scholarly journals Synthesis and biological activity of N6-mannopyranosyladenines

2021 ◽  
Vol 11 (2) ◽  
pp. 310-317
Author(s):  
I. S. Cherepanov ◽  
A. A. Kamasheva ◽  
E. I. Kashapova
Keyword(s):  
Copper Ions ◽  
Triticum Aestivum L ◽  
Structural Features ◽  
Water Systems ◽  
Future Research ◽  
Side Reactions ◽  
Hydrolytic Cleavage ◽  
Experimental Conditions ◽  
Double Yield ◽  
Substituted Adenines

In this work, potentially bioactive condensation products of adenine with D-mannose and 6-deoxy-L-mannose (L-rhamnose) were synthesized in water and ethanol solutions. According to FTIR spectroscopy and elemental analysis, mono-N6-glycosylated adenines were isolated from water systems in satisfactory yields, while ethanol solutions contained mixtures of N6 and N9-products, as well as complexes of the latter with copper ions. A detailed analysis of the vibrational spectra of N6-glycosyladenines confirmed the structure of carbohydrate fragments in the form of pyranose rings, while some part of the product was obtained in the form of deoxyaminoketosis. N-rhamnosyladenine was formed with a more than double yield because of a higher stability of rhamnose with regard to side reactions. The reflection spectra of model solutions of glycosyladenines, recorded 4 days after preparation, showed no bands characteristic of free adenine in the range of 1250-1110 cm-1, which indicates a sufficient resistance of the synthesized products towards hydrolytic cleavage under experimental conditions. The conducted biotesting of the isolated products on wheat seeds (Triticum aestivum L.) showed an increase in the content of chlorophylls in seedlings for both mannosilade-nines compared to the control. A decrease in the concentration of synthesized products in germination solutions from 0.1 to 0.001% led to an increase in the accumulation of photosynthetic pigments, while this effect was more pronounced for rhamnosyladenine. The latter can be connected with the structural features of car-bohydrate fragments, in particular, the differences in the hydroxylation degree of glucoside fragments. Future research will investigate the mechanisms of transformation and action of N6-substituted adenines.

scholarly journals Naturally Occurring Ecdysteroids in Triticum aestivum L. and Evaluation of Fenarimol as a Potential Inhibitor of Their Biosynthesis in Plants

2021 ◽  
Vol 22 (6) ◽  
pp. 2855
Author(s):  
Anna Janeczko ◽  
Jana Oklestkova ◽  
Danuše Tarkowská ◽  
Barbara Drygaś
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Triticum Aestivum L ◽  
Growth Conditions ◽  
Animal Kingdom ◽  
Experimental Conditions ◽  
P450 Monooxygenase ◽  
Naturally Occurring ◽  
Regulatory Effects ◽  
Potential Use

Ecdysteroids (ECs) are steroid hormones originally found in the animal kingdom where they function as insect molting hormones. Interestingly, a relatively high number of these substances can also be formed in plant cells. Moreover, ECs have certain regulatory effects on plant physiology, but their role in plants still requires further study. One of the main aims of the present study was to verify a hypothesis that fenarimol, an inhibitor of the biosynthesis of ECs in the animal kingdom, also affects the content of endogenous ECs in plants using winter wheat Triticum aestivum L. as a model plant. The levels of endogenous ECs in winter wheat, including the estimation of their changes during a course of different temperature treatments, have been determined using a sensitive analytical method based on UHPLC-MS/MS. Under our experimental conditions, four substances of EC character were detected in the tissue of interest in amounts ranging from less than 1 to over 200 pg·g−1 FW: 20-hydroxyecdysone, polypodine B, turkesterone, and isovitexirone. Among them, turkesterone was observed to be the most abundant EC and accumulated mainly in the crowns and leaves of wheat. Importantly, the level of ECs was observed to be dependent on the age of the plants, as well as on growth conditions (especially temperature). Fenarimol, an inhibitor of a cytochrome P450 monooxygenase, was shown to significantly decrease the level of naturally occurring ECs in experimental plants, which may indicate its potential use in studies related to the biosynthesis and physiological function of these substances in plants.

scholarly journals Unusual Structural Features in the Adduct of Dirhodium Tetraacetate with Lysozyme

2021 ◽  
Vol 22 (3) ◽  
pp. 1496
Author(s):  
Domenico Loreto ◽  
Giarita Ferraro ◽  
Antonello Merlino
Keyword(s):  
Anticancer Agents ◽  
Structural Features ◽  
Side Chain ◽  
Side Chains ◽  
Valuable Insight ◽  
Experimental Conditions ◽  
Egg White Lysozyme ◽  
Potential Applications ◽  
Model Protein ◽  
Hen Egg White

The structures of the adducts formed upon reaction of the cytotoxic paddlewheel dirhodium complex [Rh2(μ-O2CCH3)4] with the model protein hen egg white lysozyme (HEWL) under different experimental conditions are reported. Results indicate that [Rh2(μ-O2CCH3)4] extensively reacts with HEWL:it in part breaks down, at variance with what happens in reactions with other proteins. A Rh center coordinates the side chains of Arg14 and His15. Dimeric Rh–Rh units with Rh–Rh distances between 2.3 and 2.5 Å are bound to the side chains of Asp18, Asp101, Asn93, and Lys96, while a dirhodium unit with a Rh–Rh distance of 3.2–3.4 Å binds the C-terminal carboxylate and the side chain of Lys13 at the interface between two symmetry-related molecules. An additional monometallic fragment binds the side chain of Lys33. These data, which are supported by replicated structural determinations, shed light on the reactivity of dirhodium tetracarboxylates with proteins, providing useful information for the design of new Rh-containing biomaterials with an array of potential applications in the field of catalysis or of medicinal chemistry and valuable insight into the mechanism of action of these potential anticancer agents.

scholarly journals Kinetics of Non-Enzymatic Synthesis of Dipeptide Cbz-Phe-Leu with AOT Reversed Micelles

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1003
Author(s):  
Michiaki Matsumoto ◽  
Tadashi Hano
Keyword(s):  
Enzymatic Synthesis ◽  
Maximum Yield ◽  
Side Reactions ◽  
Experimental Conditions ◽  
Operational Conditions ◽  
Ph Dependency ◽  
Optimum Water Content ◽  
Short Time ◽  
Kinetics Of ◽  
Aot Reversed Micelles

The non-enzymatic synthesis of N-benzyloxycarbonyl-L-phenylalanyl-L-leucine (Cbz-Phe-Leu) from lipophilic N-benzyloxycarbonyl-L-phenylalanine (Cbz-Phe) and hydrophilic L-leucine (Leu), by N, N’-dicyclohexylcarbodiimide (DCC) as a condensing agent, was carried out using a reversed micellar system composed of bis(2-ethylhexyl) sodium sulfosuccinate (AOT) as a surfactant and isooctane. We successfully synthesized Cbz-Phe-Leu in a short time and investigated the effects of its operational conditions, the DCC concentration, w0, and the pH on the kinetic parameters and the maximum yields. For dipeptide synthesis, we had to add an excess of DCC with the substrates because of the side reactions of Cbz-Phe. From the pH dependency of the reactivity, a partially cationic form of Leu was better for a synthesis reaction because of the enrichment of Leu at the interface by anionic AOT. The optimum water content on the dipeptide synthesis was w0 = 28 due to the competition of the peptide synthesis and the side reactions. The maximum yield of Cbz-Phe-Leu was 0.565 at 80 h under optimum experimental conditions.

scholarly journals Validation of Reference Genes for Studying Different Abiotic Stresses in oat (Avena sativa L.) by RT-qPCR

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1272
Author(s):  
Judit Tajti ◽  
Magda Pál ◽  
Tibor Janda
Keyword(s):  
Gene Expression ◽  
Avena Sativa ◽  
Abiotic Stresses ◽  
Reference Genes ◽  
Nutritional Value ◽  
Tissue Type ◽  
Future Research ◽  
Experimental Conditions ◽  
Expression Studies ◽  
Gene Expression Studies

Oat (Avena sativa L.) is a widely cultivated cereal with high nutritional value and it is grown mainly in temperate regions. The number of studies dealing with gene expression changes in oat continues to increase, and to obtain reliable RT-qPCR results it is essential to establish and use reference genes with the least possible influence caused by experimental conditions. However, no detailed study has been conducted on reference genes in different tissues of oat under diverse abiotic stress conditions. In our work, nine candidate reference genes (ACT, TUB, CYP, GAPD, UBC, EF1, TBP, ADPR, PGD) were chosen and analysed by four statistical methods (GeNorm, Normfinder, BestKeeper, RefFinder). Samples were taken from two tissues (leaves and roots) of 13-day-old oat plants exposed to five abiotic stresses (drought, salt, heavy metal, low and high temperatures). ADPR was the top-rated reference gene for all samples, while different genes proved to be the most stable depending on tissue type and treatment combinations. TUB and EF1 were most affected by the treatments in general. Validation of reference genes was carried out by PAL expression analysis, which further confirmed their reliability. These results can contribute to reliable gene expression studies for future research in cultivated oat.

scholarly journals DEVELOPMENT AND VALIDATION OF A SPECTROPHOTOMETRIC METHOD TO EVALUATE BIOSAFETY CAPACITY OF BARU (Dipteryx alata) PEELS

2018 ◽  
Vol 15 (30) ◽  
pp. 221-240
Author(s):  
E. C. CESARINO ◽  
D. S. MULHOLLAND ◽  
W. FRANCISCO
Keyword(s):  
Contact Time ◽  
Limit Of Detection ◽  
Copper Ions ◽  
Maximum Adsorption Capacity ◽  
Limit Of Quantification ◽  
Experimental Conditions ◽  
Inorganic Matter ◽  
Pseudo Second Order ◽  
Development And Validation ◽  
Dipteryx Alata

This study developed a new analytical method using Molecular Absorption Spectroscopy (MAS) to track the ion cover in adsorption solution per peel (mesocarp) of Baru (Dipteryx alata). The adsorption study was conducted at different pH and contact time (kinetic), encountering 4.0 as the best pH for adsorption experimental conditions. The variation of contact time showed a pseudo-second-order adsorption kinetic behavior. The interpretation of the isotherms allowed to approach the Langmuir model with R² of 0.918 and to determine the maximum adsorption capacity (qmáx) as 11.481 mg.g⁻¹. The characterization of biomass by MAS in the Infrared (FT-IR) identified the possible functional groups belonging to protein, fatty acids and lipids, while thermal analysis (TG-DSC) showed a greater removal of inorganic matter by the biomass washed with water. The method underwent analytical validation, being classified as specific, sensitive, linear, robust, precise and accurate, with LD (limit of detection) and LQ (limit of quantification) equal to 3.873 and 12.912 mg.L⁻¹, respectively. The results obtained demonstrated the potential use of mesocarp Baru as a natural adsorbent for copper ions in solution, opening power for future expansion and improvement of the method.

scholarly journals Purification and properties of a phytase from Candida melibiosica 2491

2018 ◽  
Author(s):  
Danail Georgiev ◽  
Georgi Dobrev ◽  
Stefan Shilev
Keyword(s):  
Molecular Weight ◽  
Copper Ions ◽  
Phytase Activity ◽  
Gel Chromatography ◽  
Experimental Conditions ◽  
Cobalt Ions ◽  
Whole Cells ◽  
Inhibition Effect ◽  
Total Inhibition ◽  
Purification And Properties

Aim: To characterize the enzyme phytase produced by phytase-active Candida melibiosica 2491 for subsecuent use in feed industry. Methods: C. melibiosica 2491 had been selected among 118 strains as the most productive strain of phytase. In present study, the enzyme was first purified through electrophoresis grade in four steps: precipitation with organic solvent, ultrafiltration, gel chromatography and Denaturing gel electrophoresis (SDS–PAGE). Results: Higher levels of purification were obtained using ethanol. The gel chromatography showed an elution maximum at 11-12 fractions that characterize the corresponding one as high-molecular weight phytase. The purification level was found to be 19.5 folds with specific enzyme activity of 2.75 U/mg protein and yield – 19.64 %. Furthermore, the molecular weight of purified phytase was estimated to 35.9 кDa, with optimum of pH – at 4.5 and optimum of temperature at 55 °C. Maximum phytase activity in case of whole cells was found at 50 оС, which was less than using the purified enzyme. It was activated through 5 mM of Ba2+, 10 mM of Mn2+ and K+ ions. Total inhibition effect was achieved from Fe3+, Hg2+ and Zn2+. Copper ions (Cu2+) in concentrations at 5 mM conducted to partial inhibition effect, but at 10 mM the phytase activity was equal to zero. Low inhibition effect was determined in case of cobalt ions (Co2+) at concentrations of 10 mM. The phytase displayed broad sub­strate specificity and the Km for phytate was estimated to be 0.21 mM under the experimental conditions, while Vmax – 19.9 µМ/ml. Conclusion: Although the phytase produced by C. melibiosica 2491 is a promising enzyme to be used successfully in feed production, more investigations are needed to ensure its advantages.

scholarly journals A Facile Colorimetric Method For Ultra-Rapid And Sensitive Detection of Copper Ions In Water

2021 ◽  
Author(s):  
Lei Chen ◽  
Yan Li ◽  
Ping Sun ◽  
Hualin Chen ◽  
He Li ◽  
...  
Keyword(s):  
Color Change ◽  
Copper Ions ◽  
Colorimetric Method ◽  
Ethanol Solution ◽  
Sensitive Detection ◽  
World Health ◽  
Great Promise ◽  
Experimental Conditions ◽  
Interesting Phenomenon ◽  
Health Organization

Abstract It is of great meaning to develop a facile, reliable and sensitive method to detect copper ions in water. In the study, a facile method has been developed for rapid and sensitive detection of Cu2+. An interesting phenomenon has been observed that 3,3',5,5'-tetramethylbenzidine (TMB) ethanol solution can be extremely fast passed from colorless to yellow once Cu2+ ions are added. It easily occurs to us that Cu2+ can be quantitatively determined via the absorbance at 904 nm of the color changed TMB solution. More importantly, some specific anions (Cl- , Br- ) can significantly enhance the absorption intensity. Under the optimized experimental conditions, this method exhibits a good linear response range for Cu2+ from 0.5 to 100 μM, with the detection limit of 93 nM. Moreover, the possible detection principle has been explored. It is worth mentioning that the color change can be clearly observed by naked eyes for the detection of 1 μM Cu2+, which is far below the threshold limit of Cu2+ in drinking water suggested by World Health Organization. It means that this method possess great promise for on-site Cu2+ detection.

The Role of Incubation in Creative Problem Solving: Within a Collectivistic Cultural Context

2021 ◽  
pp. 108-118
Author(s):  
Rabia Anjum ◽  
Ivan Suneel
Keyword(s):  
Problem Solving ◽  
Cultural Context ◽  
Creative Thinking ◽  
Cultural Psychology ◽  
Cross Cultural ◽  
Future Research ◽  
Creative Problem Solving ◽  
Experimental Conditions ◽  
Significance Level ◽  
Creative Problem

Creative thinking is essential for the progress in education, industry and life in general. Incubation is a widely studied phenomenon in creativity research, referring to leaving a problem aside for a period, to accrue performance on a creative problem. This study investigated the effect of incubation on creative problem-solving by means of a pretest-posttest quasi-experimental design, and remote associates tasks (RATs) were used as a measure of creative problem-solving. For this purpose, a sample of 60 students (22 males, 38 females) was recruited from the population of a private university. They were assigned to a control condition and two different experimental conditions based on the time of onset of incubation. The data collected was analyzed for a significant effect across all conditions by means of a chi-squared test and covariates were inferred by means of Spearman's Rho, with a significance level set at ?<.05. The results did not find an incubation effect in creative problem-solving, and several possible explanations may account for this trend, especially the limited cross-cultural application of measurement tools and theoretical paradigms. The disparity is especially prominent with regards to Pakistan, which is predominantly collectivistic, and the educational system stymies creative thinking. Future research must take into account the relevance of culture in creative problem-solving, and propose solutions to circumvent the dearth of creative potential in developing nations such as Pakistan. Keywords: Incubation, Creative Problem-Solving, Creativity, Remote Associate Tasks, Cross-Cultural Psychology

Data Mining in Gene Expression Analysis

2008 ◽  
pp. 1643-1673
Author(s):  
Jilin Han ◽  
Le Gruenwald ◽  
Tyrrell Conway
Keyword(s):  
Gene Expression ◽  
Data Mining ◽  
Biological Information ◽  
Future Research ◽  
Gene Expression Data Analysis ◽  
Experimental Conditions ◽  
Single Experiment ◽  
Important Approach ◽  
Future Research Directions ◽  
Gene Expression Levels

The study of gene expression levels under defined experimental conditions is an important approach to understand how a living cell works. High-throughput microarray technology is a very powerful tool for simultaneously studying thousands of genes in a single experiment. This revolutionary technology results in an extensive amount of data, which raises an important question: how to extract meaningful biological information from these data? In this chapter, we survey data mining techniques that have been used for clustering, classification and association rules for gene expression data analysis. In addition, we provide a comprehensive list of currently available commercial and academic data mining software together with their features. Lastly, we suggest future research directions.

scholarly journals Challenges and Advances in Genome Editing Technologies in Streptomyces

Biomolecules ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 734 ◽  
Author(s):  
Yawei Zhao ◽  
Guoquan Li ◽  
Yunliang Chen ◽  
Yinhua Lu
Keyword(s):  
Natural Product ◽  
Genome Editing ◽  
Genetic Manipulation ◽  
Chemical Compounds ◽  
Gene Clusters ◽  
Future Research ◽  
Biosynthetic Gene ◽  
Biosynthetic Gene Clusters ◽  
Research Focus ◽  
Experimental Conditions

The genome of Streptomyces encodes a high number of natural product (NP) biosynthetic gene clusters (BGCs). Most of these BGCs are not expressed or are poorly expressed (commonly called silent BGCs) under traditional laboratory experimental conditions. These NP BGCs represent an unexplored rich reservoir of natural compounds, which can be used to discover novel chemical compounds. To activate silent BGCs for NP discovery, two main strategies, including the induction of BGCs expression in native hosts and heterologous expression of BGCs in surrogate Streptomyces hosts, have been adopted, which normally requires genetic manipulation. So far, various genome editing technologies have been developed, which has markedly facilitated the activation of BGCs and NP overproduction in their native hosts, as well as in heterologous Streptomyces hosts. In this review, we summarize the challenges and recent advances in genome editing tools for Streptomyces genetic manipulation with a focus on editing tools based on clustered regularly interspaced short palindrome repeat (CRISPR)/CRISPR-associated protein (Cas) systems. Additionally, we discuss the future research focus, especially the development of endogenous CRISPR/Cas-based genome editing technologies in Streptomyces.

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