella (α-pinene), B. regnelli (δ-car-3-ene) and B. schultzii (limonene). The chemical compounds of the essential oils of B. schultzii, B. regnelli and B. microdonta are described for the first time in this work.Keywords: Asteraceae; Baccharis ssp.; essential oil composition. INTRODUÇÃOO gênero Baccharis L. (Asteraceae), caracterizado botanicamente por apresentar espécimes na forma de arbustos ou até mesmo como árvores pequenas, conta com aproximadamente 400 espé-cies distribuídas predominantemente na América do Sul, sendo 120 delas de ocorrência brasileira.1 Tais espécies são encontradas principalmente no sul e sudeste do país, principalmente nas regiões de Campos de Altitude que consistem em biomas que compreendem uma série de formações fresco-úmidas, dominadas por gramíneas e arbustos, restritas às regiões mais elevadas (que começam em alturas de 1800-2000 m) da região da Mata Atlântica. 2 Diversas espécies de Baccharis são usadas na medicina popular para tratamento de dor de cabeça, diabetes e desordens hepáti-cas, principalmente devido ao acúmulo de metabólitos secundári-os bioativos, tais como terpenóides, flavonóides, cromenos, etc. RESULTADOS E DISCUSSÃOOs rendimentos dos óleos essenciais obtidos das folhas de B. dracunculifolia, B. microdonta, B. regnelli, B. uncinella, B. schultzii e B. trimera variaram entre 0,08-0,21%. Foram identificados 67 compostos (que correspondem a 70-92% do conteúdo total dos óle-os), como mostrado na Tabela 1.Comparativamente, a composição química dos óleos essenciais dessas seis espécies de Baccharis revelou uma proporção elevada de monoterpenos em B. schultzii (34,93%), em B. regnelli (35,79%) e em B. uncinella (21,34%), enquanto que esses compostos são minoritários apenas em B. dracunculifolia (0,30%). As quantidades de monoterpenos nos óleos de B. microdonta e de B. trimera mostraram-se similares, com proporções de 9,23 e 7,20%, respectivamente. Por outro lado, os hidrocarbonetos sesquiterpênicos foram mais abundantes em B. dracunculifolia (63,10%), B. regnelli (37,76%) e B. trimera (53,52%), enquanto que no óleo de B. microdonta os sesquiterpenos oxigenados foram predominantes (49,91%). Em B. schultzii e em B. uncinella, as proporções relativas de hidrocarbonetos sesquiterpênicos e de sesquiterpenos oxigenados mostraram-se similares (29,33/28,30% e 2...

Metalloproteases play a fundamental role in snake venom envenomation inducing hemorrhagic, fibrigen(ogen)olytic and myotoxic effects in their victims. Several snake venoms, such as those from the Bothrops genus, present important local effects which are not efficiently neutralized by conventional serum therapy. Consequently, these accidents may result in permanent sequelae and disability, creating economic and social problems, especially in developing countries, leading the attention of the World Health Organization that considered ophidic envenomations a neglected tropical disease. Aiming to produce an efficient inhibitor against bothropic venoms, we synthesized different molecules classified as quinolinones - a group of low-toxic chemical compounds widely used as antibacterial and antimycobacterial drugs - and tested their inhibitory properties against hemorrhage caused by bothropic venoms. The results from this initial screening indicated the molecule 2-hydroxymethyl-6-methoxy-1,4-dihydro-4-quinolinone (Q8) was the most effective antihemorrhagic compound among all of the assayed synthetic quinolinones. Other in vitro and in vivo experiments showed this novel compound was able to inhibit significantly the hemorrhagic and/or proteolytic activities of bothropic crude venoms and isolated snake venom metalloproteases (SVMPs) even at lower concentrations. Docking and molecular dynamic simulations were also performed to get insights into the structural basis of Q8 inhibitory mechanism against proteolytic and hemorrhagic SVMPs. These structural studies demonstrated that Q8 may form a stable complex with SVMPs, impairing the access of substrates to the active sites of these toxins. Therefore, both experimental and structural data indicate that Q8 compound is an interesting candidate for antiophidic therapy, particularly for the treatment of the hemorrhagic and necrotic effects induced by bothropic venoms.

Comparative gas chromatographic analyses of airborne volatiles produced by males and females of the sugarcane weevil Sphenophorus levis, showed one male-specific compound. Gas chromatography-mass spectrometry data indicated an aliphatic alcohol that was identified as 2-methyl-4-octanol. Both optical isomers were synthesized in five steps by employing commercially available (R)- and (S)-2.2-dimethyl-1,3-dioxolane-4-methanol as starting material. Enantiomeric resolution by gas chromatography with a chiral column demonstrated that the natural alcohol possessed the S configuration. Preliminary indoor observations suggested that the alcohol elicited aggregation behavior among adults. The same compound has been previously described as an aggregation pheromone in several other curculionid species.

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