346 research outputs found
Mineralogical and physicochemical properties of talc from Emirdaǧ, Afyonkarahisar, Turkey
Lens-shaped talc deposits related to Mesozoic gabbroic rocks are exposed in an area of 2 km
, about 80 km northwest of
Afyonkarahisar (western Anatolia). Different alteration zones in talc deposits were determined depending on differences related to the
texture and color of the host rock. In order to determine mineralogical, geochemical, and physicochemical features of the Emirdağ talc
deposits, X-ray diffractometer, scanning electron microscope (SEM), FT-IR and Mössbauer spectroscopy, differential thermogravimetric
analyses, BET-specific surface area, color, water soluble substance, acid–soluble carbonate, and acid–soluble iron tests were performed
on the samples collected from different alteration zones in the lateral direction. Four groups of mineral paragenesis were determined: i)
talc and chlorite-bearing actinolite (E1), ii) actinolite-rich talc (E-2), iii) chlorite and calcite-bearing talc (E-3), and iv) pure talc (E-4).
Talc, actinolite, and chlorite are dominant. SEM analyses show that fine shreds, like microcrystalline talc crystals, are associated mainly
with actinolite and chlorite, and actinolites are mainly transformed into chlorite and talc. Ni and Cr contents of the Emirdağ talcs are
consistent with the composition of the talc deposits formed in relation to ultramafic rocks. Energy dispersive X-ray spectrometry,
chemical analysis, and Mössbauer spectroscopy results show that iron in the Emirdağ samples was mainly derived from talc minerals
and this iron occurs as Fe
+2
2
in the crystal lattice structure of talc. Because removal of iron from Emirdağ talc seems difficult during
mineral processing techniques, the Emirdağ talc can be used in its crude state in the cosmetic, paint, and paper industries as a secondary
raw material
Secondary sulfonamides as effective lactoperoxidase inhibitors
Secondary sulfonamides (4a–8h) incorporating acetoxybenzamide, triacetoxybenzamide,
hydroxybenzamide, and trihydroxybenzamide and possessing thiazole, pyrimidine, pyridine,
isoxazole and thiadiazole groups were synthesized. Lactoperoxidase (LPO, E.C.1.11.1.7), as a natural
antibacterial agent, is a peroxidase enzyme secreted from salivary, mammary, and other mucosal
glands. In the present study, the in vitro inhibitory effects of some secondary sulfonamide derivatives
(4a–8h) were examined against LPO. The obtained results reveal that secondary sulfonamide
derivatives (4a–8h) are effective LPO inhibitors. The Ki values of secondary sulfonamide derivatives
(4a–8h) were found in the range of 1.096 × 10−3
to 1203.83 µM against LPO. However, the most
effective inhibition was found for N-(sulfathiazole)-3,4,5-triacetoxybenzamide (6a), with Ki values of
1.096 × 10−3 ± 0.471 × 10−3 µM as non-competitive inhibition
Phytochemical profile and some biological activities of three Centaurea species from Turkey
Purpose: To characterise the phytochemical profile of whole plants of Centaurea balsamita, C. depressa and C. lycopifolia with LC-ESI-MS/MS, and as well as their antioxidant, anticholinesterase and antimicrobial activities.Methods: Organic and aqueous extracts of the three Centaurea species were evaluated for DPPH free radical, ABTS cation radical scavenging and cupric reducing antioxidant capacity (CUPRAC). Acetyland butyryl-cholinesterase enzyme inhibition abilities of the extracts using petroleum ether, acetone, methanol and water were studied to determine anticholinesterase activity, while antimicrobial activity was determined by disc diffusion method using appropriate antimicrobial standards and organisms. The phytochemical components of the methanol extracts were assessed by LC-MS/MS.Results: The methanol extract of C. balsamita exhibited much higher DPPH free and ABTS cation radicals scavenging activities (with IC50 of 62.65 ± 0.97 and 24.21 ± 0.70 mg/ml, respectively) than the other extracts. The petroleum ether extracts of the plant species exhibited moderate inhibitory activity against butyrylcholinesterase enzymes while the acetone extract of C. balsamita showed good antifungal activity against Candida albicans. Quinic acid (17513 ± 813 μg/g, 63874 ± 3066 μg/g and 108234 ± 5195 μg/g) was the major compound found in the methanol extracts of C. balsamita, C. depressa and C. Lycopifolia, respectively.Conclusion: These results indicate quinic acid is the major compound in the three plant species and that Centaurea balsamita has significant antioxidant, anticholinesterase and antimicrobial properties. Further studies to identify the compounds in the extracts responsible for the activities are required.Keywords: Centaurea, LC-ESI-MS/MS, Anticholinesterase, Antioxidant, Antimicrobia
The acorn honey used for a published study was mistakenly listed as quercus pyrenaica and should be corrected to quercus species
A critical review letter1
was published concerning the article “Quercus pyrenaica honeydew honey effects on gastric
adenocarcinoma cells” published in Integrative Cancer
Therapies in 2019.2
According to the letter, the authors
reported that the Quercus pyrenaica mentioned in the study
was neither found in Mount Ida nor within the borders of
Turkey as stated in the study, therefore the results obtained
in the study may belong to another Quercus species
Quercus pyrenaica honeydew honey with high phenolic contents cause dna damage, apoptosis, and cell death through generation of reactive oxygen species in gastric adenocarcinoma cells
Many studies have shown that honey with high phenolic contents prevents cancer formation. Furthermore, recent studies have demonstrated that honey can be used for the treatment of cancer as well as cancer prevention. Antineoplastic effects of honey are often associated with their antioxidant phenolic contents. However, very few studies have dealt with the association of phenolic contents of honeys in terms of antiproliferative effects. The aim of this study was, therefore, to elucidate the cytotoxic, genotoxic, apoptotic, and reactive oxygen species (ROS) generating effects of honey samples on the basis of their phenolic and flavonoid contents. Fourteen different honey varieties were collected from various parts of Turkey, and their characteristics regarding total phenols, flavonoids, and antioxidant contents were determined to test their effects on gastric cancer cells (AGS). For convenience, 2 honey varieties were selected, namely, Ida Mountains Quercus pyrenaica honeydew honey (QPHH-IM) having the highest phenolic and antioxidant content and Canakkale multifloral honey (MFH-C) with the lowest phenolic and antioxidant content. Levels of 11 different phenolic compounds in QPHH-IM and MFH-C samples were determined by LC-MS/MS. AGS cells were incubated with different concentrations of QPHH-IM and MFH-C for 24 hours, then the cell viability, DNA damage, apoptosis, and generation of ROS were determined. We found that QPHH-IM had more cytotoxic, genotoxic, and apoptotic effects than that of MFH-C. We think that these effects are probably related to pro-oxidant activities due to the high phenolic contents present. Therefore, further research on high-phenolic honey may contribute to the future development of cancer therapeutics
“Osmanlı Döneminde Açılan İlk Resmî Akademi’nin Yeri ve Beyoğlu’nda Bilinmeyen Bir Akademi Hakkında”
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