Forest ecosystems within national parks are threatened by various biotic and abiotic factors. To determine the causes of the desiccation and death of trees in mixed coniferous and deciduous forests ...of Tara National Park (TNP), Serbia, we monitored defoliation and mortality of individual trees in permanent experimental plots. Data on the desiccation of a large number of trees were gathered by determining the total volume of dry trees and areas of forests under drying stress. The two sets of data were combined to determine the impact of climatic events, primarily drought periods, on the desiccation of forests. Combining data from the International Co-operative Program on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests) with TNP data helped relate forest desiccation to climate events. Key climate signals were identified by monitoring tree defoliation changes in two permanent experimental plots, and then assessed for their influence on tree desiccation in the entire national park. The standardized precipitation evapotranspiration index (SPEI) was used for a more detailed analysis of the drought period. Despite the lack of climate data for a certain period, the SPEI index revealed a link between climate variables and the defoliation and desiccation of forests. Furthermore, the desiccation of trees was preceded by a long drought period. Although mixed coniferous-deciduous forests are often considered less vulnerable to natural influences, this study suggests that forest ecosystems can become vulnerable regardless of tree species composition due to multi-year droughts. These findings contribute to a better understanding of important clues for predicting possible future desiccation of forests. Continuous monitoring of the state of forests and of more permanent experimental plots in national parks could provide better quality data and timely responses to stressful situations.
The main goal of this study was to establish the chemical profile of Osage orange (Maclura pomifera) leaf extracts, obtained by conventional maceration technique, and to examine its antimicrobial ...activity. The identification and quantification of the extract compounds were done using ultra‐high‐performance liquid chromatography, with a diode array detector coupled with triple‐quadrupole mass spectrometer and gas chromatography–mass spectrometry techniques. Thirty‐one polyphenolic compounds were detected and identified in the ethanolic extracts, whereby 5‐O‐caffeoylquinic acid was found to be the dominant compound. Among other compounds, pentacosane and palmitic acid were the most abundant compounds in the dichloromethane extract. The preliminary antimicrobial activity screening shows that Gram‐positive bacteria tend to be more sensitive to the investigated extracts. The highest antimicrobial activity was determined against Enterococcus faecalis ATCC 19433 and Listeria monocytogenes ATCC 35152. From these results, Osage orange leaves can be considered as plant material with significant antimicrobial properties.
The chemical profile of Osage orange (Maclura pomifera) leaf extracts obtained by conventional maceration was established, identifying 31 polyphenolic compounds in the ethanolic extracts, with 5‐O‐caffeoylquinic acid as the main compound. The highest antimicrobial activity was determined against Enterococcus faecalis ATCC 19433 and Listeria monocytogenes ATCC 35152.
Display omitted
•Bay laurel’s essential oil from Serbia (SRBL) and Russia (RFBL) (EO) were analyzed.•The oils evaporation process took place in two steps.•SRBL evaporated slower at the higher ...temperatures then RFBL.•Antioxidant activity assays showed that SRBL was more potent then RFBL.•Antimicrobial activity showed different affinity oils toward tested microorganisms.
Laurus nobilis (bay laurel) form Serbia (SRBL) and Russia (RFBL) were analyzed in order to establish the chemical profile, thermal properties and biological activity. The GC/MS analysis showed that α-pinene (31.97%) is principal compound in the RFBL followed by eucalyptol (27.95%) and α-terpineol (10.28%). In the case of the SRBL, eucalyptol (40.51%) is the most abundant compound followed by α-terpineol (15.46%), while α-pinene was found in much lower amount (4.45%). Thermal analysis showed that the evaporation process of both oils was complex process and took place in two phases. Moreover, results indicated that the SRBL evaporated slower at the higher temperatures than the RFBL. In order to assess biological activity, the antioxidant and antimicrobial activities were investigated. The SRBL was more potent antioxidant agent in the case of both assays (DPPH and total reduction capacity). In the case of the antimicrobial activity, the SRBL showed greater potential of antimicrobial activities toward all tested microorganisms, while RFBL was found to be effective against all the bacteria and yeast, but did not possess any inhibitory action against fungi. Results indicate that both oils may be used in the food and pharmaceutical industries as antioxidant and antimicrobial agent.
Interactions of an array of nucleic acid structures with a small series of benzothiazole ligands (bis-benzothiazolyl-pyridines-group 1, 2-thienyl/2-benzothienyl-substituted ...6-(2-imidazolinyl)benzothiazoles-group 2, and three 2-aryl/heteroaryl-substituted 6-(2-imidazolinyl)benzothiazoles-group 3) were screened by competition dialysis. Due to the involvement of DNA:RNA hybrids and triplex helices in many essential functions in cells, this study's main aim is to detect benzothiazole-based moieties with selective binding or spectroscopic response to these nucleic structures compared to regular (non-hybrid) DNA and RNA duplexes and single-stranded forms. Complexes of nucleic acids and benzothiazoles, selected by this method, were characterized by UV/Vis, fluorescence and circular dichroism (CD) spectroscopy, isothermal titration calorimetry, and molecular modeling. Two compounds (
and
) from groups 1 and 2 demonstrated the highest affinities against 13 nucleic acid structures, while another compound (
) from group 2, despite lower affinities, yielded higher selectivity among studied compounds. Compound
significantly inhibited RNase H. Compound
could differentiate between B- (binding of
dimers inside minor groove) and A-type (intercalation) helices by an induced CD signal, while both
and
selectively stabilized ATT triplex in regard to AT duplex. Compound
induced strong condensation-like changes in CD spectra of AT-rich DNA sequences.
This article attempts to assess differences in social capital of religious and nonreligious respondents in Mediterranean and Continental Croatia, based on the results of a 2018 nationally ...representative survey. The approach to analysis is based primarily on Bourdieu's concept of social capital, but in addition to "structural" (networks of relationships and reliance), it also includes "cultural" (different forms of trust) indicators. The results of the analysis reveal that religiosity of the respondents and the types of their social capital are differently distributed in Mediterranean and Continental Croatia, as well as in the capital city of Zagreb, which was analysed separately, since previous research suggested that numerous indicators for that city differ significantly from those of the general sample. The analysis also revealed differences in the levels of "generalized trust" and trust in institutions, which were included to complement insights gained by the application of Bourdieu's (structural) analytical categories. The religiosity of the respondents has been shown to be related to their social capital in all the analysed geographical regions (both in its "structural" and "cultural" aspects), yet in somewhat different ways. These differences can be partly explained by different histories of the interpenetration of religiosity and culture in different regions. However, the results suggest that the position of the respondents in the space of social inequalities should also be further researched.
This work is about synergy of theory and experiment in revealing mechanism of binding of dipeptidyl peptidase III (DPP III) and Kelch-like ECH-associated protein 1 (KEAP1), the main cellular sensor ...of oxidative stress. The NRF2 ̶ KEAP1 signaling pathway is important for cell protection, but it is also impaired in many cancer cells where NRF2 target gene expression leads to resistance to chemotherapeutic drugs. DPP III competitively binds to KEAP1 in the conditions of oxidative stress and induces release of NRF2 and its translocation into nucleus. The binding is established mainly through the ETGE motif of DPP III and the Kelch domain of KEAP1. However, although part of a flexible loop, ETGE itself is firmly attached to the DPP III surface by strong hydrogen bonds. Using combined computational and experimental study, we found that DPP III ̶ Kelch binding is a two-step process comprising the endergonic loop detachment and exergonic DPP III ̶ Kelch interaction. Substitution of arginines, which keep the ETGE motif attached, decreases the work needed for its release and increases DPP III ̶ Kelch binding affinity. Interestingly, mutations of one of these arginine residues have been reported in cBioPortal for cancer genomics, implicating its possible involvement in cancer development.
Communicated by Ramaswamy H. Sarma
Takayasu's arteritis (TA) is well-known yet rare disorder, defined as a chronic large vessel vasculitis mainly involving the aorta and its major branches. We present a complex case of a 51-year-old ...female patient who first presented with acute myocardial infarction as an initial manifestation of Takayasu arteritis, and later with an acute onset of ischemic stroke.
We present a case of 51-year-old female patient who was admitted at the Clinic of Nephrology and Clinical Immunology. During hospitalization, a sudden onset of intense chest pain occurred, followed by a development of heart failure to the level of cardiogenic shock. Electrocardiography showed signs of ST-elevated myocardial infarction (STEMI) of the anterior wall, and an increase in cardiospecific enzymes. CT angiography indicated an occlusion of the left common carotid artery (ACC), subclavian and axillary arteries as well as a penetrating aortic ulcer localized infrarenal. In the further course of treatment, left-sided weakness of the body was registered. Head CT scan showed an acute ischemic lesion high parietal on the right, as well as a chronic ischemic lesion on the front right. Doppler ultrasonography of carotid and vertebral arteries registered left occlusion, right ACC/external carotid artery (ACE) stenosis with suspected "macaroni sign". Final diagnosis of Takayasu arteritis was established and corticosteroids were included in the therapy (primarily in pulse doses) with the first pulse of cyclophosphamide of 1000mg.
This disease should be considered in female patients who present with chronic inflammation and acute coronary syndrome.
Dipeptidyl peptidase III (DPP III) is a zinc dependant peptidase which catalyses hydrolysis of the second peptide bond from the N-termini of its substrates. DPP III is an enzyme of broad substrate ...specificity and it has been found in many organisms. It has been recognised in several processes of interest for drug development like pain modulation and defence against oxidative stress. However, its fundamental physiological role is unknown and specific inhibitors would be of significant help in identifying this role. In this work we combined experimental (UV/Vis, fluorimetry and microcalorimetry experiments) with molecular dynamic simulations to study the binding of several newly designed and synthesised guanidiniocarbonyl-pyrrole-aryl conjugates to human DPP III. We found that new compounds bind with micromolar affinity to the enzyme and with varied efficiency inhibit hydrolysis of Arg-Arg-2-naphthylamide, the standard synthetic substrate of DPP III. The molecular modelling study revealed multiple binding modes of the guanidiniocarbonyl-pyrrole-aryl conjugates into the active site of human DPP III. In order to elucidate which one is the most favourable we studied the molecular determinants for their binding to DPP III as well as their influence on protein structure. It seems that the main requirement for a good DPP III inhibitor is a bulky aryl-substituent and a linker of suitable length and flexibility between it and the guanidiniocarbonyl-pyrrole. The obtained results gave directions for future development and improvement of DPP III inhibitors.
Brassica rapa auxin amidohydrolase (BrILL2) participates in the homeostasis of the plant hormones auxins by hydrolyzing the amino acid conjugates of auxins, thereby releasing the free active form of ...hormones. Herein, the potential role of the two conserved Cys residues of BrILL2 (at sequence positions 139 and 320) has been investigated by using interdisciplinary approaches and methods of molecular biology, biochemistry, biophysics and molecular modelling. The obtained results show that both Cys residues participate in the regulation of enzyme activity. Cys320 located in the satellite domain of the enzyme is mainly responsible for protein stability and regulation of enzyme activity through polymer formation, as has been revealed by enzyme kinetics and differential scanning calorimetry analysis of the BrILL2 wild type and mutants C320S and C139S. Cys139 positioned in the active site of the catalytic domain is involved in the coordination of one Mn(2+) ion of the bimetal center and is crucial for the enzymatic activity. Although the point mutation Cys139 to Ser causes the loss of enzyme activity, it does not affect the metal binding to the BrILL2 enzyme, as has been shown by isothermal titration calorimetry, circular dichroism spectropolarimetry and differential scanning calorimetry data. MD simulations (200 ns) revealed a different active site architecture of the BrILL2C139S mutant in comparison to the wild type enzyme. Additional possible reasons for the inactivity of the BrILL2C139S mutant have been discussed based on MD simulations and MM-PBSA free energy calculations of BrILL2 enzyme complexes (wt and C139S mutant) with IPA-Ala as a substrate.
PDF
