HPLC-DAD Analysis and Versatile Bioactivities of Turkish Sunflower Honeys Using Chemometric Approaches

Sunflower honey (SH) is bright yellow, fragrant, pollen-flavoured, slightly herbaceous and has a unique taste. The present research aims to examine the enzyme inhibitory, antioxidant, anti-inflammatory, antimicrobial and anti-quorum sensing activities and phenolic compositions of 30 sunflower honeys (SHs) produced from several regions of Turkey with chemometric study. SAH from Samsun exhibited the best antioxidant activity in β-carotene linoleic acid (IC₅₀: 7.33±0.17 mg/mL) and CUPRAC (A_0.50: 4.94±0.13 mg/mL) assays, anti-urease activity (60.63±0.87 %) and anti-inflammatory activity against COX-1 (73.94±1.08 %) and COX-2 (44.96±0.85 %). SHs exhibited mild antimicrobial activity against the test microorganisms while they showed high quorum sensing inhibition zones measured in the range of 42–52 mm against the CV026 strain. The phenolic composition was determined by high performance liquid chromatography with diode array detection (HPLC-DAD) system and levulinic, gallic, p-hydroxybenzoic, vanillic and p-coumaric acids were identified in all studied SHs. The classification of SHs was performed the using PCA and HCA. This study revealed that phenolic compounds and biological properties are effective in classification of SHs according to their geographical origin. The results suggest that studied SHs could be valued as potential agents with versatile bioactivities in oxidative stress-related disease, microbial infections, inflammation, melanoma, and peptic ulcer.     

Design,in Silico Studies and Biological Evaluation of New Chiral Thiourea and 1,3-Thiazolidine-4,5-dione Derivatives

In this study, new chiral thiourea and 1,3-thiazolidine-4,5-dione derivatives were synthesized, it was aimed to evaluate the various biological activities and molecular docking of these compounds. Firstly, the new thioureas ( 1 – 16 ) were obtained by reacting 1-naphthylisothiocyanate with different chiral amines. Then, the chiral thioureas were cyclized with oxalyl chloride to obtain 1,3-thiazolidine-4,5-dione derivatives ( 17 – 32 ). All compounds were evaluated with several in vitro antioxidant and enzyme inhibition activities. Compound 30 was the most active compound against AChE, with a value of IC₅₀=8.09±0.58 μM. On the other hand, all compounds were tested in silico absorption, distribution, metabolism, and excretion (ADME) assays to better understand their bioavailability. These physicochemical properties, pharmacokinetics, and drug-likeness of all compounds were calculated using SwissADME. Furthermore, according to molecular docking analyses compound 30 exhibited significant binding affinities for all enzymes. Based on our overall observations, compound 30 could be recommended as a potential lead for the therapuetic of Alzheimer's.     

Synthesis of Schiff Bases and Secondary Amines with Indane Skeleton; Evaluation of Their Antioxidant,Antibiotic, and Antifungal Activities

In this study, Schiff bases were synthesized by utilizing the reaction of 4- and 5-aminoindane with substituted benzaldehydes. After the reduction of isolated Schiff bases with NaBH₄, the corresponding secondary amine derivatives were obtained. The structures of all synthesized molecules were confirmed by ¹H-NMR, ¹³C-NMR, FT-IR, and ESI-MS. Antioxidant activities of all synthesized molecules were investigated by DPPH method, and IC₅₀ values were calculated. In addition, antibacterial activities of targets were investigated by the well diffusion method, and then MIC99 values were calculated. While only four of the sixteen synthesized molecules showed a high level of antioxidant activity, all of the molecules exhibited biological activity against Gram-positive and Gram-negative bacteria to varying degrees. In addition, all the synthesized molecules showed high antifungal activity. In antioxidant capacity studies, the IC₅₀ values of 2-(((2,3-dihydro-1H-inden-5-yl)amino)methyl)-6-methoxyphenol ( 4 d ) and 2-(((2,3-dihydro-1H-inden-4-yl)amino)methyl)-6-methoxyphenol ( 7 d ) were determined to be 18.1 μg and 35.1 μg, respectively, and these values are much stronger than BHT (butylated hydroxytoluene) and BHA (butylated hydroxyanisole) used as positive controls. The fact that targets have the same core structure with different substituents has revealed a good structure-activity relationship.     

On the production,elemental composition (C,N, P) and distribution of photosynthetic organic matter in the Southern Black Sea

Chemical oceanographic understanding of the southernBlack Sea has been improved by recent measurements ofthe optical transparency, phytoplankton biomass (interms of chlorophyll-a and particulate organic matter)and primary productivity. During the spring-autmunperiod of 1995–1996, light generally penetrated onlyinto the upper 15–40 m, with an attenuation coefficientvarying between 0.125 and 0.350 m^2122;1. The averagechlorophyll-a (Chl-a) concentrations for the euphoticzone ranged from 0.1 to 1.5 μg l^2122;1. Coherentsub-surface Chl-a maxima were formed near the base ofthe euphotic zone only in summer. Production rate variedbetween 247 and 1925 in the spring and between 405 and687 mgC m^2122;2 d^2122;1 in the summer-autumn period.The average POM concentrations in the euphotic zonevaried regionally and seasonally between 3.8 and28.6 μm for POC, 0.5 and 3.1 μm for PON and0.02 and 0.1 μm for PP. Atomic ratios of C/N, C/Pand N/P, derived from the regressions of POM data,ranged between 7.5 and 9.6, 109 and 165, and 11.2 and16.6, respectively. In the suboxic/anoxic interface,the elemental ratios change substantially due to anaccumulation of PP cohering to Fe and Mn oxides. Thechemocline boundaries and the distinct chemicalfeatures of the oxic/anoxic transition layer (the so-called suboxic zone) are all located at specificdensity surfaces; however, they exhibit remarkablespatial and temporal variations both in their positionand in their magnitude, which permit the definition of long-term changes in the biochemical properties of theBlack Sea upper layer. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effect of methylenetetrahydrofolate reductase gene polymorphisms and oxidative stress in silent brain infarction

Ischemic infarctions occur under the influence of genetic and environmental factors. In our study, the role of ischemia-modified albumin and thiol balance, which are new markers in determining oxidative damage together with MTHFR gene polymorphisms and homocysteine levels, in the development of SBI was investigated. White matter lesions in the magnetic resonance imaging (MRI) results of the patients were evaluated according to the Fazekas scale and divided into groups (Grade 0, 1, 2, and 3). Homocysteine, folate, B12, IMA, total thiol, and native thiol were measured by biochemical methods. The polymorphisms in MTHFR genes were investigated by the RT-PCR method. According to our results, a significant difference was found between the groups in age, homocysteine, folate, IMA, total thiol, and native thiol parameters (p?<?0.05). When we compared the groups in terms of genotypes of the C677T gene, we found a significant difference in TT genotype between grades 0/3 and 1/3 (p?<?0.05). We determined that homocysteine and IMA levels increased and folate levels decreased in CC/TT and CT/TT genotypes in the C677T gene (p?<?0.05). Considering our results, the observation of homocysteine and IMA changes at the genotype level of the MTHFR C677T gene and between the groups, and the deterioration of thiol balance between the groups suggested that these markers can be used in the diagnosis of silent brain infarction.

     

Feeding biology and resource partitioning of the Mullidae family members off the northeastern Levantine coast of Turkey

The introduction of invasive exotic species can have strong ecological impacts on the native biota, with direct consequences for commercial fisheries. Feeding ecology studies are among the primary sources for improving predictions related to community structures, for example, by revealing potential competitive interactions between native and invasive species. We compared the stomach contents and studied diet overlaps among a native (Mullus barbatus) and two invasive (Upeneus moluccensis and U. pori) mullid species, collected off the coasts of the northeastern Levantine where invasive mullids have been part of the ecosystem for more than half a century. We also assessed the effect of sex, sampling period, depth and size on stomach contents. Schoener’s index indicated significant diet overlaps between U. moluccensis–U. pori and U. moluccensis–M. barbatus. Diets of U. pori and M. barbatus did not significantly overlap, which was explained by their differing depth preferences. Assessment of stomach contents showed that Crustacea, specifically Decapoda, was the main prey group across the studied mullid species. Polychaeta was also of high importance in the diet of the native M. barbatus, but not for the two invasive Upeneus species. A trophic level analysis revealed the two invasive mullids to have a higher trophic level than the native species (U. moluccensis: 3.58, U. pori: 3.55 versus M. barbatus: 3.38). The lack of a clear separation in habitat and diet preferences documented here between native and invasive mullids may pose a risk for the persistence of the economically valuable native M. barbatus in the Mediterranean Sea.

     

Chemical Composition and Pharmacological Evaluation and of Toddalia asiatica (Rutaceae) Extracts and Essential Oil by in Vitro and in Silico Approaches.

Toddalia asiatica (L.) Lam. is extensively used in traditional medicinal systems by various cultures. Despite its frequent use in traditional medicine, there is still a paucity of scientific information on T. asiatica growing on the tropical island of Mauritius. Therefore, the present study was designed to appraise the pharmacological and phytochemical profile of extracts (methanol, ethyl acetate and water) and essential oil obtained from aerial parts of T. asiatica. Biological investigation involved the evaluation of in vitro antioxidant and enzyme inhibitory potentials. The chemical profile of the EO was determined using gas chromatography coupled to mass spectrometry (GC/MS) analysis, while for the extracts, the total phenolic (TPC) and flavonoid content were quantified as well as their individual phenolic compounds by LC/MS/MS. Quinic acid, fumaric acid, chlorogenic acid, quercitrin and isoquercitrin were the main compounds in the extracts. Highest total phenolic (82.5±0.94 mg gallic acid equivalent (GAE/g)) and flavonoid (43.8±0.31 mg rutin equivalent (RE/g)) content were observed for the methanol extract. The GC/MS analysis has shown the presence of 26 compounds with linalool (30.9 %), linalyl acetate (20.9 %) and β-phellandrene (7.9 %) being most abundant components in the EO. The extracts and EO showed notable antioxidant properties, with the methanol extract proved to be superior source of antioxidant compounds. Noteworthy anti-acetylcholinesterase (AChE) and anti-butyrylcholinesterase (BChE) effects were recorded for the tested samples, while only the methanol and ethyl acetate extracts were active against tyrosinase. With respect to antidiabetic effects, the extracts and EO were potent inhibitors of α-glucosidase, while modest activity was recorded against α-amylase. Docking results showed that linalyl acetate has the highest affinity to interact with the active site of BChE with docking score of −6.25 kcal/mol. The findings amassed herein act as a stimulus for further investigations of this plant as a potential source of bioactive compounds which can be exploited as phyto-therapeutics.     

Protective Effect of Nigella sativa and Nigella damascena Fixed Oils Against Aflatoxin Induced Mutagenicity in the Classical and Modified Ames Test

The antioxidant and mutagenic/antimutagenic activities of the fixed oils from Nigella sativa (NSO) and Nigella damascena (NDO) seeds, obtained by cold press-extraction from the cultivar samples, were comparatively investigated for the first time. The antimutagenicity test was carried out using classical and modified Ames tests. The fatty acid composition of the fixed oils was characterized by gas chromatography–mass spectrometry (GC-MS) while the quantification of thymoquinone in the fixed oils was determined by UPC². The main components of the NSO and NDO were found to be linoleic acid, oleic acid, and palmitic acid. The results of the Ames test confirmed the safety of NSO and NDO from the viewpoint of mutagenicity. The results of the three antioxidant test methods were correlated with each other, indicating NDO as having a superior antioxidant activity, when compared to the NSO. Both NSO and NDO exhibited a significant protective effect against the mutagenicity induced by aflatoxin B1 in Salmonella typhimurium TA98 and TA100 strains. When microsomal metabolism was terminated after metabolic activation of the mycotoxin, a significant increase in antimutagenic activity was observed, suggesting that the degradation of aflatoxin B1 epoxides by these oils may be a possible antimutagenic mechanism. It is worthy to note that this is the first study to assess the mutagenicity of NSO and NDO according to the OECD 471 guideline and to investigate antimutagenicity of NDO in comparison to NSO against aflatoxin.     

Evaluation of the standards compliance of the queen bees reared in the Mediterranean region in Turkey

The influence of different commercial queen producers on the quality of Apis mellifera queens was assessed. It was aimed to determine the quality characteristics of queens reared by commercial queen producers located in the province of Antalya, which is an important region in queens production due to its climatic characteristics. For this purpose, the quality characteristics of a total of 105 queen bees obtained from 21 enterprises were determined. Differences between the enterprises in terms of the number of spermatozoa (P < 0.01) were determined. In terms of the diameter of spermatheca, spermatheca volume and live weight, statistical differences between the enterprises were also observed (P < 0.05). When the relationships between the measured characteristics were examined, significant values were obtained statistically between live weight and diameter of spermathecae (0.268) and spermatheca volume (0.258). It was also determined that there is a significant correlation between spermatheca diameter and spermatheca volume (0.995). The spermatheca diameter of a good quality queen bee should not be <1.2 mm, spermatheca volume 0.90 mm³ and live weight not <200 mg. Only live weight was found to be within the normal quality standard values when the average results of the quality criteria are taken into consideration. Other characters such as spermathecae diameter, spermathecae volume and number of spermatozoa in spermathecae seem to be below quality standard values.     

Clinical and pathological significance of programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) expression in high grade serous ovarian cancer

We investigated programmed cell death 1 (PD-1) / programmed cell death ligand 1 (PD-L1) expression in high grade serous ovarian cancer (HGSOC) and its relationship to tumor infiltrating lymphocytes (TIL) and prognosis. Formalin fixed paraffin embedded (FFPE) samples of 94 HGSOC cases were included in the study. Immunohistochemical analysis (CD3, CD4, CD8, PD-1 and PD-L1) was performed. Samples were analyzed for expression of immune proteins in the peritumoral stromal and intratumoral areas, scored, and expression was correlated with overall survival, stage, and age. PD-L1 staining ratio with a score greater than 0 was found to have lower survival. There were two positive staining patterns, patchy/diffuse and patchy/focal patterns, in 24 (25.5%) cases. Considering the threshold value ≥5%, we demonstrated that the PD-L1 positive cancer cell membrane immunoreactivity rate and patchy/diffuse PD-L1 expression were 9.6% (n = 9). There was statistically significant relationship between high PD-1 scores and PD-L1 cases of ≥ 5%. A statistically significant difference was found between PD-L1 staining and survival in patients with a threshold ≥ 5%. However an appropriate rate for treatment was determined in 9.6% cases. There was a statistically significant correlation between PD-1 positive TIL score and intratumoral CD3, peritumoral stromal CD3, intratumoral CD4 and intratumoral CD8 positive cells. Survival was lower in cases with higher PD-L1 positive stromal TIL score.