Annelated medium-sized azaheterocycles as attractive scaffolds for CNS targeted leads.

Medium-sized nitrogen heterocycles (7-to-15-membered) have widespread interest in organic synthesis and medicinal chemistry. Indeed, such heterocyclic rings are found as subunits or core structures in natural and bioactive molecules, including pharmaceutical products, whereas on the other hand they often can serve as key intermediates in the synthesis of bicyclic compounds by selective transformations (e.g., transannular ring-contractions, cycloadditions). These molecular frameworks, particularly annelated 7-to-10-membered aza-heterocycles, have long drawn our attention as potential scaffolds for developing new multitarget- directed ligands (MTDLs) for treating Alzheimer's disease (AD) and other neurodegenerative syndromes.AD, the most common form of dementia affecting people worldwide, is a progressive neurodegenerative disorder, whose multifactorial pathogenesis is still not completely understood. The main histopathological changes include synaptic dysfunction and neuronal loss resulting from intracellular and extracellular fibrillar aggregates of Beta-amyloid (Abeta),hyperphosphorilated and beta-folded tau proteins, cholinergic impairment, oxidative stress, neuroinflammation, metal dys-homeostasis and mitochondrial damage. Among others, N- methyl-D-aspartate receptors (NMDARs) play a major role in learning and memory, and their overactivation causes excessive calcium influx and consequent excitotoxicity, which is associated with CNS diseases, including Parkinson's disease. Starting from our old1,2 and recent 3 findings on the suitability of partially hydrogenated benzo-, chromane-4- one- and indole-fused azepine and azocine derivatives targeted at enzymes, receptors and biochemical pathways involved in the pathogenesis of AD, we extended the investigation to novel derivatives of annelated azonines and azecines. Herein, our recent advances of benzo- and indol-fused 7-to-10-membered nitrogen heterocycles as molecular tools for AD-associated targets (e.g., butyryl- and acetylcholinesterase, monoamine oxidases A and B, Abeta aggregation, ROS insult, NMDAR antagonist), along with the results from investigation on cell and ex vivo/in vivo animal models, will be presented and discussed in an effort of rationalizing structure-activity relationships and progressing drug optimization of the examined CNS-targeted lead compounds

Synthesis of 8-phenyl substituted 3-benzazecines with allene moiety, their thermal rearrangement and evaluation as acetylcholinesterase inhibitors

Various 4′-R-substituted phenyl azacyclic allenes were synthesized in good yields, and their thermal transformations were studied. For the first time, the obtained rearrangement products—new N-bridged cyclopenta[a]indenes, and the corresponding parent allenes were evaluated as potential inhibitors of acetyl- and butyrylcholinesterase. Among the tested compounds, the allene derivative 2g proved to competitively inhibit human AChE with inhibition constant value (Ki) in the low micromolar range. Graphic abstract: [Figure not available: see fulltext.

Homobivalent Lamellarin-Like Schiff Bases: In Vitro Evaluation of Their Cancer Cell Cytotoxicity and Multitargeting Anti-Alzheimer's Disease Potential

Marine alkaloids belonging to the lamellarins family, which incorporate a 5,6-dihydro-1-phenylpyrrolo[2,1-a]isoquinoline (DHPPIQ) moiety, possess various biological activities, spanning from antiviral and antibiotic activities to cytotoxicity against tumor cells and the reversal of multidrug resistance. Expanding a series of previously reported imino adducts of DHPPIQ 2-carbaldehyde, novel aliphatic and aromatic Schiff bases were synthesized and evaluated herein for their cytotoxicity in five diverse tumor cell lines. Most of the newly synthesized compounds were found noncytotoxic in the low micromolar range (<30 μM). Based on a Multi-fingerprint Similarity Search aLgorithm (MuSSeL), mainly conceived for making protein drug target prediction, some DHPPIQ derivatives, especially bis-DHPPIQ Schiff bases linked by a phenylene bridge, were prioritized as potential hits addressing Alzheimer's disease-related target proteins, such as cholinesterases (ChEs) and monoamine oxidases (MAOs). In agreement with MuSSeL predictions, homobivalent para-phenylene DHPPIQ Schiff base 14 exhibited a noncompetitive/mixed inhibition of human acetylcholinesterase (AChE) with Ki in the low micromolar range (4.69 μM). Interestingly, besides a certain inhibition of MAO A (50% inhibition of the cell population growth (IC50) = 12 μM), the bis-DHPPIQ 14 showed a good inhibitory activity on self-induced β-amyloid (Aβ)1-40 aggregation (IC50 = 13 μM), which resulted 3.5-fold stronger than the respective mono-DHPPIQ Schiff base 9

Management of MDR-TB in HIV co-infected patients in Eastern Europe: Results from the TB:HIV study

Objectives Mortality among HIV patients with tuberculosis (TB) remains high in Eastern Europe (EE), but details of TB and HIV management remain scarce. Methods In this prospective study, we describe the TB treatment regimens of patients with multi-drug resistant (MDR) TB and use of antiretroviral therapy (ART). Results A total of 105 HIV-positive patients had MDR-TB (including 33 with extensive drug resistance) and 130 pan-susceptible TB. Adequate initial TB treatment was provided for 8% of patients with MDR-TB compared with 80% of those with pan-susceptible TB. By twelve months, an estimated 57.3% (95%CI 41.5\u201374.1) of MDR-TB patients had started adequate treatment. While 67% received ART, HIV-RNA suppression was demonstrated in only 23%. Conclusions Our results show that internationally recommended MDR-TB treatment regimens were infrequently used and that ART use and viral suppression was well below the target of 90%, reflecting the challenging patient population and the environment in which health care is provided. Urgent improvement of management of patients with TB/HIV in EE, in particular for those with MDR-TB, is needed and includes widespread access to rapid TB diagnostics, better access to and use of second-line TB drugs, timely ART initiation with viral load monitoring, and integration of TB/HIV care

Occurrence and molecular characterization of Bacillus spp. strains isolated from gnocchi ingredients and ambient gnocchi stored at different temperatures

Ambient gnocchi is a potato-based product with a shelf-life of 12 months at room temperature, due to pasteurisation and incorporation of organic acids. Aim of this study was to investigate the microbiological characteristics of ambient gnocchi and their ingredients. In addition to their industrial formulation, ambient gnocchi were analysed when lactic and sorbic acids were partially or totally removed, at different storage temperatures, to identify the main microbial groups. Floury ingredients were the most contaminated, with total mesophilic count and presumptive Bacillus spp. up to 5 log CFU/g. Industrial gnocchi were stable, while gnocchi without acids showed loads up to 7 log CFU/g after 7 day at 37 °C. Bacillus spp. were isolated and characterized through rMLST, 7-loci MLST, and kSNP3 analysis. Virulence factors and antibiotic resistance determinants were detected in isolates of the Bacillus cereus group. Bacillus subtilis was the most frequently isolated species, showing spoilage potential, as observed by reddish slime on some samples during storage, but also interesting features evidenced by bacteriocin production genes. Therefore, we demonstrated that flour ingredients were the primary sources of contamination, and that Bacillus spp. was the microbial group of greatest interest for both safety and quality of this product

An overview of the natural antimicrobial alternatives for sheep meat preservation

Sheep meat is consumed and appreciated all over the world for its nutritional value and flavor. However, this meat is very perishable and easily subjected to the action of both spoilage and pathogenic microorganisms. For this reason, in combination with cold storage, effective preservation techniques are required. There is increasing interest in the application of natural antimicrobials, such as essential oils, extracts, spices, and by-products of the food industry. This review analyses the studies on natural antimicrobials in sheep meat and sheep meat products and gathers evidence about the encouraging results achieved on the reduction and/or elimination of spoilage and pathogenic microorganisms. The use of these natural antimicrobial alternatives might open up important perspectives for industrial application, considering that this specific meat is often traded over long distances. In fact, on the basis of scientific literature, natural antimicrobials can be considered a sustainable and affordable alternative to extend the shelf life of sheep meat and guarantee its safety, although many factors need to be further investigated, such as the sensory impact, potential toxicity, and economic aspects. For all these issues, investigated in some of the studies reviewed here, it is fundamental to obtain the antimicrobial effect with the minimum amount of effective substance to avoid sensory modifications, toxic effects, and unbearable costs. This study sets foundations for the possible direction of future studies, which will contribute to identify effective solutions for industrial applications of natural antimicrobials in the sheep meat industry

Combination of rosemary extract and buffered vinegar inhibits Pseudomonas and Shewanella growth in common carp (Cyprinus carpio)

BACKGROUND: Aquaculture is the fastest growing food-production sector, and common carp (Cyprinus carpio) is one of the most cultivated fish species in the world. Due to its intrinsic characteristics, fish meat is highly susceptible to microbiological spoilage. Pseudomonas and Shewanella are the primary and secondary occurring microbiota during storage of fish meat, with significant contribution to spoilage with the formation of hydrolytic enzymes (lipases and proteases). RESULTS: With in vitro testing, we show that rosemary extract (Inolens4), buffered vinegar and their combination (SyneROX) exhibit antimicrobial effects against P. fragi, P. psychrophila, S. putrefaciens and S. xiaemensis at concentrations of 3.13 and 1.56 mg mL−1. The combination was the most effective in inhibiting growth of selected bacteria in food model, and production of lipases and proteases during 9 days at 5 °C. In situ testing of antimicrobial dip treatment of carp meat determined that aerobic mesophilic, total psychrotrophic, Pseudomonas and hydrogen sulfide producer counts were reduced in all treatments, with the most prominent influence being shown by the combination and buffered vinegar. CONCLUSIONS: Our study highlights the importance of a multilevel assessment of the antimicrobial potential of biopreservatives under conditions comparable to those of the selected food. Investigation with bacteria and food model provided coherent and consistent data for the evaluation of the antimicrobial potential for carp meat. Combination of buffered vinegar (as active antimicrobial) and rosemary extract, with well-known and researched antioxidant properties but low in situ antimicrobial activity, represents a good potential for combined effect in preservation of fish meat. © 2020 Society of Chemical Industry

Pyrrolo[2,1-a]isoquinoline scaffold in drug discovery: Advances in synthesis and medicinal chemistry

Pyrrolo[2,1-a]isoquinoline (PIq) is a nitrogen heterocyclic scaffold of diverse alkaloids endowed with several biological activities, including antiretroviral and antitumor activities. Several 5,6-dihydro-PIq (DHPIq) alkaloids, belonging to the lamellarins' family, have proved to be cytotoxic to tumor cells, as well as reversers of multidrug resistance. In this review, we provide an overview of the main achievements over the last decade in the synthetic approaches to access libraries of PIq compounds along with a survey, as comprehensive as possible, of bioactivity, mechanism of action, pharmacophore and structure-activity relationships of synthetic analogs of DHPIq-based alkaloids. The focus is mainly on the potential exploitation of the (DH)PIq scaffold in design and development of novel antitumor drugs