Suzana Leitão

The polyisoprenylated benzophenones machuone and clusiachromene A have been isolated from the fruits of Clusia columnaris. The hexane extract of the young branches with leaves afforded a new euphane derivative, whose structure was elucidated by spectroscopic methods. On the contrary, the most polar EtOAc and ButOH extracts were constituted of flavonoid C-glucosides (isovitexin, vitexin and vitexin-2"-xyloside) and seven biflavonoids of the so-called Garcinia group.

Forty eight ethanolic crude extracts and fractions (hexane, dichloromethane, ethyl acetate and n-butanol) from ten Brazilian plants (Leguminosae, Monimiaceae and Verbenaceae), 1 from Costa Rica (Verbenaceae) and 1 from Argentina (Verbenaceae) were screened for anti-mycobacterium activity against Mycobacterium tuberculosis (ATCC-27294H37Rv), by the Alamar Blue test, at a fixed concentration of 100 µg/mL. Out of the forty eight, seven were active at this concentration, corresponding to Lantana trifolia (hexane and dichloromethane extracts from leaves), Vitex cooperi (methanol:water, 1:1 extract from barks), Lippia lacunosa (hexane and dichloromethane extracts from leaves) and Lippia rotundifolia (hexane and dichloromethane extracts from leaves), all from the Verbenaceae family.

Lippia lacunosa and L. rotundifolia (Verbenaceae) are two Brazilian species of complex taxonomic delimitation. The composition of the essential oils from leaves and flowers of these plants was investigated by gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC-MS) analysis. The major components of the essential oils of flowers and leaves of L. lacunosa were: myrcene (14.7% and 11.9%), myrcenone (45.2% and 64.2%), Z-ocimenone (5.7% and 5.2%), and E-ocimenone (14.7% and 4.1%), respectively; whereas in L. rotundifolia (flowers and leaves) were a-pinene (8.7% and 1.8%), myrcene (5.1% and 3.6%), limonene (26.0% and 7.9 %), cis-pinocamphone (4.5% and 3.1%) and myrtenal (22.3% and 16.7%), respectively. The essential oils from L. lacunosa exhibited a strong and pleasant mango aroma, which was related to the presence of myrcene and myrcenone. The marked differences in the chemical composition of their essential oils may represent a powerful tool for the botanical classification.

O extrato bruto em acetona/ água das folhas de Pseudopiptadenia contorta foi purificado rendendo frações e substâncias puras. A atividade antioxidante foi avaliada para o extrato e frações, empregando-se o teste químico do DPPH. As frações contendo taninos condensados e substâncias fenólicas de baixo peso molecular mostraram ser as responsáveis pela atividade antioxidante do extrato bruto das folhas de P. contorta.

Thirty-six plant extracts from the brazilian Atlantic Forest were tested for their antimycobacterial activity against Mycobacterium tuberculosis H37Rv and M. kansasii, using the method REMA in seriate concentrations of 100 to 0.20 µg/mL. Among the thirty six extracts tested, five were active against M. tuberculosis, and three of these extracts also showed activity against M. kansasii. Cytotoxicity test with VERO cells was performed with the five extracts active against M. tuberculosis. Only the extract of Peschiera affinis was identified as non-toxic in the concentration of 100µg/mL.

Lippia species from Cadeia do Espinhaço (MG, Brazil), were collected and established at the Botanical Experimental Station, Juiz de Fora, MG. The flowering of plants was evaluated in both natural and controlled conditions. Germination test was accomplished with seeds obtained from natural conditions. The rooting of cuttings was evaluated in plants cultivated in the Botanical Experimental Station. The majority of species blossomed either in the dry or in the rainy seasons. Only one species blooms in both seasons. At controlled conditions, the flowering period increased in species that flourish in the summer. Some species presented better germination with fresh collected seeds while others when the seeds were stored, evidencing both viability loss and seed dormancy. GA3 stimulates the germination in some species, while it inhibited or not influenced on others. Some species germinate better in the darkness, while others under white light. Some of them germinate in the light or in the darkness. Adventitious roots formation in cuttings of wild species was very low and did not vary in response to season variation and auxin concentration. On the other hand, rooting of cuttings of L. alba (Mill.) N.E. Br. varied in response both to season variation and to auxin types and concentration. This is the first report on physiological reproductive aspects of endemic Lippia species from the Cadeia do Espinhaço. The results indicate the possibility to use seeds in the propagation of wild Lippia species and, they also show that reproduction through conventional vegetative propagation techniques presents quite reduced efficiency.

A new ecdysteroid, 26-hydroxypinnatasterone (1), together with 20-hydroxyecdysone, was isolated from the stem barks of Vitex cymosa. 20-Hydroxyecdysone, ajugasterone C, ajugasterone C monoacetonide and turkesterone were isolated from the branches of V. polygama. The structure of 1 was determined by spectroscopic methods.