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A simple analytical method for the determination of vitamin E isomers in grape seeds by reversed-phase high-performance liquid chromatography with UV detection is described. The method is based on a solid-liquid extraction separation on an ODS column, and the analytes are monitored at 295 nm with a UV detector. Tocopherols are extracted in n-hexane and directly injected onto the column without using any purification step, such as saponification, prior to the separation and determination. The chromatographic separation of tocopherols is achieved in 12 min with a mobile phase that consists of n-hexane and isopropyl alcohol (99.99:0.01, v/v). The method is reproducible and accurate, with respect to demonstrating a relative standard deviation between 2.57% and 3.30% (n = 10, for 500 ng/mL) and a relative error between 0.84% and 6.54% (n = 10, for 500 ng/mL), respectively. The theoretical limits are estimated as 25 ng/mL for α-tocopherol, 43 ng/mL for γ-tocopherol, and 83 ng/mL for δ-tocopherols. The method is then applied for the determination of tocopherols in grape seeds grown in Turkey. The amounts of tocopherols are calculated by using the standard addition method.

This paper includes the results of the first study about the phenolic characteristics and antimicrobial analyses of Geranium ibericum subsp. jubatum species found in Turkey. In present work the phenolic contents of different parts of the G. ibericum (flower, root, leaf) were determined by HPLC-DAD and LC-MS/MS. Following phenolic compounds were investigated: catechin, protocatechuic acid, gallic acid, ellagic acid, chlorogenic acid, 4-hydroxybenzaldehyde, p-coumaric acid, rutin, naringenin, kaempferol. According to the results obtained, the root and flower parts of the plant are very rich in ellagic acid (3473.57 µg g-1 dry plant) and catechin (2228.76µg g-1 dry plant). Chlorogenic acid level (54.570 µg g-1 dry plant) is also high in the roots. The amount of protocatechuic acid (122.5 µg g-1 dry plant) and gallic acid (725.34 µg g-1 dry plant) is high in the leaves. In addition, the total extract of G. ibericum obtained from leaf, flower, and root were tested against six gram-negative bacteria, and Candida albicans. The G. ibericum extract was nearly as effective as commercial antibiotics at some concentrations for Acinetobacter baumannii, Klebsiella pneumonia, Proteus mirabilis, and Bacillus cereus.

Bee bread is a unique natural product made by bees and good for human health. It has many bioactive molecules that can treat or prevent diseases. In this study, melissopalynological methods were used to examine five bee bread samples. Major plant sources found in bee bread were Lotus spp., Trifolium spp., and Xeranthemum spp., which are from the Fabaceae and Asteraceae families. Then, the amount of phenolic compounds and major carotenoids in bee bread (BB) samples were quantified. Gallic acid, caffeic acid, quercetin, and kaempferol were found in all BB samples, with β-carotene being the most abundant carotenoid in all but BB1. In addition, the total phenolic/flavonoid content and antioxidant activities of all BB samples were determined. Total flavonoid, total phenolic, DPPH * , and ABTS * + values were varied between 5.6 -10.00 mg GAE/g DW, 1.2 -4.3 mg QE/g DW, 1.2 -5.5 mg TEAC/g DW, and 2.6-15.4 mg TEAC/g DW, respectively.

Investigation of pycnogenol from different pine bark species grown in Turkey was performed using a reversed-phase high pressure liquid chromatography with ultraviolet (RP-HPLC-UV) method. All pycnogenol constituents were separated in <26 min on reversed-phase C18 column with gradient mobile phase that consists of orthophosphoric acid, methanol and acetonitrile. Detections were made on an UV detector at 280 nm and at a flow rate of 1 mL/min. Samples were prepared according to Masqueller’s conventional sample preparation method with slight modifications. To avoid the reduction in extraction efficiency the sample preparation step was carried out under argon atmosphere. The linearity of the method was between 0.994 and 0.9999. The detection limits for the five pycnogenol constituents ranged from 0122 to 0.324 mg/L. Catechin and taxifolin were found in all pine barks at a concentration of 0.065 ± 0.002–1.454 ± 0.004 and 0.015 ± 0.001–23.164 ± 0.322 mg/g, respectively. Epicatechin was determined in four pine barks between 0.027 ± 0.001 and 0.076 ± 0.002 mg/g, ferulic acid in two pine barks between 0.010 ± 0.001 and 0.022 ± 0.001 mg/g and epicatechin gallate in only one of the pine barks at 0.025 ± 0.001 mg/g. Finally, the total amount of phenolic compounds and antioxidant capacities of the pine barks were found to be very high.

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: The extracts' antioxidant and antimicrobial properties are linked to phenolic compounds, one of the most abundant classes of secondary metabolites. In order to add new information to the scientific literature, it is crucial to investigate the phenolic content and bioactivity of previously unstudied or unknown plant parts. Lonicera caucasica Pallas subsp. orientalis is an endemic species that grows in a few cities in Turkey. In this study, methanolic extraction of Lonicera caucasica leaves was performed, and the obtained fraction was analyzed by Liquid Chromatography-High Resolution Mass Spectrometry (LC-HRMS) to determine the phenolic content of the extract. The amounts of 22 of the 56 identified phenolic compounds were determined. The three highest of these are chlorogenic acid (2.223 ± 0.065 mg g-1), quinic acid (2.163 ± 0.057 mg g-1) and syringic acid (1.192 ± 0,036 mg g-1). At the same time, the antioxidant activities of the extracts were examined and ABTS•+ and DPPH• (SC50, mg/mL) values were determined as 0.0135 ± 0.0001 and 0.0136 ± 0.0001, respectively. In addition, the obtained extract was tested against three gram-negative (P. aeruginosa, E. aerogenes and E. coli) and three gram-positive (E. fecalis, B. megaterium and S. pyogenes) bacteria and the results were recorded. The best antimicrobial activity was observed at 19.33 mm against P. aeruginosa at a dose of 3.9 mg mL-1. These results show that Lonicera caucasica leaves have rich phenolic content, high antioxidant activity, and a strong antimicrobial effect.

Scientific tafsīr has a long history that goes back to al-Ghazalī and Razī. Early scholars and Muslim philosophers used their cumulative knowledge in order to