Synthesis and SAR Analysis of Novel 4-Hydroxytamoxifen Analogues Based on Their Cytotoxic Activity and Electron-Donor Character.

Utilizing McMurry reactions of 4,4'-dihydroxybenzophenone with appropriate carbonyl compounds, a series of 4-Hydroxytamoxifen analogues were synthesized. Their cytotoxic activity was evaluated in vitro on four human malignant cell lines (MCF-7, MDA-MB 231, A2058, HT-29). It was found that some of these novel Tamoxifen analogues show marked cytotoxicity in a dose-dependent manner.

The Role of IgG Fc Region N-Glycosylation in the Pathomechanism of Rheumatoid Arthritis.

Anti-citrullinated protein antibodies (ACPAs) are involved in the pathogenesis of rheumatoid arthritis. N-glycosylation pattern of ACPA-IgG and healthy IgG Fc differs. The aim of this study is to determine the relative sialylation and galactosylation level of ACPAs and control IgG to assess their capability of inducing TNFα production, and furthermore, to analyze the correlations between the composition of Fc glycans and inflammatory markers in RA.

Topoisomerases inhibition and DNA binding mode of daunomycin-oligoarginine conjugate.

Cancer is a major health issue adsorbing the attention of a biomedical research. To fight this disease, new drugs are developed, specifically tailored to target biological pathways or peculiar components of the tumour cells. Particularly interesting is the use of intercalating agents as drugs capable to bind DNA and inhibit enzymes involved in DNA metabolism.

Tailoring Uptake Efficacy of HSV-1 gD Derived Carrier Peptides.

Regions of the virus-1 (HSV-1) glycoprotein D (gD) were chosen to design carrier peptides based on the known tertiary structure of the virus entry receptor complexes. These complexes consist of the following: HSV-1 gD-nectin-1 and HSV-1 gD-herpesvirus entry mediator (HVEM). Three sets of peptides were synthesised with sequences covering the (i) -terminal HVEM- and nectin-1 binding region -5-42, (ii) the 181-216 medium region containing nectin-1 binding sequences and (iii) the -terminal nectin-1 binding region 214-255.

Novel Polycondensed Partly Saturated β-Carbolines Including Ferrocene Derivatives: Synthesis, DFT-Supported Structural Analysis, Mechanism of Some Diastereoselective Transformations and a Preliminary Study of Their in vitro Antiproliferative Effects.

Use of a Pictet-Spengler reaction of tryptamine and l-tryptophan methyl ester and subsequent reduction of the nitro group followed by further cyclocondensation with aryl aldehydes and formyl-substituted carboxylic acids, including ferrocene-based components, furnished a series of diastereomeric 6-aryl-substituted 5,6,8,9,14,14b-hexahydroindolo[2',3':3,4]pyrido[1-]-quinazolines and 5,5b,17,18-tetrahydroindolo[2',3':3,4]pyrido[1,2-]isoindolo[2,1-]quinazolin-11-(15b)-ones with the elements of central-, planar and conformational chirality. The relative configuration and the conformations of the novel polycyclic indole derivatives were determined by H- and C-NMR methods supplemented by comparative DFT analysis of the possible diastereomers. The structure of one of the pentacyclic methyl esters with defined absolute configuration "" was also confirmed by single crystal X-ray diffraction measurement.

The effect of the branched chain polypeptide carrier on biodistribution of covalently attached B-cell epitope peptide (APDTRPAPG) derived from mucin 1 glycoprotein.

In order to establish structure-function relationship for the design of a new group of oligopeptide antigen-macromolecule conjugate, multiple copies of mucin-1 B-cell epitope peptide, APDTRPAPG were conjugated with branched chain polymeric polypeptides possessing poly[L-Lys] backbone. By the synthesis, radiolabeling (I) and in vivo treatment of BALB/c mice with epitope conjugates containing XK/XAK type carrier, where X = Glu (EK or EAK) or Leu (LAK), the influence of the polypeptide structure on the blood clearance profile and on tissue distribution profile concerning the epitope delivery to relevant organs (e.g.

Seropositivity and Antibody Profiling of Patients Are Dramatically Impacted by the Features of Peptides Used as Immunosorbents: A Lesson from Anti-Citrullinated Protein/Peptide Antibody.

Quantification of Abs toward a single epitope is critical to understanding immunobiological processes. In autoimmunity, the prognostic value of the serological profiles of patients draws much attention, but the detection of Abs toward a single epitope is not well controlled. Particularly, the rheumatoid arthritis (RA)-specific anti-citrullinated protein/peptide Abs (ACPA) are specific to a two-atom change on arginyl residues and are considered a heterogeneous family of Abs.

Ferrocene-Containing Impiridone (ONC201) Hybrids: Synthesis, DFT Modelling, In Vitro Evaluation, and Structure⁻Activity Relationships.

Inspired by the well-established clinical evidence about the interplay between apoptotic TRAIL (tumour necrosis factor-related apoptosis-inducing ligand) mechanism and reactive oxygen species (ROS)-mediated oxidative stress, a set of novel ONC201 hybrids containing the impiridone core and one or two differently positioned ferrocenylalkyl groups were synthesised in our present work. These two types of residues have been implicated in the aforementioned mechanisms associated with cytotoxic activity. A straightforward, primary amine-based synthetic approach was used allowing the introduction of a variety of -substituents into the two opposite regions of the heterocyclic skeleton.

The effect of conjugation on antitumor activity of vindoline derivatives with octaarginine, a cell-penetrating peptide.

Some Vinca alkaloids (eg, vinblastine, vincristine) have been widely used as antitumor drugs for a long time. Unfortunately, vindoline, a main alkaloid component of Catharanthus roseus (L.) G.

Mapping the tandem mass spectrometric characteristics of citrulline-containing peptides.

Rationale: Protein citrullination (deimination) is a post-translational modification of proteins converting arginine(s) into citrulline(s). "Overcitrullination" could be associated with severe pathological conditions. Mass spectrometric analysis of modified proteins is hindered by several problems.

Affinity Purification and Comparative Biosensor Analysis of Citrulline-Peptide-Specific Antibodies in Rheumatoid Arthritis.

Background: In rheumatoid arthritis (RA), anti-citrullinated protein/peptide antibodies (ACPAs) are responsible for disease onset and progression, however, our knowledge is limited on ligand binding affinities of autoantibodies with different citrulline-peptide specificity.

Methods: Citrulline-peptide-specific ACPA IgGs were affinity purified and tested by ELISA. Binding affinities of ACPA IgGs and serum antibodies were compared by surface plasmon resonance (SPR) analysis.

Ferrocene-cinchona hybrids with triazolyl-chalcone linkers act as pro-oxidants and sensitize human cancer cell lines to paclitaxel.

Recently, we demonstrated that ferrocene-containing compounds with a cinchona moiety displayed marked anticancer activity. Here we report on the effects of the most promising isomers encompassing quinine- (compounds 4 and 5) and quinidine-epimers (compounds 6 and 7) - synthesized using improved methods providing controlled diastereoselectivity - in three different human multidrug resistant (MDR) cancer cell lines and their sensitive counterparts (non-small cell lung carcinoma NCI-H460/R/NCI-H460, colorectal carcinoma DLD1-TxR/DLD1 and glioblastoma U87-TxR/U87). We observed that the presence of the MDR phenotype did not diminish the activity of the compounds suggesting that ferrocene quinine- and quinidine-epimers are not substrates for P-glycoprotein, which has been indicated as a major mechanism of MDR in the cell lines used.

Comparative analysis of internalisation, haemolytic, cytotoxic and antibacterial effect of membrane-active cationic peptides: aspects of experimental setup.

Cationic peptides proved fundamental importance as pharmaceutical agents and/or drug carrier moieties functioning in cellular processes. The comparison of the in vitro activity of these peptides is an experimental challenge and a combination of different methods, such as cytotoxicity, internalisation rate, haemolytic and antibacterial effect, is necessary. At the same time, several issues need to be addressed as the assay conditions have a great influence on the measured biological effects and the experimental setup needs to be optimised.

Cellular Uptake Mechanism of Cationic Branched Polypeptides with Poly[l-Lys] Backbone.

Cationic macromolecular carriers can be effective carriers for small molecular compounds, drugs, epitopes, or nucleic acids. Polylysine-based polymeric branched polypeptides have been systematically studied on the level of cells and organisms as well. In the present study, we report our findings on the cellular uptake characteristics of nine structurally related polylysine-based polypeptides with cationic side chains composed of (i) single amino acid (poly[Lys(X)], XK) or (ii) oligo[dl-alanine] (poly[Lys(dl-Ala)], AK) or (iii) oligo[dl-alanine] with an additional amino acid (X) at the terminal position (poly[Lys(X-dl-Ala)] (XAK)) or (iv) at the position next to the polylysine backbone (poly[Lys(dl-Ala-X)] (AXK)).

Pitfalls in the synthesis of fluorescent methotrexate oligopeptide conjugates.

Methotrexate (MTX) conjugates with poly[Lys(DL-Ala)] based polymeric polypeptides are efficient against Leishmania donovani parasite infection, but the mechanism of the effect is not known yet. We prepared therefore the 5(6)-carboxyfluorescein (Cf) labeled oligopeptide [Cf-K(AaAa)] (a: D-alanine, A: L-alanine) and the corresponding MTX conjugates [Cf-K(MTX-AaAa)] as model compounds for structure-activity experiments. The conjugate aimed to be synthesized with solid phase methodology on MBHA resin with Boc strategy, using Fmoc-Lys(Boc)-OH.

Cell-penetrating conjugates of pentaglutamylated methotrexate as potential anticancer drugs against resistant tumor cells.

The emerging resistance of tumor cells against methotrexate (MTX) is one of the major limitations of the MTX treatment of tumorous diseases. The disturbance in the polyglutamation which is a main step in the mechanism of methotrexate action is often the reason of the resistance. Delivery of polyglutamylated MTX into cells may evade the mechanisms that are responsible for drug resistance.

In vitro eradication of citrullinated protein specific B-lymphocytes of rheumatoid arthritis patients by targeted bifunctional nanoparticles.

Background: Autoreactive B cells are crucial players in the pathogenesis of rheumatoid arthritis (RA). Autoantibodies specific for citrullinated proteins (ACPA), present in the serum of approximately 60-70 % of patients, have a pathogenic role in the disease. B cell depleting therapies may result in a transient immunosuppression, increasing the risk of infections.

Synthesis, structure and in vitro cytostatic activity of ferrocene-Cinchona hybrids.

Exploring copper(I)- and ruthenium(II)-catalyzed azide-alkyne cycloadditions and a Sonogashira protocol, novel cytostatic ferrocene-cinchona hybrids were synthetized displaying significant in vitro activity on HepG-2 and HT-29 cells. Preliminary SAR studies disclosed that compounds incorporating linkers with 1,2,3-triazole and chalchone residues can be considered as promising lead structures. According to the best of our knowledge this is the first letter on the incorporation of ferrocene nucleus in the reputed cinchona family via triazole and chalcone linkers with established pharmaceutical profile.

Population tailored modification of tuberculosis specific interferon-gamma release assay.

Objectives: Blood-based Interferon-Gamma Release Assays (IGRA) identify Mycobacterium tuberculosis (MTB) sensitisation with increased specificity, but sensitivity remains impaired in human immunodeficiency virus (HIV) infected persons. The QuantiFERON-TB Gold In-Tube test contains peptide 38-55 of Rv2654c, based on data indicating differential recognition between tuberculosis patients and BCG vaccinated controls in Europe. We aimed to fine map the T cell response to Rv2654c with the view of improving sensitivity.

Synthetic Peptide-Based ELISA and ELISpot Assay for Identifying Autoantibody Epitopes.

Enzyme-linked immunosorbent assay (ELISA) is an invaluable diagnostic tool to detect serum autoantibody binding to target antigen. To map the autoantigenic epitope(s), overlapping synthetic peptides covering the total sequence of a protein antigen are used. A large set of peptides synthesized on the crown of pins can be tested by Multipin ELISA for fast screening.

Characterization of desmoglein-3 epitope region peptides as synthetic antigens: analysis of their in vitro T cell stimulating efficacy, cytotoxicity, stability, and their conformational features.

Desmoglein-3 (Dsg3) adhesion protein is the main target of autoantibodies and autoreactive T cells in Pemphigus vulgaris (PV) autoimmune skin disorder. Several mapping studies of Dsg3 T cell epitope regions were performed, and based on those data, we designed and synthesized four peptide series corresponding to Dsg3 T cell epitope regions. Each peptide series consists of a 17mer full-length peptide (Dsg3/189-205, Dsg3/206-222, Dsg3/342-358, and Dsg3/761-777) and its N-terminally truncated derivatives, resulting in 15 peptides altogether.

Antimycobacterial activity of peptide conjugate of pyridopyrimidine derivative against Mycobacterium tuberculosis in a series of in vitro and in vivo models.

New pyridopyrimidine derivatives were defined using a novel HTS in silico docking method (FRIGATE). The target protein was a dUTPase enzyme (EC 3.6.

Effect of SXWS/WSXWS peptides on chemotaxis and adhesion of the macrophage-like cell line J774.

WSXWS motif is a conserved amino acid sequence that is present in type I cytokine receptors. This motif that can be found both in the ligand binding chains and signal transducer molecule of the receptors with different amino acids at the position "X" plays a role in the receptor folding, ligand binding and signal transduction as well. Structural analysis proved that WSEWS motif of IL-6R is located in a highly accessible location in the protein.

Nanoparticle encapsulated lipopeptide conjugate of antitubercular drug isoniazid: in vitro intracellular activity and in vivo efficacy in a Guinea pig model of tuberculosis.

Considering that Mycobacterium tuberculosis (Mtb) can survive in host phagocytes for decades and currently applied drugs are largely ineffective in killing intracellular Mtb, novel targeted delivery approaches to improve tuberculosis chemotherapy are urgently needed. In order to enhance the efficacy of a clinically used antitubercular agent (isoniazid, INH) a novel lipopeptide carrier was designed based on the sequence of tuftsin, which has been reported as a macrophage-targeting molecule. The conjugate showed relevant in vitro activity on Mtb H37Rv culture with low cytotoxicity and hemolytic activity on human cells.