Recebido em 17/11/03; aceito em 17/5/04; publicado na web em 9/9/04 THE Baccharis GENUS (ASTERACEAE): CHEMICAL, ECONOMIC AND BIOLOGICAL ASPECTS. The Baccharis genus is represented by more than 500 species distributed mainly in the tropical areas of South America. Many of them are extensively used in folk medicine in the treatment or prevention of anemias, inflammations, diabetes and stomach, liver and prostate diseases. Phytochemical and biological investigations in about 120 species resulted mainly in the isolation of clerodane and labdane diterpenes and flavonoid aglicones with the flavone unit being the most frequent.Keywords: Baccharis; flavonoids; terpenes. INTRODUÇÃOA família Asteraceae é o grupo sistemático mais numeroso dentro das Angiospermas, compreendendo cerca de 1.100 gêneros e 25.000 espécies. São plantas de aspecto extremamente variado, incluindo principalmente pequenas ervas ou arbustos e raramente ár-vores 1 . Cerca de 98% dos gêneros são constituídos por plantas de pequeno porte, e são encontradas em todos os tipos de habitats, mas principalmente nas regiões tropicais montanhosas na América do Sul 2 .Plantas dessa família são extensivamente estudadas quanto a sua composição química e atividade biológica, sendo que algumas têm proporcionado o desenvolvimento de novos fármacos, inseticidas, entre outros 3 . Dentre inúmeras plantas da família Asteraceae utilizadas na medicina caseira está a Artemisia absinthium, uma erva de sabor amargo conhecida popularmente como losna, com benéficas funções digestivas, usada também na fabricação da bebida absinto 2 . Inúmeros trabalhos científicos realizados com espécies da família Asteraceae apresentaram o isolamento de uma variedade de metabólitos secundários com destaque aos flavonóides, alocados como importantes marcadores quimiotaxonômicos 4 , além de sua reconhecida importância para a medicina, no tratamento e prevenção de várias doenças 5 .O gênero Baccharis (tribo Astereae) está representado por mais de 500 espécies distribuídas principalmente no Brasil, Argentina, Colômbia, Chile e México, ocupando as regiões mais elevadas 6,7 . A alta concentração de espécies no Brasil e nos Andes indica que uma dessas áreas é o provável centro de origem desse gênero 8 . No Brasil estão descritas 120 espécies de Baccharis, com a maior parte delas localizadas na região sudeste do País 9 . Estima-se em 100 as espécies na Argentina 10 , 28 no México 11 e cerca de 40 na Colômbia, constituindo um dos mais importantes grupos de plantas neste país 12,13 , das quais 38% são endêmicas 14,15 .As espécies do gênero Baccharis são no geral arbustos como a carqueja, a vassoura ou vassourinha e medem em média de 0,5 a 4,0 m de altura. Apresentam elevado valor sócio-econômico, com ampla dispersão nos estados de Santa Catarina, Paraná, São Paulo e Rio Grande do Sul, entre outras regiões do país, onde grande núme-ro delas são utilizadas na medicina popular para controle ou tratamento de várias doenças. São consumidas principalmente na forma de chás com indicações para males do estômago,...

The antioxidant activity of extracts and fractions of six vegetal species from the Brazilian Atlantic Forest were determined. The total antioxidant activity was assessed based on the scavenging activity of the stable DPPH free radical. Eight extracts or fractions of plants showed significant DPPH scavenging activity (IC 50 10.0 mg=mL) compared with the values obtained for ascorbic acid (IC 50 ¼ 8.4 mg=mL) and gallic acid (IC 50 ¼ 2.6 mg=mL). The extracts or fractions were as follows: ethanol extracts of leaves, flowers, and stems of Baccharis illinita DC., ethanol extracts of leaves and stems of B. platypoda DC., hydroalcoholic extract and ethyl acetate fraction of leaves of Cyathea phalerata Mart. and hydroalcoholic extract of bark of Trichilia catigua A. Juss. Seven flavonoids present in the plant extracts were also investigated. The most active compounds were taxifolin, quercetin, and luteolin, which possess the catechol group 3 0 ,4 0 -diOH. In addition, the total phenolic or flavonoid contents of these extracts and fractions were evaluated. The phenolic content of the sample was determined using Folin-Ciocalteu reagent and varied from 489.07 to 11.29 mg=g dry weight expressed as gallic acid equivalents (GAE). The total flavonoid concentrations, detected using 2% aluminum chloride, varied from 61.82 to 5.6 mg quercetin equivalents (QE)=g dry weight. These results suggest that the level of antioxidant activity in these plants varies by a great extent. They also suggest that the phenolic content in these plants provides substantial antioxidant activity. The flora of Brazil appears to be a rich and interesting source for supplementary ethnomedical and phytochemical studies.

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The essential oils of the leaves of Eugenia brasiliensis, Eugenia beaurepaireana, and Eugenia umbelliflora were analyzed by GC-MS. The major compounds found in the oil of E. brasiliensis were spathulenol (12.6%) and tau-cadinol (8.7%), of E. beaurepaireana were beta-caryophyllene (8.0%) and bicyclogermacrene (7.2%), and of E. umbelliflora were viridiflorol (17.7%) and beta-pinene (13.2%). These oils were assayed to determine their antibacterial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. All of the oils analyzed showed antibacterial activity, ranging from moderate to strong, which was most accentuated for the E. umbelliflora and E. brasiliensis oils, which strongly inhibited the growth of S. aureus giving values of MIC = 119.2 and 156.2 microg/mL, respectively.

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Inflammatory skin disorders, such as psoriasis and atopic dermatitis, are very common in the population; however, the treatments currently available are not well tolerated and are often ineffective. Averrhoa carambola L. (Oxalidaceae) is an Asian tree that has been used in traditional folk medicine in the treatment of several skin disorders. The present study evaluates the topical anti-inflammatory effects of the crude ethanolic extract of A. carambola leaves, its hexane, ethyl acetate, and butanol fractions and two isolated flavonoids on skin inflammation. Anti-inflammatory activity was measured using a croton oil-induced ear edema model of inflammation in mice. Topically applied ethanolic extract reduced edema in a dose-dependent manner, resulting in a maximum inhibition of 73 ± 3% and an ID50 value of 0.05 (range: 0.02–0.13) mg/ear. Myeloperoxidase (MPO) activity was also inhibited by the extract, resulting in a maximum inhibition of 60 ± 6% (0.6 mg/ear). All of the fractions tested caused inhibition of edema formation and of MPO activity. Treatment with the ethyl acetate fraction was the most effective, resulting in inhibition levels of 75 ± 5 and 54 ± 8% for edema formation and MPO activity, respectively. However, treatment of mice with isolated compounds [apigenin-6-C-β-l-fucopyranoside and apigenin-6-C-(2″-O-α-l-rhamnopyranosyl)-β-l-fucopyranoside] did not yield successful results. Apigenin-6-C-(2″-O-α-l-rhamnopyranosyl)-β-l-fucopyranoside caused only a mild reduction in edema formation (28 ± 11%). Taken together, these preliminary results support the popular use of A. carambola as an anti-inflammatory agent and open up new possibilities for its use in skin disorders.

A bioanalytical platform combining magnetic ligand fishing for α-glucosidase inhibition profiling and HPLC-HRMS-SPE-NMR for structural identification of α-glucosidase inhibitory ligands, both directly from crude plant extracts, is presented. Magnetic beads with N-terminus-coupled α-glucosidase were synthesized and characterized for their inherent catalytic activity. Ligand fishing with the immobilized enzyme was optimized using an artificial test mixture consisting of caffeine, ferulic acid, and luteolin before proof-of-concept with the crude extract of Eugenia catharinae. The combination of ligand fishing and HPLC-HRMS-SPE-NMR identified myricetin 3-O-α-l-rhamnopyranoside, myricetin, quercetin, and kaempferol as α-glucosidase inhibitory ligands in E. catharinae. Furthermore, HPLC-HRMS-SPE-NMR analysis led to identification of six new alkylresorcinol glycosides, i.e., 5-(2-oxopentyl)resorcinol 4-O-β-d-glucopyranoside, 5-propylresorcinol 4-O-β-d-glucopyranoside, 5-pentylresorcinol 4-O-[α-d-apiofuranosyl-(1→6)]-β-d-glucopyranoside, 5-pentylresorcinol 4-O-β-d-glucopyranoside, 4-hydroxy-3-O-methyl-5-pentylresorcinol 1-O-β-d-glucopyranoside, and 3-O-methyl-5-pentylresorcinol 1-O-[β-d-glucopyranosyl-(1→6)]-β-d-glucopyranoside.

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