Lignin and organic free radicals in maize (Zea mays L.) seeds in response to aflatoxin B1 contamination: an optical and EPR spectroscopic study.

BACKGROUND: Aflatoxin B1 (AFB1 ) is the most dangerous of the mycotoxins that contaminate cereal seeds naturally. A stress lignin formation is linked with the accumulation of reactive oxygen species causing a change in the redox status and formation of stable organic radicals, constituting the first layer of defense. The relationship between AFB1 and changes in lignin organic free radicals in seeds is not known, nor is the part of the seed that is more targeted. Using optical and electron paramagnetic resonance spectroscopy, we investigated AFB1 -induced changes in lignin and organic free radicals in seeds, and whether the inner and outer seed fractions differ in response to increasing AFB1 . RESULTS: Different changes in the content of lignin and free radicals with increasing AFB1 concentrations were observed in the two seed fractions. There was a significant positive linear correlation (R = 0.9923, P = 0.00005) between lignin content and AFB1 concentration in the outer fraction, and no correlation between the lignin content and the AFB1 concentration in the inner fraction. We found a positive correlation between the area of the green spectral emission component (C4) and the AFB1 concentration in the outer fraction. CONCLUSIONS: To the best of our knowledge, the results showed, for the first time, that maize seed fractions respond differently to aflatoxin with regard to their lignin and organic free radical content. Lignin content and (C4) area may be reliable indicators for the screening of lignin changes against AFB1 content in the seeds, and thus for seed protection capacity. © 2021 Society of Chemical Industry.

Controlled killing of human cervical cancer cells by combined action of blue light and C-doped TiO2 nanoparticles.

In this study, C-doped TiO2 nanoparticles (C-TiO2) were prepared and tested as a photosensitizer for visible-light-driven photodynamic therapy against cervical cancer cells (HeLa). X-ray diffraction and Transmission Electron Microscopy confirmed the anatase form of nanoparticles, spherical shape, and size distribution from 5 to 15 nm. Ultraviolet-visible light spectroscopy showed that C doping of TiO2 enhances the optical absorption in the visible light range caused by a bandgap narrowing. The photo-cytotoxic activity of C-TiO2 was investigated in vitro against HeLa cells. The lack of dark cytotoxicity indicates good biocompatibility of C-TiO2. In contrast, a combination with blue light significantly reduced the survival of HeLa cells: illumination only decreased cell viability by 30% (15 min of illumination, 120 µW power), and 60% when HeLa cells were preincubated with C-TiO2. We have also confirmed blue light-induced C-TiO2-catalyzed generation of reactive oxygen species in vitro and intracellularly. Oxidative stress triggered by C-TiO2/blue light was the leading cause of HeLa cell death. Fluorescent labeling of treated HeLa cells showed distinct morphological changes after the C-TiO2/blue light treatment. Unlike blue light illumination, which caused the appearance of large necrotic cells with deformed nuclei, cytoplasm swelling, and membrane blebbing, a combination of C-TiO2/blue light leads to controlled cell death, thus providing a better outcome of local anticancer therapy.

Spatial distribution of apoplastic antioxidative constituents in maize root.

Apoplastic antioxidative constituents (enzymes, primary and secondary metabolites, ROS) from different root zones of hydroponically grown maize (Zea mays L.) were investigated using a noninvasive isolation procedure: filter strip method. Filter strips were placed at specific positions on the root surface: apical zone (tip) and basal zone (base) to absorb apoplastic fluid. Three major classes of low-weight metabolites (organic acids, sugars, and phenolics) have been identified by HPLC-ECD. The longitudinal distribution of sugars and organic acids had the same pattern: higher concentration in the tip than the base, while it was vice versa for phenolics. The specific activities of guaiacol peroxidase, superoxide dismutase, and ascorbate peroxidase were higher in the apoplastic fluid from the root base than the tip, and their different isoforms were separated by isoelectric focusing. Electron paramagnetic resonance (EPR) spectroscopy coupled with the spin-trapping method using DEPMPO showed a persistent generation of hydroxyl radical in the root tip. In vivo EPR imaging of the whole maize root with membrane-permeable and impermeable aminoxyl spin-probes, enabling real-time detection of ROS formation within and outside the membranes, demonstrated ROS accumulation on the root surface, while endodermis and central cylinder were ROS free. For the first time in plant research, 2D EPR images enabled the direct demonstration of site-specific free radical production along the root. Highly sensitive analytical techniques combined with the filter strips, as a non-invasive tool, have increased our knowledge of metabolic processes occurring in the apoplast and their spatial-temporal changes in small regions of the intact root tissue.

Bifunctional catalytic activity of Zn1-xFexO toward the OER/ORR: seeking an optimal stoichiometry.

Eco-friendly and rapid microwave processing of a precipitate was used to produce Fe-doped zinc oxide (Zn1-xFexO, x = 0, 0.05, 0.1, 0.15 and 0.20; ZnO:Fe) nanoparticles, which were tested as catalysts toward the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in a moderately alkaline solution. The phase composition, crystal structure, morphology, textural properties, surface chemistry, optical properties and band structure were examined to comprehend the influence of Zn2+ partial substitution with Fe3+ on the catalytic activity of ZnO:Fe. Linear sweep voltammetry showed an improved catalytic activity of ZnO:5Fe toward the ORR, compared to pure ZnO, while with increased amounts of the Fe-dopant the activity decreased. The improvement was suggested by a more positive onset potential (0.394 V vs. RHE), current density (0.231 mA cm-2 at 0.150 V vs. RHE), and faster kinetics (Tafel slope, b = 248 mV dec-1), and it may be due to the synergistic effect of (1) a sufficient amount of surface oxygen vacancies, and (2) a certain amount of plate-like particles composed of crystallites with well developed (0001) and (0001[combining macron]) facets. Quite the contrary, the OER study showed that the introduction of Fe3+ ions into the ZnO crystal structure resulted in enhanced catalytic activity of all ZnO:Fe samples, compared to pure ZnO, probably due to the modified binding energy and an optimized band structure. With the maximal current density of 1.066 mA cm-2 at 2.216 V vs. RHE, an onset potential of 1.856 V vs. RHE, and the smallest potential difference between the OER and ORR (ΔE = 1.58 V), ZnO:10Fe may be considered a promising bifunctional catalyst toward the OER/ORR in moderately alkaline solution. This study demonstrates that the electrocatalytic activity of ZnO:Fe strongly depends on the defect chemistry and consequently the band structure. Along with providing fundamental insight into the electrocatalytic activity of ZnO:Fe, the study also indicates an optimal stoichiometry for enhanced bifunctional activity toward the OER/ORR, compared to pure ZnO.

Liposomal integration method for assessing antioxidative activity of water insoluble compounds towards biologically relevant free radicals: example of avarol.

The liposomal integration method, in conjunction with electron paramagnetic resonance (EPR) spectroscopy, has been presented for the investigation of antioxidant activity of selected water-insoluble compound towards biologically relevant free radicals. This method was applied to avarol, a sesquiterpenoid hydroquinone isolated from the marine sponge Dysidea avara. The antioxidant activity of water-insoluble avarol towards •OH, O2•- and NO• radicals was attained by its incorporation into the DPPC liposomes bilayer, and towards ascorbyl radicals in the organic solvent. Avarol's activity towards •OH, O2•-, NO• and ascorbyl radicals was 86.2%, 50.9%, 23.6% and 61.8%, respectively, showing its significant radical scavenging potential.

Impact of Differences in Economic Development and Socioeconomic Stability on Benzodiazepine Exposure between the Three Balkans Countries.

INTRODUCTION: Anxiety disorders are among the most common mental disorders. Benzodiazepines belong to the group of anxiolytic sedatives and the most prescribed drugs in the world. The aim in ours study was to evaluate the differences in the exposure of the population to benzodiazepines (in period from 2014-2018) between Serbia, Slovenia and Croatia, the three countries of the Southwestern Balkans with varying degrees of socioeconomic development. STUDY DESIGN: A academic investigator initiated, pharmacoepidemiological difference-in-difference time series analysis of population exposure to benzodiazepines between the three, geographically close Balkans countries (Slovenia, Serbia, Croatia) with varying degrees of socioeconomic development has been carried out. Study was conducted as academic investigator initiated, in a retrospective manner on monthly basis international data set from January 2014 to December 2018. RESULTS: At the annual level, during the study period from January 2014 to December 2018, compared to Slovenia, Serbia and Croatia had higher DIDs, from 5 fold (Croatia) to 6 fold (Serbia), for all benzodiazepines in total. By analyzing the differences-in-difference, we have shown that influence of both time (month) and country on DIDs is significant as well as their mutual interaction (the country x month) for all benzodiazepines in total. CONCLUSION: Serbia and Croatia must implement explicit measures of reducing benzodiazepine prescription in health primary care based on evidence-based recommendations in the indications where general medicine practitioners/family doctors most commonly prescribe these medicines. Without providing a realistic supplement/alternative to benzodiazepines such as increasing the availability of psychotherapy and improving the structure of psychiatric professionals in healthcare settings, implicit measures are not recommended for reducing prescription, implementing accountability measures for prolonged prescription of benzodiazepines, and in particular for "masked" somatic diseases. All this comes to the fore by raising economic development and socioeconomic stability.

Changes of the peripheral blood mononuclear cells membrane fluidity from type 1 Gaucher disease patients: an electron paramagnetic resonance study.

Gaucher disease (GD) is a lysosomal storage disorder, caused by an impaired function of ß-glucocerebrosidase, which results in accumulation of glucocerebroside in cells, and altered membrane ordering. Using electron paramagnetic resonance spin labeling, a statistically significant difference in the order parameter between the peripheral blood mononuclear cell membranes of GD patients and healthy controls was observed. Moreover, the results show that the introduction of the enzyme replacement therapy leads to the restoration of the physiological membrane fluidity. Accordingly, this simple method could serve as a preliminary test for GD diagnosis and therapy efficiency.

Maleimido-proxyl as an EPR spin label for the evaluation of conformational changes of albumin.

Albumin is the most abundant plasma protein and as such has been the subject of many studies using a variety of techniques. One of them, capable of monitoring the conformational changes and the binding capacity of proteins, is electron paramagnetic resonance spectroscopy (EPR) spin labeling. To date, albumin has been investigated using a number of different spin labels, mostly spin-labeled fatty acids (SLFAs). However, albumin can bind up to seven equivalents of fatty acids, making it difficult to determine which parts of the molecule undergo conformational changes. To obtain information from a specific site on a protein, spin labels that bind to free cysteine residues may be used. In this work, the applicability of such a label, 3-maleimido proxyl (5-MSL), was evaluated for monitoring conformational changes of bovine serum albumin (BSA) at different temperatures and pH values. Also, the effect of ethanol, reactive oxygen species (hydrogen peroxide and superoxide radical), and the binding of ligands specific for albumin, namely fatty acids, and several drugs were evaluated. The results indicate that the labeling of albumin at its free cysteine residue (Cys-34) using 5-MSL may successfully be used for the detection of conformational changes, even in the case of the subtle alterations induced by ligand binding.

Investigation of the Halogenate-Hydrogen Peroxide Reactions Using the Electron Paramagnetic Resonance Spin Trapping Technique.

The differences in the mechanism of the halogenate reactions with the same oxidizing/reducing agent, such as H2O2 contribute to the better understanding of versatile halogen chemistry. The reaction between iodate, bromate, and chlorate with hydrogen peroxide in acidic medium at 60 °C is investigated by using the electron paramagnetic resonance (EPR) spin trapping technique. Essential differences in the chemistry of iodate, bromate, and chlorate in their reactions with hydrogen peroxide have been evidenced by finding different radicals as governing intermediates. The reaction between KIO3 and H2O2 is supposed to be the source of IO2• radicals. The KBrO3 and H2O2 reaction did not produce any EPR signal, whereas the KClO3-H2O2 system was found to be a source of HO• radical. Moreover, KClO3 dissolved in sulfuric acid without hydrogen peroxide produced HO• radical as well. The minimal-core models explaining the origin of obtained EPR signals are proposed. Current findings suggested the inclusion of IO2• and HOO• radicals, and ClO2• and HO• radicals in the particular kinetic models of iodate-hydrogen peroxide and chlorate-hydrogen peroxide systems, as well as possible exclusion of BrO2• radical from the kinetic scheme of the bromate-hydrogen peroxide system. Obtained results may pave the way for understanding more complex, nonlinear reactions of these halogen-containing species.

Variation in nutritional quality and chemical composition of fresh strawberry fruit: combined effect of cultivar and storage.

Bioclimatic air ionisation system (BI) works by neutralising air pollutants and microorganisms by means of oxidation with "activated oxygen". We investigated the effects of storage on changes in weight loss, chemical and sensory fruit properties in eight cultivars of strawberries (Fragaria x ananassa Duch.). All cultivars were evaluated for their standard parameters of quality (soluble solids content, total acidity, vitamin C content, total antioxidant activity - TAC, total phenolic and anthocyanins content) at different store conditions: fresh fruits-control, cold stored (at 4 °C) fruits without controlled atmospheres and cold stored (at 4 °C) fruits in BI. The present study outlines that anthocyanins of the strawberries stored in BI were subjected to significant degradation. These strawberries have prolonged shelf-life accompanied by weight loss reduction, TAC increment, and sensory properties improvement in tested cultivars, retaining other nutritional fruit qualities.

Effects of terminal dimethylation and metal coordination of proline-2-formylpyridine thiosemicarbazone hybrids on lipophilicity, antiproliferative activity, and hR2 RNR inhibition.

The nickel(II), copper(II), and zinc(II) complexes of the proline-thiosemicarbazone hybrids 3-methyl-(S)-pyrrolidine-2-carboxylate-2-formylpyridine thiosemicarbazone (L-Pro-FTSC or (S)-H2L(1)) and 3-methyl-(R)-pyrrolidine-2-carboxylate-2-formylpyridine thiosemicarbazone (D-Pro-FTSC or (R)-H2L(1)), as well as 3-methyl-(S)-pyrrolidine-2-carboxylate-2-formylpyridine 4,4-dimethyl-thiosemicarbazone (dm-L-Pro-FTSC or (S)-H2L(2)), namely, [Ni(L-Pro-FTSC-2H)]2 (1), [Ni(D-Pro-FTSC-2H)]2 (2), [Ni(dm-L-Pro-FTSC-2H)]2 (3), [Cu(dm-L-Pro-FTSC-2H)] (6), [Zn(L-Pro-FTSC-2H)] (7), and [Zn(D-Pro-FTSC-2H)] (8), in addition to two previously reported, [Cu(L-Pro-FTSC-2H)] (4), [Cu(D-Pro-FTSC-2H)] (5), were synthesized and characterized by elemental analysis, one- and two-dimensional (1)H and (13)C NMR spectroscopy, circular dichroism, UV-vis, and electrospray ionization mass spectrometry. Compounds 1-3, 6, and 7 were also studied by single-crystal X-ray diffraction. Magnetic properties and solid-state high-field electron paramagnetic resonance spectra of 2 over the range of 50-420 GHz were investigated. The complex formation processes of L-Pro-FTSC with nickel(II) and zinc(II) were studied in aqueous solution due to the excellent water solubility of the complexes via pH potentiometry, UV-vis, and (1)H NMR spectroscopy. The results of the antiproliferative activity in vitro showed that dimethylation improves the cytotoxicity and hR2 RNR inhibition. Therefore, introduction of more lipophilic groups into thiosemicarbazone-proline backbone becomes an option for the synthesis of more efficient cytotoxic agents of this family of compounds.

Increased survival after irradiation followed by regeneration of bone marrow stromal cells with a novel thiol-based radioprotector.

AIM: To investigate the survival of laboratory rats after irradiation and to study the cellularity of their bone marrow and the multipotential mesenchymal stem cells (BM-MSCs) in groups treated with or without a new thiol-based radioprotector (GM2011). METHODS: Animals were irradiated by a Cobalt gamma source at 6.7 Gy. Treated animals were given i.p. GM2011 30 minutes before and 3 and 7 hours after irradiation. Controls consisted of sham irradiated animals without treatment and animals treated without irradiation. After 30 days post-irradiation, animals were sacrificed and bone marrow cells were prepared from isolated femurs. A colony forming unit-fibroblast (CFU-F) assay was performed to obtain the number of BM-MSCs. RESULTS: In the treated group, 87% of animals survived, compared to only 30% in the non-treated irradiated group. Irradiation induced significant changes in the bone marrow of the treated rats (total bone marrow cellularity was reduced by~60%--from 63 to 28 cells × 10(6)/femur and the frequency of the CFU-F per femur by~70% - from 357 to 97), however GL2011 almost completely prevented the suppressive effect observed on day 30 post-irradiation (71 cells × 10(6)/femur and 230 CFU-F/femur). CONCLUSION: Although the irradiation dosage was relatively high, GL2011 acted as a very effective new radioprotector. The recovery of the BN-MSCs and their counts support the effectiveness of the studied radioprotector.

Bridging the buzz: In vivo EPR imaging unlocking the secrets of honey bee health.

Honey bees play a pivotal role in shaping ecosystems and sustaining human health as both pollinators and producers of health-promoting products. However, honey bee colony mortality is on the rise globally, driven by various factors, including parasites, pesticides, habitat loss, poor nutrition, and climate change. This has far-reaching consequences for the environment, economy, and human welfare. While efforts to address these issues are underway, the current progress in electron paramagnetic resonance (EPR) instrumentation affords using the immense potential of this magnetic resonance technique to study small samples such as honey bees. This paper presents the pioneering 2D in vivo EPR imaging experiment on a honey bee, revealing the ongoing redox-status of bees' intestines. This way, by monitoring the spatio-temporal changes of the redox-active spin-probes' EPR signal, it is possible to gain access to valuable information on the course of ongoing bees' pathologies and the prospect of following-up on the efficiency of applied therapies. Employing a selection of diverse spin-probes could further reveal pH levels and oxygen concentrations in bee tissues, allowing a noninvasive assessment of bee physiology. This approach offers promising strategies for safeguarding pollinators and understanding their biology, fostering their well-being and ecological harmony.

Radicals in the Bray-Liebhafsky oscillatory reaction.

This study investigates the formation of free radicals in the Bray-Liebhafsky (BL) oscillatory reaction. The results indicate that radicals are produced during both monotonous and oscillatory dynamics observed as the change of the electron paramagnetic signal (EPR) of the spin-probe TEMPONE. EPR spin-trapping with DEPMPO suggested that the most abundant radical produced in the BL reaction is an iodine-centered radical. The EPR spectrum of the DEPMPO/iodine-centered radical adducts has not been previously reported. This study may aid in establishing a more realistic reaction mechanism of the BL reaction and related chemical oscillators.

Hydrogen peroxide and ecdysone in the cryoprotective dehydration strategy of Megaphorura arctica (Onychiuridae: Collembola).

The Arctic springtail, Megaphorura arctica, survives sub-zero temperatures in a dehydrated state via trehalose-dependent cryoprotective dehydration. Regulation of trehalose biosynthesis is complex; based in part on studies in yeast and fungi, its connection with oxidative stress caused by exposure of cells to oxidants, such as hydrogen peroxide (H2O2), or dehydration, is well documented. In this respect, we measured the amount of H2O2 and antioxidant enzyme activities (superoxide dismutases: copper, zinc--CuZnSOD and manganese containing--MnSOD, and catalase--CAT), as the regulatory components determining H2O2 concentrations, in Arctic springtails incubated at 5 °C (control) versus -2 °C (threshold temperature for trehalose biosynthesis). Because ecdysone also stimulates trehalose production in insects and regulates the expression of genes involved in redox homeostasis and antioxidant protection in Drosophila, we measured the levels of the active physiological form of ecdysone--20-hydroxyecdysone (20-HE). Significantly elevated H2O2 and 20-HE levels were observed in M. arctica incubated at -2 °C, supporting a link between ecdysone, H2O2, and trehalose levels during cryoprotective dehydration. CAT activity was found to be significantly lower in M. arctica incubated at -2 °C versus 5 °C, suggesting reduced H2O2 breakdown. Furthermore, measurement of the free radical composition in Arctic springtails incubated at 5 °C (controls) versus -2 °C by Electron Paramagnetic Resonance spectroscopy revealed melanin-derived free radicals at -2 °C, perhaps an additional source of H2O2. Our results suggest that H2O2 and ecdysone play important roles in the cryoprotective dehydration process in M. arctica, linked with the regulation of trehalose biosynthesis.

Solanum dulcamara L. Berries: A Convenient Model System to Study Redox Processes in Relation to Fruit Ripening.

The present study provides, for the first time, a physicochemical and biochemical characterization of the redox processes associated with the ripening of Solanum dulcamara L. (bittersweet) berries. Electron Paramagnetic Resonance Spectroscopy (EPRS) and Imaging (EPRI) measurements of reactive oxygen species (ROS) were performed in parallel with the tissue-specific metabolic profiling of major antioxidants and assessment of antioxidant enzymes activity. Fruit transition from the mature green (MG) to ripe red (RR) stage involved changes in the qualitative and quantitative content of antioxidants and the associated cellular oxidation and peroxidation processes. The skin of bittersweet berries, which was the major source of antioxidants, exhibited the highest antioxidant potential against DPPH radicals and nitroxyl spin probe 3CP. The efficient enzymatic antioxidant system played a critical protective role against the deleterious effects of progressive oxidative stress during ripening. Here, we present the EPRI methodology to assess the redox status of fruits and to discriminate between the redox states of different tissues. Interestingly, the intracellular reoxidation of cell-permeable nitroxide probe 3CP was observed for the first time in fruits or any other plant tissue, and its intensity is herein proposed as a reliable indicator of oxidative stress during ripening. The described noninvasive EPRI technique has the potential to have broader application in the study of redox processes associated with the development, senescence, and postharvest storage of fruits, as well as other circumstances in which oxidative stress is implicated.

Free radicals identification from the complex EPR signals by applying higher order statistics.

EPR spin-trapping technique, using spin-trap DEPMPO, has been shown to be capable of simultaneous detection of multiple free radical species which are generated in the same system. However, such approach proved to be unsuitable due to the complexity of the obtained composite EPR signal of the spin-adducts. Although rather unique, each individual spin-adduct signal is composed of at least eight EPR peaks, thus many of them could be overlapped, making the signal separation process almost impossible to accomplish by using ordinary chemometrics methods such as fast independent component analysis (FastICA), factor analysis (FA), or parallel factor analysis (PARAFAC). We have proposed a new approach which involves cumulative usage of two different statistical techniques. Applied algorithms are based on the second order statistics, second order blind identification with the robust orthogonalization algorithm (SOBI-RO), and the constrained independent component analysis (CICA).

Silicon ameliorates manganese toxicity in cucumber by decreasing hydroxyl radical accumulation in the leaf apoplast.

This work was focused on the role of silicon (Si) in amelioration of manganese (Mn) toxicity caused by elevated production of hydroxyl radicals (·OH) in the leaf apoplast of cucumber (Cucumis sativus L.). The plants were grown in nutrient solutions with adequate (0.5 µM) or excessive (100 µM) Mn concentrations with or without Si being supplied. The symptoms of Mn toxicity were absent in the leaves of Si-treated plants subjected to excess Mn, although the leaf Mn concentration remained extremely high. The apoplastic concentration of free Mn(2+) and H(2)O(2) of high Mn-treated plants was significantly decreased by Si treatment. Si supply suppressed the Mn-induced increased abundance of peroxidase (POD) isoforms in the leaf apoplastic fluid, and led to a rapid suppression of guaiacol-POD activity under excess Mn. The spin-trapping reagent 5-(diethoxyphosphoryl)-5-methyl-1-pyrroline-N-oxide was used to detect ·OH by electron paramagnetic resonance spectroscopy. Although supplying Si markedly decreased the accumulation of ·OH in the leaf apoplast with excess Mn, adding monosilicic acid to the Mn(2+)/H(2)O(2) reaction mixture did not directly affect the Fenton reaction in vitro. The results indicate that Si contributes indirectly to a decrease in ·OH in the leaf apoplast by decreasing the free apoplastic Mn(2+), thus regulating the Fenton reaction. A direct inhibitory effect of Si on guaiacol-POD activity (demonstrated in vitro) may also contribute to decreasing the POD-mediated generation of ·OH.

Raman microspectroscopy as a biomarking tool for in vitro diagnosis of cancer: a feasibility study.

AIM: To elucidate whether Raman spectroscopy aided by extensive spectral database and neural network analysis can be a fast and confident biomarking tool for the diagnosis of various types of cancer. METHODS: Study included 27 patients with 11 different malignant tumors. Using Raman microscopy (RM) a total of 540 Raman spectra were recorded from histology specimens of both tumors and surrounding healthy tissues. Spectra were analyzed using the principal component analysis (PCA) and results, along with histopathology data, were used to train the neural network (NN) learning algorithm. Independent sets of spectra were used to test the accuracy of PCA/NN tissue classification. RESULTS: The confident tumor identification for the purpose of medical diagnosis has to be performed by taking into account the whole spectral shape, and not only particular spectral bands. The use of PCA/NN analysis showed overall sensitivity of 96% with 4% false negative tumor classification. The specificity of distinguishing tumor types was 80%. These results are comparable to previously published data where tumors of only one tissue type were examined and can be regarded satisfactorily for a relatively small database of Raman spectra used here. CONCLUSION: In vitro RM combined with PCA/NN is an almost fully automated method for histopathology at the level of macromolecules. Supported by an extensive tumor spectra database, it could become a customary histological analysis tool for fast and reliable diagnosis of different types of cancer in clinical settings.

Rich in Phenolics-Strong Antioxidant Fruit? Comparative Study of 25 Strawberry Cultivars.

Phenolic compounds of 25 newly introduced strawberry cultivars were profiled using spectrophotometry, electron paramagnetic resonance (EPR) spectroscopy, and high-performance liquid chromatography-mass spectrometry. Total phenolic and anthocyanin content (TPC and TACY, respectively), as well as vitamin C, and concentrations of individual phenolic compounds in fruits were evaluated to identify the most promising cultivars according to their phenolic profile. The highest values of TPC, TACY, and vitamin C were recorded in 'Premy' (1.53 mg eq GA g-1 FW), 'Sandra' (30.60 mg eq Pg-3-g 100 g-1 FW), and 'Laetitia' (56.32 mg 100 g-1 FW), respectively. The DPPH and •OH radicals scavenging activity of fruit methanolic extracts was estimated using EPR spectroscopy. All cultivars are almost uniformly effective in the scavenging of •OH radical, while 'Tea', 'Premy', and 'Joly' were marked as highly potent cultivars (over 70%) in terms of DPPH-antiradical activity. Specific peroxidase activities were the highest in 'Garda', 'Federica', and 'Rumba' (0.11, 0.08, and 0.06 U mg-1 prot, respectively). 'Laetitia', 'Joly', 'Arianna', 'Tea', and 'Mila' cultivars were distinguished from others as the richest concerning almost all flavonoids and phenolic acids, including some other parameters of bioactivity. These cultivars could be recommended to consumers as functional fruit foods.