Detection of Water and Sediments Pollution of An Arid Saltern (Sfax, Tunisia) by Coupling the Distribution of Microorganisms With Hydrocarbons

We investigated the coupling of abundance of bacteria, phytoplankton and ciliates with hydrocarbons in the surface water and sediments of five interconnected ponds in the arid Sfax solar salterns. This study aimed at determining the potential sources of hydrocarbons and the effects of salinity gradients on microorganism metabolism. Hydrocarbon analysis was performed by gas chromatography (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS). The GC-FID allowed the detection of aliphatic hydrocarbons and n-alkanes ranging from n-C₁₃ to n-C₃₀. Total aliphatic hydrocarbon concentrations varied from 92.5 mg. l^?1 in the first pond (having marine characteristics) to 661.1 mg. l^?1 in the last pond (crystallizer) (316.8?±?120.1 mg. l^?1) for water samples and from 26.7 to 127.8 μg. g^?1 dry weight for sediment samples. The GC-MS enabled us to detect halogenated hydrocarbons (bromoalkanes and chloroalkanes) and n-alkenes. The distribution of n-alkanes indices coupled to several environmental factors suggests that a major fraction of hydrocarbons resulted from both prokaryotic (bacteria) and eukaryotic (protists) developments. A low hydrocarbon fraction might be petrogenic.     

Responses of Spodoptera littoralis larvae to Tunisian plant extracts and to neo-clerodane diterpenoids isolated from Ajuga pseudoiva leaves

Thirteen plants growing in Tunisia were tested against Spodoptera littoralis larvae. From the acetone extract of Ajuga pseudoiva leaves, showing interesting antifeedant activity, three new (1-3) and two known (4-5) active clerodane diterpenoids were isolated following a bioassay-guided chromatography.     

Antioxidant compounds from Ebenus pinnata

Activity-guided fractionation of the methanol extract of Ebenus pinnata aerial parts led to the isolation of ombuoside (1), kaempferol 3-O-rutinoside (2), rutin (3), catechin (4), and picein (5), along with beta-sitosterol and beta-sitosterol glucoside. Compounds 1-4 showed significant antioxidant activity in the DPPH, and TEAC, reducing power assays.     

Extraction, identification and dyeing studies of Isosalipurposide, a natural chalcone dye from Acacia cyanophylla flowers on wool

A chalcone compound Isosalipurposide 1 was qualitatively isolated from Acacia cyanophylla yellow flowers. The dyeing of wool fabrics with this chalcone compound as a natural dye has been studied. The effect of dye bath pH and dyeing temperature were investigated. The obtained shades were bright with generally a good fastness. A post-mordanting method was used in the dyeing of wool with this chalcone dye. It was found that, generally, mordanting improved light fastness especially in the case of zinc sulphate.