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We disclose a general 2-step synthesis of electron-poor 1,4- and 1,1,4-substituted buta-1,3-dienes bearing electron-withdrawing substituents at both termini of the conjugated system. The method relies on a base-promoted C-allylation of primary or secondary alkylsulfones with γ-bromocrotonate or related amide, nitrile, or sulfone and subsequent vinylogous retro-Michael dehydrosulfinylation. The geometry of the resulting dienes is substrate-dependent, and predominantly E,E-dienes are formed from E-electrophiles. This phosphorus- and transition-metal-free method tolerates a variety of functionalities and could serve as a supplement to Wittig, HWE, and Julia olefinations.

Recycling of all-trans-retinal to 11-cis-retinal through the visual cycle is a fundamental metabolic pathway in the eye. A potent retinoid isomerase (RPE65) inhibitor, (R)-emixustat, has been developed and tested in several clinical trials; however, it has not received regulatory approval for use in any specific retinopathy. Rapid clearance of this drug presents challenges to maintaining concentrations in eyes within a therapeutic window. To address this pharmacokinetic inadequacy, we rationally designed and synthesized a series of emixustat derivatives with strategically placed fluorine and deuterium atoms to slow down the key metabolic transformations known for emixustat. Crystal structures and quantum chemical analysis of RPE65 in complex with the most potent emixustat derivatives revealed the structural and electronic bases for how fluoro substituents can be favorably accommodated within the active site pocket of RPE65. We found a close (∼3.0 Å) F−π interaction that is predicted to contribute ∼2.4 kcal/mol to the overall binding energy.

TLR4, a member of the Toll-like receptor (TLR) family, serves as a pattern recognition receptor in the innate immune response to microbial pathogens. TLR4 also regulates the inflammatory reaction to ischemic injury in the heart. The TRIF-related adaptor molecule (TRAM) is an adapter that recruits the Toll/interleukin 1 receptor (TIR) domain, which contains adapter-inducing IFN-β (TRIF), to activate TLR4, following TRIF-dependent cytokine gene transcription. On the basis of a known TRAM-derived decoy peptide, 10 of its peptidomimetics were synthesized. One of them, 1-benzyl-5-methyl-4-(n-octylamino)pyrimidin-2(1H)-one (21), exhibited high potency and efficacy in vitro. In vitro results and in silico analysis provided evidence for the possible direct interaction of 21with the TLR4 complex. Administered in mice, 21was able to block the pathophysiological manifestation of MI, restoring the concomitant tissue damage, with a 100% survival rate. Thus, inhibition of TLR4-mediated inflammation in postischemic myocardium could be used as an approach for developing cardioprotective drugs.

Both pancreatic β-cell membranes and presynaptic active zones of neurons include in their structures similar protein complexes, which are responsible for mediating the secretion of bioactive molecules. In addition, these membrane-anchored proteins regulate interactions between neurons and guide the formation and maturation of synapses. These proteins include the neuroligins (e.g., NL-2) and their binding partners, the neurexins. The insulin secretion and maturation of β-cells is known to depend on their 3-dimensional (3D) arrangement. It was also reported that both insulin secretion and the proliferation rates of β-cells increase when cells are cocultured with clusters of NL-2. Use of full-length NL-2 or even its exocellular domain as potential β-cell functional enhancers is limited by the biostability and bioavailability issues common to all protein-based therapeutics. Thus, based on molecular modeling approaches, a short peptide with the potential ability to bind neurexins was derived from the NL-2 sequence. Here, we show that the NL-2-derived peptide conjugates onto innovative functional maghemite (γ-Fe2O3)-based nanoscale composite particles enhance β-cell functions in terms of glucose-stimulated insulin secretion and protect them under stress conditions. Recruiting the β-cells’ “neuron-like” secretory machinery as a target for diabetes treatment use has never been reported before. Such nanoscale composites might therefore provide a unique starting point for designing a novel class of antidiabetic therapeutic agents that possess a unique mechanism of action.

We tested the antiproliferative activity and mechanism of the action of several novel aminoacridine derivatives. Six different cancer cell lines were used to evaluate the potential cytotoxic effect of eleven aminoacridine-based molecules. A standard MTT assay was used for cell bioavailability analysis. Additionally, the potential cytotoxic effect of the tested compounds on non-cancer cells was investigated in rat skeletal muscle myotubes (L6) and in bovine aortic smooth muscle cells. In order to investigate whether the DNA binding activity of tested compounds correlated with their cytotoxic effect, circular dichroism (CD) measurement and DNA T4 ligase assay were performed. Finally, the potential mutagenic activity of the lead compound 5 was investigated. The cytotoxic effect of compound 5 in cancer cells was obtained in lower concentrations than the well-known: 9- aminoacridine based drug, amsacrine. The lead compound binds to DNA, but in a different mode than the parent molecules. Additionally, compound 5 was not cytotoxic in the effective range of concentrations in non-cancer cells. In identical concentrations, the parent compound (9-aminoacridine) and amsacrine were extremely toxic for both types of these normal cells. Finally, based on CD measurement and T4 ligase assay, it was confirmed that 5 binds to DNA but in different from the parent compounds manner. Important to mention, that compound 5 might have increased mutagenic activity which must be verified in vivo. Based on these in vitro results, we conclude that 5 is a more potent and more selective antiprolifirative compound than amsacrine. Compound 5 was also more effective in HepG2 and P-12 cells. Thus, 5 is suitable for future in vivo biological evaluation and its structure might be used as a basis for developing novel anticancer drugs.

Bovine aortic endothelial and smooth-muscle cells down-regulate the rate of glucose transport in the face of hyperglycaemia, thus providing protection against deleterious effects of increased intracellular glucose levels. When exposed to high glucose concentrations these cells reduced the mRNA and protein content of their typical glucose transporter, GLUT-1, as well as its plasma-membrane abundance. Inhibition of the lipoxygenase (LO) pathway, and particularly 12-LO, reversed this glucose-induced down-regulatory process and restored the rate of hexose transport to the level seen in vascular cells exposed to normal glucose levels. This reversal was accompanied by increased levels of GLUT-1 mRNA and protein, as well as of its plasma-membrane content. Exposure of the vascular cells to elevated glucose concentrations increased by 2–3-fold the levels of cell-associated and secreted 12-hydroxyeicosatetraenoic acid (12-HETE), the product of 12-LO. Inhibition of 15- and 5-LO, cyclo-oxygenases 1 and 2, and eicosanoid-producing cytochrome P450 did not modify the hexose-transport system in vascular cells. These results suggest a role for HETEs in the autoregulation of hexose transport in vascular cells. 8-Iso prostaglandin F2α, a non-enzymic oxidation product of arachidonic acid, had no effect on the hexose-transport system in vascular cells exposed to hyperglycaemic conditions. Taken together, these findings show that hyperglycaemia increases the production rate of 12-HETE, which in turn mediates the down-regulation of GLUT-1 expression and the glucose-transport system in vascular endothelial and smooth-muscle cells.

Intact actin microfilaments are required for insulin-regulated glucose transporter isoform 4 (GLUT4) translocation to the plasma membrane. Lipoxygenase (LO) metabolites have recently been shown to contribute to the regulation of actin cytoskeleton rearrangement. In the present investigation, ventricular cardiomyocytes were used to study the effects of two structurally different LO inhibitors (esculetin and nordihydroguaiaretic acid) on insulin signalling events, glucose uptake, GLUT4 translocation and the actin network organization. Insulin stimulation increased glucose uptake 3-fold in control cells, whereas LO inhibition completely blocked this effect. This was paralleled by a slight reduction in the insulin-induced tyrosine phosphorylation of insulin receptor substrate (IRS)-1 and IRS-2. However, inhibition of 12-LO did not affect the association of phosphatidylinositol 3-kinase with IRS-1 and the phosphorylation of Akt/protein kinase B in response to insulin. Addition of 12(S)-hydroxyeicosatetraenoic acid almost completely restored the insulin action in cells exposed to nordihydroguaiaretic acid. Insulin stimulation increased cell surface GLUT4 2-fold in control cells, whereas LO inhibition abrogated the insulin-stimulated GLUT4 translocation. LO inhibition induced a prominent disassembly of actin fibres compared with control cells. In conclusion, we show here that 12(S)-hydroxyeicosatetraenoic acid plays a role in the organization of the actin network in cardiomyocytes. LO inhibition blocks GLUT4 translocation without affecting downstream insulin signalling. These data suggest that LO metabolites participate in the regulation of glucose transport by contributing to a rearrangement of actin cytoskeletal elements.