0000000000002895
AUTHOR
Ilva Nakurte
showing 32 related works from this author
Arabidopsis mutant dnd2 exhibits increased auxin and abscisic acid content and reduced stomatal conductance
2019
Arabidopsis thaliana cyclic nucleotide-gated ion channel gene 4 (AtCNGC4) loss-of-function mutant dnd2 exhibits elevated accumulation of salicylic acid (SA), dwarfed morphology, reduced hypersensitive response (HR), altered disease resistance and spontaneous lesions on plant leaves. An orthologous barley mutant, nec1, has been reported to over-accumulate indole-3-acetic acid (IAA) and to exhibit changes in stomatal regulation in response to exogenous auxin. Here we show that the Arabidopsis dnd2 over-accumulates both IAA and abscisic acid (ABA) and displays related phenotypic and physiological changes, such as, reduced stomatal size, higher stomatal density and stomatal index. dnd2 showed i…
Chemical Composition Analysis, Antimicrobial Activity and Cytotoxicity Screening of Moss Extracts (Moss Phytochemistry)
2015
Mosses have been neglected as a study subject for a long time. Recent research shows that mosses contain remarkable and unique substances with high biological activity. The aim of this study, accordingly, was to analyze the composition of mosses and to screen their antimicrobial and anticancer activity. The total concentration of polyphenols and carbohydrates, the amount of dry residue and the radical scavenging activity were determined for a preliminary evaluation of the chemical composition of moss extracts. In order to analyze and identify the substances present in mosses, two types of extrahents (chloroform, ethanol) and the GC/MS and LC-TOF-MS methods were used. The antimicrobial activ…
The influence of pH on the stability of antazoline: kinetic analysis
2015
Degradation of the drug antazoline was studied in aqueous solutions by means of pH-rate profiling (pH 0–7.4). The novel approach of Runge–Kutta numerical integration in combination with multi-parameter optimisation was applied to UV-Vis spectral data to determine a valid kinetic model and kinetic parameters of the degradation process. The overall degradation mechanism was found to be dependent on the environmental pH. In the pH range of 3.0–7.4, the formation of the antazoline hydrolysis product (N-(2-aminoethyl)-2-(N-benzylanilino)acetamide) through three different pathways (acidic, non-catalysed, and semi-alkaline hydrolysis) was observed. In highly acidic media (pH 0–2), the degradation …
Anti-Bacterial Activity and Online HPLC-DPPH Based Antiradical Kinetics of Medicinal Plant Extracts of High Relevance for Cosmetics Production
2018
The present study provides an assessment of extracts of six medicinal plants for their applicability in cosmetic formulations aimed at anti-UV protection and anti-acne treatment. Ethanol extracts of Chelidonium majus L., Myrtus communis L., Hamamelis virginiana L., Juniperus communis L., Alchemilla vulgaris and Ilex paraguariensis are analysed for the phytochemical content, antimicrobial activity, antiradical activity and antiradical kinetics. The phytochemical composition of the plants is investigated by LC-MS analysis and the most active antioxidants in plant extracts are determined by online HPLC-DPPH assay. The kinetic parameters of the antiradical reaction are determined both for the s…
Structure Effect of Imidazolium-Based Dicationic Ionic Liquids on Claisen Rearrangement
2014
A large group of imidazolium-based dicationic ionic liquids (DILs) has been prepared in good yields. Thermal stability of all DILs has been determined. The effects of the reaction time, cation, imidazolium C2–H acidity, and anion on the Claisen rearrangement of allyl phenyl ether have been investigated. Type of anion and the presence of the acidic C2–H bond in the imidazolium moieties have proven to be essential for this reaction. The simple procedure and the possibility of avoiding the use catalysts and volatile organic solvents make this synthetic method environmentally benign and adaptable for large-scale applications.
Intra-Nasally Administered Oligopeptide Lunasin Acts as a Possible Anti-Psychotic Agent in Mice Models
2019
Background and Objectives: Previously we have shown that synthetic lunasin, a 43 amino acid residue-containing peptide, after its central (intracisternal) administration in mice demonstrated antagonism against dopaminergic drug behavioural effects, indicating a putative antipsychotic/anti-schizophrenic profile of lunasin. The aims of the present studies were: to test whether lunasin would show an influence on the dopaminergic system after intranasal administration, and to examine the effect(s) of lunasin on serotonin and glutamatergic systems, which could play an essential role in antipsychotic action. Materials and Methods: Lunasin was administered intra-nasally at doses 0.1 and 1 nmol/mou…
Differential disease resistance response in the barley necrotic mutant nec1
2010
Abstract Background Although ion fluxes are considered to be an integral part of signal transduction during responses to pathogens, only a few ion channels are known to participate in the plant response to infection. CNGC4 is a disease resistance-related cyclic nucleotide-gated ion channel. Arabidopsis thaliana CNGC4 mutants hlm1 and dnd2 display an impaired hypersensitive response (HR), retarded growth, a constitutively active salicylic acid (SA)-mediated pathogenesis-related response and elevated resistance against bacterial pathogens. Barley CNGC4 shares 67% aa identity with AtCNGC4. The barley mutant nec1 comprising of a frame-shift mutation of CNGC4 displays a necrotic phenotype and co…
Wild
2021
Graphical abstract
Development and Validation of a Reversed-Phase Liquid Chromatography Method for the Simultaneous Determination of Indole-3-Acetic Acid, Indole-3-Pyru…
2011
A simple, sensitive, precise, and specific reverse HPLC method was developed and validated for the determination of plant hormones in barley (Hordeum vulgareL.). The method includes extraction in aqueous organic solvent followed by solid-phase extraction, sample evaporation, and reversed-phase HPLC analysis in a general purpose UV-visible (abscisic acid (ABA)) and fluorescence detection (indole-3-acetic acid (IAA) and indole-3-pyruvic acid (IPA)), high-performance liquid chromatography system. The separation was carried out on Zorbax Eclipse XDB C8 column (150 × 4.6 mm I.D) with a mobile phase composed of methanol and 1% acetic acid (60 : 40 v/v) in isocratic mode at a flow rate of 1 ml min…
Structure and Stability of Racemic and Enantiopure Pimobendan Monohydrates: On the Phenomenon of Unusually High Stability
2017
Study of structures and physicochemical properties of racemic (rac-H) and enantiopure (enant-H) hydrates of the active pharmaceutical ingredient pimobendan revealed that both hydrates have highly similar crystal structures and exhibit unusually high stability. Both structures contain identical two-dimensional layers and very similar conformations. The most significant difference is the stacking of these layers. The high stability of both hydrates appeared as extremely low solubility over a wide temperature range as well as an exceptionally high dehydration temperature and melting point. Study of the dehydration process showed that both hydrates have different activation energies of dehydrat…
Broad Prebiotic Potential of Non-starch Polysaccharides from Oats (Avena sativa L.): an in vitro Study
2018
Abstract Prebiotics inducing the growth or activity of beneficial intestinal bacteria – probiotics producing short-chain fatty acids (SCFA) have lately received wide recognition for their beneficial influence on host intestinal microbiota and metabolic health. Some non-starch polysaccharides (NSP) are defined as prebiotics and oats being one of richest sources of NSP in grains are considered as potentially having prebiotic effect. However, information on fermentation of specific NSP of oats is limited. Moreover, bacterial cross-feeding interactions in which fermentation of prebiotics is involved is poorly characterized. Here, we report the exploration of new candidates for the syntrophic ba…
Discovery of lunasin peptide in triticale (X Triticosecale Wittmack)
2012
Lunasin is a novel, cancer-preventive, anti-inflammatory and cholesterol-reducing peptide that was originally isolated from soy and later from barley, wheat and rye. We report the first discovery of lunasin in triticale (X Triticosecale Wittmack). Moreover, we report first data of lunasin content in winter rye and wheat genotypes grown in Northern Europe. These data are novel as previously published data on finding of lunasin in cereals were obtained in genotypes grown in Korea. Lunasin content was uncovered using a previously published procedure for isolation from cereals and identified by LC-MS/MS assay. We found that triticale was the most lunasin-rich cereal, with the tested genotypes d…
Proteome Analysis of Colorectal Cancer Cell Line SW480 Released Extracellular Vesicles
2018
The detection and profiling of disease-specific extracellular vesicles (EVs) from body fluids has been challenging research area during recent years. However, the question – can EVs surface proteins be exploited as a credible tool for early cancer diagnosis – is still not answered. Objective of the current study was to find out whether hypoxia induces differences in protein profiles of EVs released from hypoxic human colorectal cancer cells SW480 (EVHyp) and EVs released from these cells grown in normoxic conditions – EVNorm. Obtained results show differences in EVs surface protein samples. Some protein fragments were found only or mostly in EVHyp surface protein samples. Finding of one or …
Colorectal Cancer Cell Line SW480 and SW620 Released Extravascular Vesicles: Focus on Hypoxia-induced Surface Proteome Changes
2018
Background/aim Extravascular vesicle (EV) proteome closely reflects the proteome of the cell of origin. Therefore, cancer cell-derived EV proteomic analysis could help in identifying cancer biomarkers. This study's goal was to investigate hypoxia-induced proteomic changes in EV released from hypoxic human isogenic non-metastatic colorectal cancer cells SW480 and metastatic colorectal cancer cells SW620. Materials and methods EV were characterized by western blot, transmission electron microscopy, proteomic analysis using liquid chromatography time-of-flight-mass spectrometry and quantified by an label-free intensity-based absolute quantitation (iBAQ) approach. Results A total of 16 proteins…
Detection of the lunasin peptide in oats (Avena sativa L)
2013
We report the first discovery of lunasin in oats (Avena sativa L). Lunasin is a novel cancer preventive, anti-inflammatory and cholesterol-reducing peptide originally isolated from soy and later found in cereals (barley, rye, wheat, triticale). Lunasin was detected in oats using LC–MS/MS analysis. The chromatograms and mass spectra of lunasin isolated from five oat genotypes were compared with those of the synthetic lunasin peptide. We measured the lunasin content in harvests of two years and found that all tested oat genotypes contained the lunasin peptide. However, we observed genotype-related fluctuations in the lunasin content. Notably, the middle early oat variety ‘Ivory’ contained the…
Stability Studies of Bioactive Compounds from Birch Outer Bark Ethanolic Extracts
2018
The literature survey summarizes information about birch outer bark phytochemical composition and details major components: betulin, betulinic acid, lupeol and ursolic acid. In the practical part of research birch outer bark major component stability against chemical and physical degradation was tested; total phenolic content and the antiradical activity of the degraded and nondegraded ethanolic extracts was studied using UV/VIS spectroscopy; the phytochemical composition of the birch outer bark ethanolic extract was investigated by HPLC-TOF/MS. The study of stability experiments has been carried out, which found that birch outer bark ethanolic extract compounds can be exposed to thermal an…
Berry press residues as a valuable source of polyphenolics: Extraction optimisation and analysis
2018
Abstract Vaccinium genus berries (bilberries, blueberries, lingonberries, cranberries) are gathered in the wild as well as cultivated on an industrial scale for use in the food industry. Extraction of juices from these berries produces press residues (pomace) as a waste product. Berry press residues are an excellent source of phenolic compounds and have a potential of use as a polyphenol-rich material. The aim of the present study was to optimise the method of extraction of polyphenols (anthocyanins specifically) from berry press residues of American cranberry using the response surface method and to validate the optimal polyphenol/anthocyanin extraction conditions also for other Vaccinium …
Determination and Toxicology Studies of Quaternary Ammonium Salts in Solution after Organoclay Processing
2018
Organoclays have potential to be used as additives in various facade paints and other finishing materials. Such new innovative materials must be rigorously tested for them to have no impact on environment. Focus of this study was to develop HPLC – TOF/MS method for determining quaternary ammonium salts in various material washing solutions and to determine organoclay toxicity by performing acute toxicity test on Daphnia magna. From the obtained results, it was possible to conclude that organoclays can be safely used as additives in various materials with low or no impact on environment. We determined that organoclays are significantly less toxic then some quaternary ammonium salts on its ow…
Identification of Abies sibirica L. Polyprenols and Characterisation of Polyprenol-Containing Liposomes
2020
The needles of conifer trees are one of the richest sources of natural polyprenols. Polyprenol homologs from Abies sibirica L. lipophilic 80% purified extract were analyzed and quantified. In total, 10 peaks (Prenol-11 to Prenol-20) were observed in the ultra-high-performance liquid chromatography&ndash
Increased Auxin Content and Altered Auxin Response in Barley Necrotic Mutant nec1
2012
The role of hormone crosstalk in plant immunity is lately emerging as significant topic of plant physiology. Although crosstalk between salicylic acid and auxin affects plant disease resistance, molecular mechanisms of this process have not yet been uncovered in details. Mutations disrupting cyclic nucleotide-gated ion channel 4 (CNGC4) affect SA-mediated disease resistance in barley Hordeum vulgare and in A. thaliana. Significantly, decreased stomatal apertures of barley CNGC4 mutant nec1 and dwarfed stature of A. thaliana CNGC4 mutant dnd2 suggest that nonfunctional CNGC4 might be affecting also auxin signaling. Excised coleoptile elongation, stomatal conductance, and cell size measuremen…
Primary culture of avian embryonic heart forming region cells to study the regulation of vertebrate early heart morphogenesis by vitamin A
2014
Background: Important knowledge about the role of vitamin A in vertebrate heart development has been obtained using the vitamin A-deficient avian in ovo model which enables the in vivo examination of very early stages of vertebrate heart morphogenesis. These studies have revealed the critical role of the vitamin A-active form, retinoic acid (RA) in the regulation of several developmental genes, including the important growth regulatory factor, transforming growth factor-beta2 (TGFβ2), involved in early events of heart morphogenesis. However, this in ovo model is not readily available for elucidating details of molecular mechanisms determining RA activity, thus limiting further examination o…
Collision-Induced Dissociation of Imidazolium-Based Zwitterionic Liquids
2009
Fragmentation pathways of some imidazolium based zwitterionic liquids—3-(3-alkyl-1-imidazolio)-propane sulfonates and 3-(2-methyl-3-alkyl-1-imidazolio)-propane sulfonates—have been studied by tandem electrospray mass spectrometry and collision-induced dissociation. The relative abundances of the lowest energy fragment ions depend on the length of the alkyl chain at the IIN of the imidazolium ring and the cone voltage. The first fragment ions originate from the scission of Cnon aromatic–N bond of compounds investigated, but with increasing collision energy, scission of C–C bonds occurs. Aggregates of the general formula [(M + H) x + (M) y]+ ( x;y = 1–2) formed. Methyl substituted zwitterion…
Suppression of Phyllospheric Microbiota Alters Content of Pharmacologically Relevant Compounds of <i>S. nigra</i> Flowers
2018
Accumulating scientific evidence suggests that medicinal plant-associated microbiota has a significant role in biosynthesis of pharmacologically relevant compounds. Suppression of S. nigra microbiota by an antibiotic treatment leads to a decreased emission of volatile terpenoids from S. nigra flowers and an altered metabolome of a host plant. However, it is not known if suppression of microbiota also affects an abundance of health promoting compounds and pharmacologically relevant properties of S. nigra. The present study reveals, that suppression of phyllospheric microbiota by an antibiotic treatment affects total phenolic content (TPC), anti-radical activity (ARA) and total flavonol conte…
Multi-technique approach for qualitative and quantitative characterization of furazidin degradation kinetics under alkaline conditions
2016
Degradation of drug furazidin was studied under different conditions of environmental pH (11-13) and temperature (30-60°C). The novel approach of hybrid hard- and soft-multivariate curve resolution-alternating least squares (HS-MCR-ALS) method was applied to UV-vis spectral data to determine a valid kinetic model and kinetic parameters of the degradation process. The system was found to be comprised of three main species and best characterized by two consecutive first-order reactions. Furazidin degradation rate was found to be highly dependent on the applied environmental conditions, showing more prominent differences between both degradation steps towards higher pH and temperature. Complim…
Pharmacological research on natural substances in Latvia: Focus on lunasin, betulin, polyprenol and phlorizin
2016
In this concise review the current research in plant bioactive compound studies in Latvia is described. The paper summarizes recent studies on substances from edible plants (e.g., cereals and apples) or their synthetic analogues, such as peptide lunasin, as well as substances isolated from inedible plants (e.g., birch and conifer), such as pentacyclic triterpenes (e.g., betulin, betulinic acid, and lupeol) and polyprenols. Latvian researchers have been first to demonstrate the presence of lunasin in triticale and oats. Additionally, the impact of genotype on the levels of lunasin in cereals was shown. Pharmacological studies have revealed effects of lunasin and synthetic triterpenes on the …
CHARACTERIZATION OF ANTIOXIDANT ACTIVITY AND TOTAL PHENOLIC COMPOUND CONTENT OF BIRCH OUTER BARK EXTRACTS USING MICRO PLATE ASSAY
2017
In modern plants, 2.7 to 2.8 m3 of solid volume veneer blocks are consumed to produce 1 m3 of plywood. After the hydrothermal treatment and debarking of blocks, waste bark is obtained, which makes up 12.5% of the wood mass, while 16-20% of bark is composed of birch outer bark (BOB). Recalculating, BOB makes up 2.0-3.4% of the veneer log mass. Bark is currently burned in boiler houses that is not rational. BOB contains large amount of valuable extractives (up to 34% from o.d. BOB) consisting of various secondary metabolites such as terpenes, flavonoids, hydrocarbons, polyphenols, tannins etc. BOB extractives exhibit antioxidant properties as well as wound-healing and anti-inflammatory activi…
Metal hydride alloys for storing hydrogen produced by anaerobic bacterial fermentation
2016
Abstract This study reports on hydrogen sorption from bacterial fermentation media with powdered palladium (Pd) and alloys (LaNi5, AB5, and AB2) that are capable of forming hydrides. Mass changes of the powders after incubation in fermentation media were measured by differential thermogravimetry. Composition and concentrations of the gases accumulated during fermentation and absorbed by Pd or the alloys were analyzed by mass spectrometry. The results demonstrated that hydrogen (H2) was absorbed and stored by powdered Pd and alloys directly from nutritional broth. The best sorption was obtained with Pd, followed by alloys AB5 and AB2. Scanning electron microscopy revealed that bacteria were …
Cviterjonu šķidrumu hromatogrāfija un masspektrometrija
2009
Promocijas darbs veltits lidz šim zinatniskaja periodika neaprakstitu jonu škidrumu - cviterjonu škidrumu sorbcijas petijumiem, izmantojot apgrieztas fazes sorbentus augstefektivas škidrumu hromatografijas apstaklos. Darba gaita noteikti analizejamo savienojumu sorbcijas koeficienti, joslu asimetrijas un efektivitates faktori atkariba no organiska modifikatora daudzuma eluenta un jonu paru reagenta veida. Parbaudita lineara solventa stipruma modela atbilstiba sorbcijas koeficientu prognozešanai homologu rindu ietvaros. Noskaidrota temperaturas un organiska modifikatora ietekme uz analizejamo cviterjonu škidrumu termodinamiskiem sorbcijas parametriem - entalpiju, entropiju un Gibsa energiju.…
CCDC 910846: Experimental Crystal Structure Determination
2016
Related Article: Kārlis Bērziņš, Artis Kons, Ilze Grante, Diana Dzabijeva, Ilva Nakurte, Andris Actiņš|2016|J.Pharm.Biomed.Anal.|129|433|doi:10.1016/j.jpba.2016.07.039
CCDC 1453864: Experimental Crystal Structure Determination
2017
Related Article: Toms Rekis, Agris Be̅rziņš, Dia̅na Džabijeva, Ilva Nakurte, Lia̅na Orola, and Andris Actiņš|2017|Cryst.Growth Des.|17|1814|doi:10.1021/acs.cgd.6b01780
CCDC 1453863: Experimental Crystal Structure Determination
2017
Related Article: Toms Rekis, Agris Be̅rziņš, Dia̅na Džabijeva, Ilva Nakurte, Lia̅na Orola, and Andris Actiņš|2017|Cryst.Growth Des.|17|1814|doi:10.1021/acs.cgd.6b01780
CCDC 910834: Experimental Crystal Structure Determination
2016
Related Article: Kārlis Bērziņš, Artis Kons, Ilze Grante, Diana Dzabijeva, Ilva Nakurte, Andris Actiņš|2016|J.Pharm.Biomed.Anal.|129|433|doi:10.1016/j.jpba.2016.07.039