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.

Phytochemical constituents from Salsola tetrandra

The new norisoprenoid 3beta-hydroxy-5alpha,6alpha-epoxy-beta-ionone-2alpha-O-beta-d-glucopyranoside (1) and the long-chain hydroxy fatty acids 9,12,13-trihydroxyoctadeca-10(E),15(Z)-dienoic acid (2) and 9,12,13-trihydroxyoctadeca-10(E)-dienoic acid (3) were isolated from Salsola tetrandra aerial parts, together with 3,4,5-trimethoxyphenyl-beta-d-glucopyranoside (4), 9-hydroxylinaloyl glucoside (5), taxiphyllin (6), trans-N-feruloyltyramine (7), and S-(-)-trans-N-feruloyloctopamine (8). Their structures were elucidated by extensive spectroscopic analysis and chemical methods. Compounds 6 and 8 displayed mild antibacterial activity against Staphylococcus aureus, whereas compound 6 showed the highest activity in the Artemia salina bioassay.