Chemical investigation and antimicrobial properties of mastic water and its major constituents

Mastic water is a commercial flavouring obtained during the steam distillation of mastic resin (the resin of Pistacia lentiscus var. chia) for the production of mastic oil. The mastic water extracts were analysed by GC−MS. The major compounds identified were verbenone, α-terpineol, linalool and trans-pinocarveol. Overall the composition was found to be very different from that of mastic oil. Additional GC−MS revealed the enantiomeric ratio of the chiral constituents of mastic water. The antimicrobial activity of mastic water extract, as well as that of its major constituents, was examined against Escherichia coli, Staphylococcus aureus and Candida spp. including ATCC wild clinical and food-borne strains. Linalool and α-terpineol were found to be the most potent antimicrobial constituents. Finally the stability of mastic water at different temperatures was studied, showing no change in the GC−MS profile of the organic extract for a period of 4 months at storage temperatures up to 4 °C.     

Influence of extraction procedures on phenolic content and antioxidant activity of Cretan barberry herb

The main goal of present study was the development, optimization and application of different extraction protocols, especially those employing green technologies, in order to obtain from Berberis cretica extracts with high antioxidant capacity. For this purpose, the applied methods: maceration, ASE and SFE coupled with ASE were incorporated. The antioxidant assessment was carried out using DPPH and total phenolic content (Folin–Ciocalteu) assays. Major constituents were elucidated using HPLC-DAD and UHPLC–HRMS/MS (hybrid IT-Orbital trap spectrometer) equipped with an ESI probe.     

Bioactive non-coloured polyphenols content of grapes,wines and vinification by-products: Evaluation of the antioxidant activities of their extracts

The comparative quantization of main non-coloured polyphenols, the assessment of total polyphenolic content (TPC) and the detailed evaluation of the antioxidant activities of various grape-based products – from the harvest stage up to the production of the corresponding wines – are presented. The material studied consisted of grape tissues (berries, seeds and skins) of native Greek Vitis vinifera cultivars, which provided polyphenol-rich extracts via an optimized ultrasound extraction procedure, while the respective wine samples were condensed by a novel extraction procedure using XAD-4 adsorption resin column. The extraction methods accuracies were thoroughly validated and the polyphenolic content of extracts was assessed by HPLC–DAD and photometric methods. Their antioxidant properties were evaluated by following assays, modified to fit into a high throughput approach: DPPH radical scavenging, FRAP, inhibition of CuSO₄-induced LDL oxidation and the reduction of intracellular reactive oxygen species (ROS) in smooth muscle cell cultures. Seed samples exhibited the highest TPC values, which are well correlated with their significant antioxidant properties in all assays performed. Of special interest is the significant capability of the tested extracts to prevent the LDL oxidation at very low concentrations. Furthermore, the good correlation between the antioxidant activities assessed for the LDL oxidation inhibition and the intracellular ROS assays is indicative of the possible in vivo antioxidant properties of the extracts. Results herein reveal the considerable antioxidant potential of the Greek grapevine production and exploits their vinification by-products as a potential inexpensive source of high added value antioxidants.     

A single-step isolation of squalene from olive oil deodorizer distillates by using centrifugal partition chromatography

High added-value squalene (SQ) was purified in one step from olive oil deodorizer distillates (OODD) using preparative centrifugal partition chromatography (CPC) method, operating in the dual mode. The fractionation was performed using a non-aqueous biphasic solvent system consisting of heptane–acetonitrile–butanol (1.8:1.4:0.7, v/v/v), leading to the isolation of the target compound in 4 hours, using a preparative 1L column. Furthermore, a fast UHPLC-DAD method was developed and applied for the identification and quantification of SQ in both OODD and purified form. The content of SQ in the initial material was 23.4%, while the purity of the isolated SQ was 95.5%. The recovery of SQ was calculated at 76.3%. The productivity of the process was calculated at 234 mg/h/L.     

Synthesis and cytotoxic activity of pyranocoumarins of the seselin and xanthyletin series

This article illustrates how thermodynamic functions can be calculated from moisture sorption isotherms for water-solid systems. The materials evaluated include the drugs albuterol sulfate and indomethacin, the carbohydrates sucrose, raffinose, and trehalose, and the polymers poly(vinyl pyrrolidone) and microcrystalline cellulose. The results demonstrated that significant positive and negative deviations from ideality occurred for water and solid components, respectively, producing higher free energy materials than for the ideal mixtures. The calculations quantitatively discriminated major differences in thermodynamic activity and free energy for all of the solid phases studied, arising from the uniqueness in chemical interactions. This approach to analyzing moisture sorption data is invaluable in advancing our understanding of the physical chemistry of water-solid systems.