Hexahydrocannabinol on the Light Cannabis Market: The Latest "New" Entry

Introduction: Hexahydrocannabinols (HHCs), referred to as (9R)-HHC and (9S)-HHC diastereoisomers, are poorly studied cannabinoids naturally found in small concentrations in the pollen and the seeds of the hemp plants. Aim: In this study, for the first time, we describe the finding of (9R)-HHC and (9S)-HHC in two commercialized hemp derived products. Methods: The achievement of reference standards by semisynthetic or isolation approach allows us to develop and validate a gas chromatography mass spectrometry method for the identification and quantification of HHCs in hemp-derived resin. Results: The two analyzed samples showed percentage of 42.5 and 41.5 for (9R)-HHC and of 23.6 and 23.6 for (9S)-HHC. Conclusions: Despite the lack of in-depth studies about HHCs activity, potency, toxicity, and safety, these cannabinoids are emerging on the light-cannabis (hemp) market probably because legislations still do not clearly regulate them. Since analytical assay for hemp-derived products usually include only Δ9-THC, THC-A, CBD, and CBD-A, a thorough investigation could be carried out to reveal the possible addition of "new" compounds that might be a matter of safety.

Interplay of Modified Sialic Acid Inhibitors and the Human Parainfluenza Virus 1 Hemagglutinin-Neuraminidase Active Site

In the search for effective antivirals against Paramyxoviridae, the dynamics of human parainfluenza virus type 1 hemagglutinin-neuraminidase (hPIV1-HN) inhibition offers a promising perspective. This study focuses on the potential of C5- and C4-modified 2,3-unsaturated sialic acid (DANA) inhibitors and highlights their interaction with the hPIV1-HN enzyme. We show that a strategic substitution, replacing the C5 isopropyl group in BCX 2798 with a trifluoroacetyl function, increases inhibitory potency 3- to 4-fold. At the same time, we explore the special properties of the catalytic site of hPIV1-HN, which harbors only small substituents and favors a C4 sulfonylamido function over a carbonyl function, in contrast to the C4 pocket of Newcastle disease virus hemagglutinin-neuraminidase (NDV-HN). Based on these findings, we present a newly identified potent inhibitor that has the preferred C5 trifluoroacetamido and C4 trifluorosulfonylamide groups. The results of this study pave the way for a deeper understanding of the C4 and C5 binding pockets of hPIV1-HN and promote the development of new, more selective inhibitors.

Therapeutic Salivary Monitoring of Perampanel in Patients with Epilepsy Using a Volumetric Absorptive Microsampling Technique

The objective of this study was to validate a novel assay using the volumetric absorptive microsampling (VAMS) technique combined with liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) for the determination of the antiseizure medication perampanel in saliva and its clinical applicability in patients with epilepsy. VAMS tips were loaded with 30 μL of saliva and dried for 60 min. Analytes were extracted with methanol. The supernatant was evaporated under a gentle stream of nitrogen and reconstituted with 60 μL of methanol. Separation and quantification were achieved on a monolithic column connected to a mass spectrometer. Calibration curves were linear between 0.5 and 300 ng/mL. Intra- and inter-day accuracy was within 85.6-103.2% and intra-day and inter-day precision did not exceed 12.1%. Perampanel was stable in samples collected by VAMS and stored under different storage conditions. The VAMS-LC-MS/MS method was validated according to internationally accepted criteria and tested in patients with epilepsy who were receiving a combination of perampanel and other antiseizure medications. The method showed adequate bioanalytical performances, holding great potential as an alternative strategy to support domiciliary TDM in patients with epilepsy treated with perampanel according to the simplicity of sample collection.

Analysis of the intramolecular 1,7-lactone of N-acetylneuraminic acid using HPLC-MS: relationship between detection and stability

A subclass of the sialic acid family consists of intramolecular lactones that may function as key indicators of physiological and pathological states. However, the existence of these compounds in free form is highly improbable, since they are unlikely to exist in an aqueous solution due to their lability. Current analytical method used to detect them in biological fluids has not recognized their reactivity in solution and is prone to misidentification. However, recent advances in synthetic methods for 1,7-lactones have allowed the preparation of these sialic acid derivatives as authentic reference standards. We report here the development of a new HPLC-MS method for the simultaneous detection of the 1,7-lactone of N-acetylneuraminic acid, its γ-lactone derivative, and N-acetylneuraminic acid that overcomes the limitations of the previous analytical procedure for their identification.

Design, Synthesis, and Antiviral Evaluation of Sialic Acid Derivatives as Inhibitors of Newcastle Disease Virus Hemagglutinin-Neuraminidase: A Translational Study on Human Parainfluenza Viruses

Global infections with viruses belonging to the Paramyxoviridae, such as Newcastle disease virus (NDV) or human parainfluenza viruses (hPIVs), pose a serious threat to animal and human health. NDV-HN and hPIVs-HN (HN hemagglutinin-neuraminidase) share a high degree of similarity in catalytic site structures; therefore, the development of an efficient experimental NDV host model (chicken) may be informative for evaluating the efficacy of hPIVs-HN inhibitors. As part of the broad research in pursuit of this goal and as an extension of our published work on antiviral drug development, we report here the biological results obtained with some newly synthesized C4- and C5-substituted 2,3-unsaturated sialic acid derivatives against NDV. All developed compounds showed high neuraminidase inhibitory activity (IC₅₀ 0.03-13 μM). Four molecules (9, 10, 23, 24) confirmed their high in vitro inhibitory activity, which caused a significant reduction of NDV infection in Vero cells, accompanied by very low toxicity.

Sphingolipids and Atherosclerosis: The Dual Role of Ceramide and Sphingosine-1-Phosphate

Sphingolipids are bioactive molecules that play either pro- and anti-atherogenic roles in the formation and maturation of atherosclerotic plaques. Among SLs, ceramide and sphingosine-1-phosphate showed antithetic properties in regulating various molecular mechanisms and have emerged as novel potential targets for regulating the development of atherosclerosis. In particular, maintaining the balance of the so-called ceramide/S1P rheostat is important to prevent the occurrence of endothelial dysfunction, which is the trigger for the entire atherosclerotic process and is strongly associated with increased oxidative stress. In addition, these two sphingolipids, together with many other sphingolipid mediators, are directly involved in the progression of atherogenesis and the formation of atherosclerotic plaques by promoting the oxidation of low-density lipoproteins (LDL) and influencing the vascular smooth muscle cell phenotype. The modulation of ceramide and S1P levels may therefore allow the development of new antioxidant therapies that can prevent or at least impair the onset of atherogenesis, which would ultimately improve the quality of life of patients with coronary artery disease and significantly reduce their mortality.

Cenobamate: A Review of its Pharmacological Properties, Clinical Efficacy and Tolerability Profile in the Treatment of Epilepsy

Cenobamate is a novel antiseizure medication (ASM) commercially available in Europe and in the U.S. for the treatment of focal seizures in adults. The mechanisms responsible for its antiseizure activity include enhancement of the inactivated state of voltage-gated sodium channels with blockade of the persistent sodium current and positive allosteric modulation of GABAA receptors at a non-benzodiazepine binding site. Cenobamate has a high oral bioavailability that is not influenced by food intake. The terminal half-life is 50-60 hours, allowing for once-daily dosing. Cenobamate is a CYP2C19 inhibitor and an inducer of CYP3A4 and CYP2B6, and consequently, it can cause a number of drug-drug interactions. Efficacy and safety have been evaluated in two randomized, double-blind, placebo-controlled adjunctive therapy trials in adults with focal seizures. In both trials, cenobamate decreased significantly the frequency of focal seizures, with relatively high seizure freedom rates. Adverse events most commonly reported in double-blind trials included dizziness, somnolence, headache, fatigue, and diplopia. The occurrence of three cases of drug reaction with eosinophilia and systemic symptoms (DRESS) during early clinical development led to the conduction of a Phase 3 open-label long-term safety study in a total of 1339 patients. In this study, no serious idiosyncratic adverse reactions were observed using a start-low and go-slow approach. Further studies are required to determine whether the clinical activity profile of cenobamate extends to protection against other seizure types and to evaluate its efficacy and safety profile in special patient groups such as infants, children, the elderly, and patients with comorbid conditions.

2-Arachidonoylglycerol Synthesis: Facile and Handy Enzymatic Method That Allows to Avoid Isomerization

A simple and practical synthesis of 2-arachidonoyl glycerol (2-AG), an endogenous agonist for cannabinoid receptors, based on a two-step enzymatic process and a chemical coupling, was achieved with a good yield and negligible amount of the isomerization product 1-AG. Commercial preparation of immobilized lipase from Mucor miehei (MML) was selected as the most suitable enzyme to catalyze the efficient protection of glycerol using vinyl benzoate as an acyl transfer reagent in tetrahydrofuran. The same enzyme was used to remove the protective groups in positions 1 and 3. Owing to the mild neutral conditions and easy suitability of the method, 2-AG was obtained without any isomerization to the more stable 1-AG and air oxidation of acid chain. The synthetic method proposed here allows us to easily obtain 2-AG from the protected precursor in a one-step reaction without purification requirement.

Human Sarcopenic Myoblasts Can Be Rescued by Pharmacological Reactivation of HIF-1α

Sarcopenia, an age-related decline in muscle mass and strength, is associated with metabolic disease and increased risk of cardiovascular morbidity and mortality. It is associated with decreased tissue vascularization and muscle atrophy. In this work, we investigated the role of the hypoxia inducible factor HIF-1α in sarcopenia. To this end, we obtained skeletal muscle biopsies from elderly sarcopenic patients and compared them with those from young individuals. We found a decrease in the expression of HIF-1α and its target genes in sarcopenia, as well as of PAX7, the major stem cell marker of satellite cells, whereas the atrophy marker MURF1 was increased. We also isolated satellite cells from muscle biopsies and cultured them in vitro. We found that a pharmacological activation of HIF-1α and its target genes caused a reduction in skeletal muscle atrophy and activation of PAX7 gene expression. In conclusion, in this work we found that HIF-1α plays a role in sarcopenia and is involved in satellite cell homeostasis. These results support further studies to test whether pharmacological reactivation of HIF-1α could prevent and counteract sarcopenia.

On-Line Solid Phase Extraction High Performance Liquid Chromatography Method Coupled With Tandem Mass Spectrometry for the Therapeutic Monitoring of Cannabidiol and 7-Hydroxy-cannabidiol in Human Serum and Saliva

Cannabidiol is a novel antiseizure medication approved in Europe and the US for the treatment of seizures associated with Lennox-Gastaut syndrome, Dravet syndrome and tuberous sclerosis complex. We describe in this article a new and simple liquid chromatography-mass spectrometry method (LC-MS/MS) for the determination of cannabidiol and its active metabolite 7-hydroxy-cannabidiol in microvolumes of serum and saliva (50 μl), to be used as a tool for therapeutic drug monitoring (TDM) and pharmacokinetic studies. After on-line solid phase extraction cannabidiol, 7-hydroxy-cannabidiol and the internal standard cannabidiol-d3 are separated on a monolithic C18 column under gradient conditions. Calibration curves are linear within the validated concentration range (10–1,000 ng/ml for cannabidiol and 5–500 ng/ml for 7-hydroxy-cannabidiol). The method is accurate (intraday and interday accuracy within 94–112% for cannabidiol, 91–109% for 7-hydroxy-cannabidiol), precise (intraday and interday precision <11.6% for cannabidiol and <11.7% for 7- hydroxy-cannabidiol) and sensitive, with a LOQ of 2.5 ng/ml for cannabidiol and 5 ng/ml for 7-hydroxy-cannabidiol. The stability of the analytes was confirmed under different storage conditions. Extraction recoveries were in the range of 81–129% for cannabidiol and 100–113% for 7-hydroxy-cannabidiol. The applicability of the method to TDM was demonstrated by analysis of human serum and saliva samples obtained from patients with epilepsy treated with cannabidiol.

Neu3 Sialidase Activates the RISK Cardioprotective Signaling Pathway during Ischemia and Reperfusion Injury (IRI)

Coronary reperfusion strategies are life-saving approaches to restore blood flow to cardiac tissue after acute myocardial infarction (AMI). However, the sudden restoration of normal blood flow leads to ischemia and reperfusion injury (IRI), which results in cardiomyoblast death, irreversible tissue degeneration, and heart failure. The molecular mechanism of IRI is not fully understood, and there are no effective cardioprotective strategies to prevent it. In this study, we show that activation of sialidase-3, a glycohydrolytic enzyme that cleaves sialic acid residues from glycoconjugates, is cardioprotective by triggering RISK pro-survival signaling pathways. We found that overexpression of Neu3 significantly increased cardiomyoblast resistance to IRI through activation of HIF-1α and Akt/Erk signaling pathways. This raises the possibility of using Sialidase-3 activation as a cardioprotective reperfusion strategy after myocardial infarction.

A New Ultrasensitive Bioluminescence-Based Method for Assaying Monoacylglycerol Lipase

A novel bioluminescent Monoacylglycerol lipase (MAGL) substrate 6-O-arachidonoylluciferin, a D-luciferin derivative, was synthesized, physico-chemically characterized, and used as highly sensitive substrate for MAGL in an assay developed for this purpose. We present here a new method based on the enzymatic cleavage of arachidonic acid with luciferin release using human Monoacylglycerol lipase (hMAGL) followed by its reaction with a chimeric luciferase, PLG2, to produce bioluminescence. Enzymatic cleavage of the new substrate by MAGL was demonstrated, and kinetic constants Km and Vmax were determined. 6-O-arachidonoylluciferin has proved to be a highly sensitive substrate for MAGL. The bioluminescence assay (LOD 90 pM, LOQ 300 pM) is much more sensitive and should suffer fewer biological interferences in cells lysate applications than typical fluorometric methods. The assay was validated for the identification and characterization of MAGL modulators using the well-known MAGL inhibitor JZL184. The use of PLG2 displaying distinct bioluminescence color and kinetics may offer a highly desirable opportunity to extend the range of applications to cell-based assays.

Oxynet: A collective intelligence that detects ventilatory thresholds in cardiopulmonary exercise tests

The problem of the automatic determination of the first and second ventilatory thresholds (VT1 and VT2) from cardiopulmonary exercise test (CPET) still leads to controversy. The reliability of the gold standard methodology (i.e. expert visual inspection) feeds into the debate and several authors call for more objective automatic methods to be used in the clinical practice. In this study, we present a framework based on a collaborative approach, where a web-application was used to crowd-source a large number (1245) of CPET data of individuals with different aerobic fitness. The resulting database was used to train and test an artificial intelligence (i.e. a convolutional neural network) algorithm. This automatic classifier is currently implemented in another web-application and was used to detect the ventilatory thresholds in the available CPET. A total of 206 CPET were used to evaluate the accuracy of the estimations against the expert opinions. The neural network was able to detect the ventilatory thresholds with an average mean absolute error of 178 (198) mlO₂/min (11.1%, r = 0.97) and 144 (149) mlO₂/min (6.1%, r = 0.99), for VT1 and VT2 respectively. The performance of the neural network in detecting VT1 deteriorated in case of individuals with poor aerobic fitness. Our results suggest the potential for a collective intelligence system to outperform isolated experts in ventilatory thresholds detection. However, the inclusion of a larger number of VT1 examples certified by a community of experts will be likely needed before the abilities of this collective intelligence can be translated into the clinical use of CPET.

The antithetic role of ceramide and sphingosine-1-phosphate in cardiac dysfunction

Cardiovascular diseases (CVDs) are the leading cause of death globally and the number of cardiovascular patients, which is estimated to be over 30 million in 2018, represent a challenging issue for the healthcare systems worldwide. Therefore, the identification of novel molecular targets to develop new treatments is an ongoing challenge for the scientific community. In this context, sphingolipids (SLs) have been progressively recognized as potent bioactive compounds that play crucial roles in the modulation of several key biological processes, such as proliferation, differentiation, and apoptosis. Furthermore, SLs involvement in cardiac physiology and pathophysiology attracted much attention, since these molecules could be crucial in the development of CVDs. Among SLs, ceramide and sphingosine-1-phosphate (S1P) represent the most studied bioactive lipid mediators, which are characterized by opposing activities in the regulation of the fate of cardiac cells. In particular, maintaining the balance of the so-called ceramide/S1P rheostat emerged as an important novel therapeutical target to counteract CVDs. Thus, this review aims at critically summarizing the current knowledge about the antithetic roles of ceramide and S1P in cardiomyocytes dysfunctions, highlighting how the modulation of their metabolism through specific molecules, such as myriocin and FTY720, could represent a novel and interesting therapeutic approach to improve the management of CVDs.

HIF-1α Directly Controls WNT7A Expression During Myogenesis

Herein we unveil that Hypoxia-inducible factor-1α (HIF-1α) directly regulates WNT7A expression during myogenesis. In fact, chromatin immunoprecipitation (ChiP) and site-directed mutagenesis experiments revealed two distinct hypoxia response elements (HREs) that are specific HIF-1α binding sites on the WNT7A promoter. Remarkably, a pharmacological activation of HIF-1α induced WNT7A expression and enhanced muscle differentiation. On the other hand, silencing of WNT7A using CRISPR/Cas9 genome editing blocked the effects of HIF-1α activation on myogenesis. Finally, treatment with prolyl hydroxylases (PHDs) inhibitors improved muscle regeneration in vitro and in vivo in a cardiotoxin (CTX)-induced muscle injury mouse model, paving the way for further studies to test its efficacy on acute and chronic muscular pathologies.

Intramolecular Lactones of Sialic Acids

The so-called "sialo-chemical-biology" has become an attractive research area, as an increasing number of natural products containing a sialic acid moiety have been shown to play important roles in biological, pathological, and immunological processes. The intramolecular lactones of sialic acids are a subclass from this crucial family that could have central functions in the discrimination of physiological and pathological conditions. In this review, we report an in-depth analysis of the synthetic achievements in the preparation of the intramolecular lactones of sialic acids (1,4-, 1,7- and γ-lactones), in their free and/or protected form. In particular, recent advances in the synthesis of the 1,7-lactones have allowed the preparation of key sialic acid derivatives. These compounds could be used as authentic reference standards for their correct determination in biological samples, thus overcoming some of the limitations of the previous analytical procedures.

Abstract 255: Cardiac Ischemia and Reperfusion Injury: The Emerging Role of Sialidase Neu3

Reperfusion strategies, together with thrombolytic therapies, represent life-saving approaches to restore the blood flow in the cardiac tissue after acute myocardial infarction (AMI). However, they inevitably induce the so-called ischemia/reperfusion injury (IRI), resulting in increased cardiomyocytes damage and heart failure. In this context, many efforts have been made to clarify the molecular mechanisms involved in IRI, and the activation of pro-survival kinases, such as Akt and Erk, as well as of the hypoxia-inducible factor (HIF) has been recognized to be critical. Along this line, we discovered a novel mechanism of HIF-1α activation mediated by sialidase Neu3, which is PHDs independent, and that it increased muscle cells resistance to hypoxic stress, through the activation of Akt and Erk pathways. Moreover, an upregulation of Neu3 expression was observed under chronic hypoxia in cyanotic congenital cardiac patients.On these premises, this study aims at investigating the role of Neu3 in protecting cardiac cells against IRI. In particular, H9C2 rat cardiomyoblasts were exposed to an IRI model in vitro revealing a marked reduction in cell proliferation. This was accompanied by the modulation of Neu3 that was characterized by its progressive down-regulation during the ischemic phase, followed by its reactivation during reperfusion. These experiments resembled Neu3 modulation we observed in an IRI mouse model, obtained by the temporary occlusion of the LAD coronary vessel. Interestingly, overexpression of Neu3 significantly increased cardiomyoblasts resistance to IRI, both in terms of cell proliferation and resistance to apoptosis, as well as promoted HIF-1α and Akt/Erk activation. Remarkably, the treatment with Akt and Erk inhibitors completely reverted the beneficial effects mediated by Neu3 upregulation. Likewise, sialidase Neu3 inhibition reduced Akt/Erk activation, resulting in the complete loss of Neu3-mediated cardioprotection. In conclusion, our results demonstrate the role of sialidase Neu3 in counteracting the detrimental effects of IRI, calling for further studies to unveil its full potential as a therapeutic target to support current strategies to manage cardiac damage and to improve patients recover after AMI.

2β-3,4-Unsaturated sialic acid derivatives: Synthesis optimization, and biological evaluation as Newcastle disease virus hemagglutinin-neuraminidase inhibitors

The optimization of the synthetic protocol to obtain the 3,4-unsaturated sialic acid derivatives, through the fine-tuning of both the Ferrier glycosylation conditions and the subsequent hydrolysis work-up, is herein reported. The accomplishment of the desired β-anomers and some selected α-ones, in pure form, led us to evaluate their specific inhibitory activity towards NDV-HN and human sialidase NEU3. Importantly, the resulting data allowed the identification, for the first time, of three active 3,4-unsaturated sialic acid analogs, showing IC₅₀ values against NDV-HN in the micromolar range.

Relationship between saliva and plasma rufinamide concentrations in patients with epilepsy

The assay of saliva samples provides a valuable alternative to the use of blood samples for therapeutic drug monitoring (TDM), at least for certain categories of patients. To determine the feasibility of using saliva sampling for the TDM of rufinamide, we compared rufinamide concentrations in paired samples of saliva and plasma collected from 26 patients with epilepsy at steady state. Within-patient relationships between plasma rufinamide concentrations and dose, and the influence of comedication were also investigated. Assay results in the two tested fluids showed a good correlation (r²  = .78, P < .0001), but concentrations in saliva were moderately lower than those in plasma (mean saliva to plasma ratio = 0.7 ± 0.2). In eight patients evaluated at three different dose levels, plasma rufinamide concentrations increased linearly with increasing dose. Patients receiving valproic acid comedication had higher dose-normalized plasma rufinamide levels than patients comedicated with drugs devoid of strong enzyme-inducing or enzyme-inhibiting activity. Overall, these findings indicate that use of saliva represents a feasible option for the application of TDM in patients treated with rufinamide. Because rufinamide concentrations are lower in saliva than in plasma, a correction factor is needed if measurements made in saliva are used as a surrogate for plasma concentrations.

The acidic hydrolysis of N-acetylneuraminic 4,5-oxazoline allows a direct functionalization of the C5 position of Neu5Ac2en (DANA)

The Neu5Ac 4,5-oxazoline ring-opening allows the direct generation of a free C5-amino group key to synthesize antiviral drugs.

Analysis of hydroxy-cocaine metabolites as evidence of cocaine consumption: Identification by parent ion search and quantitation by UHPLC-MS/MS in hair

Over the last decade, hair analysis has become a routine procedure in most forensic laboratories and, complementary to blood and urine, hair is a unique biological matrix which gives the opportunity to establish a temporal consumption profile. Despite hair is widely used to identify drug use, environmental contamination continues to represent a challenging factor of this procedure, especially for cocaine (COC). In the last few years several strategies have been proposed in order to distinguish between actual use and external contamination, however the commonly detected COC metabolites probably are insufficient for demonstrating cocaine use through hair testing. Thus, the aim of this study is to develop an ultra high performance liquid cromatography - tandem mass spectrometry (UHPLC-MS/MS) method able to detect and quantify hydroxy-COC metabolites, as specific markers of COC abuse, in hair samples from COC consumers, thus enabling unambiguous evidence of COC consumption. At the beginning, since no commercial reference materials were available, COC-positive hair samples were tested using parent ion scan-based analysis to extract hydroxy COC metabolites target ions. Once identified, the reference materials were synthesized by our analytical laboratory allowing the development of the first UHPLC-MS/MS validated method to quantify p- and m-isomers of hydroxy COC, as well as hydroxy benzoylecgonine (BE) and hydroxy norcocaine (NCOC). The method was successfully applied to a large number of COC-positive hair samples and introduced into a routine procedure for testing drug ingestion in order to evaluate for the first-time hydroxy metabolites of COC ranges in hair and their correlation with COC and BE.

Lactonization Method To Assign the Anomeric Configuration of the 3,4-Unsaturated Congeners of N-Acetylneuraminic Acid

Assigning the correct configuration at C2 in sialosides is a standing problem because of the absence of an anomeric hydrogen. All different empirical rules that have been proposed over the years lack general applicability. In particular, the correct configuration of several 3,4-unsaturated derivatives of N-acetylneuraminic acid (Neu5Ac), which have been recently shown to be novel sialidase/neuraminidase inhibitors, could only be tentatively assigned by similarity with the reported 3,4-unsaturated 2O-methyl sialosides. In this work, we overcome this problem as we devised a rapid synthetic method to unequivocally resolve the anomeric configuration of the 3,4-unsaturated Neu5Ac derivatives through the synthesis of the corresponding unreported unsaturated 1,7-lactones. Moreover, we discovered a diagnostic ¹³C nuclear magnetic resonance signal that allows the formulation of a new empirical rule for the direct assignment of the C2 stereochemistry of these molecules, even when only one of the two C2 epimers is available.

Curcumin and Novel Synthetic Analogs in Cell-Based Studies of Alzheimer's Disease

Alzheimer's disease (AD) is a chronic neurodegenerative disorder that is associated with the most common type of dementia and is characterized by the presence of deposits of the protein fragment amyloid beta (Aβ) in the brain. The natural product mixture of curcuminoids that improves certain defects in innate immune cells of AD patients may selectively enhance Aβ phagocytosis by alteration of gene transcription. In this work, we evaluated the protective effects of curcuminoids in cells from AD patients by investigating the effect on NF-κB and BACE1 signaling pathways. These results were compared to the gene expression profile of the clearance of Aβ. The minor curcumin constituent, bisdemethoxycurcumin (BDC) showed the most potent protective action to decrease levels of NF-κB and BACE1, decrease the inflammatory cascade and diminish Aβ aggregates in cells from AD patients. Moreover, mannosyl-glycoprotein 4-beta-N-acetylglucosaminyltransferase (MGAT3) and vitamin D receptor (VDR) gene mRNAs were up-regulated in peripheral blood mononuclear cells from AD patients treated with BDC. BDC treatment impacts both gene expression including Mannosyl (Beta-1,4-)-Glycoprotein Beta-1,4-N-Acetylglucosaminyltransferase, Vitamin D and Toll like receptor mRNA and Aβ phagocytosis. The observation of down-regulation of BACE1 and NF-κB following administration of BDC to cells from AD patients as a model system may have utility in the treatment of asymptomatic AD patients.

Synthesis and chemical characterization of several perfluorinated sialic acid glycals and evaluation of their in vitro antiviral activity against Newcastle disease virus

Newcastle Disease Virus (NDV), belonging to the Paramyxoviridae family, causes a serious infectious disease in birds, resulting in severe losses in the poultry industry every year. Haemagglutinin neuraminidase glycoprotein (HN) has been recognized as a key protein in the viral infection mechanism, and its inhibition represents an attractive target for the development of new drugs based on sialic acid glycals, with the 2-deoxy-2,3-didehydro-d-N-acetylneuraminic acid (Neu5Ac2en) as their backbone. Herein we report the synthesis of several Neu5Ac2en glycals and of their perfluorinated C-5 modified derivatives, including their respective stereoisomers at C-4, together with evaluation of their in vitro antiviral activity. While all synthesized compounds were found to be active HN inhibitors in the micromolar range, we found that their potency was influenced by the chain-length of the C-5 perfluorinated acetamido functionality. Thus, the binding modes of the inhibitors were also investigated by performing a docking study. Moreover, the perfluorinated glycals were found to be more active than the corresponding normal C-5 acylic derivatives. Finally, cell-cell fusion assays on NDV infected cells revealed that the addition of a newly synthesized C-4α heptafluorobutyryl derivative almost completely inhibited NDV-induced syncytium formation.

Elucidation of several neglected reactions in the GC-MS identification of sialic acids as heptafluorobutyrates calls for an urgent reassessment of previous claims

The current analytical protocol used for the GC-MS determination of free or 1,7-lactonized natural sialic acids (Sias), as heptafluorobutyrates, overlooks several transformations. Using authentic reference standards and by combining GC-MS and NMR analyses, flaws in the analytical protocol were pinpointed and elucidated, thus establishing the scope and limitations of the method. It was demonstrated that (a) Sias 1,7-lactones, even if present in biological samples, decompose under the acidic hydrolysis conditions used for their release; (b) Sias 1,7-lactones are unpredicted artifacts, accidentally generated from their parent acids; (c) the N-acetyl group is quantitatively exchanged with that of the derivatizing perfluorinated anhydride; (d) the partial or complete failure of the Sias esterification-step with diazomethane leads to the incorrect quantification and structure attribution of all free Sias. While these findings prompt an urgent correction and improvement of the current analytical protocol, they could be instrumental for a critical revision of many incorrect claims reported in the literature.

Synthesis and biological evaluation of several dephosphonated analogues of CMP-Neu5Ac as inhibitors of GM3-synthase

Previous studies demonstrated that reducing the GM3 content in myoblasts increased the cell resistance to hypoxic stress, suggesting that a pharmacological inhibition of the GM3 synthesis could be instrumental for the development of new treatments for ischemic diseases. Herein, the synthesis of several dephosphonated CMP-Neu5Ac congeners and their anti-GM3-synthase activity is reported. Biological activity testes revealed that some inhibitors almost completely blocked the GM3-synthase activity in vitro and reduced the GM3 content in living embryonic kidney 293A cells, eventually activating the epidermal growth factor receptor (EGFR) signaling cascade.

Correction: The first synthesis of N-acetylneuraminic acid 1,7-lactone

Correction for ‘The first synthesis of N-acetylneuraminic acid 1,7-lactone’ by Raffaele Colombo et al., Chem. Commun., 2008, 5517–5519.

Chemical structure, biosynthesis and synthesis of free and glycosylated pyridinolines formed by cross-link of bone and synovium collagen

This review focuses on the chemical structure, biosynthesis and synthesis of free and glycosylated pyridinolines (Pyds), fluorescent collagen cross-links, with a pyridinium salt structure. Pyds derive from the degradation of bone collagen and have attracted attention for their use as biochemical markers of bone resorption and to assess fracture risk prediction in persons suffering from osteoporosis, bone cancer and other bone or collagen diseases. We consider and critically discuss all reported syntheses of free and glycosylated Pyds evidencing an unrevised chemistry, original and of general utility, analysis of which allows us to also support a previously suggested non-enzymatic formation of Pyds in collagen better rationalizing and justifying the chemical events.

A simple synthesis of N-perfluoroacylated and N-acylated glycals of neuraminic acid with a cyclic aminic substituent at the 4α position as possible inhibitors of sialidases

A simple protocol for the synthesis of N-perfluoroacylated and N-acylated glycals of neuraminic acid, with a secondary cyclic amine (morpholine or piperidine) at the 4α position, has been set-up, starting from peracetylated N-acetylneuraminic acid methyl ester that undergoes, sequentially to its direct N-transacylation followed by a C-4 amination, a β-elimination, and a selective hydrolysis of the ester functions, without affecting the sensitive perfluorinated amide.

Simultaneous free and glycosylated pyridinium crosslink determination in urine: validation of an HPLC-fluorescence method using a deoxypyridinoline homologue as internal standard

Pyridinoline (Pyr), deoxypyridinoline (D-Pyr), galactosyl-pyridinoline (Gal-Pyr) and glucosyl-galactosyl pyridinoline (GluGal-Pyr) are enzymatic mature pyridinium crosslinks. Generally, only total Pyr and D-Pyr urinary amounts (free+bound forms) are evaluated by HPLC as indices of bone resorption. This report describes the validation of an HPLC-fluorescence method for the simultaneous evaluation of free Pyr and D-Pyr, together with GluGal-Pyr and Gal-Pyr, in urine of healthy women (n=20, aged 27-41) and girls (n=20, aged 5-10). The use of an unnatural D-Pyr homologue, here proposed for the first time as internal standard, and of pure Pyr, D-Pyr, GluGal-Pyr and Gal-Pyr synthesized to be used as primary calibrators, guarantees method specificity and correct crosslink quantification. Urine, spiked with IS, was solid-phase extracted prior to HPLC analysis. Total Pyr and D-Pyr amounts were also evaluated after urine hydrolysis. The HPLC method was validated for selectivity, sensitivity, linearity, precision, accuracy, recovery and stability for all measured crosslinks. Both free and total Pyr and D-Pyr as well as GluGal-Pyr and Gal-Pyr amounts were significantly higher in girls than in women (p<0.0001), indicating an increased collagen turnover rather than only bone turnover. Gal-Pyr, for the first time evaluated in girls, was under its lower quantification limit (<LLOQ, <21.20 pmol/mL) in women. The measurement of free and glycosylated pyridinium crosslinks might provide more information on the degradation of various types of collagen than only that of total Pyr and D-Pyr. Moreover, this validated method could be a useful non-invasive technique for studying pathological conditions characterized by modified glycosylation enzyme activity and for more clinical investigation on bone fragility.

The first synthesis of N-acetylneuraminic acid 1,7-lactone

N-Acetylneuraminic acid is transformed into its until now unavailable and rather unwieldy 1,7-lactone, via the manageable 2-benzyloxycarbonyl N-acetylneuraminic acid 1,7-lactone which generates the free lactone in quantitative yield by hydrogenolysis.

[Genetic characterisation of wild measles strains circulating in European part of Russia in 1998-2002]

The primary structure of the N-gene COOH terminus of measles virus isolated, 1998-2000, in Russia's European part was investigated. The general analysis as well as an analysis of the primary gene structure showed the two group's isolates as belonging to the D4 genotype. A subsequent analysis of the primary structure of the N-gene COOH-terminus of Moscow/2002/61 isolated during the 2002 measles outbreak in Moscow also showed it as belonging to the D4 genotype. The obtained data are indicative of that the wild measles strains belonging to the D4 genotype have been recently circulating in Russia's territory.

[Features of primary structure of genes and proteins from passaged variations of measles virus]

Primary structure and proteins of measles virus variants passaged in tissue culture were studied. The findings suggest that genetic determinants responsible for measles virus attenuation are not linked with the genes coding for envelope proteins and nucleoprotein of this virus. However the detected nucleotide substitutions can be considered as the main prerequisites for the appearance of mutations in other regions of viral genome, leading to decrease of virulence for humans.

Nipah virus infection in bats (order Chiroptera) in peninsular Malaysia

Nipah virus, family Paramyxoviridae, caused disease in pigs and humans in peninsular Malaysia in 1998-99. Because Nipah virus appears closely related to Hendra virus, wildlife surveillance focused primarily on pteropid bats (suborder Megachiroptera), a natural host of Hendra virus in Australia. We collected 324 bats from 14 species on peninsular Malaysia. Neutralizing antibodies to Nipah virus were demonstrated in five species, suggesting widespread infection in bat populations in peninsular Malaysia.

Evaluation of recombinant vaccinia virus--measles vaccines in infant rhesus macaques with preexisting measles antibody

Immunization of newborn infants with standard measles vaccines is not effective because of the presence of maternal antibody. In this study, newborn rhesus macaques were immunized with recombinant vaccinia viruses expressing measles virus hemagglutinin (H) and fusion (F) proteins, using the replication-competent WR strain of vaccinia virus or the replication-defective MVA strain. The infants were boosted at 2 months and then challenged intranasally with measles virus at 5 months of age. Some of the newborn monkeys received measles immune globulin (MIG) prior to the first immunization, and these infants were compared to additional infants that had maternal measles-neutralizing antibody. In the absence of measles antibody, vaccination with either vector induced neutralizing antibody, cytotoxic T cell (CTL) responses to measles virus and protection from systemic measles infection and skin rash. The infants vaccinated with the MVA vector developed lower measles-neutralizing antibody titers than those vaccinated with the WR vector, and they sustained a transient measles viremia upon challenge. Either maternal antibody or passively transferred MIG blocked the humoral response to vaccination with both WR and MVA, and the frequency of positive CTL responses was reduced. Despite this inhibition of vaccine-induced immunity, there was a reduction in peak viral loads and skin rash after measles virus challenge in many of the infants with preexisting measles antibody. Therefore, vaccination using recombinant vectors such as poxviruses may be able to prevent the severe disease that often accompanies measles in infants.