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A method based on the use of difluoroboron complexes was developed for the introduction of aminopyrimidinyl substituents into the side chain of ring A in (13α)-estrones. [ABSTRACT FROM AUTHOR]

An efficient synthetic approach based on the chelate methodology and difluoroboron complexes was developed for estrone derivatives containing pyrazolo[1,5-a]pyrimidine substituents at the side chain of ring A. [ABSTRACT FROM AUTHOR]

An effective method for the synthesis of heterocyclic steroids with the [1,2,5]oxadiazolo[3,4-b]pyrazine and [1,2,5]thiadiazolo[3,4-b]-pyrazine fragments was developed. The structure of the products was confirmed by X-ray structural analysis. The resulting compounds showed high antiproliferative activity against breast (MCF7) and prostate (22Rv1) cancer cells, which was not inferior to that of cisplatin and abiraterone acetate. [ABSTRACT FROM AUTHOR]

A method for the synthesis of 1,3,4-thiadiazoline spiro steroids via ring A by the reaction of steroid 3-ketones with oxamic acid thiohydrazides was developed. It was shown that if a keto group was present both in ring A and in ring D of the precursor steroid, the reaction occurred only at the keto group of ring A. A number of new steroidal 3-spiroandrostene-substituted 1,3,4-thiadiazolines were obtained, which could be easily acetylated at the thiadiazole NH group. [ABSTRACT FROM AUTHOR]

A method for the synthesis of spiro-1,3,4-thiadiazolines by the reaction of cyclic ketones with oxamic acid thiohydrazides was developed. A number of new nonsteroidal spiro-1,3,4-thiadiazolines was obtained in high yields. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the peculiarities and localization of the current source of α- and θ-rhythms accompanying competition and cooperation with another player, as well as solo figure building in a computer game. The sample included 42 volunteers (24 females) aged from 18 to 47 years. The analysis of differences in the current source density registered with a 127-channel EEG in different game conditions was performed in the eLoreta software. The θ-rhythm spectral density was greater during competition than during cooperation and most prominent in the anterior cingulate cortex and medial prefrontal cortex. According to the literature on functional correlates of the θ-rhythm, it can be suggested that the greater increase in the frontal-midline θ-rhythm detected during competition may be related to focused attention and cognitive control processes. The source density of α-rhythm in the parietal and visual cortex areas during interactive game modes (cooperation and competition) was lower compared to the solo mode. During cooperation the α-rhythm spectral density was lower compared to the competition mode. The greatest decrease of α-rhythm spectral density in the cooperation mode was consistent with the concept of relation between α-rhythm decrease and the processes of understanding the other person's intentions. [ABSTRACT FROM AUTHOR]

This article, published in the journal Crustaceana, discusses the first recorded sighting of Caromiobenella helgolandica in the Okhotsk Sea. Monstrilloid copepods are parasites of benthic invertebrates and have a planktonic adult stage. The genus Caromiobenella contains about 10 species, including C. helgolandica, which has a worldwide distribution but had not been previously recorded in Russia or adjacent waters. The article provides a detailed description of the female specimen collected from the Okhotsk Sea, including its morphology and distinctive characteristics. [Extracted from the article]

Data on the influence of solvents, ratios and nature of reagents on the distribution of typical impurities and yields of target products of the reaction of 19-norpregna-1,3,5(10),16-tetraen-20-one derivatives with 4-dimethylamino-, 3,4-dimethoxy-, and 4-bromobenz-aldehydes and 3-pyridinecarbaldehyde were studied and summarized. A mechanism for the formation of 1,3-diketones in the reaction of 17-acetyl-substituted steroids with 4-dimethyl-aminobenzaldehyde in the presence of lithium diisopropylamide in THF was proposed. The Claisen-Schmidt condensation results were shown to be critically affected by the base and the steroid solubility. Optimization possibilities were considered and an improved procedure for the synthesis of new 21-benzylidene-substituted steroids was proposed. [ABSTRACT FROM AUTHOR]

Progesterone exerts multiple effects in different tissues through nuclear receptors (nPRs) and through membrane receptors (mPRs) of adiponectin and progestin receptor families. The effect of progesterone on the cells through different types of receptors can vary significantly. At the same time, it affects the processes of proliferation and apoptosis in normal and tumor tissues in a dual way, stimulating proliferation and carcinogenesis in some tissues, suppressing them and stimulating cell death in others. In this study, we have shown the presence of high level of mPRβ mRNA and protein in the HepG2 cells of human hepatocellular carcinoma. Expression of other membrane and classical nuclear receptors was not detected. It could imply that mPRβ has an important function in the HepG2 cells. The main goal of the work was to study functions of this protein and mechanisms of its action in human hepatocellular carcinoma cells. Previously, we have identified selective mPRs ligands, compounds LS-01 and LS-02, which do not interact with nuclear receptors. Their employment allows differentiating the effects of progestins mediated by different types of receptors. Effects of progesterone, LS-01, and LS-02 on proliferation and death of HepG2 cells were studied in this work, as well as activating phosphorylation of two kinases, p38 MAPK and JNK, under the action of three steroids. It was shown that all three progestins after 72 h of incubation with the cells suppressed their viability and stimulated appearance of phosphatidylserine on the outer surface of the membranes, which was detected by binding of annexin V, but they did not affect DNA fragmentation of the cell nuclei. Progesterone significantly reduced expression of the proliferation marker genes and stimulated expression of the p21 protein gene, but had a suppressive effect on the expression of some proapoptotic factor genes. All three steroids activated JNK in these cells, but had no effect on the p38 MAPK activity. The effects of progesterone and selective mPRs ligands in HepG2 cells were the same in terms of suppression of proliferation and stimulation of apoptotic changes in outer membranes, therefore, they were mediated through interaction with mPRβ. JNK is a member of the signaling cascade activated in these cells by the studied steroids. [ABSTRACT FROM AUTHOR]

Efficient stereoselective methods for the synthesis of 5α-androst-1-ene-3β,17β-diol, which is used as a reference compound for identification of anabolic steroids and their metabolites, were elaborated. The key factor of the synthesis is the use of the sodium borohydride—cerium(III) chloride system as a reducing agent. [ABSTRACT FROM AUTHOR]

Water-soluble forms of fullerene C60 possess unique physicochemical and biological properties, making them promising candidates for the development of various drugs in the fields of medicine and veterinary science. Of particular interest are studies on the synthesis and characterization of C60 fullerene derivatives with biogenic additives such as amino acids and peptides. This review focuses on different approaches to the synthesis of amino acid derivatives of fullerene C60 and their promising biomedical applications. [ABSTRACT FROM AUTHOR]

We report here a study of 45 students (all men) of different ethnicities (mainly Tajik and Kyrgyz) aged 17–28 years, who moved to the North (Yakutsk, Republic of Sakha (Yakutia)). The study addressed the balance of connectivity of resting state networks in study condition 1, when participants entered new and unfamiliar living conditions, and in study condition 2, when subjects had lived in these conditions for one year. The 128-channel EEG was recorded at rest. Connectivity between nodes of the resting state networks and the rest of the brain was calculated. Connectivity contrasts the attention networks vs default mode network in conditions 1 and 2 were performed. Condition 1 was characterized by a predominance of attention networks over the default mode network of the brain, which may be associated with an increase in attention focused on the perception of new stimuli and tasks in the new conditions. In condition 2, after living in these environmental conditions for one year, the balance of the resting state networks shifted towards a predominance of the brain's default mode network over the attention networks. [ABSTRACT FROM AUTHOR]

This article explores the synthesis of phosphorylthioformic acid morpholides, which have potential applications as pesticides and herbicides. The authors found that the reaction of α-chloromethylphosphonates with sulfur in a morpholine medium resulted in the formation of phosphorylthioformic acid morpholides as the main products. However, isolating the products proved challenging due to the presence of excess sulfur and morpholine hydrochloride. The document provides technical information about the compound's spectra and includes details about its synthesis and characterization. It also acknowledges funding sources and does not involve human or animal subjects in the research. [Extracted from the article]

The reaction of hydroxylamine and steroid obtained by the condensation of 16α,17α-epoxypregn-5-en-20-one with DMF dimethyl acetal proceeded through the involvement of the epoxide fragment and led to the formation of 3β-hydroxy-4′-hydroxylaminoandrost-5-eno[16,17-b]pyridine l′-N-oxide. [ABSTRACT FROM AUTHOR]

A convenient synthesis method for new 17-pyrimidinylandrostanes based on 3β-hydroxy-17-[3-dimethylamino)acryloyl]-16α,17α- epoxyandrost-5-ene is proposed. The reaction of the epoxyandrostene with guanidine and acetamidine yielded 3β-hydroxy-17-(pyrimidin- 4-yl)-16α,17α-epoxyandrost-5-enes, and its reaction with 3-aminopyrazole or 3-amino-1,2,4-triazole resulted in the formation of the respective 3β-hydroxy-17-(pyrazolo[1,5-a]pyrimidin-7-yl)-16α,17α-epoxyandrost-5-ene and 3β-hydroxy-17-(1,2,4-triazolo[1,5-a]- pyrimidin-5-yl)-16α,17α-epoxyandrost-5-ene. [ABSTRACT FROM AUTHOR]

We propose a new approach to the synthesis of 17-pyrazolylandrostanes on the basis of 17β-[3-(dimethylamino)acryloyl]-16α,17α-epoxy-3β-hydroxyandrost-5-ene. This epoxyandrostene was shown to react with hydrazine hydrate, producing 17α-hydrazinyl-3β,16α-dihydroxy-17β-(1H-pyrazolyl-3-yl)androst-5-ene that was used in reactions with aromatic aldehydes, leading to 17-hydrazones. The treatment of 17β-[3-(dimethylamino)acryloyl]-16α,17α-epoxy-3β-hydroxyandrost-5-ene with phenylhydrazine led to the formation of 3β,16α-dihydroxy-17-(1-phenyl-1H-pyrazol-5-yl)androst-5-ene. At the same time, the reactions of epoxyandrostene with methylhydrazine or benzylamine proceeded with conservation of the epoxide ring and led to the formation of 16α,17-epoxyandrostanes containing a 1-methyl-1H-pyrazol-5-yl or 3-(benzylamino)acryloyl substituent at position 17, respectively. The obtained hydrazones exhibited a moderate antiproliferative activity against the MCF-7 breast cancer cell line. The strongest antiproliferative potential was identified in the case of 17α-[(4-bromobenzylidene)hydrazinyl]-3β,16α-dihydroxy-17β-(1H-pyrazol-3-yl)androst-5-ene with an IC50 value around 16 μM. [ABSTRACT FROM AUTHOR]

The search for effective and environmentally friendly plant growth regulators in modern conditions makes it possible to identify and reduce the impact on plant development, its metabolic processes, the biomass of its various parts, and crops. Substances with the least toxicity to living organisms are of particular interest in this field; in particular, these include C60 and C70 fullerenes and their derivatives. This paper describes the impact of both fullerenes themselves and their derivatives on plant growth, yield, and metabolic and morphological changes observed depending on the processing methods, the chemical structure of the derivative, and the amount of substance used for processing. [ABSTRACT FROM AUTHOR]

An efficient synthesis of (13α)-estrone derivatives containing pyran, isoxazole, or pyrazole moieties on the A-ring was performed based on difluoroborate complexes using the chelate methodology. Difluoroborate complexes were synthesized from (13α)-2-acetyl-3-hydroxyestra-1(10),2,4-trien-17-one. [ABSTRACT FROM AUTHOR]

Heterocycles functionalized with pentavalent phosphorus are of great importance since they include a great variety of biologically active compounds and pharmaceuticals, advanced materials, and valuable reactive intermediates for organic synthesis. Significant progress in synthesis of P(O)R2-substituted six-membered heterocycles has been made in the past decade. This review covers the synthetic strategies towards aromatic monocyclic six-membered N-heterocycles, such as pyridines, pyridazines, pyrimidines, and pyrazines bearing phosphonates and phosphine oxides, which were reported from 2012 to 2022. [ABSTRACT FROM AUTHOR]

A comparative analysis was performed for 13C NMR chemical shifts of C-4 and C-4a (or C-5) atoms in previously synthesized pyrido[2,3-d]-pyrimidin-5-ones, pyrido[2,3-d]pyrimidin-7-ones, pyrimido[4,5-d]pyrimidines, and 5-acetylpyrimidines containing methylsulfanyl, methylsulfonyl, butoxy, and amino groups at position 4. It was possible to determine the type of heteroatom (sulfur, oxygen, or nitrogen) bonded to the C-4 carbon atom on the basis of chemical shifts observed for C-4a carbon atom in the spectra of fused heterocycles or C-5 carbon atom in the spectra of pyrimidines. At the same time, the chemical shift values of C-4a (or C-5) atoms practically did not depend on the particular sulfur-containing functionality: sulfanyl or sulfonyl group. A significant upfield shift was observed for the C-4 atom in 13C NMR spectra of sulfones compared to the spectra of compounds containing a methylsulfanyl moiety. [ABSTRACT FROM AUTHOR]

The promising antitumor effects of progesterone derivatives have been identified in many studies. However, the specific mechanism of action of this class of compounds has not been fully described. Therefore, in this study, we investigated the antiproliferative and (anti)estrogenic activities of novel pentacyclic derivatives and benzylidenes of the progesterone series. The antiproliferative effects of the compounds were evaluated on hormone-dependent MCF7 breast cancer cells using the MTT test. Estrogen receptor α (ERα) activity was assessed by a luciferase-based reporter assay. Immunoblotting was used to evaluate the expression of signaling proteins. All benzylidenes demonstrated inhibitory effects with IC50 values below 10 µM, whereas pentacyclic derivatives were less active. These patterns may be associated with the lability of the geometry of benzylidene molecules, which contributes to an increase in the affinity of interaction with the receptor. The selected compounds showed significant anti-estrogenic potency. Benzylidene 1d ((8 S,9 S,10R,13 S,14 S,17 S)-17-[(2E)-3-(4-fluorophenyl)prop-2-enoyl]-10,13-dimethyl-1,2,6,7,8,9,11,12,14,15-decahydrocyclopenta[a]phenanthren-3-one) was the most active in antiproliferative and anti-estrogenic assays. Apoptosis induced by compound 1d was accompanied by decreases in CDK4, ERα, and Cyclin D1 expression. Compounds 1d and 3d were characterized by high inhibitory potency against resistant breast cancer cells. Apoptosis induced by the leader compounds was confirmed by PARP cleavage and flow cytometry analysis. Compound 3d caused cell arrest in the G2/M phase. Further analysis of novel derivatives of the progesterone series is of great importance for medicinal chemistry, drug design, and oncology. [ABSTRACT FROM AUTHOR]

The influence of various durations of anodic and cathodic polarization during plasma electrolytic oxidation (PEO) is studied. The changes in structure of a protective coating formed on a ML5 foundry magnesium alloy by PEO method are analyzed. We found that the variation in duration of polarization pulses from 50 to 250 μs changes the structure and protective properties. Indeed, the variation in duration of polarization made it possible to change the geometry of pores and their location within the volume of a PEO coating, which had a positive influence on the electrochemical properties. The calculation of consumed electrical energy showed that it is possible to decrease the consumption of electrical energy with a pulse duration of 50 μs, and the protective properties of a PEO coating remain high. [ABSTRACT FROM AUTHOR]

The review summarizes literature data on the methods of synthesis of o-aminopyrimidine aldehydes and o-aminopyrimidine ketones and their application for the construction of fused pyrimidines, in particular pyrido[2,3-d]pyrimidines, pyrimido[4,5-d]pyrimidines, pyrazolo-[3,4-d]pyrimidines, quinazolines, pyrimido[4,5,6-de]quinazolines, thieno[2,3-d]pyrimidines, pyrrolo[2,3-d]pyrimidines, cyclopenta[d]-pyrimidines, pyrimido[4,5-b]azepines, and pyrimido[4,5-b]quinolines. [ABSTRACT FROM AUTHOR]

The reaction of N-chlorocarbonylmethyl-N'-methoxydiazene N-oxide with hydroxy groups of various steroids afforded new potential nitric oxide generators containing N'-alkoxydiazene N-oxide groups at different positions of the steroid skeleton which may have antitumor activity. [ABSTRACT FROM AUTHOR]

Alkylation of 5-aminotetrazole with chloromethylnitrazaalkanes led to 1-nitrazaalkyl derivatives, which reacted with formalin solution and sodium carbonate followed by treatment with nitroform to form 1-nitrazaalkyl-5-(1,1,1-trinitro-3-azapropyl)tetrazoles. The latter were nitrated for the first time to obtain tetrazoles containing both trinitromethyl and nitrazaalkyl groups. [ABSTRACT FROM AUTHOR]

New straightforward synthesis of benzothiazole‐2‐carboxamides and benzoxazole‐2‐carboxamides from 2‐chloracetamides, 2‐amino(thio)phenols and elemental sulfur has been developed. Main advantage of this protocol is the utilization of water as reaction media, which lead to simple reaction procedure. Also this process is distinguished by good tolerance toward different functional groups. Yields of products is up to 99 %. [ABSTRACT FROM AUTHOR]

Methods for extending the side chain of 20-oxopregnanes were summarized. The possibilities of alkylation of 3-methoxy-19-norpregna-1,3,5(10)-trien-20-one and its 16α,17α-methano and -butano derivatives with alkyl halides in the presence of lithium diisopropylamide were studied. The Claisen—Schmidt condensation of these steroids with aromatic aldehydes resulted in a series of the corresponding 21-benzylidenesteroids. Carrying out the Claisen—Schmidt condensation in an aprotic solvent in the presence of lithium diisopropylamide yielded, in addition to the target 21-benzylidenesteroids, the corresponding 21-benzoyl derivatives — steroidal 1,3-diketones. [ABSTRACT FROM AUTHOR]

An efficient method for the synthesis of functionalized thieno[2,3-d]pyrimidines and 2-(thieno[2,3-d]pyrimidin-6-yl)pyrido[2,3-d]pyrimidines from 5-acetyl-6-aminopyrimidine-4(3H)-thiones and a series of reagents containing an active chloromethylene fragment has been developed. [ABSTRACT FROM AUTHOR]

Two routes were proposed for the synthesis of pyrimido[4,5-d]pyrimidine derivatives from 5-acetyl-4-aminopyrimidines. Acylation of 5-acetyl-4-aminopyrimidines followed by cyclization by the action of NH4OAc made it possible to access pyrimido[4,5-d]pyrimidines with alkyl, aryl, and hetaryl substituents in positions 2 and 7. Reductive amination of the acetyl group in 5-acetyl-4-aminopyrimidines and subsequent cyclization with DMF–DMA or HC(OEt)3 resulted in the formation of 6-alkyl-3,4-dihydropyrimido[4,5-d]pyrimidines. [ABSTRACT FROM AUTHOR]

Carbocyclic steroids D-annulated at 16α and 17α positions with a 5-membered ring E are easily accessible via the interrupted Nazarov cyclization. Three steroid series have been structurally studied: chlorine-containing D-annulated pentacyclic steroids 2, their reduced derivatives 3 and their synthetic precursors – benzylidines of tetracyclic steroids 1. The presence of two conformers for pentacyclic steroids 2 and 3 have been found in crystals, where formation is evidently caused by the conformational flexibility of the ring E. Geometries obtained from X-ray diffraction experiments have been used as the initial ones for semi-empirical and ab initio quantum chemical calculations to confirm the reproducibility of the steroids' geometries by these methods and further used for docking studies against the human androgen receptor ligand-binding domain. The docking results have confirmed that the geometries of the studied D-annulated pentacyclic steroids perfectly match the human androgen receptor active site. Geometry analysis of docking results allowed us to explain the influence of subtle structural differences in series 2 and 3 on the ligand binding energy. Compounds with the highest binding energies have been studied in experiments on AR-positive 22Rv1 prostate cancer cells. Selected steroids revealed antiproliferative potency and inhibited AR pathways in 22Rv1 prostate cancer cells, including downregulation in NKX3.1 and PSA expression. A combination of pentacyclic steroid 2d with non-steroidal antiandrogen bicalutamide exhibited significant antiproliferative effects in 22Rv1 cells. The obtained results for this family of pentacyclic steroids provides insights for further structure–activity relationship studies towards novel drugs targeting nuclear receptors in cancer cells. Pentacyclic steroids are of great interest for the development of innovative therapeutic approaches in the treatment of prostate cancer. [ABSTRACT FROM AUTHOR]

A model is developed for describing the transport of charged colloidal particles in an evaporating sessile droplet on the electrified metal substrate in the presence of a solvent flow. The model takes into account the electric charge of colloidal particles and small ions produced by electrolytic dissociation of the active groups on the colloidal particles and solvent molecules. We employ a system of self-consistent Poisson and Nernst–Planck equations for electric potential and average concentrations of colloidal particles and ions with the appropriate boundary conditions. The fluid dynamics, temperature distribution and evaporation process are described with the Navier–Stokes equations, equations of heat conduction and vapor diffusion in air, respectively. The developed model is used to carry out a first-principles numerical simulation of charged silica colloidal particle transport in an evaporating aqueous droplet. We find that electric double layers can be destroyed by a sufficiently strong fluid flow. [ABSTRACT FROM AUTHOR]

Novel derivatives of 4,4‐difluoro‐1,3,5,7,8‐pentamethyl‐4‐bora‐3a,4a‐diaza‐s‐indacene (BODIPY) functionalized at the meso‐position with polyamines and polyoxyethylenes were synthesized through single‐step condensation of fluorogenic 8‐CH2Cl‐substituted BODIPY and corresponding amines. The systematic spectroscopic characterization (UV‐Vis, fluorescence) of stable in storage dyes bearing polyoxyethylene substituents was carried out. One compound showed promise for UV‐Vis and "off‐on" fluorescence Cu2+ detection in acetonitrile solutions. The ligand detects Cu2+ ions selectively in the presence of eighteen different alkaline earth metal cations. [ABSTRACT FROM AUTHOR]

Methods were developed for the synthesis of new pyrido[2,3-d]pyrimidin-5-ones and pyrido[2,3-d]pyrimidin-7-ones from 5-acetyl-N-acyl-6-amino-4-methylsulfanyl-2-phenylpyrimidines. Heating the latter with MeONa at reflux in BuOH led to selective formation of pyrido[2,3-d]pyrimidin-5-ones or pyrido[2,3-d]pyrimidin-7-ones (containing an intact SMe group or resulting in its substitution with OBu group), depending on the nature of the acyl group. The possible substitution of SMe and OBu groups in pyridopyrimidinones was explored by using BnNH2. It was demonstrated that prior oxidation of SMe group with m-chloroperbenzoic acid allowed for simpler introduction of the NHBn moiety. [ABSTRACT FROM AUTHOR]

Progesterone and its synthetic analogues act on cells through different types of receptors, affecting proliferation and apoptosis. These compounds exert their effect through the nuclear receptors and the insufficiently studied membrane progesterone receptors (mPRs) belonging to the progestin and adiponectin Q receptor (PAQR) family. We have identified two selective ligands of mPRs that activate only this type of progesterone receptors – 19-hydroxypregn-4-en-20-one (LS-01) and 19-hydroxy-5β-pregn-3-en-20-one (LS-02). The goal of this work is to study the effect of these compounds on proliferation and death of human pancreatic adenocarcinoma cells BxPC3 and involvement of the two kinases (p38 MAPK and JNK) in signaling pathways activated by progestins through mPRs. It was shown that progesterone and the compound LS-01 significantly (p < 0.05) inhibited the BxPC3 cell viability, with JNK serving as a mediator. The identified targets of these two steroids are the genes of the proteins Ki67, cyclin D1, PCNA, and p21. Progesterone and the compound LS-01 significantly (p < 0.05) stimulate DNA fragmentation, enhancing the cell death. The p38 mitogen-activated protein kinase (MAPK) is a key mediator of this process. The BCL2A1 protein gene was identified as a target of both steroids. The compound LS-02 significantly (p < 0.05) alters membrane permeability and changes the exposure of phosphatidylserine on the outer membrane leaflet, also enhancing the cell death. This compound acts on these processes by activating both kinases, JNK and p38 MAPK. The compound LS-02 targets the genes encoding the proteins HRK, caspase 9, and DAPK. [ABSTRACT FROM AUTHOR]

A new approach to the synthesis of isomeric 19-hydroxypregn-4-en-20-one (1) and 19-hydroxy-5β-pregn-3-en-20-one (2), the selective ligands of membrane progesterone receptors, in a ratio of 1.5:1 is presented. The effect of these steroids on the gene expression of several cytokines (TNFα, IL-1β, IL-6, and TGFβ) in K562 cells was studied. Progesterone and compound 1 acted unidirectionally, significantly decreasing the TGFβ mRNA levels in these cells. The highest activity was exhibited by compound 2 which regulated the expression of the three studied genes, increasing the level of TNFα mRNA and IL-1β mRNA and decreasing the level of TGFβ mRNA. The immunomodulatory effect of the synthesized selective ligands of membrane progesterone receptors found in K562 cells is comparable (for 1) or even surpasses (for 2) the effect of a natural hormone. [ABSTRACT FROM AUTHOR]

Methods were developed for the synthesis of new pyrido[2,3-d]pyrimidine and pyrimidino[4,5-d][1,3]oxazine derivatives. When heated under reflux with MeONa in BuOH, 5-acetyl-4-aminopyrimidines, acylated with carboxylic anhydrides or acid chlorides, are transformed into pyrido[2,3-d]pyrimidin-5-one derivatives, i.e., the acetyl methyl group and the amide carbonyl moiety are involved in the cyclization. In the presence of an activated CH2 group (e.g., PhCH2) in the amide moiety, the cyclization involves this group and the acetyl carbonyl giving rise to pyrido[2,3-d]pyrimidin-7-one derivatives. The reaction of 5-acetyl-4-aminopyrimidines with carboxylic acid chlorides under reflux in xylene followed by addition of a base affords pyrimidino[4,5-d][1,3]oxazines. [ABSTRACT FROM AUTHOR]

A new method for the synthesis of quinazolines based on the annulation of the benzene ring to 5-acetyl-6 methylpyrimidin-2-one(thione) derivatives has been proposed. Condensation of the latter at the methyl group with dimethylformamide dimethyl acetal in boiling PhH leads to the formation of 5-acetyl-6-[2-(dimethylamino)vinyl]pyrimidin-2-ones(thiones), which, when boiled with MeONa in MeOH, cyclize to 5-hydroxyquinazolin-2-ones(thiones). Similarly, 5-acetyl-6-methyl-4-(trifluoromethyl)pyrimidine was converted to 5-hydroxy-4-(trifluoromethyl)quinazoline. Quinazolines are not formed from 5-acetyl-6-methylpyrimidines condensed with dimethylformamide dimethyl acetal at the acetyl group, but 5-acetyl-6-methylpyrimidines can be used to obtain pyrido[2,3-d] pyrimidine derivatives. [ABSTRACT FROM AUTHOR]

The influence of exogenous factors on the selectivity of biotransformation of cholesterol 3β-methyl ether by Mycobacterium sp. was studied. The main product of the microbiological transformation was Δ5-dehydroepiandrosterone 3β-methyl ether. The presence of methyl-β-cyclodextrin in the bacterial growth medium led to a change in the ratio of the reaction products and an increase in the yield of Δ4-androstene-3,17-dione. Aliphatic saturated and unsaturated carboxylic acids were also formed in the course of biotransformation. [ABSTRACT FROM AUTHOR]

The reaction of 6-(R-amino)-5-acetyl-4-methylsulfonyl-2-phenylpyrimidines with amines was studied. 6-Arylamino derivatives react with alkylamines to form 6-alkylamino-4-arylamino-5-acetyl-2-phenylpyrimidines, which upon refluxing in benzene with dimethylformamide dimethylacetal are converted to 4-alkylamino-8-aryl-2-phenylpyrido[2,3-d]pyrimidin-5(8H)-ones. The cyclization proceeds selectively with participation of the arylamino group only, the alkylamino group being not involved. At the same time, refluxing of 5-acetyl-4,6-dibenzylamino-2-phenylpyrimidine with dimethylformamide dimethylacetal in toluene affords the product of condensation on the acetyl group, which upon refluxing in o-xylene transforms to 4-benzylamino-8-benzyl-2-phenylpyrido[2,3-d]pyrimidin-5(8H)-one. [ABSTRACT FROM AUTHOR]

In recent years, the transition‐metal catalyzed three‐component coupling of an aldehyde, an alkyne and an amine, commonly called A3 coupling has become a powerful tool in organic synthesis. The aim of this review is to give a general overview of A3 coupling utility in the synthesis of heterocycles, highlighting the variety of compounds that can be directly accessed from single reactions. The diverse A3 coupling based methodologies that have been developed for the synthesis of N,O,S‐heterocycles are presented, emphasizing the influence of the reaction conditions and the use of additional reagents in the outcome of the transformations. [ABSTRACT FROM AUTHOR]

One hundred years ago N.I. Vavilov formulated the Law of homologous series in hereditary variability. Among the broad range of examples that encouraged N.I. Vavilov to make this important generalization, homologous series in plant height variability were mentioned. In the current review, we compare data collected over the century on genetic basis and molecular mechanisms behind the series in plant height variability with the stress on "Green revolution" genes. Application of fertilizers boosted redirection of artificial selection from tall-growing varieties to those with reduced height. The sources of GA-sensitive and GA-insensitive reduced height (Rht) genes in wheat and rice first were involved in crosses in Japan and China. The commercially valuable alleles of the Rht genes were spread broadly in varieties released in 1960s all over the world. Results of genetic studies into inheritance of the Rht genes are summarized for rice and wheat (together with further Triticeae crops–barley and rye). Three orthologous series of reduced plant height genes have been found within Triticeae tribe species and rice: (1) wheat Rht12 and rye Ddw1; (2) wheat Rht-B1/D1 and barley Dwf2; (3) barley denso/sdw1 and rice sd1. Molecular and cell mechanisms underlying plant reduced height are considered with focus on metabolic pathways regulated by commercially valuable alleles of Rht genes: GA-insensitive Rht-B1/D1 and GA-sensitive sd1, denso/sdw1, Rht8, Rht12, Rht18, Ddw1. Overall, in spite of similar metabolic pathways, the certain genes conferring variability for plant height are often distinct, resulting in existence of several "short" orthologous series of genes rather than one series through different cereal taxa. [ABSTRACT FROM AUTHOR]

A copolymer of perfluoro-2-ethyl-2-methyldioxole and perfiuoropropyl vinyl ether was prepared by the method of high-pressure polymerization. The synthesized polymer has high optical transparency, a low refractive index, and a low material dispersion in the telecommunication wavelength ranges near 0.85, 1.3, and 1.5 µm. In addition, the polymer is predominantly amorphous and has high glass-transition and decomposition temperatures. The synthesized polymer is able to film formation and promising for the design and construction of high-speed optoelectronic printed circuit boards in which a metallic conductor-based electrical data bus is supplemented with an optical data bus based on a polymeric waveguide array. Films with a thickness of 4–8 µm were fabricated from the synthesized polymer by centrifuging. The polymer was characterized by DSC, DTGA, TMA, X-ray diffraction analysis (XRD), and IR spectroscopy. [ABSTRACT FROM AUTHOR]