Konformaciona analiza tri germakranolida PM3 semi-empirijskom metodom

The conformations of the C-6 lactomized germacranolides 1-3 were calculated by applying the PM3 semi-empirical method, The low-temperature H-1-NMR spectra of parthenolide (1) were also measured. The relations between the calculated and the experimentally determined geometries were established using a modified Karplus equation. The applied quantum-chemical calculations proved to be an efficient and easy-to-use tool for die elucidation and prediction of die properties of germacranolide-type sesquiterpene lactones.Konformacije germakranolida 1–3, laktonizovanih u položaju (6), izračunate su primenom PM3 semi-empirijske MO metode. Takođe su snimljeni protonski NMR spektri partenolida (1) na niskim temperaturama. Pomoću modifikovane Karplusove jednačine je uspostavljena korelacija između eksperimentalno utvrđenih i izračunatih najstabilnijih konformacija. Zaključeno je da primenjena kvantno-hemijska izračunavanja brzo i pouzdano mogu predvideti i objasniti osobine seskviterpenskih laktona tipa germakranolida

Antioxidant Enzymes in Blood of Women With Uterine Hyperplasia

The literature emphasizes the involvement of oxidative stress in the etiopathogenesis of many uterine diseases. Antioxidant system (AOS) represents the protective mechanism used by cells to neutralize overproduced reactive oxygen species (ROS) and prevent oxidative stress. We have previously shown that in gynecological patients with various diagnoses, the reproductive and other factors may be associated with antioxidant capacity and the ability to defend against oxidative damage. In this study, we examined the changes in expression of antioxidant enzymes (AOE): superoxide dismutases (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) in the blood of women with endometrial hyperplasia. Our results indicate that hyperplasia induces perturbance in oxidative balance, particularly in glutathione redox cycle enzymes

Supplementary data for the article: Gojgic-Cvijovic, G. D.; Jakovljevic, D. M.; Loncarevic, B. D.; Todorovic, N. M.; Pergal, M. V.; Ciric, J.; Loos, K.; Beškoski, V.; Vrvić, M. M. Production of Levan by Bacillus Licheniformis NS032 in Sugar Beet Molasses-Based Medium. International Journal of Biological Macromolecules 2019, 121, 142–151. https://doi.org/10.1016/j.ijbiomac.2018.10.019

Supplementary material for: [https://www.sciencedirect.com/science/article/pii/S0141813018332847?via%3Dihub]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/350]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/2799

Antioxidant Activity of Selected Polyphenolics in Yeast Cells: The Case Study of Montenegrin Merlot Wine

Screens of antioxidant activity (AA) of various natural products have been a focus of the research community worldwide. This work aimed to differentiate selected samples of Merlot wines originated from Montenegro, with regard to phenolic profile and antioxidant capacity studied by survival rate, total sulfhydryl groups and activities of glutathione peroxidase (GPx), glutathione reductase and catalase in H2O2-stressed Saccharomyces cerevisiae cells. In this study, DPPH assay was also performed. Higher total phenolic content leads to an enhanced AA under both conditions. The same trend was observed for catechin and gallic acid, the most abundant phenolics in the examined wine samples. Finally, the findings of an Artificial Neural Network (ANN) model were in a good agreement (r(2) = 0.978) with the experimental data. All tested samples exhibited a protective effect in H2O2-stressed yeast cells. Pre-treatment with examined wines increased survival in H2O2-stressed cells and shifted antioxidative defense towards GPx-mediated defense. Finally, sensitivity analysis of obtained ANN model highlights the complexity of the impact that variations in the concentrations of specific phenolic components have on the antioxidant defense system

Supplementary data for the article: Gojgic-Cvijovic, G. D.; Jakovljevic, D. M.; Loncarevic, B. D.; Todorovic, N. M.; Pergal, M. V.; Ciric, J.; Loos, K.; Beškoski, V.; Vrvić, M. M. Production of Levan by Bacillus Licheniformis NS032 in Sugar Beet Molasses-Based Medium. International Journal of Biological Macromolecules 2019, 121, 142–151. https://doi.org/10.1016/j.ijbiomac.2018.10.019

Supplementary material for: [https://www.sciencedirect.com/science/article/pii/S0141813018332847?via%3Dihub]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/350]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/2799

Distinct cytotoxic mechanisms of pristine versus hydroxylated fullerene

The mechanisms underlying the cytotoxic action of pure fullerene suspension (nano-C-60) and water-soluble polyhydroxylated fullerene [C-60(OH)(n)] were investigated. Crystal violet assay for cell viability demonstrated that nano-C-60 was at least three orders of magnitude more toxic than C-60(OH)(n) to mouse L929 fibrosarcoma, rat C6 glioma, and U251 human glioma cell lines. Flow cytometry analysis of cells stained with propidium iodide (PI), PI/annexin V-fluorescein isothiocyanate, or the redox-sensitive dye dihydrorhodamine revealed that nano-C-60 caused rapid (observable after few hours), reactive oxygen species (ROS)-associated necrosis characterized by cell membrane damage without DNA fragmentation. In contrast, C-60(OH)(n) caused delayed, ROS-independent cell death with characteristics of apoptosis, including DNA fragmentation and loss of cell membrane asymmetry in the absence of increased permeability. Accordingly, the antioxidant N-acetylcysteine protected the cell lines from nano-C-60 toxicity, but not C-60(OH)(n) toxicity, while the pan-caspase inhibitor z-VAD-fmk blocked C-60(OH)(n)-induced apoptosis, but not nano-C-60-mediated necrosis. Finally, C-60(OH)(n) antagonized, while nano-C-60 synergized with, the cytotoxic action of oxidative stress-inducing agents hydrogen peroxide and peroxynitrite donor 3-morpholinosydnonimine. Therefore, unlike polyhydroxylated C-60 that exerts mainly antioxidant/cytoprotective and only mild ROS-independent pro-apoptotic activity, pure crystalline C-60 seems to be endowed with strong pro-oxidant capacity responsible for the rapid necrotic cell death

Guaianolides from Centaurea nicolai: antifungal activity

A new guaianolide, 3-deacetyl-9-O-acetylsalograviolide A, along with four known closely related lactones, salograviolide A, 9-O-acetylsalograviolide A, kandavanolide and salograviolide B were detected in the aerial parts of the flowering plant Centaurea nicolai. Antifungal tests performed on salograviolide A and its 9-O-acetyl and 3-O-deacetyl-9-O-acetyl derivatives revealed inhibitory activity against Aspergillus niger, A. ochraceus, Penticillium ochrochloron,Cladosporium cladosporodies, Fusharium tricinctum and Phomopsis helianthi. Neither of them was active against Trichoderma viride. (C) 1999 Elsevier Science Ltd. All rights reserved