Effect of Phosphate Starvation on Gene Expression in Cells.

Phosphorus is a key nutrient for all organisms. The study of phosphate metabolism and its regulation is important for understanding the evolutionary processes of regulatory systems in eukaryotic cells. The methylotrophic yeast is an efficient producer organism, and it is actively used in biotechnological production.

Facile synthesis of diiodoheteroindenes and understanding their Sonogashira cross-coupling selectivity for the construction of unsymmetrical enediynes.

Electrophile-promoted cyclizations of functionalized alkynes offer a useful tool for constructing halogen-substituted heterocycles primed for further derivatization. Preinstallation of an iodo-substituent at the alkyne prior to iodo-cyclization opens access to di-iodinated heterocyclic precursors for the preparation of unsymmetrical heterocycle-fused enediynes. This general approach was used to prepare 2,3-diiodobenzothiophene, 2,3-diiodoindole, and 2,3-diiodobenzofuran, a useful family of substrates for systematic studies of the role of heteroatoms on the regioselectivity of cross-coupling reactions.

Tungsten Oxide Dispersed on Silica as Robust and Readily Available Oxo/Imido Heterometathesis Catalyst.

Continuing our investigation of catalytic oxo/imido heterometathesis as novel water-free method for C=N bond construction, we report here the application of classical transition metal oxides dispersed on silica (MO/SiO, M=V, Mo, W) as cheap, robust and readily available alternative to the catalysts prepared via Surface Organometallic Chemistry (SOMC). The oxide materials demonstrated activity in heterometathetical imidation of ketones, WO/SiO being the most efficient. We also describe a new well-defined supported W imido complex (≡SiO)W(=NMes)(MePyr) (Mes=2,4,6-MeCH, MePyr=2,5-dimethylpyrrolyl) and characterize it with SOMC protocols, which allowed us to identify the position of W on the oxo/imido heterometathesis activity scale (Mo View Article and Find Full Text PDF

Readily available Ti-based catalytic system for oxo/imido heterometathesis.

We investigate Ti(NEt) supported on silica dehydroxylated at 700 °C as an easily accessible pre-catalyst for oxo/imido heterometathesis reactions. Being activated with TolNH, the supported Ti amide (SiO)Ti(NEt) (1) demonstrates catalytic activity in the imidation of ketones with -sulfinylamines comparable with the most active previously described well-defined imido catalyst (SiO)Ti(NBu)(MePyr)(py) (2) (MePyr = 2,5-dimethylpyrrolyl), which implies the formation of surface imido species in this system. The materials obtained treatment of 1 with anilines (TolNH (1a) and -MeOCHNH (1b)) were studied with IR, EA and H, C, N and 2D solid-state NMR, although the proposed imido intermediate has not been detected, pointing towards tris-amides (SiO)Ti(NHCHX) (X = Me, OMe) being the major surface species in the isolated materials 1a and 1b.

Effect of Biotin Starvation on Gene Expression in Komagataella phaffii Cells.

Methylotrophic yeast Komagataella phaffii is widely used in biotechnology for recombinant protein production. Due to the practical significance of these yeasts, it is extremely important to properly select cultivation conditions and optimize the media composition. In this study the effect of biotin starvation on gene expression in K.

Alternative PCR-Based Approaches for Generation of Strains.

() is a widely known microbial host for recombinant protein production and an emerging model organism in fundamental research. The development of new materials and techniques on this yeast improves heterologous protein synthesis. One of the most prominent ways to enhance protein production efficiency is to select strains with multiple expression cassettes and generate Mut strains using various vectors.

Effect of Methionine on Gene Expression in Cells.

yeast plays a prominent role in modern biotechnology as a recombinant protein producer. For efficient use of this yeast, it is essential to study the effects of different media components on its growth and gene expression. We investigated the effect of methionine on gene expression in cells using RNA-seq analysis.

4,5-Bis(arylethynyl)-1,2,3-triazoles-A New Class of Fluorescent Labels: Synthesis and Applications.

Cu-catalyzed 1,3-dipolar cycloaddition of ethyl 2-azidoacetate to iodobuta-1,3-diynes and subsequent Sonogashira cross-coupling were used to synthesize a large series of new triazole-based push-pull chromophores: 4,5-bis(arylethynyl)-1-1,2,3-triazoles. The study of their optical properties revealed that all molecules have fluorescence properties, the Stokes shift values of which exceed 150 nm. The fluorescent properties of triazoles are easily adjustable depending on the nature of the substituents attached to aryl rings of the arylethynyl moieties at the C4 and C5 atoms of the triazole core.

Transcriptome Analysis Unveils the Effects of Proline on Gene Expression in the Yeast .

yeast is one of the most important biocompounds producing microorganisms in modern biotechnology. Optimization of media recipes and cultivation strategies is key to successful synthesis of recombinant proteins. The complex effects of proline on gene expression in the yeast was analyzed on the transcriptome level in this work.

4-Azidocinnoline-Cinnoline-4-amine Pair as a New Fluorogenic and Fluorochromic Environment-Sensitive Probe.

A new type of fluorogenic and fluorochromic probe based on the reduction of weakly fluorescent 4-azido-6-(4-cyanophenyl)cinnoline to the corresponding fluorescent cinnoline-4-amine was developed. We found that the fluorescence of 6-(4-cyanophenyl)cinnoline-4-amine is strongly affected by the nature of the solvent. The fluorogenic effect for the amine was detected in polar solvents with the strongest fluorescence increase in water.

Design and Synthesis of New 5-aryl-4-Arylethynyl-1-1,2,3-triazoles with Valuable Photophysical and Biological Properties.

Cu-catalyzed 1,3-dipolar cycloaddition of methyl 2-azidoacetate to iodobuta-1,3-diynes and subsequent Suzuki-Miyaura cross-coupling were used to synthesize new triazoles derivatives: 5-aryl-4-arylethynyl-1-1,2,3-triazoles. Investigation of their optical properties by using UV absorption and fluorescence emission spectroscopies revealed that all molecules possess fluorescence properties with the values of the Stokes shift more than 100 nm. The photophysical behavior of the two most promising triazoles in polar and non-polar solvents was also studied.

In Vivo Production of RNA Aptamers and Nanoparticles: Problems and Prospects.

RNA aptamers are becoming increasingly attractive due to their superior properties. This review discusses the early stages of aptamer research, the main developments in this area, and the latest technologies being developed. The review also highlights the advantages of RNA aptamers in comparison to antibodies, considering the great potential of RNA aptamers and their applications in the near future.

Direct imidation of lactones catalytic oxo/imido heterometathesis.

We report the first examples of direct imidation of lactones giving the corresponding cyclic imidates via oxo/imido heterometathesis with N-sulfinylamines catalysed by a well-defined silica-supported Ti imido complex.

Cytokinin biosynthesis genes expressed during nodule organogenesis are directly regulated by the KNOX3 protein in Medicago truncatula.

Cytokinin is an important regulator of symbiotic nodule development. Recently, KNOTTED1-LIKE HOMEOBOX 3 transcription factor (TF) was shown to regulate symbiotic nodule development possibly via the activation of cytokinin biosynthesis genes. However, the direct interaction between the KNOX3 TF and its target genes has not been investigated up to date.

Synthesis and Properties of 6-Aryl-4-azidocinnolines and 6-Aryl-4-(1,2,3-1-triazol-1-yl)cinnolines.

An efficient approach towards the synthesis of 6-aryl-4-azidocinnolines was developed with the aim of exploring the photophysical properties of 6-aryl-4-azidocinnolines and their click reaction products with alkynes, 6-aryl-4-(1,2,3-1-triazol-1-yl)cinnolines. The synthetic route is based on the Richter-type cyclization of 2-ethynyl-4-aryltriazenes with the formation of 4-bromo-6-arylcinnolines and nucleophilic substitution of a bromine atom with an azide functional group. The developed synthetic approach is tolerant to variations of functional groups on the aryl moiety.

Relative Reactivity of Benzothiophene-Fused Enediynes in the Bergman Cyclization.

To find promising analogues of naturally occurring enediyne antibiotics with a sufficient reactivity in the Bergman cyclization and moderately stable under isolation and storage, a scale of relative enediynes reactivity was created on the basis of calculated free activation energies for the Bergman cyclization within 12 known and new benozothiophene, benzene, and cinnoline annulated 9- and 10-membered enediynes. To verify the predicted reactivity/stability balance, three new carbocyclic enediynes fused to a benzothiophene core bearing 3,4,5-trimethoxybenzene, fluoroisopropyl, and isopropenyl substituents were synthesized using the Nicholas-type macrocyclization. It was confirmed that annulation of a 3,4,5-trimethoxybenzene moiety to a 10-membered enediyne macrocycle imparts high reactivity to an enediyne while also conferring instability under ambient temperature.

Crystal structure of (1,4)-2,5-diazo-niabi-cyclo[2.2.1]heptane dibromide.

The cage of 2,5-di-aza-bicyclo-[2.2.1]heptane is frequently employed in synthetic chemistry as a rigid bicyclic counterpart of the piperazine ring.

Crystal structure of (1,5)--(8-methyl-8-azoniabi-cyclo-[3.2.1]oct-3-yl)ammonium aqua-tri-chlorido-nitratocopper(II).

The structure of a salt of diprotonated -3-amino-tropane crystallized with a copper(II) anionic cluster is reported, (CHN)[CuCl(NO)(HO)]. Neither ion in the salt has been structurally characterized previously. In the crystal, the ions pack together to form a three-dimensional structure held together by a network of inter-molecular N-H⋯O, O-H⋯Cl and N-H⋯Cl hydrogen-bonding inter-actions.

The 7-aza-norbornane nucleus of epibatidine: 7-aza-bicyclo-[2.2.1]heptan-7-ium chloride.

7-Aza-bicyclo-[2.2.1]heptane (7-aza-norbornane) is a bridged heterocyclic nucleus found in epibatidine, the alkaloid isolated from the skin of the tropical poison frog .

Between Adamantane and Atrane: Intrabridgehead Interactions in the Cage-Like Phosphane Related to a Novel Tris(homoadamantane) Ring System.

Herein, we report unusual four-center interactions in the novel cage-like phosphane, 1,4,7-triaza-9-phosphatricyclo[5.3.2.