Metabolite profiling, enzyme inhibitory activity and antioxidant potential of different extracts from Glycyrrhiza foetida Desf. (Fabaceae, Galegeae, Glycyrrhizinae).

Obesity, a risk factor for the development of type 2 diabetes, represents a socio-economic burden for healthcare systems. Consequently multiple studies aiming to facilitate early diagnostic and prevent complications have demonstrated the promising role of phenolic derivatives on diabetes management. In this frame, the present study aimed to establish for the first time the chemical ingredients and to appraise the antioxidant and the enzyme inhibitory properties of Glycyrrhiza foetida aerial parts and roots extracts using methanol, ethyl acetate and chloroform solvents. The phytochemicals were analyzed via (HPLC-MS/MS). In addition, the extracts were tested for inhibitory activities against α-amylase, α-glucosidase, acetylcholinesterase, butyrylcholinesterase, and tyrosinase. The antioxidant capabilities were evaluated using various methods (phospho­molybdenum, DPPH, ABTS, FRAP, CUPRAC, and metal chelating assays). Notably, twenty-nine secondary metabolites, namely eleven phenolic acids, seventeen flavonoids and a non-phenolic acid have been identified. Delphinidin 3,5-diglucoside, rutin, isoquercitrin, hyperoside, catechin, phloridzin and hesperidin were the major compounds in the aerial parts extracts while trans-cinnamic acid was the dominant compound in roots. Among phenolic acids, vanillic acid was found to be the main constituent in all extracts. The tested extracts were found to yield TPC in amounts ranging from 34.08 to 49.36 mg GAE/g and TFC ranging from 7.01 to 45.74 mg RE/g. G. foetida extracts showed interesting in vitro antioxidant properties. Additionally, all extracts showed a significant anti-tyrosinase activity, with inhibition values ranging between 52.84 and 80.34 mg KAE/g. Thus, G. foetida remains an exceptional matrix for further investigations and application in cosmetics and food additives.

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.

The effect of pressure on the characteristics of supercritical carbon dioxide extracts from Calamintha nepeta subsp. nepeta.

Chemists and industrialists are continuously attempting to develop greener and more environmentally benign chemical processes to extract essential oils and bioactive metabolites of high purity, finding various applications in cosmetics, detergents, nutraceuticals and pharmaceuticals. An increase preferenced for natural products over synthetic ones has made supercritical fluid technology a primary alternative for the generation of high-value bioactive ingredients. This effective technique requires only moderate temperatures, eliminates clean-up steps and avoids the use of harmful organic solvents. In this context, our study was focused on the chemical analysis of Calamintha nepeta subsp. nepeta aromatic extracts obtained with supercritical carbon dioxide. The effect of different operating conditions on the capacity of the lipophilic solvent to extract the targeted volatile components was also studied. The process was carried out at a fairly low constant temperature of 40°C, and with varying the pressure from 90 to 300 bar. The chemical composition of the extracts was analyzed by gas chromatography-mass spectroscopy. The results showed that the composition pattern, the concentrations of individual components and the quality of the extractable analytes were affected by pressure increase. The extraction yields varied from 0.73 to 1.21 wt% at 90 and 300 bar, respectively.

Effect of pressure variation on the efficiency of supercritical fluid extraction of wild carrot (Daucus carota subsp. maritimus) extracts.

The present study was conducted to check the comparative qualities of essential oils prepared by hydrodistillation (HD) and supercritical fluid techniques. It constitutes the first attempt to investigate the chemical composition of Daucus carota subsp. maritimus extracts using supercritical fluid technology (SFE) as an environmentally clean innovative method of extraction. The effect of pressure on the nature of extractable substances from wild carrot has been performed at a constant temperature of 50 °C and two different pressures (100 and 300 bar). The experimental results showed that pressure had a significant enhancing effect on the fluid transport properties and therefore on yield values. The extraction yield increases from 1.167 to 2.986% while increasing pressure. The chemical compositions of the essential oils prepared by HD and SFE were analyzed on the basis of gas chromatography-mass spectroscopy (GC-MS). Thus, we noticed that all analyzed samples were enriched in geranyl acetate and ß­bisabolene, and that the quantities of different identified substances were extremely sensitive to the extraction method and to the pressure variation in case of SFE.

Chromatographic analysis, antimicrobial and insecticidal activities of the essential oil of Phlomis floccosa D. Don.

The present study was conducted to investigate for the first time the chemical composition and insecticidal and antimicrobial properties of Phlomis floccosa D. Don. essential oil isolated by hydro-distillation of its aerial parts. Qualitative and quantitative analyses of the essential oil on the basis of gas chromatography and mass spectrometry (GC/FID and GC/MS) revealed the presence of 59 organic volatiles representing 86.9% of the total constituents. The major compounds were germacrene-D (19.7%) followed by ß-caryophyllene (15.5%), caryophyllene oxide (8.3%), hexadecenoic acid (7.9%) and carvacrol (6.1%). The broth microdilution method was conducted to test the antimicrobial activity of the essential oil against five pathogens: Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, Staphylococcus aureus, Bacillus subtilis and the yeast Candida albicans. The oil of P. floccosa D. Don. shows promising activity against the Gram-positive bacteria S. aureus and B. subtilis and the yeast C. albicans (minimum inhibitory concentration = 625 µg.mL-1 ). The effectiveness of the essential oil was assessed on both Tribolium confusum and Sitophilus zeamais pest insects and it was more pronounced against T. confusum, showing a moderate mortality of 47.5%.