Altitude Variation in the Composition of Essential Oils, Fatty Acid Methyl Esters, and Antimicrobial Activities of Two Subspecies of Primula vulgaris Grown in Turkey.

In this study, the changes caused by variation of altitude to the essential oils (EOs), fatty acid methyl esters (FAMEs), and antimicrobial activities of Primula vulgaris Huds. subsp. vulgaris (Pvv) and P. vulgaris Huds. subsp. sibthorpii (Hoffmanns) W.W.Sm. & Forrest (Pvs)) grown in Turkey were investigated. Major fluctuations in the composition of Pvv and Pvs oils included methyl-4-methoxy salicylate (4.5-35.3%; Pvv and 3.2-37.2%; Pvs), (Z,Z,Z)-7,10,13- hexadecatrienal (5.1-21.8%; Pvv and 4.4-15.2%; Pvs ) and flavone (5.5-14.9%; Pvv and 1.6-18.0%; Pvs). Fatty acid profile (C60-CI6o) changes were noted in .Pvv and Pvs. Methyl hexadecanoate (2.4-9.3%) and methyl octadecanoate (1.0-4.7%) were present in all the FAME samples of the plants. The antimicrobial activity of the EOs of Pvv and Pvs were tested against nine bacterial species, which showed activity against Mycobacterium smegmatis with minimum inhibitory concentrations (MIC) varying from 8.5 to 59.2 pg/mL in all samples, respectively, depending on the altitude at which the oils were obtained.

Effect of increased exposure times on amount of residual monomer released from single-step self-etch adhesives.

BACKGROUND: The aim of this study was to evaluate the effect of increased exposure times on the amount of residual Bis-GMA, TEGDMA, HEMA and UDMA released from single-step self-etch adhesive systems. METHODS: Two adhesive systems were used. The adhesives were applied to bovine dentin surface according to the manufacturer's instructions and were polymerized using an LED curing unit for 10, 20 and 40 seconds (n = 5). After polymerization, the specimens were stored in 75% ethanol-water solution (6 mL). Residual monomers (Bis-GMA, TEGDMA, UDMA and HEMA) that were eluted from the adhesives (after 10 minutes, 1 hour, 1 day, 7 days and 30 days) were analyzed by high-performance liquid chromatography (HPLC). The data were analyzed using 1-way analysis of variance and Tukey HSD tests. RESULTS: Among the time periods, the highest amount of released residual monomers from adhesives was observed in the 10th minute. There were statistically significant differences regarding released Bis-GMA, UDMA, HEMA and TEGDMA between the adhesive systems (p<0.05). There were no significant differences among the 10, 20 and 40 second polymerization times according to their effect on residual monomer release from adhesives (p>0.05). CONCLUSIONS: Increasing the polymerization time did not have an effect on residual monomer release from single-step self-etch adhesives.

Simple time-saving method for iron determination based on fluorescence quenching of an azaflavanon-3-ol compound.

A simple and time-saving spectrofluorometric method developed using an azaflavanon-3-ol compound was used for the determination of iron in various food samples. Nitric acid and hydrogen peroxide were used for digestion of samples in a closed microwave system. The method was validated by analyzing two certified reference materials (CRM-SA-C Sandy Soil C and Mixed Polish Herbs INCT-MPH-2). Measurements were carried out using a modified standard addition method. The standard addition graph was linear until 21.6 mg/L in the determination of iron(III). Detection and quantification limits were 0.81 and 2.4 mg/L, respectively. Satisfactory accuracy was obtained for spinach, dill, mint, purslane, rocket, red lentils, dry beans, and two iron medicinal tablets. High recoveries were found for streamwater samples fortified at three different concentrations. The method is simple, time-saving, cost-effective, and suitable for the determination of the iron content of foods.