The essential oils of seven aromatic plants from Córdoba, San Luis and San Juan Provinces (Argentina) were isolated by steam distillation and analysed by a gas chromatography/mass spectrometry technique. The oils were screened for cytotoxicity and in vitro inhibitory activity against herpes simplex virus type 1 (HSV-1), dengue virus type 2 (DENV-2) and Junin virus (JUNV) by a virucidal test. The oils showed a variable virucidal action according to the virus. The better relationship between cytotoxicity and antivirus action was observed with the essential oils of Heterothalamus alienus and Buddleja cordobensis against JUNV, with virucidal concentration 50% (VC50) values of 44.2 and 39.0 ppm and therapeutic indices (cytotoxicity to virucidal activity ratio) of 3.3 and 4.0, respectively. The inhibitory action was exerted by a direct interaction of virions with the oils. Virions inactivated with B. cordobensis and H. alienus essential oil were not affected in their ability to bind to the host cell. The therapeutic indices shown by these essential oils in toto were very modest, but given the complexity of their chemical composition the future identification of the precise active principle may allow the elimination of cytotoxic components and increase the selectivity of the effective compound.

Chemical composition, GC and GC-MS analysis and in vitro antibacterial activity of the essential oils of the aerial parts of Satureja parvifolia (Phil.) Epling collected in San Juan Province Argentine were performed. Twenty six compounds were identified accounting for 94.1% (area %) of the essential oil. The major constituents were piperitone (34.9%), piperitenone (27.3%), cis-piperitenone epoxide (15.0%) and piperitenone oxide (6.0%). The in vitro antimicrobial activity of the essential oil was investigated by the microdilution method, with Cefotaxime as the standard antibiotic against seven Gram-negative and three Gram-positive bacteria. A strongest activity was observed for the essential oil against all Gram negative bacteria assayed, principally Yersinia enterocolítica-PI and Salmonella enteritidis-MI with a MIC value equal to 0.82 mg/ml.

The chemical composition of the essential oils obtained from the leaves stage (S1) and leaves and flowers (S2) in the flowering stage of Heterothalamus alienus (Spreng.) Kuntze from Argentina were examined by combined GC and GC-MS analysis. The oil obtained from H. alienus was characterized by the presence of β β β β β -pinene (S1, 35.5%; S2, 65.0%), spathulenol (S1, 10.7%; S2, 3.2%) and germacrene D (S1, 6.8%; S2, 2.4%) as the major constituents. Copyright