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Öğe Biological Activity of Natural Formulation with Propolis, Lavender and Thyme Oil on Candida Species(2023) Yoldas, Pinar Agyar; Sıpahı, Nisa; Rasgele, Pinar Goc; Goksu, HaydarObjective: Candida strains have been frequently associated with nosocomial infections in recent years. On the other hand, the public prefers natural resources rather than synthetic materials. Therefore, it is essential to research the combined effects of natural products. This study aimed to investigate the antifungal and antibiofilm effectiveness of essential oils and propolis-containing samples on Candida species and the toxicity of samples. Materials-Methods: Three different samples were prepared with propolis, lavender oil, and thyme oil. Gas Chromatography-mass Spectrometry (GC/MS) GC/MS was used to determine organic compounds in samples. The antifungal effects of a natural product mix were tested against C. albicans, C. krusei, and C. parapsilosis by disk diffusion method. MIC and MFC tests of the mixture were performed against a standard such as Nystatin. Antibiofilm tests were performed with the microplate system, taking into account the detected concentrations, and finally, the cytotoxicity test was investigated in the L929 cell line with the WST-1 kit. Results: C. albicans was determined as the most sensitive species (MIC50: 90 ppm, MIC90: 750 ppm MFC: 3120 ppm). In the antibiofilm tests, it was determined that the sample was more effective on C. albicans, and it inhibited biofilm formation. Also, it was determined that the IC50 value was 5052 ppm. Conclusion: The natural product mixture, which has a scientifically proven antifungal effect, has a feature that has high added value and contributes to the economy. However, of course, it has to investigate by further studies. The findings of this study may lead to new therapeutic approaches with standardized natural products in the future.Öğe Chemoselective hydrogenation of aromatic nitro compounds in the presence of homogeneous Pd based catalysts(Pergamon-Elsevier Science Ltd, 2021) Zengin, Nursefa; Goksu, Haydar; Sen, FatihThe chemoselective reduction of aromatic nitro compounds to amine derivatives was easily performed with remarkable yields under ultrasonic conditions in a H2O/MeOH mixture (v/v = 1/4). In this process, commercially available BINAP.PdCl2 and NaBH4 were used as homogenous catalysts and the hydrogen source, respectively. The developed method has a high economic value and can be adapted to the industry. A variety of nitroarene derivatives were reacted by undergoing the BINAP.PdCl2 catalyzed reduction reaction. All nitroarenes were selectively hydrogenated to aromatic primary amines with quantitative yields in 15 min. The obtained primary amines were determined by 1H and 13C nuclear magnetic resonance spectroscopy.Öğe Investigation of the efficacy on tyrosinase enzyme of 5-substituted-1H-tetrazole derivatives synthesized with Pd-containing nanoparticle(Indian Acad Sciences, 2024) Aydinli, Elif; Hameed, Zeyad Adil; Goksu, Haydar; Adem, SevkiSynthesis of 5-substituted-1H-tetrazole derivatives from aryl aldehydes under the influence of Palladium nanoparticles entrapped in aluminum hydroxide matrix (Pd/AlO(OH) NPs) was carried out in ethanol for 3-6 h. The use of the catalyst in this synthesis is the first. Sodium azide and malononitrile used in the reaction are chemical compounds required in the synthesis of tetrazoles. The reactions were concluded with good yields under thermal conditions. In the reactions, twelve derivatives were synthesized. The synthesized compounds were characterized by IR, 1H, and 13C NMR. The olefinic proton's signal, which is around 8.5 ppm, reveals the formation of the tetrazole ring. The tyrosinase enzyme activity for each synthesized derivative was examined, and the results were recorded. According to the results obtained, all tetrazole derivatives were found to be effective compounds for tyrosinase enzyme inhibition. 3-(3,4-dichlorophenyl)-2-(1H-tetrazol-5-yl)acrylonitrile (2k) with two chloride groups at the meta and para position of the phenyl ring seems to be the most potent tyrosinase inhibitor with an IC50 value of 45 mu M.Graphical abstractSYNOPSIS: 5-substituted-1H-tetrazole derivatives were synthesized under the influence of PdAlO(OH) NPs and under mild conditions. Tyrosinase enzyme activity was investigated for each of the twelve synthesized derivatives. As a result, synthesized tetrazole derivatives were identified as potential tyrosinase inhibitors.Öğe A Novel Hydrogenation of Nitroarene Compounds with Multi Wall Carbon Nanotube Supported Palladium/Copper Nanoparticles (PdCu@MWCNT NPs) in Aqueous Medium(Nature Publishing Group, 2020) Goksu, Haydar; Zengin, Nursefa; Burhan, Hakan; Cellat, Kemal; Sen, FatihA novel nanocatalyst, multi-wall carbon nanotube supported palladium/copper (PdCu@MWCNT) nanoparticles, was synthesized for the reduction of nitroarene compounds. Characterization of the nanocatalyst was achieved by XRD, XPS, TEM, and Raman spectroscopy analysis. In this study, the hydrogenation of nitroarenes to primary amine compounds was achieved in aqueous medium at room temperature. The aniline derivatives were synthesized with high yields at mild conditions via novel PdCu@MWCNT nanocatalyst. The conversion of nitroarenes to amine derivatives was accomplished at 99% efficiency. In addition to its high activity, the PdCu@MWCNT catalyst was determined to be stable and reusable after the 3rd consecutive use for the reaction and provided 99% conversion of various compounds in the reduction reaction.Öğe Preparation of Centella asiatica (L.) and Hypericum perforatum (St. John's Wort) Plant Extracts and Development of Anti-Aging Herbal Cream Formulations(2023) Aydınlı, Elif; Demir, Bayram; Goksu, HaydarObjective: The study aims to use two different plant extracts, St. John's Wort (Hypericum perforatum) and Centella asiatica (L.), in the cream formulation and determine the new formulation's anti-aging effect. Materials-Methods: The plants used in the study were obtained commercially, and plant extracts were obtained using the classical extraction techniques in the literature. The active ingredients in the obtained extracts were determined by the HPLC method. Physical, protective efficacy, microbial analysis, and anti-aging tests were carried out for cream formulations obtained with extracts. Results: Plant extraction studies were carried out in the study. Centella asiatica (L.) was extracted with a 20.8% yield at 20 mL of methanol and 60?. As a result of HPLC analysis, it was determined that there were 1740 mg/kg asiatic acid and 4380 mg/kg madecasic acid in the extract. In the extraction studies performed on Hypericum perforatum, the expected active ingredient, hypericin, was not found. For this reason, a commercial extract containing 2.5% hyperforin was obtained, and the studies were continued on these extracts, and final cream formulations were obtained. Conclusion: pH, viscosity, density, protective effectiveness tests, and microbial analysis tests of the final formulations were performed. In addition, in vitro, anti-aging studies have been carried out in accredited laboratories. In-vitro anti-aging tests determined that the level of collagen 1A increased more in the formulation where both extracts were used together.Öğe Single-Walled Carbon Nanotube Supported PtNi Nanoparticles (PtNi@SWCNT) Catalyzed Oxidation of Benzyl Alcohols to the Benzaldehyde Derivatives in Oxygen Atmosphere(Nature Publishing Group, 2020) Goksu, Haydar; Cellat, Kemal; Sen, FatihThis study reports a developed process which is a general and facile method for the oxidation of benzyl alcohol (BnOH) compounds to the benzaldehyde (BA) derivatives, under mild conditions. The oxidation of BnOH species catalyzed by PtNi@SWCNT in toluene (3ml) at 80 degrees C under a continuous stream of O-2. Single wall carbon nanotube supported PtNi (PtNi@SWCNT) nanoparticles were synthesized using a single-step modified reduction process. The characterization of PtNi@SWCNT nanocatalyst was performed by transmission electron microscope (TEM), X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), and elemental analysis by ICP-OES. A variety of BnOH compounds were oxidized by the PtNi@SWCNT catalyst and all the expected oxidation products were obtained in high efficiency in 2hours of reaction time. TLC was used to monitoring the reaction progress, and the products were identified by H-1/C-13-NMR analysis.Öğe Synthesis of benzylidenemalononitrile by Knoevenagel condensation through monodisperse carbon nanotube-based NiCu nanohybrids(Nature Publishing Group, 2020) Zengin, Nursefa; Burhan, Hakan; Savk, Aysun; Goksu, Haydar; Sen, FatihMonodisperse nickel/copper nanohybrids (NiCu@MWCNT) based on multi-walled carbon nanotubes (MWCNT) were prepared for the Knoevenagel condensation of aryl and aliphatic aldehydes. The synthesis of these nanohybrids was carried out by the ultrasonic hydroxide assisted reduction method. NiCu@MWCNT nanohybrids were characterized by analytical techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM), and Raman spectroscopy. According to characterization results, NiCu@MWCNT showed that these nanohybrids form highly uniform, crystalline, monodisperse, colloidally stable NiCu@MWCNT nanohybrids were successfully synthesized. Thereafter, a model reaction was carried out to obtain benzylidenemalononitrile derivatives using NiCu@MWCNT as a catalyst, and showed high catalytic performance under mild conditions over 10-180 min.
