88,222 results match your criteria analogues

25-hydroxycholesterol interacts differently with lipids of the inner and outer membrane leaflet - The Langmuir monolayer study complemented with theoretical calculations.

J Steroid Biochem Mol Biol 2021 May 10:105909. Epub 2021 May 10.

Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387, Kraków, Poland.

25-hydroxycholesterol (25-OH), a molecule with unusual behavior at the air/water interface, being anchored to the water surface alternatively with a hydroxyl group at C(3) or C(25), has been investigated in mixtures with main membrane phospholipids (phosphatidylcholines - PCs, and phosphatidylethanolamines - PEs), characteristic of the outer and inner membrane leaflet, respectively. To achieve this goal, the classical Langmuir monolayer approach based on thermodynamic analysis of interactions was conducted in addition to microscopic imaging of films (in situ with BAM and after transfer onto mica with AFM), surface-sensitive spectroscopy (PM-IRRAS), as well as theoretical calculations. Our results show that the strength of interactions is primarily determined by the kind of polar group (strong, attractive interactions leading to surface complexes formation were found to occur with PCs while weak or repulsive ones with PEs). Read More

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Synthesis, Characterization, and Density Functional Theory Studies of Three-Dimensional Inorganic Analogues of 9,10-Diboraanthracene-A New Class of Lewis Superacids.

J Am Chem Soc 2021 May 13. Epub 2021 May 13.

Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, P. R. China.

The three-dimensional inorganic analogues of 9,10-diboraanthracene, BX(CBH) (X = Cl, ; X = Br, ), were attained by salt elimination of LiCBH and trihaloboranes. The methyl- and phenyl-substituted compounds BMe(CBH) () and BPh(CBH) () were obtained by treating or with the corresponding Grignard reagents. These compounds were fully characterized by NMR, cyclic voltammetry (CV), IR, and single-crystal X-ray diffraction analyses. Read More

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PanD Structure-Function Analysis and Identification of a Potent Pyrazinoic Acid-Derived Enzyme Inhibitor.

ACS Chem Biol 2021 May 13. Epub 2021 May 13.

School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore.

A common strategy employed in antibacterial drug discovery is the targeting of biosynthetic processes that are essential and specific for the pathogen. Specificity in particular avoids undesirable interactions with potential enzymatic counterparts in the human host, and it ensures on-target toxicity. Synthesis of pantothenate (Vitamine B5), which is a precursor of the acyl carrier coenzyme A, is an example of such a pathway. Read More

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Treatment with somatostatin analogues and PRRT in metastatic middle ear adenoma with neuroendocrine features.

Endocrinol Diabetes Metab Case Rep 2021 May 1;2021. Epub 2021 May 1.

Department of Internal Medicine, Section of Endocrinology, ENETS Center of Excellence, Erasmus Cancer Institute, Erasmus Medical Center, Rotterdam, The Netherlands.

Summary: Middle ear adenomas with neuroendocrine features (ANEF) are rare, with an estimated 150 reported cases. They usually pursue an indolent clinical course. Four reported cases of middle ear ANEF with distant metastases were treated with surgery, external beam radiation therapy (EBRT) and chemotherapy. Read More

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Development and characterization of two novel Ga labelled Neuropeptide Y short analogues with potential application in breast cancer imaging.

Chem Biol Drug Des 2021 May 12. Epub 2021 May 12.

Área de Radioquímica, Departamento Estrella Campos, Facultad de Química, Universidad de la República (UdelaR), Montevideo, Uruguay.

In vivo receptor targeting with radiolabelled peptide-based probes is an attractive approach for the development of novel radiotracers for Molecular Imaging. This work presents the development and characterisation of two novel Neuropeptide Y analogues labelled with a positron emitter Ga, for potential use in breast cancer imaging. Both analogues share the same amino acid sequence and were derivatised with NOTA through either a lysine linker (L1) or an acetylated lysine (L2). Read More

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Improved development of mouse SCNT embryos by chlamydocin analogues, class I and IIa histone deacetylase inhibitors†.

Biol Reprod 2021 May 12. Epub 2021 May 12.

RIKEN BioResource Research Center, 3-1-1 Koyadai, Tsukuba, Ibaraki, 305-0074 Japan.

In mammalian cloning by somatic cell nuclear transfer (SCNT), treatment of reconstructed embryos with histone deacetylase (HDAC) inhibitors improves efficiency. So far, most of those used for SCNT are hydroxamic acid derivatives-such as trichostatin A-characterized by their broad inhibitory spectrum. Here, we examined whether mouse SCNT efficiency could be improved using chlamydocin analogues, a family of newly designed agents that specifically inhibit Class I and IIa HDACs. Read More

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Application of the Meerwein reaction of 1,4-benzoquinone to a metal-free synthesis of benzofuropyridine analogues.

Beilstein J Org Chem 2021 30;17:977-982. Epub 2021 Apr 30.

Department of Molecular Design and Synthesis, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium.

Several new heterocyclic systems based on a hydroxybenzofuro[2,3-]pyridine building block were prepared. This benzofuropyridine is easily available from the Meerwein reaction of benzoquinone and a heterocyclic diazonium salt, followed by reduction and cyclization. Electrophilic substitution and further condensations give polycyclic systems, including oxazolo- and chromeno-fused analogues. Read More

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Molecular networking as a novel approach to unravel toxin diversity of four strains of the dominant Dinophysis species from French coastal waters.

Harmful Algae 2021 Mar 31;103:102026. Epub 2021 Mar 31.

Université de Nantes, MMS, EA 2160, Nantes, France; ThalassOMICS Metabolomics Facility, Plateforme Corsaire, Biogenouest, Nantes, France. Electronic address:

Some species of the genus Dinophysis contain Diarrhetic shellfish Poisoning (DSP) toxins and are the main threat to shellfish farming in Europe including France. Dinophysis species are known to produce two families of bioactive lipophilic toxins: (i) okadaic acid (OA) and their analogues dinophysistoxins (DTXs) and (ii) pectenotoxins (PTXs). Only six toxins (OA, DTX1, DTX2, DTX3, PTX1 and PTX2) regulated by the European Union Legislation (EC No. Read More

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[Oral nucleos(t)ide analogues antiviral therapy reduces HBV-related HCC: consensus and contention].

C Han X G Dou

Zhonghua Gan Zang Bing Za Zhi 2021 Apr;29(4):293-296

Department of Infectious Diseases, Shengjing Hospital of China Medical University, Shenyang 110022, China.

Patients with chronic hepatitis B (CHB) who cannot receive effective antiviral therapy timely will eventually develop liver cirrhosis and/or hepatocellular carcinoma (HCC). Therefore, receiving nucleos(t)ide analogues (NAs) therapy can effectively inhibit hepatitis B virus (HBV) replication, improve liver tissue inflammation and fibrosis, prevent or delay the disease progression, and greatly reduce the occurrence of HBV-related HCC. However, it is often found in clinical practice that some patients treated with long-term NAs therapy can still develop HCC despite the effective inhibition of HBV replication. Read More

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Target therapies plus somatostatin analogues in NETs: a network meta-analysis.

Endocr Relat Cancer 2021 May 1. Epub 2021 May 1.

F de Braud, Medical Oncology, Fondazione IRCCS Istituto Nazionale Tumori Milano, Milan, Italy.

Although combination therapy is not recommended in patients with gastro-entero-pancreatic (GEP) neuroendocrine tumors (NETs), this strategy is widely used in clinical practice. This network meta-analysis of randomized trials evaluates targeted therapies and somatostatin analogues in GEP advanced NETs, either alone or in combination, comparing the efficacy of different single or combined treatment strategies in terms of progression-free survival (PFS). Interventions were grouped as analogues, everolimus, everolimus plus SSAs, sunitinib and placebo. Read More

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Design, synthesis and anti-HIV evaluation of novel 5-substituted diarylpyrimidine derivatives as potent HIV-1 NNRTIs.

Bioorg Med Chem 2021 May 5;40:116195. Epub 2021 May 5.

Department of Medicinal Chemistry, Key Laboratory of Chemical Biology, Ministry of Education, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Ji'nan 250012, China; China-Belgium Collaborative Research Center for Innovative Antiviral Drugs of Shandong Province, 44 West Culture Road, 250012 Jinan, Shandong, PR China. Electronic address:

Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are widely used in combination therapies against HIV-1. As a continuation of our efforts to discover and develop "me-better" drugs of DAPYs, novel diarylpyrimidine derivatives were designed, synthesized and evaluated for their anti-HIV activities in MT-4 cells. All the compounds demonstrated strong inhibition activity against wide-type HIV-1 strain (III) with EC values in the range of 2. Read More

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Design, synthesis and anti-influenza virus activity of furan-substituted spirothiazolidinones.

Bioorg Chem 2021 Apr 30;112:104958. Epub 2021 Apr 30.

Faculty of Pharmacy, Department of Pharmaceutical Chemistry, Istanbul University, Istanbul, Turkey.

A new series of N-(3-oxo-1-thia-4-azaspiro[4.5]decan-4-yl)carboxamides have been designed, synthesized and evaluated as antiviral agents. The compounds were prepared by condensation of 2-methylfuran-3-carbohydrazide, appropriate carbonyl compounds and sulfanyl acids. Read More

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Convergent Palladium-Catalyzed Stereospecific Arginine Glycosylation Using Glycals.

Org Lett 2021 May 12. Epub 2021 May 12.

Department of Chemistry, University at Albany, State University of New York, 1400 Washington Avenue, Albany, New York 12222, United States.

A stereospecific convergent peptide arginine glycosylation method is reported for the first time. A recently discovered arginine glycosylation invigorated the interests of arginine modification, which has been challenging, because of the inertness of the guanidino side chain. The approach renders the arginine glycoside construction convergently. Read More

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Aminoalkoxycarbonyloxymethyl Ether Prodrugs with a pH-Triggered Release Mechanism: A Case Study Improving the Solubility, Bioavailability, and Efficacy of Antimalarial 4(1)-Quinolones with Single Dose Cures.

J Med Chem 2021 May 12. Epub 2021 May 12.

Department of Chemistry, University of South Florida, CHE 205, 4202 E. Fowler Avenue, Tampa, Florida 33620, United States.

Preclinical and clinical development of numerous small molecules is prevented by their poor aqueous solubility, limited absorption, and oral bioavailability. Herein, we disclose a general prodrug approach that converts promising lead compounds into aminoalkoxycarbonyloxymethyl (amino AOCOM) ether-substituted analogues that display significantly improved aqueous solubility and enhanced oral bioavailability, restoring key requirements typical for drug candidate profiles. The prodrug is completely independent of biotransformations and animal-independent because it becomes an active compound via a pH-triggered intramolecular cyclization-elimination reaction. Read More

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Improving the Gastrointestinal Stability of Linaclotide.

J Med Chem 2021 May 12. Epub 2021 May 12.

Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.

High susceptibility to proteolytic degradation in the gastrointestinal tract limits the therapeutic application of peptide drugs in gastrointestinal disorders. Linaclotide is an orally administered peptide drug for the treatment of irritable bowel syndrome with constipation (IBS-C) and abdominal pain. Linaclotide is however degraded in the intestinal environment within 1 h, and improvements in gastrointestinal stability might enhance its therapeutic application. Read More

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Synthesis of Thio-lignan Analogues, Bioequivalent Salvinal without Unfavored Aldehyde.

J Org Chem 2021 May 12. Epub 2021 May 12.

School of Pharmaceutical Sciences, College of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa 920-1192, Japan.

The oxygen in the benzofuran (BF) of three antiproliferative natural neolignans, salvinal (), obovaten (), and 2-[7-methoxy-2-(4-methoxyphenyl)-3-methylbenzofuran-5-yl]ethanol (), was replaced with sulfur to form the new biological scaffold benzothiophene (BT) thio-lignans -. Compounds - and synthesized derivatives were evaluated for antiproliferative activity against five human cancer cell lines, including a multidrug-resistant cell line. Thio-salvinal () displayed significant antiproliferative effects with half-maximal inhibitory concentration (IC) values of 0. Read More

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Effects of Side-Chain Spacing and Length on Hydration States of Poly(2-methoxyethyl acrylate) Analogues: A Molecular Dynamics Study.

ACS Biomater Sci Eng 2021 May 12. Epub 2021 May 12.

Institute for Materials Chemistry and Engineering, Kyushu University, Fukuoka 819-0395, Japan.

Hydration states of polymers are known to directly influence the adsorption of biomolecules. Particularly, intermediate water (IW) has been found able to prevent protein adsorption. Experimental studies have examined the IW content and nonthrombogenicity of poly(2-methoxyethyl acrylate) analogues with different side-chain spacings and lengths, which are HP ( is the number of backbone carbons in a monomer) and PMCA ( is the number of carbons in-between ester and ether oxygens of the side-chain) series, respectively. Read More

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Beyond small molecules: targeting G-quadruplex structures with oligonucleotides and their analogues.

Nucleic Acids Res 2021 May 12. Epub 2021 May 12.

Organic and Biomimetic Chemistry Research Group, Ghent University, Krijgslaan 281 S4, B-9000 Ghent, Belgium.

G-Quadruplexes (G4s) are widely studied secondary DNA/RNA structures, naturally occurring when G-rich sequences are present. The strategic localization of G4s in genome areas of crucial importance, such as proto-oncogenes and telomeres, entails fundamental implications in terms of gene expression regulation and other important biological processes. Although thousands of small molecules capable to induce G4 stabilization have been reported over the past 20 years, approaches based on the hybridization of a synthetic probe, allowing sequence-specific G4-recognition and targeting are still rather limited. Read More

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Hydride-Transfer Reaction to a Mononuclear Manganese(III) Iodosylarene Complex.

Inorg Chem 2021 May 12. Epub 2021 May 12.

Department of Chemistry, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea.

Metal iodosylarene species have received interest because of their potential oxidative power as a catalyst. We present the first example of hydride-transfer reactions to a mononuclear manganese(III) iodosylbenzene complex, [Mn(TBDAP)(OIPh)(OH)] (; TBDAP = ,-di--butyl-2,11-diaza[3.3](2,6)pyridinophane), with dihydronicotinamide adenine dinucleotide (NADH) analogues. Read More

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Divergent Entry to Walsucochin Nortriterpenoids: Total Syntheses of (±)-Walsucochin A and (±)-Walsucochinoids C-F.

J Org Chem 2021 May 12. Epub 2021 May 12.

College of Plant Protection, Northwest A&F University, 3 Taicheng Road, Yangling 712100, Shaanxi, China.

Nortriterpenoids isolated from have attracted much attention from both synthetic and medicinal chemists, yet only recently have efficient synthetic approaches to any members appeared. Shown here is that the common intermediate with a 6/6/5/6-fused tetracyclic ring nucleus can be converted to walsucochin family members. The first total syntheses of (±)-walsucochin A, (±)-walsucochinoids C-F, and their analogues were achieved in this work. Read More

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Towards highly specific aptamer-affinity monolithic column by efficient UV light-initiated polymerization in "one-pot".

Anal Chim Acta 2021 Jun 17;1165:338517. Epub 2021 Apr 17.

Institute of Food Safety and Environment Monitoring, Fuzhou University, Fuzhou, 350108, People's Republic of China; Engineering Technology Research Center on Reagent and Instrument for Rapid Detection of Product Quality and Food Safety, Fujian, Fuzhou, 350108, People's Republic of China.

Time-consuming or tedious operation in multiple-step process might is the obstacle for efficiently preparing aptamer-affinity monolithic column. Here, a new and facile strategy to prepare aptamer-based hybrid affinity monolith in "one-pot" at room temperature was exploited, in which UV light-initiated free-radical polymerization and "thiol-ene" click reaction were implemented simultaneously. Only 7 min was cost for finishing the polymerization reaction, which was only 1/100 of that for the traditional thermal polymerization. Read More

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Chemical Screen for Vancomycin Antagonism Uncovers Probes of the Gram-Negative Outer Membrane.

ACS Chem Biol 2021 May 11. Epub 2021 May 11.

Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8N 3Z5, Canada.

The outer membrane of Gram-negative bacteria is a formidable permeability barrier which allows only a small subset of chemical matter to penetrate. This outer membrane barrier can hinder the study of cellular processes and compound mechanism of action, as many compounds including antibiotics are precluded from entry despite having intracellular targets. Consequently, outer membrane permeabilizing compounds are invaluable tools in such studies. Read More

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Deazapurine Nucleoside Analogues for the Treatment of .

ACS Infect Dis 2021 May 11. Epub 2021 May 11.

Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, U.K.

Trichomoniasis is the most common nonviral sexually transmitted disease in humans, but treatment options are limited. Here, we report a resorufin-based drug sensitivity assay for high-throughput microplate-based screening under hypoxic conditions. A 5203-compound enamine kinase library and several specialized compound series were tested for the inhibition of growth at 10 μM with ' values of >0. Read More

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Microparticles enhance the formation of seven major classes of natural products in native and metabolically engineered actinobacteria through accelerated morphological development.

Biotechnol Bioeng 2021 May 11. Epub 2021 May 11.

Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany.

Actinobacteria provide a rich spectrum of bioactive natural products and therefore display an invaluable source towards commercially valuable pharmaceuticals and agrochemicals. Here, we studied the use of inorganic talc microparticles (hydrous magnesium silicate, 3MgO·4SiO2·H2O, 10 µm) as a general supplement to enhance natural product formation in this important class of bacteria. Added to cultures of recombinant Streptomyces lividans, talc enhanced production of the macrocyclic peptide antibiotic bottromycin A2 and its methylated derivative Met-bottromycin A2 up to 109 mg L , the highest titer reported so far. Read More

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The impact of trace metal cations and absorbed water on colour transition of turquoise.

R Soc Open Sci 2021 Feb 3;8(2):201110. Epub 2021 Feb 3.

School of Gemmology, China University of Geosciences (Beijing), Beijing 100083, People's Republic of China.

Thirty-five gem-quality turquoise samples with various colours were investigated using energy-dispersive X-ray fluorescence spectroscopy, ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy and scanning electron microscopy. Sample chemical and spectral analyses indicate that Fe contributes to green hue of turquoise, whose absorption band exhibits a bathochromic shift from 426 to 428 nm with increasing V content in the solid-solution series turquoise-chalcosiderite. V enhances absorption in the blue and orange regions, and Cr increases absorption in the green region, both of which are responsible for the vivid greenish yellow in faustite. Read More

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February 2021

Structural analogues in herbal medicine ginseng hit a shared target to achieve cumulative bioactivity.

Commun Biol 2021 May 10;4(1):549. Epub 2021 May 10.

College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, 210023, People's Republic of China.

By a pilot trial on investigating immunomodulatory activity and target of ginsenosides, the major bioactive components of ginseng, here we report that structural analogues in herbal medicines hit a shared target to achieve cumulative bioactivity. A ginsenoside analogues combination with definite immunomodulatory activity in vivo was designed by integrating pharmacodynamics, serum pharmacochemistry and pharmacokinetics approaches. The cumulative bioactivity of the ginsenoside analogues was validated on LPS/ATP-induced RAW264. Read More

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First report on the use of pasireotide in a case of severe congenital hyperinsulinism due to a homozygous ABCC8 mutation.

Ann Pediatr Endocrinol Metab 2021 May 7. Epub 2021 May 7.

Department of Pediatric Endocrinology, Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands.

ABCC8 and KCJN11 mutations cause the most severe diazoxide-resistant forms of congenital hyperinsulinism (CHI). Somatostatin analogues are considered as second-line treatment in diazoxide-unresponsive cases. Current treatment protocols include the first-generation somatostatin analogue octreotide while pasireotide, a second-generation somatostatin analogue, may be more effective in reducing insulin secretion. Read More

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Method development for the identification of methoxpropamine, 2-fluoro-deschloroketamine and deschloroketamine and their main metabolites in blood and hair and forensic application.

Forensic Sci Int 2021 May 4;323:110817. Epub 2021 May 4.

Department of Healthcare Surveillance and Bioethics, Section of Legal Medicine, Università Cattolica del Sacro Cuore F. Policlinico Gemelli IRCCS, Rome, Italy. Electronic address:

The constant increase of new psychoactive substances, often available on the illicit drug market as 'research chemicals', poses a concern for public health and a significant analytical and legislative challenge. Β-keto-arylcyclohexamines represent a class of dissociative anesthetics recently introduced on the market of New Psychoactive Substances (NPS). There is still a lack of information about the pharmacological activity of many of such substances, usually depending on the potential chemical modifications introduced to circumvent the law. Read More

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Anti-inflammatory β-sitosterols from the Asiatic loop-root mangrove Rhizophora mucronata attnuate 5-lipoxygenase and cyclooxygenase-2 enzymes.

Steroids 2021 May 7:108860. Epub 2021 May 7.

Marine Biotechnology Division, Central Marine Fisheries Research Institute, Ernakulam North, P.B. No. 1603, Cochin, India.

Four biogenic β-sitosterol analogues were identified from methanolic extract of the leaves of loop-root mangrove Rhizophora mucronata. These were characterized as 4, 14, 23-trimethyl-3β-sitosterol (1), 7-ethyl-3β-sitosterol (2), sitosteryl-3β-(3E)-pent-3-enoate (3) and 12α-hydroxy-3β-sitosterol (4) based on comprehensive spectroscopic techniques. Anti-inflammatory activities of β-sitosterol 4 against pro-inflammatory enzymes 5-lipoxygenase and cyclooxygenase-2 were found to be significantly higher (IC 1. Read More

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