Volatile oils from the leaves of Verbenaceae species Aloysia virgata, Lantana camara, Lantana trifolia, Lantana montevidensis, Lippia brasiliensis and Lippia sericea were investigated for its chemical composition and antibacterial activity. The volatile oils were characterized by a high content of sesquiterpenes of which (E)-caryophyllene (10-35%), germacrene-D (5-46%) and bicyclogermacrene (7-17%) were the major components for all studied species. For the flowers, a higher concentration of monoterpenes was observed for the species L. camara, L. trifolia and L. brasiliensis. These compounds probably act as attractive to specific pollinators. The volatile oils from A. virgata was the most active, exhibiting moderate antimicrobial activity against the bacteria Staphylococcus aureus, Bacillus cereus and Escherichia coli.

A reação de cicloadição [4+3] entre o furano e o cátion oxialílico, gerado in situ a partir da 2,4-dibromopentan-3-ona, forneceu o 2alfa,4alfa-dimetil-8-oxabiciclo[3.2.1]oct-6-en-3-ona (1). A oxidação catalítica do oxabiciclo 1 com tetróxido de ósmio em presença de peróxido de hidrogênio em excesso levou à formação do acetonídeo 10, a partir do qual foram obtidos os álcoois 2, 11-15, com rendimentos de 23-86%. O tratamento dos álcoois 11-13 com cloreto de tionila, em presença de piridina, resultou nos respectivos alquenos 17 (94%), 18 (89%) e 19 (80%). A atividade herbicida dos compostos foi avaliada sobre o desenvolvimento do sistema radicular de Sorghum bicolor L. e Cucumis sativus L., nas concentrações de 100 e 250 ppm.

The [4+3] cycloaddition between furan and the oxyallyl cation generated from 2,4-dibromopentan-3-one resulted in the formation of 2alpha,4alpha-dimethyl-8-oxabicyclo[3.2.1]oct-6-en-3-one (1). The catalytic oxidation of 1 with osmium tetraoxide and excess hydrogen peroxide resulted in the formation of acetonide 10. This was further converted into the alcohols 2, 11-15 with 23-86% yield. The alcohols 11-13 were treated with thionyl chloride in pyridine, forming their respective alkenes 17 (94%), 18 (89%) and 19 (80%). The herbicidal activity of the compounds was evaluated on the development of radicle of Sorghum bicolor L. and Cucumis sativus L., at the concentration of 100 and 250 ppm.