Chemical composition, antifungal and antibiofilm activities of essential oils from Glycyrrhiza foetida (Desf.) growing in Tunisia.

This study was designated to investigate the chemical composition, the antifungal activity and antibiofilm properties of Glycyrrhiza foetida (Desf.) growing in Tunisia and recognized for its pharmacological and therapeutic effects. The chemical analysis of essential oil samples prepared via hydrodistillation of the aerial parts was performed by gas chromatography-mass spectrometry (GC-MS). Moreover, the antifungal activity of G. foetida essential oil was developed against three dermatophyte strains, two molds and Candida spp. yeasts using the broth microdilution assay. According to the percentages, the main constituents are δ-cadinene (13.9%), (E)-caryophyllene (13.2%) and γ-cadinene (8.3%). The efficiency of the essential oil in inhibiting Candida albicans biofilms formation was also evaluated in terms of inhibitory percentages. The results showed that C. albicans and Microsporum canis were the most sensitive to G. foetida essential oil with a complete inhibition at 0.4 and 0.2 mg ml-1 , respectively. Candida albicans biofilm development was reduced by 80% by the volatile oil at a concentration of 0.8 mg ml-1 . The essential oil of G. foetida has a promising role in the control of fungal agents with medical interest and in inhibition of Candida biofilm development.

Adsorption of nitrate, phosphate, nickel and lead on soils: Risk of groundwater contamination.

Agricultural activities pose a significant risk of groundwater pollution. Indeed, fertilizers and treated wastewater used for irrigation are, in part, responsible for the deterioration of groundwater and surface water quality. In some cases, soil may provide a protective barrier against this pollution, but this depends on the nature of the soil and the contaminant. This work presents the effect of the soil clay content on the retention of four different pollutants in order to evaluate the risk they represent for the groundwater. These contaminants are generated by two main agricultural activities: 1/soil fertilization with phosphate and nitrate fertilizers and 2/irrigation with treated wastewater in which heavy metals such as nickel and lead are persistent. Firstly, the characterization of the sand and clay used in this work was performed and showed a cation exchange capacity of 1.24 and 25 meq/100 g, a specific surface area of 0.12 and 67.98 m2/g and a percentage of organic matter of 0.15 and 2% for sand and clay, respectively. The retention isotherms on all pollutants and the Langmuir, Freundlich, Freundlich-Langmuir, Hill and Koble-Corrigan models were applied. All experimental isotherms have been successfully adjusted using the Koble-Corrigan expression. The amounts of nitrates, phosphates, nickel and lead retained by the sandy soil, for an initial pollutant concentration equal to 1 meq/L, were evaluated at 0.29, 3.89, 5.97 and 8.56 µeq/g respectively. In contact with a soil containing 30% clay, the adsorbed amounts were estimated at 3.55, 15.00, 6.97 and 8.79 µeq/g for nitrates, phosphates, nickel and lead, respectively. These results mean that the pollutants that pose the greatest risk of groundwater contamination when carried by water through sandy soil are classified as follows lead < nickel < phosphate < nitrate while for a clayey soil, the classification becomes as follows: phosphates < lead < nickel < nitrate.

Sorption of paracetamol onto biomaterials.

Pharmaceutical residues released into the environment are posing more and more public health problems. It is worthwhile to study the retention of pharmaceuticals residues by adsorption on solid supports. Batch sorption experiments are intended to identify the adsorption isotherms of the pharmaceutically active ingredient on the biomaterials. The results obtained in this study have shown that the retention possibilities of these compounds by bio-adsorbents (clay and sand) are not significant. The negligible sorption for these media is explained by the low hydrophobicity of paracetamol (Log K(ow) = 0.46). The retention of paracetamol on the dehydrated sewage sludge and on Posidonia oceanica showed a relatively significant adsorption with a maximal quantity of 0.956 mg g(-1) and 1.638 mg g(-1) for the dehydrate sludge and P. oceanica, respectively. On the other hand, the study of paracetamol retention on the powdered activated carbon showed a high adsorption capacity of about 515.27 mg g(-1). Isotherm data show a good fit with Langmuir's model. An infrared analysis is carried out. It shows identical bands before and after adsorption, with some modifications.

Essential Oil Composition, Antioxidant, Cytotoxic and Antiviral Activities of Teucrium pseudochamaepitys Growing Spontaneously in Tunisia.

The chemical composition, antioxidant, cytotoxic and antiviral activities of the essential oil obtained by hydrodistillation from the aerial parts of Teucrium pseudochamaepitys (Lamiaceae) collected from Zaghouan province of Tunisia are reported. The essential oil was analyzed by gas chromatography equipped with a flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC/MS). Thirty-one compounds were identified representing 88.6% of the total essential oil. Hexadecanoic acid was found to be the most abundant component (26.1%) followed by caryophyllene oxide (6.3%), myristicin (4.9%) and α-cubebene (3.9%). The antioxidant capacity of the oil was measured on the basis of the scavenging activity to the stable 2,2-diphenyl-1-picrylhydrazyl (DPPH). The IC50 value of the oil was evaluated as 0.77 mg·mL(-1). In addition, the essential oil was found to possess moderate cytotoxic effects on the HEp-2 cell line (50% cytotoxic concentration (CC50)=653.6 µg·mL(-1)). The potential antiviral effect was tested against Coxsackievirus B (CV-B), a significant human and mouse pathogen that causes pediatric central nervous system disease, commonly with acute syndromes. The reduction of viral infectivity by the essential oil was measured using a cytopathic (CPE) reduction assay.

Dyeing of advanced denim fabrics (blend of cotton/bicomponent polyester filaments) using different processes and artificial intelligence method.

Denim clothes are the must-have items of clothing around the world. This kind of fabrics is evolving with the increasing consumer demand in order to keep its place as a versatile article. In this context, this paper contributes to the development and dyeing of a new blend fabric made of cotton fibers and bicomponent polyester filaments (PET/PTT). A comparative study between the mechanical and thermal properties of this fabric and conventional fabrics has confirmed the great interest to use bicomponent (PET/PTT) filaments in the manufacture of denim fabrics; these bicomponent filaments allow to give to wearer the desired elasticity and comfort. For dyeing (cotton/bicomponent polyester filaments) blend fabric, three different processes, using reactive and disperse dyes, were tested and analyzed. These dyeing processes are: two-baths/two-phases, one-bath/two-phases, and one-bath/one-phase processes. In addition, in order to obtain uniform shades between cotton fibers dyed with reactive dyes and bicomponent polyester filaments dyed with disperse dyes, an ant colony algorithm was elaborated to predict the optimal dye recipes. By observing obtained results, the developed algorithm is very effective; it allows to find the combination of reactive dyes necessary to achieve the same shade obtained by the disperse dyes with very small color differences between the two components and without having to make corrections mainly for the one-bath/two-phases process. Indeed, dyeing using the two processes (two baths/two phases and one bath/two phases) presents the best values of color yield (K/S) with almost similar results (ΔECMC(2:1) < < 1). For the one-bath/one-phase process, it presents less significant results; We can observe ΔECMC(2:1) greater than 1 in certain shades. This is due to the strongly pH value (basic pH of 11) of reactive dyeing.

Environmentally friendly dyeing of wool and silk fabrics with natural colorant of turnsole (Chrozophora tinctoria L.).

With the increasing demand for environmentally friendly dyes, natural dye has become an attractive option replacing toxic synthetic dyes. Within the framework of this research, the natural dye of Chrozophora tinctoria L. was extracted using the microwave-assisted extraction method under different operating conditions. The influence of different factors influencing the extraction process (such as pH, extraction time, and microwave power) on the extraction efficiency was investigated by means of a multilevel three-factor design. The suggested model has a high coefficient of determination, indicating high predictability and good approximation. Optimal microwave extraction process conditions were obtained at a value of microwave power equal to 650 W, at a pH of 5 during a period of 3 min. Dyed wool and silk fabrics showed very good washing and light fastness properties.

Acidic and alkaline deep eutectic solvents pre-treatment to produce high aspect ratio microfibrillated cellulose.

This study highlights the microfibrillation potential of three deep eutectic solvents (DES) composed of betaine hydrochloride-urea, choline chloride-urea and choline chloride-monoethanolamine. Cellulose fibres (eucalyptus and cotton) were first treated in DES (100 °C for 4 h) and then ground with an ultra-fine grinder to produce microfibrillated cellulose (MFC). DES pre-treatment especially betaine hydrochloride-urea system has significantly improved the microfibrillation process with reduced energy consumption comparable to that of enzymatic treatment (reference pre-treatment). Long and thin microfibril bundles (widths around 50 nm) and individualised microfibrils (widths between 5 and 10 nm) were obtained. MFC gels and nanopapers were characterised using several techniques. Nanopapers produced from DES treated MFC showed good mechanical properties with Young's modulus higher than 10 GPa. In addition, they exhibited higher quality index (between 73 and 76) than those produced from enzymatic hydrolysis (quality index around 68). DES pre-treatment is a promising way to produce MFC with high aspect ratio.

Impact of the Extraction Method on the Chemical Composition and Antioxidant Potency of Rosmarinus officinalis L. Extracts.

Rosmarinus officinalis L. is a dietary source that produces polyphenols as secondary metabolites. These natural compounds with potent antioxidant abilities are increasingly recommended as a supplement to inhibit oxidative stress. In the current work, we evaluated the impact of the extraction method on the chemical composition of R. officinalis extract, especially on the content of carnosic (CA) and rosmarinic (RA) acids using UPLC-MS-DAD as well as on their antioxidant potency. Four extracts of Tunisian rosemary were obtained from non-conventional extraction techniques:ultrasound-assisted extraction (UAE),supercritical extraction (SFE) and UAE and SFE combined ((UAE-SFE(I), UAE-SFE(II)). The UAE exhibited the best total phenolic compounds (i.e., 85.27 mg GAEg-1), the highest content of CAand RA and the strongest antioxidant abilities (i.e., IC50 = 0.13 mg/mL and EC50 = 0.93 mg/mL for DPPH scavenging test and iron reducing power ability assay). The evaluation of antioxidant activity of UAE inhuman skin fibroblast (HS-68) cell line was carried out after the induction of oxidative stress. The results determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed a strong protective effect against H2O2oxidative stress induction in cells pretreated with UAE. The obtained results allow us to give new insight about the effect of the extraction method on the chemical composition and biological activities of the extract and the importance of the choice of the most appropriate processing technique to prepare rosemary extract with a high antioxidant potency and protective effect against oxidative stress.

Effects of Deep Eutectic Solvents on cellulosic fibres and paper properties: Green "chemical" refining.

This work aims to study the effects of Deep Eutectic Solvents (DES) on cellulosic fibre structure. A focus was made on the induced fibrillation phenomena which could facilitate the further production of microfibrillated cellulose. Three DES of different pH (acid, neutral and alkaline), namely betaine hydrochloride-urea, choline chloride-urea and choline chloride-monoethanolamine, were tested. Eucalyptus and cotton pulps were used to investigate the effects of DES on both hemicelluloses and cellulose. Interestingly, cellulose was esterified during acidic DES treatment. Moreover, an internal and external fibrillation occurred with DES treatment without a great extent of modification in terms of chemical composition, crystallinity and degree of polymerisation. Compared to enzymatic hydrolysis (used as a conventional pre-treatment for cellulose microfibrillation), DES have significantly enhanced the mechanical properties of resulting papers. To conclude, DES treatment can be considered as a soft and green "chemical" refining that could be applied as a pre-treatment for cellulose microfibrillation.

Kinetics study of dyeing bicomponent polyester textiles (PET/PTT) using environmentally friendly carriers.

The biobased carriers o-vanillin, p-vanillin, and coumarin, can be used to dye poly(ethylene terephthalate)/poly(trimethylene terephthalate) (PET/PTT) bicomponent filaments at low temperature without affecting their excellent elasticity and elastic recovery. These ecological carriers, which are free from any toxic product, present an effective solution for obtaining an ecological and economical dyeing process. This paper presents a study of the effects of the kinetics when dyeing bicomponent (PET/PTT) filaments with three disperse dyes having different molecular weights at 100 °C (upon adding ecological carriers) and at a high temperature (130 °C). The physicochemical characterization of bicomponent filaments was done using several techniques, such as SEM, BET and DSC, before carrying out a modelling study. Different models (pseudo first-order, pseudo second-order, Elovich, and intra-particle diffusion models) were used to identify an acceptable dyeing mechanism. The dyeing rate constants, the half dyeing times, and the rise time coefficients were then determined and analyzed. The results of this work explain the adsorption mechanism during the dyeing process of bicomponent (PET/PTT) filaments using ecological carriers and provide an experimental foundation for future research.

Ecological and cleaner process for dyeing bicomponent polyester filaments (PET/PTT) using ecological carriers: analysis of dyeing performance.

Thanks to their excellent properties, bicomponent filaments, in particular, polyethylene terephthalate (PET)/polytrimethylene terephthalate (PTT) are more and more used in stretchable clothing. Despite the researchers' efforts, the dyeing of these filaments still presents several problems which should be resolved. Manufacturers must choose between dyeing polyester under pressure at high temperatures (close to 130 °C) to have less toxic and cheaper textile effluents and/or dyeing at low temperatures (not exceeding 100 °C) which needs the use of toxic carriers. This paper presents a new opportunity and the feasibility of dyeing bicomponent polyester filaments using an economic and clean process at a temperature equal to 100 °C and by replacing toxic carriers by ecological ones. Three kinds of ecological carriers, namely o-Vanillin, p-Vanillin and Coumarin, are used to improve the dyeing performance of bicomponent filaments with three disperse dyes having different molecular weights. They were compared to three conventional ones largely used in industry. The effect of each carrier on dyeing performance (dye bath exhaustion, color strength and CIELab coordinates) was then investigated. The obtained results prove that ecofriendly carriers constitute a good solution to replace the toxic ones and allow to obtain the same, or even better dyeing performance and fastness properties.

Chemical Composition and Antioxidant Activity of Essential Oils and Hexane Extract of Onopordum arenarium from Tunisia.

In the present study, volatile oils from Onopordum arenarium fresh flowers and stems were obtained by hydrodistillation and the non-polar aerial part hexane extract was prepared using a Soxhlet apparatus. The constituents of different organs were identified for the first time by gas chromatography equipped with flame ionization detector and gas chromatography coupled to mass spectrometry. A total of 29 and 25 compounds were identified constituting over 91.6 and 89.2% of the whole constituents from flower and stem volatile oils, respectively. Both organs were constituted mainly of long-chain hydrocarbons (23.3-36.4%) followed by oxygenated long-chain hydrocarbons (31.5-33.8%) and oxygenated monoterpenes (14.4-6.6%). The major identified compound was palmitic acid [25.5% in O. arenarium flower essential oil (EO) and 28.7% in the stem EO]. Eighteen compounds representing 80.7% of the whole constituents were identified in the n-hexane extract, which was characterized by high amounts of triterpenoids (39.6%) and dominated by lupeol acetate (19.2%) and ß-amyrin acetate (10.1%). Moreover, all extracts were evaluated for antioxidant potential using 1,1-diphenyl-2-picrylhydrazyl radical assay. The obtained results demonstrated that the EOs and the hexane extract could be a new source of natural potentially bioactive molecules.

Fatty acids from high rate algal pond's microalgal biomass and osmotic stress effects.

The extraction of oil from a wild microalgae biomass collected from a domestic wastewater treatment facility's high rate algal pond (HRAP) was investigated. An experiment plan was used to determine the most efficient extraction method, the optimal temperature, time and solvent system based on total lipids yield. Microwave-assisted extraction was the most efficient method whether in n-hexane or in a mixture of chloroform/methanol compared to Soxhlet, homogenization, and ultrasounds assisted extractions. This same wild biomass was cultivated in a photobioreactor (PBR) and the effect of osmotic stress was studied. The lipids extraction yield after 3days of stress increased by more than four folds without any significant loss of biomass, however, the quality of extracted total lipids in terms of saturated, monounsaturated and polyunsaturated fatty acids was not affected by salinity change in the culture medium.

Antiproliferative metabolites from the Northern African endemic plant Daucus virgatus (Apiaceae).

Chemical analysis of the dichloromethane fraction obtained from aerial parts of the Northern African endemic plant Daucus virgatus led to the isolation of three previously undescribed sesquiterpenoids, namely the daucane vaginatin B, a eudesmane and the elemane elemavirgolide, along with five known metabolites. The structures of these compounds were determined by a detailed MS and NMR analysis and they were evaluated for antiproliferative activity against three human cell lines, A375 (melanoma), MCF-7 (breast adenocarcinoma), and HACAT (keratinocyte). The phytoalexin 6-methoxymellein revealed a previously unreported antiproliferative activity, while the eudesmane and the elemane derivatives exhibited a selective activity (SI = 11.1 and 3.3, respectively) against melanoma tumor cell lines.

Microalgae from domestic wastewater facility's high rate algal pond: Lipids extraction, characterization and biodiesel production.

In this study, the harvesting of a biomass from a high rate algal pond (HRAP) of a real-scale domestic wastewater treatment facility and its potential as a biomaterial for the production of biodiesel were investigated. Increasing the medium pH to 12 induced high flocculation efficiency of up to 96% of the biomass through both sweep flocculation and charge neutralization. Lipids extracted by ultrasounds from this biomass contained around 70% of fatty acids, with palmitic and stearic acids being the most abundant. The extract obtained by supercritical CO2 contained 86% of fatty acids. Both conventional solvents extracts contained only around 10% of unsaturated fats, whereas supercritical CO2 extract contained more than 40% of unsaturated fatty acids. This same biomass was also subject to direct extractive-transesterification in a microwave reactor to produce fatty acid methyl esters, also known as, raw biodiesel.

New bioactive labdane diterpenoids from Marrubium aschersonii.

A phytochemical investigation of the ethanol extract of Marrubium aschersonii Magnus (Lamiaceae) collected from Tunisia led to the isolation and identification of two new labdane diterpenoids, marrubaschs A (1) and B (2), along with two known compounds (3 and 4). Their structures were elucidated by spectroscopic methods including HRESIMS and NMR techniques. All compounds were evaluated for their inhibitory effects on the nitric oxide (NO) production induced by lipopolysaccharide in RAW 264.7 macrophage cells. Compound 2 exhibited weak inhibition of NO production with an IC50 value of 35 ± 1.0 µM.

Essential Oil Constituents and Antioxidant Activity of Asplenium Ferns.

Two fern species Asplenium adiantum-nigrum L. and Asplenium trichomanes L. collected from the Kroumiria region (Northwest of Tunisia) were individually submitted to hydrodistillation in a Clevenger type apparatus. Volatile organic compounds were identified by GC-MS and GC-FID. Thus, 35 compounds were identified in A. adiantum-nigrum essential oil accounting for 77.5% of the whole constituents dominated by palmitic acid (34.5%); however, only 29 volatiles were identified in A. trichomanes showing a high amount of phytol, an odorous diterpene alcohol, representing 14.4% of the total oil contents. The total phenolic content and the antioxidant effects of crude extracts from both pteridophytes were determined using Folin-Ciocalteu and 2,2'-diphenyl-1-picrylhydrazyl free radical-scavenging assays, respectively. A. adiantum-nigrum ethyl acetate extract is shown to be lower in total phenolic contents (49.3 mg gallic acid equivalent/g) than similar extract from A. trichomanes (55.4 mg GAE/g).