Phenylalanine Butyramide: A Butyrate Derivative as a Novel Inhibitor of Tyrosinase.

Metabolites resulting from the bacterial fermentation of dietary fibers, such as short-chain fatty acids, especially butyrate, play important roles in maintaining gut health and regulating various biological effects in the skin. However, butyrate is underutilized due to its unpleasant odor. To circumvent this organoleptic unfavorable property, phenylalanine butyramide (PBA), a butyrate precursor, has been synthesized and is currently available on the market. We evaluated the inhibition of mushroom tyrosinase by butyrate and PBA through in vitro assays, finding IC50 values of 34.7 mM and 120.3 mM, respectively. Docking calculations using a homology model of human tyrosinase identified a putative binding mode of PBA into the catalytic site. The anti-aging and anti-spot efficacy of topical PBA was evaluated in a randomized, double-blind, parallel-arm, placebo-controlled clinical trial involving 43 women affected by photo-damage. The results of this study showed that PBA significantly improved skin conditions compared to the placebo and was well tolerated. Specifically, PBA demonstrated strong skin depigmenting activity on both UV and brown spots (UV: -12.7% and -9.9%, Bs: -20.8% and -17.7% after 15 and 30 days, respectively, p < 0.001). Moreover, PBA brightened and lightened the skin (ITA°: +12% and 13% after 15 and 30 days, respectively, p < 0.001). Finally, PBA significantly improved skin elasticity (Ua/Uf: +12.4% and +32.3% after 15 and 30 days, respectively, p < 0.001) and firmness (Uf: -3.2% and -14.9% after 15 and 30 days, respectively, p < 0.01).

Clinical Studies Using Topical Melatonin.

Melatonin is ubiquitously present in all animals and plants, where it exerts a variety of physiological activities thanks to its antioxidant properties and its key role as the first messenger of extracellular signaling functions. Most of the clinical studies on melatonin refer to its widespread oral use as a dietary supplement to improve sleep. A far smaller number of articles describe the clinical applications of topical melatonin to treat or prevent skin disorders by exploiting its antioxidant and anti-inflammatory activities. This review focuses on the clinical studies in which melatonin was applied on the skin as a photoprotective, anti-aging, or hair growth-promoting agent. The methodologies and results of such studies are discussed to provide an overall picture of the state of the art in this intriguing field of research. The clinical studies in which melatonin was applied on the skin before exposure to radiation (UV, sunlight, and high-energy beams) were all characterized by an appropriate design (randomized, double-blind, and placebo-controlled) and strongly support its clinical efficacy in preventing or reducing skin damage such as dermatitis, erythema, and sunburn. Most of the studies examined in this review do not provide a clear demonstration of the efficacy of topical melatonin as a skin anti-aging or as a hair growth-promoting agent owing to limitations in their design and/or to the use of melatonin combined with extra active ingredients, except for one trial that suggests a possible beneficial role of melatonin in treating some forms of alopecia in women. Further research efforts are required to reach definitive conclusions concerning the actual benefits of topical melatonin to counteract skin aging and hair loss.

NAD-Driven Sirtuin Activation by Cordyceps sinensis Extract: Exploring the Adaptogenic Potential to Promote Skin Longevity.

In recent years, there has been increasing interest in utilizing Traditional Chinese Medicine principles and natural bioactive compounds to combat age-related ailments and enhance longevity. A Cordyceps sinensis mycelium hydroethanolic extract (CsEx), which was standardized in cordycepin and adenosine using UHPLC-DAD, was investigated for its adaptogenic properties using in vitro assays and a double-blind, placebo-controlled clinical trial involving 40 subjects. The CsEx demonstrated activity at a concentration of 0.0006%, significantly increasing sirtuin expression (SirT1: +33%, SirT3: +10%, SirT6: +72%, vs. CTR, p < 0.05) and NAD+ synthesis in HaCat cells (+20% vs. CTR, p < 0.001). Moreover, the CsEx boosted ATP production by 68% in skin cells, correlating with higher skin energy values (+52.0% at D28, p < 0.01) in the clinical trial. Additionally, CsEx notably reduced cytosolic reactive oxygen species (ROS) by 30% in HaCaT cells (p < 0.05) and enhanced collagen production both in vitro (+69% vs. CTR, p < 0.01) and in vivo (+10% vs. D0, p < 0.01), confirmed by ultrasound examination. Furthermore, CsEx's stimulation of fibroblasts, coupled with its antioxidant and energizing properties, led to a significant reduction in wrinkles by 28.0% (D28, p < 0.001). This study underscores Cordyceps sinensis hydroethanolic extract's potential in regulating skin cell energy metabolism and positively influencing the mechanisms associated with skin longevity control.

Annurca Apple Oleolite as Functional Ingredient for the Formulation of Cosmetics with Skin-Antiaging Activity.

The identification of natural remedies for the management of the skin aging process is an increasingly growing issue. In this context, ursolic acid (UA), a ubiquitous molecule, mainly contained in Annurca apple (AA) fruit, has demonstrated valuable cosmetic potential. To this end, in the current study, the AA oleolite (AAO, extract in sunflower oil containing 784.40 ± 7.579 µg/mL of UA) was evaluated to inhibit porcine elastase enzymatic reactions through a validated spectrophotometric method. AAO has shown a valuable capacity to contrast the elastase enzyme with a calculated IC50 of 212.76 mg/mL, in comparison to UA (IC50 of 135.24 µg/mL) pure molecules and quercetin (IC50 of 72.47 µg/mL) which are used as positive controls. In this context and in view of the valuable antioxidant potential of AAO, its topical formulation with 2.5% (w/w) AAO was tested in a placebo-controlled, double-blind, two-arm clinical study on 40 volunteers. Our results indicated that after 28 days of treatment, a significant reduction of the nasolabial fold (-7.2 vs. baseline T0, p < 0.001) and forehead wrinkles (-5.3 vs. baseline T0, p < 0.001) were registered in combination with a valuable improvement of the viscoelastic skin parameters, where skin pliability/firmness (R0) and gross elasticity (R2) were significantly ameliorated (-13% vs. baseline T0, p < 0.001 for R0 and +12% vs. baseline T0, p < 0.001 for R2). Finally, considering the positive correlation between skin elasticity and hydration, the skin moisture was evaluated through the estimation of Trans epidermal water loss (TEWL) and skin conductance.

Clinical Studies on Topical Curcumin.

BACKGROUND: Curcumin is a polyphenolic compound present in turmeric (Curcuma longa). Curcumin, turmeric powder, and extracts are widely used in traditional Indian medicine and are active ingredients of dietary supplements and cosmeceutical products. The pharmacological properties of curcumin/turmeric as well as the studies performed in vitro, in animal models, and in volunteers have been the objects of a vast literature. Most of the clinical studies report on the effects of curcumin/turmeric administered orally, while only a few describe its topical applications. SUMMARY: This review focuses on clinical studies in which curcumin/turmeric was applied topically to treat various skin conditions based on its antioxidant, anti-inflammatory, and antimicrobial properties. KEY MESSAGES: The clinical studies employing curcumin/turmeric as the only active ingredient allow us to appreciate its therapeutic potential without confounding contributions coming from additional pharmacologically active substances present in the same formulation. Curcumin/turmeric was regarded as an attractive alternative to conventional drugs, such as corticosteroids and antibiotics, thanks to its characteristics of a safe and well-tolerated natural substance.

Alcohol-Related Liver Disease in the Covid-19 Era: Position Paper of the Italian Society on Alcohol (SIA).

BACKGROUND: Coronavirus Disease 2019 (COVID-19), firstly reported in China last November 2019, became a global pandemic. It has been shown that periods of isolation may induce a spike in alcohol use disorder (AUD). In addition, alcohol-related liver disease (ALD) is the most common consequence of excessive alcohol consumption worldwide. Moreover, liver impairment has also been reported as a common manifestation of COVID-19. AIMS: The aim of our position paper was to consider some critical issues regarding the management of ALD in patients with AUD in the era of COVID-19. METHODS: A panel of experts of the Italian Society of Alcohology (SIA) met via "conference calls" during the lockdown period to draft the SIA's criteria for the management of ALD in patients with COVID-19 as follows: (a) liver injury in patients with ALD and COVID-19 infection; (b) toxicity to the liver of the drugs currently tested to treat COVID-19 and the pharmacological interaction between medications used to treat AUD and to treat COVID-19; (c) reorganization of the management of compensated and decompensated ALD and liver transplantation in the COVID-19 era. RESULTS AND CONCLUSIONS: The COVID-19 pandemic has rapidly carried us toward a new governance scenario of AUD and ALD which necessarily requires an in-depth review of the management of these diseases with a new safe approach (management of out-patients and in-patients following new rules of safety, telemedicine, telehealth, call meetings with clinicians, nurses, patients, and caregivers) without losing the therapeutic efficacy of multidisciplinary treatment.

Model of Care for Microelimination of Hepatitis C Virus Infection among People Who Inject Drugs.

BACKGROUND: People who inject drugs (PWID) are the largest group at risk for HCV infection. Despite the direct acting antivirals (DAA) advancements, HCV elimination has been hindered by real-life difficulties in PWID. AIMS: This study aimed to assess the impact of a multidisciplinary intervention strategy where HCV screening, treatment and follow-up were performed at the same location on efficacy and safety of DAA-therapy in real-life PWID population. METHODS: All HCV-infected PWID referred to five specialized outpatient centers for drug addicts (SerDs) in Northern Italy were prospectively enrolled from May 2015 to December 2019. Hepatologists and SerDs healthcare workers collaborated together in the management of PWID inside the SerDs. Sustained virologic response (SVR), safety of treatment, proportion of patients lost to follow-up and reinfection rate were evaluated. RESULTS: A total of 358 PWID started antiviral treatment. About 50% of patients had advanced fibrosis/cirrhosis, 69% received opioid substitution treatment, and 20.7% self-reported recent injecting use. SVR was achieved in 338 (94.4%) patients. Two patients died during treatment; one prematurely discontinued, resulting in a non-responder; twelve were lost during treatment/follow-up; and five relapsed. No serious adverse events were reported. SVR was lower in recent PWID than in former ones (89.2% vs. 95.8%; p = 0.028). Seven reinfections were detected, equating to an incidence of 1.25/100 person-years. Reinfection was associated with recent drug use (OR 11.07, 95%CI 2.10-58.38; p = 0.005). CONCLUSION: Our embedded treatment model could be appropriate to increase the linkage to care of HCV-infected PWID. In this setting, DAA regimens are well tolerated and highly effective, achieving a lower rate of reinfection.

Allosterism vs. Orthosterism: Recent Findings and Future Perspectives on A2B AR Physio-Pathological Implications.

The development of GPCR (G-coupled protein receptor) allosteric modulators has attracted increasing interest in the last decades. The use of allosteric modulators in therapy offers several advantages with respect to orthosteric ones, as they can fine-tune the tissue responses to the endogenous agonist. Since the discovery of the first A1 adenosine receptor (AR) allosteric modulator in 1990, several efforts have been made to develop more potent molecules as well as allosteric modulators for all adenosine receptor subtypes. There are four subtypes of AR: A1, A2A, A2B, and A3. Positive allosteric modulators of the A1 AR have been proposed for the cure of pain. A3 positive allosteric modulators are thought to be beneficial during inflammatory processes. More recently, A2A and A2B AR allosteric modulators have also been disclosed. The A2B AR displays the lowest affinity for its endogenous ligand adenosine and is mainly activated as a consequence of tissue damage. The A2B AR activation has been found to play a crucial role in chronic obstructive pulmonary disease, in the protection of the heart from ischemic injury, and in the process of bone formation. In this context, allosteric modulators of the A2B AR may represent pharmacological tools useful to develop new therapeutic agents. Herein, we provide an up-to-date highlight of the recent findings and future perspectives in the field of orthosteric and allosteric A2B AR ligands. Furthermore, we compare the use of orthosteric ligands with positive and negative allosteric modulators for the management of different pathological conditions.

Novel positive allosteric modulators of A2B adenosine receptor acting as bone mineralisation promoters.

Small-molecules acting as positive allosteric modulators (PAMs) of the A2B adenosine receptor (A2B AR) could potentially represent a novel therapeutic strategy for pathological conditions characterised by altered bone homeostasis, including osteoporosis. We investigated a library of compounds (4-13) exhibiting different degrees of chemical similarity with three indole derivatives (1-3), which have been recently identified by us as PAMs of the A2B AR able to promote mesenchymal stem cell differentiation and bone formation. Evaluation of mineralisation activity of 4-13 in the presence and in the absence of the agonist BAY60-6583 allowed the identification of lead compounds with therapeutic potential as anti-osteoporosis agents. Further biological characterisation of one of the most performing compounds, the benzofurane derivative 9, confirmed that such a molecule behaves as PAM of the A2B AR.

Exploiting the Indole Scaffold to Design Compounds Binding to Different Pharmacological Targets.

Several indole derivatives have been disclosed by our research groups that have been collaborating for nearly 25 years. The results of our investigations led to a variety of molecules binding selectively to different pharmacological targets, specifically the type A γ-aminobutyric acid (GABAA) chloride channel, the translocator protein (TSPO), the murine double minute 2 (MDM2) protein, the A2B adenosine receptor (A2B AR) and the Kelch-like ECH-associated protein 1 (Keap1). Herein, we describe how these works were conceived and carried out thanks to the versatility of indole nucleus to be exploited in the design and synthesis of drug-like molecules.

Identification of novel indole derivatives acting as inhibitors of the Keap1-Nrf2 interaction.

Nine indole derivatives (9a-i) were tested as potential inhibitors of the Keap1-Nrf2 interaction. This class of compounds increases the intracellular levels of the transcription factor Nrf2 and the consequent expression of enzymes encoded by genes containing the antioxidant response element (ARE). In the ARE-luciferase reporter assay only 9e-g revealed to be remarkably more active than t-butylhydroxyquinone (t-BHQ), with 9g standing out as the best performing compound. While 9e and 9f are weak acids, 9g is an ampholyte prevailing as a zwitterion in neutral aqueous solutions. The ability of 9e-g to significantly increase levels of Nrf2, NADPH:quinone oxidoreductase 1, and transketolase (TKT) gave further support to the hypothesis that these compounds act as inhibitors of the Keap1-Nrf2 interaction. Docking simulations allowed us to elucidate the nature of the putative interactions between 9g and Keap1.

Accidental removal of devices in intensive care unit: An eight-year observational study.

BACKGROUND: In the intensive care unit, invasive devices can be accidentally removed by the patient or by the operators, increasing workload, staff stress level and hospitalisation costs. OBJECTIVE: to know the incidence of accidental removal of devices in critical patients, to identify their cause, when they occur and if they are repositioned. METHODS: Retrospective observational study carried out in an academic, tertiary-level critical care department composed of three intensive care units. All adult patients recovered between 2011 and 2018 were enrolled. We calculated rates per 1000 device-years. RESULTS: In the study period 10514 patients (194372 device-days) were admitted to the intensive care units and the number of reported accidental removal of devices was 451, corresponding to a rate of 2.3 episodes per 1000 device-days (95% confidence interval: 2.1-2-5). The overall rates of accidental removals were as follows: gastric tubes 10.2 (n = 270), intracranial devices 3.9 (n = 9), endotracheal tubes 2.4 (n = 27), central venous catheters and arterial catheters 1.5 (n = 92), peripheral intravenous catheters 1.2 (n = 25), surgical drains 0.5 (n = 15), urinary catheters 0.4 (n = 11), Extra Corporeal Membrane Oxygenation cannulas 0.4 (n = 1), tracheostomy cannulas 0.1 (n = 1). CONCLUSION: Compared to the literature, this study shows fewer incidents of accidental removal of devices. The number of accidental removals could be an indicator of the quality and safety of the care.

Alcohol-related chronic exocrine pancreatic insufficiency: diagnosis and therapeutic management. A proposal for treatment by the Italian Association for the Study of the Pancreas (AISP) and the Italian Society of Alcohology (SIA).

Current estimates of the prevalence of chronic pancreatitis, one of the most common causes of exocrine pancreatic insufficiency, are in the range of 3-10 per 100,000 people in many parts of the world. Alcohol consumption is a very important risk factor for exocrine pancreatic insufficiency and is involved in nearly half of all cases. The main hypothesis regarding the role of chronic alcohol consumption in pancreatitis is that there must be additional environmental or genetic risk factors involved for ongoing damage to occur. Treatment of patients with alcohol-related exocrine pancreatic insufficiency is complex, as the patient has two concomitant pathologies, alcohol-use disorder (AUD) and exocrine pancreatic insufficiency/chronic pancreatitis. Alcohol abstinence is the starting point for treatment, although even this along with the most advanced therapies allow only a slowdown in progression rather than restoration of function. This position paper of the Italian Association for the Study of the Pancreas and the Italian Society of Alcohology provides an overview of the pathogenesis of alcohol-related pancreatitis and discuss diagnostic issues. Treatment options for both exocrine pancreatic insufficiency/chronic pancreatitis (with a focus on pancreatic enzyme replacement therapy) and AUD (acamprosate, disulfiram, oral naltrexone, long-acting injectable naltrexone, sodium oxybate, nalmefene, baclofen, and psychosocial interventions) are also reviewed.

Diagnosis and treatment of acute alcohol intoxication and alcohol withdrawal syndrome: position paper of the Italian Society on Alcohol.

The chronic use of alcohol can lead to the onset of an alcohol use disorder (AUD). About 50% of subjects with an AUD may develop alcohol withdrawal syndrome (AWS) when they reduce or discontinue their alcohol consumption and, in 3-5% of them, convulsions and delirium tremens (DTs), representing life-threatening complications, may occur. Unfortunately, few physicians are adequately trained in identifying and treating AWS. The Italian Society on Alcohol has, therefore, implemented a task force of specialists to draw up recommendations for the treatment of AWS with the following main results: (1) while mild AWS may not require treatment, moderate and severe AWS need to be pharmacologically treated; (2) out-patient treatment is appropriate in patients with mild or moderate AWS, while patients with severe AWS need to be treated as in-patients; (3) benzodiazepines, BDZs are the "gold standard" for the treatment of AWS and DTs; (4) alpha-2-agonists, beta-blockers, and neuroleptics may be used in association when BDZs do not completely resolve specific persisting symptoms of AWS; (5) in the case of a refractory form of DTs, the use of anaesthetic drugs (propofol and phenobarbital) in an intensive care unit is appropriate; (6) alternatively to BDZs, sodium oxybate, clomethiazole, and tiapride approved in some European Countries for the treatment of AWS may be employed for the treatment of moderate AWS; (7) anti-convulsants are not sufficient to suppress AWS, and they may be used only in association with BDZs for the treatment of refractory forms of convulsions in the course of AWS.

Novel fluorescent triazinobenzimidazole derivatives as probes for labelling human A1 and A2B adenosine receptor subtypes.

The expression levels and the subcellular localization of adenosine receptors (ARs) are affected in several pathological conditions as a consequence of changes in adenosine release and metabolism. In this respect, labelled probes able to monitor the AR expression could be a useful tool to investigate different pathological conditions. Herein, novel ligands for ARs, bearing the fluorescent 7-nitrobenzofurazan (NBD) group linked to the N1 (1,2) or N10 (3,4) nitrogen of a triazinobenzimidazole scaffold, were synthesized. The compounds were biologically evaluated as fluorescent probes for labelling A1 and A2B AR subtypes in bone marrow-derived mesenchymal stem cells (BM-MSCs) that express both receptor subtypes. The binding affinity of the synthetized compounds towards the different AR subtypes was determined. The probe 3 revealed a higher affinity to A1 and A2B ARs, showing interesting spectroscopic properties, and it was selected as the most suitable candidate to label both AR subtypes in undifferentiated MSCs. Fluorescence confocal microscopy showed that compound 3 significantly labelled ARs on cell membranes and the fluorescence signal was decreased by the cell pre-incubation with the A1 AR and A2B AR selective agonists, R-PIA and BAY 60-6583, respectively, thus confirming the specificity of the obtained signal. In conclusion, compound 3 could represent a useful tool to investigate the expression pattern of both A1 and A2B ARs in different pathological and physiological processes. Furthermore, these results provide an important basis for the design of new and more selective derivatives able to monitor the expression and localization of each different ARs in several tissues and living cells.

Studies on enantioselectivity of chiral 4-acetylamino-6-alkyloxy-2-alkylthiopyrimidines acting as antagonists of the human A3 adenosine receptor.

Three A3 adenosine receptor (AR) antagonists (1-3) selected from 4-acylamino-6-alkyloxy-2-alkylthiopyrimidines previously investigated by us were modified by inserting a methyl group on their ether or thioether side chains. These compounds gave us the chance to evaluate whether their higher lipophilicity, reduced conformational freedom and chirality might improve the potency towards the A3 AR. Racemic mixtures of 1-3 were resolved using chiral HPLC methods and the absolute configurations of the enantiomers were assigned by chiroptical spectroscopy and density functional theory calculations. We measured the affinity for human A1, A2A, A2B and A3 ARs of the racemic mixtures and the pure enantiomers of 1-3 by radioligand competition binding experiments. Cell-based assays of the most potent enantiomers confirmed their A3 AR antagonist profiles. Our research led to the identification of (S)-1 with high potency (0.5 nM) and selectivity as an A3 AR antagonist. Moreover we built a docking-model useful to design new pyrimidine derivatives.

Addiction disorders: a need for change. Proposal for a new management. Position paper of SIA, Italian Society on Alcohol.

Various epidemiological and biological evaluations and the recent publication of the DSM-V (diagnostic and statistical manual of mental disorders) has imposed on the scientific community a period of reflection on the diagnosis and treatment of what in the DSM-IV was defined as "addiction". To date, the term "addiction" has been replaced by the DSM-5, because there is no global scientific consensus that has unequivocally characterized its clinical characteristics. This, we will talk about substance/alcohol use disorders (SUDs/AUDs) and disorders related to behavioral alterations (DBA) that can generate organic diseases, mental disorders, and social problems. In the first psychotic episode 40-70% of subjects meet the criteria of a SUDs/AUDs, excluding tobacco dependence. Substances can not only be the cause of a psychotic onset, but they can also disrupt a psychotic picture or interfere with drug therapy. The pharmacodynamic profiles of many substances are able to provoke the phenomenology of the main psychotic symptoms in a way that can be superimposed onto those presented by psychotic subjects without a history of SUDs/AUDs. The Department of Addictions (DAs) must not be absorbed by or incorporated into the Departments of Mental Health (DMH), with which, however, precise operational cooperation protocols will have to be defined and maintained, but it will have to maintain its own autonomy and independent connotation. Addiction Medicine is a discipline that brings together elements of public health, prevention, internal medicine, clinical pharmacology, neurology, and even psychiatry. The inclusion of the DAs in those of DMH refers purely to a problem of pathology that has to do with lifestyle, choices, and behaviors. These, over time, show their dysfunctionality and only then do related problems emerge. Moreover, epidemiological, social, and clinical motivations impose the creation of alcohological teams dedicated to alcohol-related activities. The collaboration with self-help-groups (SHGs) is mandatory. The action of SHGs is accredited in numerous international recommendations both on the basis of consensus and evidence in the literature.

4-amino-6-alkyloxy-2-alkylthiopyrimidine derivatives as novel non-nucleoside agonists for the adenosine A1 receptor.

Three 4-amino-6-alkyloxy-2-alkylthiopyrimidine derivatives (4-6) were investigated as potential non-nucleoside agonists at human adenosine receptors (ARs). When tested in competition binding experiments, these compounds exhibited low micromolar affinity (Ki values comprised between 1.2 and 1.9 µm) for the A1 AR and no appreciable affinity for the A2A and A3 ARs. Evaluation of their efficacy profiles by measurement of intracellular cAMP levels revealed that 4 and 5 behave as non-nucleoside agonists of the A1 AR with EC50 values of 0.47 and 0.87 µm, respectively. No clear concentration-response curves could be instead obtained for 6, probably because this compound modulates one or more additional targets, thus masking the putative effects exerted by its activation of A1 AR. The three compounds were not able to modulate A2B AR-mediated cAMP accumulation induced by the non-selective AR agonist NECA, thus demonstrating no affinity toward this receptor.

Enantiomeric 4-Acylamino-6-alkyloxy-2 Alkylthiopyrimidines As Potential A3 Adenosine Receptor Antagonists: HPLC Chiral Resolution and Absolute Configuration Assignment by a Full Set of Chiroptical Spectroscopy.

The chiral separation of enantiomeric couples of three potential A3 adenosine receptor antagonists: (R/S)-N-(6-(1-phenylethoxy)-2-(propylthio)pyrimidin-4-yl)acetamide (), (R/S)-N-(2-(1-phenylethylthio)-6-propoxypyrimidin-4-yl)acetamide (), and (R/S)-N-(2-(benzylthio)-6-sec-butoxypyrimidin-4-yl)acetamide () was achieved by high-performance liquid chromatography (HPLC). Three types of chiroptical spectroscopies, namely, optical rotatory dispersion (ORD), electronic circular dichroism (ECD), and vibrational circular dichroism (VCD), were applied to enantiomeric compounds. Through comparison with Density Functional Theory (DFT) calculations, encompassing extensive conformational analysis, full assignment of the absolute configuration (AC) for the three sets of compounds was obtained. Chirality 28:434-440, 2016. © 2016 Wiley Periodicals, Inc.

Deepening the Topology of the Translocator Protein Binding Site by Novel N,N-Dialkyl-2-arylindol-3-ylglyoxylamides.

As a continuation of our studies on 2-phenylindol-3-ylglyoxylamides as potent and selective translocator protein (TSPO) ligands, two subsets of novel derivatives, featuring hydrophilic group (OH, NH2, COOH) at the para-position of the pendent 2-phenyl ring (8-16) or different 2-aryl moieties, namely, 3-thienyl, p-biphenyl, 2-naphthyl (23-35), were synthesized and biologically evaluated, some of them showing Ki values in the subnanomolar range and the 2-naphthyl group performance being the best. The resulting SARs confirmed the key role played by interactions taking place between ligands and the lipophilic L1 pocket of the TSPO binding site. Docking simulations were performed on the most potent compound of the present series (29) exploiting the recently available 3D structures of TSPO bound to its standard ligand (PK11195). Our theoretical model was fully consistent with SARs of the newly investigated as well of the previously reported 2-phenylindol-3-ylglyoxylamide derivatives.