Chitosan films incorporated with thyme oil for potential applications of wound dressing were successfully prepared by solvent casting method. The water vapor permeability, oxygen transmission rate, and mechanical properties of the films were determined. Surface and crosssection morphologies and the film thicknesses were determined by Scanning Electron Microscopy (SEM). Fourier transform infrared (FT-IR) spectroscopy was conducted to determine functional group interactions between the chitosan and thyme oil. Thermal behaviors of the films were analyzed by Thermal Gravimetry (TGA) and Differential Scanning Calorimetry (DSC). In addition, the antimicrobial and the antioxidant activities of the films were investigated. The antimicrobial test was carried by agar diffusion method and the growth inhibition effects of the films including different amount of thyme oil were tested on the gram negative microorganisms of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and a gram positive microorganism of Staphylococcus aureus. The minimum thyme oil concentration in chitosan films showing the antimicrobial activity on all microorganisms used in the study was found as 1.2 % (v/v). In addition, this concentration showed the highest antioxidant activity due to mainly the carvacrol in thyme oil. Water vapor permeability and oxygen transmission rate of the films slightly increased, however, mechanical properties decreased with thyme oil incorporation. The results revealed that the thyme oil has a good potential to be incorporated into chitosan to make antibacterial and permeable films for wound healing applications.

General objective of the present work was to assess the isolation of polyphenols from olive leaves. The effects of extraction conditions on the total phenol content and antioxidant activity of olive leaf extract (OLE) were investigated. An extract with good antioxidant activity (7.52 mmol of Trolox equivalent antioxidant capacity (TEAC)/g olive leaf extract), and a high content of oleuropein (13.4%) and rutin (0.18%) could be obtained using 70% ethanol as extraction solvent. There was a good correlation between the antioxidant activity and the total phenol content. Furthermore, silk fibroin was used as a novel adsorbent to recover the polyphenols from the olive leaf extracts. The adsorbed amounts of rutin and oleuropein were 15 mg rutin/g silk fibroin and 96 mg oleuropein/g silk fibroin. Fraction consisting of mainly oleuropein and fraction rich in rutin, luteolin-7-glucoside, verbascoside, apigenin-7-glucoside were obtained by using silk fibroin filled column. Silk fibroin was found to be a promising adsorbent for the purification of oleuropein and rutin from olive leaf extracts.

The adsorption isotherms of oleuropein and rutin were evaluated at different temperatures, pH values, and solid/liquid ratios. The experimental data of adsorption isotherms were well fitted to a Langmuir model. The maximum adsorption capacities were determined as 108 mg of oleuropein/g of silk fibroin and 21 mg of rutin/g of silk fibroin. After adsorption of oleuropein and rutin, the antioxidant capacity of silk fibroin increased from 1.93 to 3.61 mmol of TEAC/g. Silk fibroin also gained antimicrobial activity against Staphylococcus aureus and Klebsiella pneumoniae after adsorption of olive leaf antioxidants. In a desorption process, 81% of rutin and 85% of oleuropein were removed from the adsorbent surface in 70% aqueous ethanol solution. Consequently, silk fibroin was found to be a promising biomaterial for the production of functional food or dietary supplements and for the purification of oleuropein and rutin from olive leaf extracts.

a b s t r a c tIn this study, inhibition of Escherichia coli glucuronidase (GUS) by a plant extract of Pistacia terebinthus was investigated. P. terebinthus (from Karaburun region in Turkey) leaf extract exhibits various bioactivities, such as antioxidant, antimicrobial and cytotoxic property because of its flavonoid, phenolic and alkaloid contents. HPLC analyses were performed to evaluate the composition of the extract and main flavonoid compounds such as luteolin, luteolin-7-glucoside and apigenin-7-glucoside were detected in extract. GUS activity and kinetic data of the GUS were obtained by measuring rate of production of resulting fluorescent 4-methylumbelliferone (4-MU) and phenolphthalein fluorometrically and spectrophotometrically, respectively. Plant leaves showed higher antioxidant capacity as 85 TEAC (trolox equivalent antioxidant capacity) value and higher antimicrobial activity towards Staphylococcus aureus. 92.4% GUS enzyme inhibition was achieved with 8.3 g ml −1 crude extract concentration, where IC 50 value was found as 2.1 (±0.2) g ml −1 . Kinetic studies by nonlinear regression revealed that inhibition type caused by plant extract was mixed type (noncompetitive and competitive together). K m and V max values were 96.94 ± 9.68 nM and 7.81 ± 0.16 nmol min −1 mg −1 , respectively. Inhibition constant (˛K i ) was found as 7.00 ± 0.93 nM having˛value 2.17 ± 0.93. Our results may provide useful information regarding the inhibition of microbial GUS activity, preventing deglucuronidation and reducing possible cancer risk by bioactive P. terebinthus crude extract.

Tartaric acid is mainly used in food, pharmaceuticals and cosmetics industries. In this study, the waste samples, which contain tartaric acid, from the wastes of wine and grape juice industries were characterized by using TG, DSC, FTIR and XRD techniques. HPLC was used to determine tartaric acid content of samples. The decomposition temperatures of waste samples were found to be relatively higher compared with that of pure tartaric acid. This difference in decomposition temperatures was attributed to the presence of potassium tartrate since high potassium content was detected with ICP-AES.Kuzenler Export & Import Ltd. Co