Purification and biochemical characterization of a novel carbonic anhydrase II from erythrocytes of camel (Camelusdromedarius).

A novel carbonic anhydrase II (CA II) from erythrocytes of camel (Camelus dromedarius) was purified to homogeneity using affinity chromatography and biochemically characterized. Specific activity of 140.88 U/mg was obtained with 745.17-fold purification and 25.37% yield. The enzyme was a monomer with a lower molecular weight (25 kDa) and lower Zn content (0.50 mol of Zn per mol of protein). The enzyme showed higher optimum temperature (70 °C) and pH (pH 9.0), moreover, it was stable at higher temperatures and strongly alkaline pH as judged by thermodynamic parameters (Ea, kd, Ed, t1/2, D-value, Z-value, ΔH, ΔG and ΔS). The enzyme was inhibited by cations (Al3+, Ca2+, Cd2+, Co2+, Cr3+, Cu2+, Fe3+, Ni2+, Mg2+ and Zn2+) as well as by anions (Br‾, CH3COO‾, ClO4‾, CN‾, F‾, HCO3‾, I‾, N3‾, NO3‾ and SCN‾), some anions (C6H5O73-, CO32-, SeO3‾ and SO42-) does not affect enzyme activity. Effect of various chemicals on enzyme activity was also investigated. Km, Vmax, kcat and kcat/Km values for 4-NPA were found to be 1.74 mM, 0.0093 U/mL, 0,0039 s-1 and 0,0023 s-1 mM-1, respectively. With these interesting biochemical properties, camel CA II represents promising candidate for harsh industrial applications, in particular, for a successful biomimetic CO2 sequestration process.

Heterologous Expression of Codon-Optimized Azurin Transferred by Magnetofection Method in MCF-10A Cells.

Transfection efficiency of the immortalized human breast epithelial cell line MCF-10A remains an issue that needs to be resolved. In this study, it was aimed to deliver a recombinant DNA (pCMV-Azu-GFP) to the MCF-10A cells by the magnetofection method using magnetic nanoparticles (MNPs) and a simple magnet to accelerate the DNA delivery. Surface positively modified silica-coated iron oxide MNPs (MSNP-NH2) were produced and characterized via TEM, FTIR, and DLS analyses. The recombinant DNA (rDNA) was obtained by the integration of codon-optimized azurin to produce a fusion protein. Then, rDNA cloned in Escherichia coli cells was validated by sequence analysis. The electrostatically conjugated rDNA on MSNP-NH2 with an enhancer polyethyleneimine (PEI) was studied by agarose gel electrophoresis and the optimum conditions were determined to apply to the cell. A dose-dependent statistical difference was observed on treated cells based on the MTS test. The expression of the fusion protein after magnetofection was determined using laser scanning confocal microscope imaging and western blot analysis. It was observed that the azurin gene could be transferred to MCF-10A cells by magnetofection. Thus, when the azurin gene is used as a breast cancer treatment agent, it can be expressed in healthy cells without toxic effects.

Sulfanilamide Modified Magnetic Nanoparticles for Purification of Carbonic Anhydrase from Bovine Blood.

Magnetic nanoparticles (MNPs) have been used for purification of specific biomolecules form mixtures. The aim of this study is to develop a new, cheap, reusable, and magnetic-based material to purify the carbonic anhydrase (CA) enzyme in a short time with high efficiency. In the first part of this study, silica-coated iron oxide magnetic nanoparticles (Fe3O4@SiO2 MNPs) were obtained. Surface modification of Fe3O4@SiO2 MNPs was accomplished with 3-(4-Hydroxyphenyl) propionic acid (PA) and sulfanilamide (SA), respectively. SA is a selective inhibitor of CA, and it selectively binds to CA. The final particle was named Fe3O4@SiO2-PA-SA MNPs and characterized by SEM, TEM, XRD, and FT-IR. It was determined that the produced MNPs contained multicore, were smaller than 100 nm in size, and had a spherical morphology. The CA was purified from bovine blood hemolysate in a short time such as 2.5 h and in a simple manner. The maximum enzyme purifying capacity of MNPs was calculated as 13.87 ± 3.27 mg CA/g MNP. SDS-PAGE analysis was confirmed that high CA purification success was achieved.

Purification and biochemical characterization of catalase that confers protection against hydrogen peroxide induced by stressful desert environment: the Camelus Dromedarius kidney catalase.

Camel is continually exposed to stressful desert environment that enhances generation of reactive oxygen species, including hydrogen peroxide (H2O2). Catalase plays an important role in detoxification of H2O2. A highly active catalase from camel kidney was purified to homogeneity, with a specific activity of 1,774,392 U/mg protein, using ion exchange and metal chelate affinity chromatography. The molecular weight of the enzyme was 268 kDa consisting of four identical subunits of 63 kDa. The enzyme showed higher optimum temperature (45 °C) and higher activation energy (4.37 kJ mol-1). The thermodynamic parameters, ΔH, ΔG and ΔS, were determined. The effect of various metal ions and chemicals on enzyme activity was investigated. Km, Vmax, kcat and kcat/Km values for H2O2 were found to be 46 mM, 10,715,045 U/mg, 48,265,968 s-1 and 2,966,562 s-1 mM-1, respectively. Camel kidney catalase displayed higher affinity efficiency for H2O2 and can protect reduced glutathione (GSH) from oxidation by H2O2. Sodium azide was found to be a noncompetitive inhibitor of enzyme with Ki and IC50 of 17.88 µM and 20.94 µM, respectively. Camel catalase showed unique biochemical properties. Interestingly, camel catalase can protect molecules (GSH) and organ functions (kidney) from the toxic effects of H2O2 induced by stressful desert environment.

Comparative heating efficiency and cytotoxicity of magnetic silica nanoparticles for magnetic hyperthermia treatment on human breast cancer cells.

Magnetic hyperthermia (MHT) is a promising treatment for a variety of cancers due to its ability to increase the sensitivity of cells to other treatments, such as chemotherapy. Superparamagnetic nanoparticles (MNPs) were used for MHT treatment due to their heat generation ability under an AC magnetic field (AMF). In this study, iron oxide and zinc-doped iron oxide MNPs were produced and modified with silica to obtain eleven different types (MSNP-I to -XI) of magnetic silica nanoparticles (MSNPs). The MSNPs which show the highest heating capacity were selected to investigate their MHT ability on non-tumourigenic MCF-10A and tumourigenic MCF-7 cell lines. The cytotoxicity results indicated that the size, the content of the magnetic core and silica coating thickness were important in the heating capacity of MSNPs under AMF. After MHT treatment, selected MSNPs showed limited cytotoxicity on MCF-10A, but significant cell death on MCF-7. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-022-03377-y.

Electrically controlled mRNA delivery using a polypyrrole-graphene oxide hybrid film to promote osteogenic differentiation of human mesenchymal stem cells.

Direct messenger ribonucleic acid (mRNA) delivery to target cells or tissues has revolutionized the field of biotechnology. However, the applicability of regenerative medicine is limited by the technical difficulties of various mRNA-loaded nanocarriers. Herein, we report a new conductive hybrid film that could guide osteogenic differentiation of human adipose-derived mesenchymal stem cells (hADMSCs) via electrically controlled mRNA delivery. To find optimal electrical conductivity and mRNA-loading capacity, the polypyrrole-graphene oxide (PPy-GO) hybrid film was electropolymerized on indium tin oxide substrates. We found that the fluorescein sodium salt, a molecule partially mimicking the physical and chemical properties of mRNAs, can be effectively absorbed and released by electrical stimulation (ES). The hADMSCs cultivated on the PPy-GO hybrid film loaded with pre-osteogenic mRNAs showed the highest osteogenic differentiation under electrical stimulation. This platform can load various types of RNAs thus highly promising as a new nucleic acid delivery tool for the development of stem cell-based therapeutics. Electronic Supplementary Material: Supplementary material (electrochemical and FT-IR analysis on the film, additional SEM, AFM and C-AFM images of the film, optical and fluorescence images of cells, and the primers used for RT-qPCR analysis) is available in the online version of this article at 10.1007/s12274-022-4613-y.

Synthesis, Characterization, Biological Activity and Molecular Docking Studies of Novel Organotin(IV) Carboxylates.

Four new carboxylates complexes with general formula R2SnL2 and R3SnL, where R = n-butyl (1, 3), methyl (2, 4) and L = 4-Chlorophenoxyacetate, were synthesized in significant yields. FT-IR analysis revealed a chelating (1 and 2) and a bridging bidentate (3 and 4) coordination modes for the carboxylate ligand in solid state which was further confirmed by the single crystal X-ray analysis of complex 4. The NMR data (1H, 13C and 119Sn) revealed a higher coordination number around the tin center in R2SnL2 (1 and 2) compared to R3SnL (3 and 4). A close matching was observed between the experimental and calculated structures (obtained at B3LYP/6-31G* + LANL2DZ basis set). Quantum chemical analysis indicates that the carboxylate moiety has the major contribution in the formation of filled and unfilled orbitals as well as in ligand to ligand intramolecular charge transfer during the electronic transitions. The cytotoxicity data of the screened compounds evaluated against lung cancer cell line (A549) and normal lung fibroblast cell line (MRC-5) revealed that 1, 3 and 4 have shown dose dependent cytotoxic effects while HL and 2 have shown steady and low cytotoxic activities. The antibacterial activity of complexes 1-4 is higher than that of HL. Molecular docking study showed an intercalation binding mode for complex 3 with DNA (docking score = -3.6005) involving four polar interactions. Complex 3 docking with tubulin (PDB ID 1SA0) with colchicine as a target protein resulted in three polar interactions (docking score -5.2957). Further, the docking analysis of the HL and 1-4 has shown an adequate interactions with the coronavirus SARS-CoV-2 spike protein, nucleocapsid protein and human angiotensin converting enzyme (ACE2).

The synergic toxicity of temperature increases and nanopolystrene on zebrafish brain implies that global warming may worsen the current risk based on plastic debris.

Global warming and plastic pollution are among the most important environmental problems today. Unfortunately, our world is warming more than expected and biological life, especially in the oceans, has come to the limit of the struggle for survival with the nano-scale plastic pollution that is constantly released from the main material. In this study, the synergic effect of one-degree temperature increase (28, 29, 30 °C) and 100 nm size polystyrene plastic nanoparticles on circadian rhythm, brain damage and metabolomics in zebrafish were investigated in an environment where temperature control with 0.05-degree precision is provided. A temperature increase of 1°, together with nanoplastic exposure, affected the circadian rhythm in zebrafish, caused damage to the brain and caused significant changes in the intensity of a total of 18 metabolites in different pathways. It was also detected Raman signals of polystyrene in the brain homogenate. As a consequence, it is suggested that one degree of temperature increase pave the way for degeneration in the brain by disrupting some metabolic pathways, thereby significantly increasing the negative effects of nano-plastic on behavior.

Magnetic nanoparticle mediated-gene delivery for simpler and more effective transformation of Pichia pastoris.

The introduction of exogenous DNA into a cell can be used to produce large quantities of protein. Here, we describe a novel gene delivery method for Pichia pastoris based on recombinant DNA delivery using magnetic nanoparticles (MNPs) under magnetic forces. For this purpose, a linear plasmid (pGKB-GFP) containing the Green Fluorescent Protein (GFP) gene is loaded on polyethyleneimine-coated iron oxide (Fe3O4@PEI) MNPs at doses that are non-toxic to the yeast cells. The pGKB-GFP loaded MNPs combined with enhancer PEI (Fe3O4@PEI + pGKB-GFP + PEI) are directly transferred to non-competent cells. An effective GFP expression was observed by the selection of antibiotic-resistant yeast cells and heterologous gene integration into the P. pastoris genome was provided. This method, which is very simple, effective, and advanced equipment-free compared to traditional methods, uses smaller amounts of DNA and the process can be performed in a shorter time. The suggested method might also be adapted for the transformation of other yeast species.

Disulfiram-loaded functionalized magnetic nanoparticles combined with copper and sodium nitroprusside in breast cancer cells.

Disulfiram (DSF), one of the members of the dithiocarbamate family, is a reactive species (RS) generator and is capable of inducing cancer cell death in breast cancer. However, it is hydrophobic and highly degradable in blood. Therefore, drug delivery systems would be of great benefit in supporting the selective accumulation of DSF in tumor cells. In this study, it was aimed to prepare a drug carrier system based on magnetic mesoporous silica nanoparticles (Fe3O4@mSiO2 MNPs) which are non-toxic, biocompatible, and have a mesoporous structure. The Fe3O4@mSiO2 MNPs were modified with folic acid linked polyethyleneimine (PEI-FA) to increase both their solubility in water and specificity for cancer cells. Thus, the cancer-selective DSF-carrier system (mMDPF) was synthesized with a high surface area but with dimensions of less than 160 nm, and were characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) analysis. The drug-loading capacity of mMDPF was measured as 4.35% by high-performance liquid chromatography (HPLC) and the best drug release kinetics of mMDPF was observed at 37 °C and pH 6.0 which is the pH in the endosome. The cytotoxicity of the mMDPF on breast cancer (MCF-7) cells was improved by applying mMDPF with copper and/or sodium nitroprusside. It was observed that mMDPF was taken up more by MCF-7 cells and its toxicity on MCF-7 cells was much higher than non-tumorigenic (MCF-10A) cells.

A novel acid phosphatase from cactus (Opuntia megacantha Salm-Dyck) cladodes: Purification and biochemical characterization of the enzyme.

Acid phosphatase (ACP) plays an important role in regulating phosphate nutrition in plants. Herein, for the first time, a novel ACP from Opuntia megacantha Salm-Dyck cladodes was purified to homogeneity and biochemically characterized. Specific activity of 8.78 U/mg was obtained with 11.29-fold purification and 15% yield. ACP was purified as monomer with molecular weight of 44 kDa as determined by SDS-PAGE under denaturing and nondenaturing conditions. Optimum pH and temperature for ACP activity was 5.5 and 60 °C, respectively. Thermodynamic parameters (Ea, ΔH, ΔG and ΔS) were also determined. ACP activity was stimulated by Ca2+, strongly inhibited by Cu2+ and Fe3+, and moderately inhibited by Mg2+ and Zn2+. Br-, CN-, F-, I- and N3- weakly inhibited ACP activity, where more than 70% of enzyme activity was remained at 5 mM. In addition, effect of ß-ME, Cys, DTT, EDTA, H2O2, PMSF, SDS and TX-100 on ACP activity was investigated. km, Vmax, kcat and kcat/km of ACP for p-NPP were found to be 0.09 mM, 2.75 U/mL, 9.60 s-1 and 106.67 s-1 mM-1, respectively. The biochemical properties of ACP from Opuntia megacantha Salm-Dyck cladodes provide novel features with other plant ACPs and basic knowledge of ACP in Opuntia species.

Tumor Homing Reactive Oxygen Species Nanoparticle for Enhanced Cancer Therapy.

Multifunctional nanoparticles that carry chemotherapeutic agents can be innovative anticancer therapeutic options owing to their tumor-targeting ability and high drug-loading capacity. However, the nonspecific release of toxic DNA-intercalating anticancer drugs from the nanoparticles has significant side effects on healthy cells surrounding the tumors. Herein, we report a tumor homing reactive oxygen species nanoparticle (THoR-NP) platform that is highly effective and selective for ablating malignant tumors. Sodium nitroprusside (SNP) and diethyldithiocarbamate (DDC) were selected as an exogenous reactive oxygen species (ROS) generator and a superoxide dismutase 1 inhibitor, respectively. DDC-loaded THoR-NP, in combination with SNP treatment, eliminated multiple cancer cell lines effectively by the generation of peroxynitrite in the cells (>95% cell death), as compared to control drug treatments of the same concentration of DDC or SNP alone (0% cell death). Moreover, the magnetic core (ZnFe2O4) of the THoR-NP can specifically ablate tumor cells (breast cancer cells) via magnetic hyperthermia, in conjunction with DDC, even in the absence of any exogenous RS supplements. Finally, by incorporating iRGD peptide moieties in the THoR-NP, integrin-enriched cancer cells (malignant tumors, MDA-MB-231) were effectively and selectively killed, as opposed to nonmetastatic tumors (MCF-7), as confirmed in a mouse xenograft model. Hence, our strategy of using nanoparticles embedded with ROS-scavenger-inhibitor with an exogenous ROS supplement is highly selective and effective cancer therapy.

Purification and biochemical characterization of a novel copper, zinc superoxide dismutase from liver of camel (Camelus dromedarius): An antioxidant enzyme with unique properties.

A novel copper, zinc superoxide dismutase (CuZnSOD) was purified to homogeneity from the liver of an animal well adapted to the stressful living conditions of the desert, the camel (Camelus dromedarius). The biochemical properties of camel liver CuZnSOD were examined. The purified enzyme had a native molecular weight of 28 kDa, as judged by gel filtration chromatography, and showed a single band at 27 kDa on SDS-PAGE, indicating that it is a monomeric protein. Optimal activity of the purified enzyme occurred at 43 °C and pH 6.0, and the activation energy was 1.42 kJ/mol. CuZnSOD activity was strongly inhibited by ß-ME, DTT, H2O2 and SDS and slightly inhibited by EDTA, NaN3 and PMSF. Al3+, Ca2+, Cd2+, Mg2+ and Zn2+ stimulated CuZnSOD activity, whereas Ba2+, Co2+, Fe2+ and Ni2+ inhibited it. The purified enzyme contained 0.010 µg of Cu and 0.69 µg of Zn per mg of protein. Km, Vmax, kcat and kcat/Km values for NBT and riboflavin were 16.27 and 0.16 µM, 20.85 and 21.54 U/mg, 9.65 and 9.97 s-1, and 0.59 and 62.33 s-1 µM-1, respectively. Camel liver CuZnSOD exhibited unique biochemical properties compared to those of other CuZnSODs, including lower molecular weight with a monomeric structure, higher optimum temperature, very low Ea, very low optimum pH, very low contents of Cu and Zn, and higher affinity, turnover number and catalytic efficiency for riboflavin. These unique properties of camel liver CuZnSOD might be related to the ability of this animal to inhabit stressful desert conditions.

Purification of camel liver catalase by zinc chelate affinity chromatography and pH gradient elution: An enzyme with interesting properties.

Climate change and increasing temperatures are global concerns. Camel (Camelus dromedarius) lives most of its life under high environmental stress in the desert and represent ideal model for studying desert adaptation among mammals. Catalase plays a key role in protecting cells against oxidative stress. For the first time, catalase from camel liver was purified to homogeneity by zinc chelate affinity chromatography using pH gradient elution, a better separation was obtained. A purification fold of 201.81 with 1.17% yield and a high specific activity of 1132539.37U/mg were obtained. The native enzyme had a molecular weight of 268kDa and was composed of four subunits of equal size (65kDa). The enzyme showed optimal activity at a temperature of 45°C and pH 7.2. Thiol reagents, ß-Mercaptoethanol and D,L-Dithiothreitol, inhibited the enzyme activity. The enzyme was inhibited by Al3+, Cd2+ and Mg2+, whereas Ca2+, Co2+ and Ni2+ stimulated the catalase activity. Reduced glutathione has no effect on catalase activity. The Km and Vmax of the enzyme for hydrogen peroxide were 37.31mM and 6185157U/mg, respectively. Sodium azide inhibited the enzyme noncompetitively with Ki value of 14.43µM, the IC50 was found to be 16.71µM. The properties of camel catalase were different comparing to those of mammalian species. Relatively higher molecular weight, higher optimum temperature, protection of reduced glutathione from hydrogen peroxide oxidation and higher affinity for hydrogen peroxide and sodium azide, these could be explained by the fact that camel is able to live in the intense environmental stress in the desert.

Promotion by phosphate of Fe(III)- and Cu(II)-catalyzed autoxidation of fructose.

Although the oxidative destruction of glucose and fructose has been studied by several investigators over the past century, the mechanism by which phosphate promotes these oxidation reactions is not known. A wide range of oxidation products have been used to monitor the oxidation of sugars and free radicals have been shown to be involved. The influence of phosphate concentration on the rate of production of free radicals and several sugar oxidation products has been studied. It was found that fructose is much more susceptible to autoxidation than glucose, galactose, or sucrose. The promotion of sugar oxidation by phosphate was found to be iron dependent. Addition of the iron chelators, diethylenetriaminepentaacetic acid (DTPA) and desferrioxamine completely suppressed the oxidation reactions, even at high concentrations of phosphate. Formaldehyde was positively identified as a product of fructose oxidation by HPLC analysis of its acetylacetone adduct. A mechanism is proposed in which phosphate cleaves the oxo bridges of the iron(III)-fructose complex, based on UV spectral analysis and magnetic susceptibility measurements, and thereby catalyzes the autoxidation of fructose.

Effects of some drugs on purified human erythrocyte CuZnSOD and in vitro inhibitiory effect of 5-fluorouracil on leukocyte total SOD activity.

The inhibition and activation effects of some drugs on the activities of superoxide dismutase enzymes (SOD) in human erythrocyte and leukocyte cells was investigated. Firstly, CuZnSOD enzyme was purified 837-fold and 12% efficiency from human erythrocytes by ethanol-chloroform treatment to remove hemoglobin and then ion exchange chromatography (DEAE-Sepharose) and copper chelate affinity chromatography techniques. Inhibition or activation effects of fourteen drugs on CuZnSOD was investigated. None of the studied drugs except for 5-fluorouracil showed any effects on the enzyme. 5-fluorouracil showed activation effects on CuZnSOD at 3.33mg/ml and 4mg/ml concentrations with 33% and 32% activation, respectively. Leukocytes were isolated from healthy human blood, lysed in liquid nitrogen and the effect of 5-fluorouracil on the lysate SOD activity investigated. 5-Fluorouracil showed inhibition effects on total SOD activity of human leukocytes at 2 mg/ml and 4 mg/ml concentrations with 42% and 62% inhibition, respectively.

Determination of the chemical composition and antioxidant activity of the essential oil of Artemisia dracunculus and of the antifungal and antibacterial activities of Turkish Artemisia absinthium, A. dracunculus, Artemisia santonicum, and Artemisia spicigera essential oils.

The essential oil isolated from Turkish tarragon (Artemisia dracunculus) by hydrodistillation was analyzed by GC-MS. Thirty compounds representing 99.5% of total oil were identified. The predominant components in the oil were (Z)-anethole (81.0%), (Z)-beta-ocimene (6.5%), (E)-beta-ocimene (3.1%), limonene (3.1%), and methyleugenol (1.8%). The antibacterial and antifungal activities of the essential oils isolated from A. dracunculus, Artemisia absinthium, Artemisia santonicum, and Artemisia spicigera oils were also evaluated. In general, the oils exhibited potent antifungal activity at a wide spectrum on the growth of agricultural pathogenic fungi. Among the oils, the weakest antifungal activity was shown by the oil of A. dracunculus. In many cases, the oils of A. absinthium, A. santonicum, and A. spicigera completely inhibited the growth of some fungal species. As compared with antibacterial activities of all of tested oils, A. santonicum and A. spicigera oils showed antibacterial activities over a very wide spectrum. However, the essential oils tested showed lower inhibition zones than the inhibition zones of penicillin. In addition, antioxidant and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities of tarragon oil were determined, and weak antioxidant and DPPH radical scavenging activities were found in comparison to butylated hydroxytoluene.

Screening of chemical composition and antifungal and antioxidant activities of the essential oils from three Turkish artemisia species.

The compositions of essential oils isolated from the aerial parts of Artemisia absinthium, Artemisia santonicum, and Artemisia spicigera by hydrodistillation were analyzed by GC-MS, and a total of 204 components were identified. The major components of these essential oils were camphor (34.9-1.4%), 1,8-cineole (9.5-1.5%), chamazulene (17.8-nd%), nuciferol propionate (5.1-nd%), nuciferol butanoate (8.2-nd%), caryophyllene oxide (4.3-1.7%), borneol (5.1-0.6%), alpha-terpineol (4.1-1.6%), spathulenol (3.7-1.3%), cubenol (4.2-0.1%), beta-eudesmol (7.2-0.6%), and terpinen-4-ol (3.5-1.2%). The antifungal activities of these essential oils were tested against 11 plant fungi and were compared with that of a commercial antifungal reagent, benomyl. The results showed that all of the oils have potent inhibitory effects at very broad spectrum against all of the tested fungi. Pure camphor and 1,8-cineole, which are the major components of the oils, were also tested for antifungal activity against the same fungal species. Unlike essential oils, these pure compounds were able to show antifungal activity against only some of the fungal species. In addition, the antioxidant and DPPH radical scavenging activities of the essential oils, camphor, and 1,8-cineole were determined in vitro. All of the studied essential oils showed antioxidant activity, but camphor and 1,8-cineole did not.

Antioxidant properties of some medicinal plants: Prangos ferulacea (Apiaceae), Sedum sempervivoides (Crassulaceae), Malva neglecta (Malvaceae), Cruciata taurica (Rubiaceae), Rosa pimpinellifolia (Rosaceae), Galium verum subsp. verum (Rubiaceae), Urtica dioica (Urticaceae).

Antioxidant and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities, reducing powers and the amount of total phenolic compounds of aqueous and/or methanolic extracts of some medicinal plants used in Eastern Turkey were studied. These plants are Prangos ferulacea (CASIR), Sedum sempervivoides (HOROZ LELESI), Malva neglecta (EBEMGUMECI), Cruciata taurica (SARILIK OTU), Rosa pimpinellifolia (KOYUN GOZU), Galium verum subsp. verum (MADAVUR OTU), Urtica dioica (ISIRGAN). The highest peroxidation inhibitions were shown by aqueous extracts of C. taurica and R. pimpinellifolia (IC(50): 0.00022 mg/l and IC(50): 23 mg/l, respectively). However, the highest DPPH radical scavenging activity, reducing power and the amount of phenolic compounds were shown by R. pimpinellifolia. The lowest antioxidant properties were shown by aqueous extract of M. neglecta.

Screening chemical composition and in vitro antioxidant and antimicrobial activities of the essential oils from Origanum syriacum L. growing in Turkey.

In the present study, essential oil from the leaves of Syrian oreganum [Origanum syriacum L. (Lauraceae)] grown in Turkish state forests of the Dortyol district, Turkey, was obtained by steam distillation. The chemical composition of oil was analysed by GC and GC-MS, and was found to contain 49.02% monoterpenes, 36.60% oxygenated monoterpenes and 12.59% sesquiterpenes. The major components are as follows: gamma-terpinene, carvacrol, p-cymene and beta-caryophyllene. Subsequently, the reducing power, antioxidant and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activities of the essential oil were studied. The reducing power was compared with ascorbic acid, and the other activities were compared with 2,6-di-tert-butyl-4-methyl phenol (BHT, butylated hydroxytoluene). The results showed that the activities were concentration dependent. The antioxidant activities of the oil were slightly lower than those of ascorbic acid or BHT, so the oil can be considered an effective natural antioxidant. Antimicrobial activities of the essential oil from the leaves of Origanum syriacum was also determined on 16 microorganisms tested using the agar-disc diffusion method, and showed antimicrobial activity against 13 of these.