The preparation and properties of 1,1-difluorocyclopropane derivatives.

Recently, the functionalization of organic molecules with fluorine substituents has grown rapidly due to its applications in such fields as medicine, agriculture or materials sciences. The aim of this article is to review the importance of 1,1-difluorocyclopropane derivatives in synthesis. It will examine the role of the fluorine substituents in both ring-forming and ring-opening reactions, as well as methods for obtaining difluorocyclopropanes as single enantiomers. Several examples are provided to highlight the biological importance of this class of compounds.

Analysis of arglabin and its derivatives using high-performance liquid chromatography.

INTRODUCTION: The chemical modification of arglabin, a natural sesquiterpene lactone, has garnered significant attention because it comprises a guaianolide structure that exhibits antitumour and immunomodulating properties. Its primarily derived from Artemisia glabella Kar. et Kir. Physicochemical characterisation of commercial anititumour drugs based on arglabin can be time-consuming and expensive; thus, high-performance liquid chromatography (HPLC) is an optimal method to identify arglabin and its derivatives. AIM: This study has a two-fold objective: to develop a unified HPLC method for quality control of arglabin and its new hybrid molecules with alkaloids (cytisine, anabasine), and to study the relationship between their structures and chromatographic behaviours. MATERIALS AND METHODS: To develop a selective method that ensures the quality of arglabin and its derivatives, HPLC was used with the Zorbax SB-C18 analytical column. Dipole moments were calculated via the restricted Hartree-Fock method (RHF/6-31G(d, p)) and the B3LYР density functional theory with full geometry optimisation by using the GAUSSIAN 03 W program. RESULTS: A novel analytical method has been developed using reversed-phase (RP) HPLC, which is selective and allows reliable as well as quantitative determination of arglabin and its derivatives. To confirm the selectivity of the developed method, the chromatographic capacity factors and column selectivity were calculated. The relationship between retention time and structure (particularly, the nature of the substituent) was studied for the first time for arglabin and its derivatives using the B3LYP/6-31G(d) quantum chemical method. The influence of the dipole moment on the retention time of arglabin and its derivatives was confirmed. CONCLUSION: A novel unified quality control method using HPLC was developed to analyse arglabin, and its new hybrid molecules with alkaloids (cytisine and anabasine). For the first time, the relationship between the chromatographic behaviour in RP-HPLC and the dipole moment for arglabin and its derivatives was revealed.

Experimental study of antiparkinsonian action of the harmine hydrochloride original compound.

BACKGROUND: The effects of chemical products on the nervous system have been studied by various scientists. In this work, the antiparkinsonian action of a water-soluble form of harmine hydrochloride was studied. The present studies aim to research antiparkinsonian action of the harmine hydrochloride original compound. METHODS: To achieve the objective of the study, the authors used haloperidol-induced catalepsy and a method of Parkinson's syndrome (PS) induced by the MPTP (the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) neurotoxin. The experiments were performed on rats and mice which were divided into groups of 10 animals. RESULTS: It was established that harmine hydrochloride (HH), at a certain dose, eliminated haloperidol-induced catalepsy in rats and reduced oligokinesia and rigidity in the parkinsonism test in mice. Seven days after the experiment, the authors found the presence of rigidity in animals which had received the neurotoxin. It manifested itself in a shortened stride length compared to this parameter in intact controls. CONCLUSIONS: During the study the efficacy of harmine hydrochloride was equivalent to the effects of levodopa at a certain dose, which suggested that harmine hydrochloride compensated dopamine deficiency in the brain.

Protein tyrosine phosphatase 1B (PTP1B) inhibitors as potential anti-diabetes agents: patent review (2015-2018).

Introduction: Protein tyrosine phosphatase 1B (PTP1B) inhibition has been recommended as a crucial strategy to enhance insulin sensitivity in various cells and this fact is supported by human genetic data. PTP1B inhibitors improve the sensitivity of the insulin receptor and have the ability to cure insulin resistance-related diseases. In the latter years, targeting PTP1B inhibitors is being considered an attractive target to treat T2DM and therefore libraries of PTP1B inhibitors are being suggested as potent antidiabetic drugs. Areas covered: This review provides an overview of published patents from January 2015 to December 2018. The review describes the effectiveness of potent PTP1B inhibitors as pharmaceutical agents to treat type 2 diabetes. Expert opinion: Enormous developments have been made in PTP1B drug discovery which describes progress in natural products, synthetic heterocyclic scaffolds or heterocyclic hybrid compounds. Various protocols are being followed to boost the pharmacological effects of PTP1B inhibitors. Moreover these new advancements suggest that it is possible to get small-molecule PTP1B inhibitors with the required potency and selectivity. Furthermore, future endevours via an integrated strategy of using medicinal chemistry and structural biology will hopefully result in potent and selective PTP1B inhibitors as well as safer and more effective orally available drugs.

Inhibition of T Cell Receptor Activation by Semi-Synthetic Sesquiterpene Lactone Derivatives and Molecular Modeling of Their Interaction with Glutathione and Tyrosine Kinase ZAP-70.

A variety of natural compounds have been shown to modulate T cell receptor (TCR) activation, including natural sesquiterpene lactones (SLs). In the present studies, we evaluated the biological activity of 11 novel semi-synthetic SLs to determine their ability to modulate TCR activation. Of these compounds, α -epoxyarglabin, cytisinyl epoxyarglabin, 1 ß ,10 α -epoxyargolide, and chloroacetate grosheimin inhibited anti-CD3-induced Ca2+ mobilization and extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation in Jurkat T cells. We also found that the active SLs depleted intracellular glutathione (GSH) in Jurkat T cells, supporting their reactivity towards thiol groups. Because the zeta-chain associated tyrosine kinase 70 kDa (ZAP-70) is essential for TCR signaling and contains a tandem SH2 region that is highly enriched with multiple cysteines, we performed molecular docking of natural SLs and their semi-synthetic derivatives into the ZAP-70 binding site. The docking showed that the distance between the carbon atom of the exocyclic methylene group and the sulfur atom in Cys39 of the ZAP-70 tandem SH2 module was 3.04⁻5.3 Å for active compounds. Furthermore, the natural SLs and their derivatives could be differentiated by their ability to react with the Cys39 SH-group. We suggest that natural and/or semi-synthetic SLs with an α -methylene- γ -lactone moiety can specifically target GSH and the kinase site of ZAP-70 and inhibit the initial phases of TCR activation.

Bioavailability and structural study of 20-hydroxyecdysone complexes with cyclodextrins.

20-Hydroxyecdysterone - (2ß,3ß,5ß,22R)-2,3,14,20,22,25-hexahydroxycholest-7-en-6-one was isolated in satisfactory yield using ethanol extraction from the aerial part of Silene wolgensis (Hornem.) Otth; sometimes Silene wolgensis (Willd.) Bess. ex Spreng. The complexation of the phytoecdysteroid with ß-cyclodextrin was studied by NMR spectroscopy. By studying the changes in chemical shifts of protons of substrates and receptors it was found that ecdysterone interacts with cyclodextrins to form supramolecular inclusion complexes of stoichiometric composition of 1:1 or 1:2. Ecdysterone-ß-cyclodextrin complexes exhibit 100 times higher solubility in water than the parent compound.

The natural sesquiterpene lactones arglabin, grosheimin, agracin, parthenolide, and estafiatin inhibit T cell receptor (TCR) activation.

Inhibition of the T cell receptor (TCR) pathway represents an effective strategy for the treatment of T cell-mediated inflammatory and autoimmune diseases. To identify natural compounds that could inhibit inflammatory T cell responses, we screened 13 sesquiterpene lactones, including achillin, arglabin, argolide, argracin, 3ß-hydroxyarhalin, artesin, artemisinin, estafiatin, grosheimin, grossmisin, leucomisine, parthenolide, and taurine, for their ability to modulate activation-induced Ca2+ mobilization in Jurkat T cells. Five of the compounds (arglabin, grosheimin, argracin, parthenolide, and estafiatin) inhibited anti-CD3-induced mobilization of intercellular Ca2+ ([Ca2⁺]i) in Jurkat cells, with the most potent being parthenolide and argacin (IC50 = 5.6 and 6.1 µM, respectively). Likewise, phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 in activated Jurkat cells was inhibited by these five compounds, with the most potent being parthenolide and estafiatin (IC50 = 13.8 and 15.4 µM, respectively). These compounds also inhibited ERK1/2 phosphorylation in primary human T cells and depleted intracellular glutathione. In contrast, none of the sesquiterpene lactones inhibited ERK1/2 phosphorylation in HL60 cells transfected with N-formyl peptide receptor 2 (FPR2) and stimulated with the FPR2 peptide agonist WKYMVM, indicating specificity for T cell activation. Estafiatin, a representative sesquiterpene lactone, was also profiled in a cell-based phosphokinase array for 43 kinase phosphorylation sites, as well as in a cell-free competition binding assay for its ability to compete with an active-site directed ligand for 95 different protein kinases. Besides inhibition of ERK1/2 phosphorylation, estafiatin also inhibited phosphorylation of p53, AMPKα1, CREB, and p27 elicited by TCR activation in Jurkat cells, but it did not bind to any of 95 kinases evaluated. These results suggest that arglabin, grosheimin, agracin, parthenolide, and estafiatin can selectively inhibit initial phases of TCR activation and may be natural compounds with previously undescribed immunotherapeutic properties.

(1S*,3R*,5S*,7S*)-4,4,8,8-Tetra-chloro-1-isopropyl-5-methyl-tri-cyclo-[5.1.0.0(3,5)]octa-ne.

The title compound, C12H16Cl4, is a derivative of the natural product 1-isopropyl-4-methyl-cyclo-hexa-1,4-diene, and represents a diastereomer with two trans-fused cyclo-propane rings. Both enanti-omers are present in the non-centrosymmetric polar space group Pna21. The central cyclo-hexane ring is planar within 0.02 (1) Å. The C atoms of di-chloro-methyl-ene groups deviate from this plane by 1.19 (1) and -1.26 (1) Å, whereas the isopropyl and methyl groups are oriented more equatorially, deviating by 0.71 (1) and -0.87 (1) Å, respectively.