Chemical composition and antimicrobial activity of volatile compounds of Tamarix boveana (Tamaricaceae).

The chemical composition of the Tamarix boveana volatile oils obtained from the whole aerial part, flowers, leaves and stems by steam distillation was analysed using gas chromatograph (GC)-flame ionization detectors (FID) and GC-MS. Sixty-two components were identified. Hexadecanoic acid (18.14%), docosane (13.34%), germacrene D (7.68%), fenchyl acetate (7.34%), Benzyl benzoate (4.11%) were found to be the major components in the whole aerial parts. This composition differed according to the tested part: 2.4 Nonadienal was the main compound in the flowers (12.13%) while germacrene D was the major component in leaves (31.43%) and hexadecanoic acid in the stems (13.94%). To evaluate in vitro antimicrobial activity, all volatile oils were tested against six Gram-positive and Gram-negative bacteria and four fungi. The T. boveana volatile oils exhibited an interesting antibacterial activity against all strains tested except Pseudomonas aeruginosa but no antifungal activity was detected.

Chemical composition and antimicrobial activity of volatile components from capitula and aerial parts of Rhaponticum acaule DC growing wild in Tunisia.

The chemical composition of the volatile fractions obtained by steam distillation from the capitula (C) and the aerial parts of Rhaponticum acaule DC were analysed by GC-MS. From the 57 identified constituents, representing 95.5% and 96.3% of the two oils, respectively, methyl eugenol, epi-13 manool, beta-ionone, beta-bisabolol, 1-octadecanol, phytol and farnesyl acetate were found to be the main components. Furthermore, the oils were tested against six Gram-positive and Gram-negative bacteria and four phytopathogenic fungi. It was found that oils from both parts of R. acaule, and especially that of C, exhibited interesting antibacterial activity, but no antifungal activity was observed.

Bio-insecticidal activities of halophytic plant extracts against Tribolium confusum (Coleoptera, Tenebrionidae).

Salt marsh plants were tested for their insecticidal activities against larvae of the confused flour beetle Tribolium confusum (Tenebrionidae). 16 aerial part extracts were obtained using organic solvents of increasing polarity and tested for their anti-feedant and toxicity effects. Responses varied with plant material and extract type. Ethyl acetate extracts of F. laevis, S. echioides and. T. boveana and petroleum ether extract of F. laevis presented, anti-feedant property. However, S. fructicosa seemed to be attractive to the tested flour beetle. Mortalities of 97, 87, 97 and 80% were observed by using respectively ethyl acetate extracts of F. laevis, S. echioides and T. boveana and petroleum ether extract of F. laevis, when applied at a dose of 1%, mixed with the insect diet. This preliminary study showed that F. laevis, S. echioides and T. boveana presented potential bio-insecticidal activity with ethyl acetate extracts, similar result was found with petroleum ether extract of F. laevis. More complementary studies are needed for the use of these extracts to control T. confusum.