G A Pinna

Università degli studi di Cagliari, Cagliari, Sardinia, Italy

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Publications (142)181.46 Total impact

  • [show abstract] [hide abstract]
    ABSTRACT: Considering the interesting pharmacological profile of the delta (δ) selective opioid agonist compound SNC-80, conformationally constrained analogs containing two diazatricyclodecane ring systems in place of dimethylpiperazine core motif were synthesized. The compounds showed subnanomolar or low nanomolar δ opioid receptor binding affinity. Depending upon the substituents on the diazatricyclodecane ring, these compounds displayed varying selectivity for δ opioid receptor over μ and κ receptors. Amongst the novel compounds, 1Aa showed the more interesting biological profile, with higher δ affinity and selectivity compared to SNC-80. The δ receptor agonist profile and antinociceptive activity of 1Aa were confirmed using ex-vivo (isolated mouse vas deferens) and in vivo (tail flick) assays.
    European journal of medicinal chemistry 09/2013; 69C:413-426. · 3.27 Impact Factor
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    ABSTRACT: Two sensitive and reproducible capillary electrophoresis and high-performance liquid chromatography-fluorescence procedures were established for quantitative determination of L-egothioneine in plasma. After derivatization of L-ergothioneine with 5-iodoacetamidofluorescein, the separation was carried out by HPLC on an ODS-2 C-18 sperisorb column by using a linear gradient elution and by HPCE on an uncoated fused silica capillary, 50 µm id, and 60 cm length. The methods were validated and found to be linear in the range of 0.3 to 10 µmol/l. The limit of quantification was 0.27 µmol/l for HPCE and 0.15 µmol/l for HPLC. The variations for intra- and inter-assay precision were around 6 RSD%, and the mean recovery accuracy close to 100% (96.11%).
    PLoS ONE 07/2013; 8(7):e70374. · 3.73 Impact Factor
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    ABSTRACT: For the past few decades membrane zinc metallopeptidases have been identified as important therapeutic targets in the control of pain. In particular neutral endopeptidase (NEP) has been shown to play critical roles in the metabolism of the endogenous peptides Met- and Leu- enkephalins. In this study we have evaluated the activity of a new fluorinated peptidase inhibitor NESS002ie in both in vitro and in vivo assays. NESS002ie has been compared to the peptidomimetic compound thiorphan and the previously reported NEP selective thiol inhibitor C20. The metallopeptidases inhibitory activity of NESS002ie was tested in vitro using a highly, sensitive, continuous, fluorometric, enzyme assay. Also, the analgesic propriety of NESS002ie, thiorphan and C20 have been evaluated in vivo, by intraplantar, intravenous and intrathecal administration, through nociception assays based on formalin test in mice. Metallopeptidases assays have shown an inhibitory potency of NESS002ie in the nanomolar range for NEP and angiotensin-converting enzyme (ACE). The new fluorinated inhibitor showed higher analgesic activity and bioavailability compared to thiorphan and C20 when administered by both intravenous and intrathecal injection. More significantly intrathecal injection of NESS002ie reduced both the first and the second phases of the formalin biphasic pain response. In addition, naltrindole and naloxone reversed the analgesic effect of NESS002ie with a diverse profile. This study, shows an improvement in relief of inflamation and pain, in vivo, using NESS002ie compared to reference compounds thiorphan and C20. This significant effect, could be due to the replacement of isobutyl chain of the thiol C20 with the trifluoromethyl group.
    Pharmacology Biochemistry and Behavior 07/2013; · 2.61 Impact Factor
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    ABSTRACT: We have recently synthesized a new series of 4,5-Dihydrobenzo-oxa-cycloheptapyrazole derivatives with the aim to discover novel CB1 antagonist agents characterized by anti-obesity activity comparable to that of SR141716A but with reduced adverse effects such as anxiety and depression. Within the novel class, the CB1 antagonist 8-Chloro-1-(2,4-dichlorophenyl)-N-piperidin-1-yl-4,5-dihydrobenzo-1H-6-oxa-cyclohepta(1,2-c)pyrazole-3-carboxamide (NESS06SM) has been selected as lead compound. We found that NESS06SM is a CB1 neutral antagonist, characterized by poor blood brain barrier permeability. Moreover, NESS06SM chronic treatment determined both anti-obesity effect and cardiovascular risk factor improvement in C57BL/6N Diet Induced Obesity (DIO) mice fed with fat diet (FD mice). In fact, the mRNA gene expression in Central Nervous System (CNS) and peripheral tissues by real time PCR, showed a significant increase of orexigenic peptides and a decrease of anorexigenic peptides elicited by NESS06SM treatment, compared to control mice fed with the same diet. Moreover, in contrast to SR141716A treatment, the chronic administration of NESS06SM did not change mRNA expression of both monoaminergic transporters and neurotrophins highly related with anxiety and mood disorders. Our results suggest that NESS06SM reduces body weight and it can restore the disrupted expression profile of genes linked to the hunger-satiety circuit without altering monoaminergic transmission probably avoiding SR141716A side effects. Therefore the novel CB1 neutral antagonist could represent a useful candidate agent for the treatment of obesity and its metabolic complications.
    Pharmacological Research 06/2013; · 4.35 Impact Factor
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    ABSTRACT: The search of new drugs and targets to treat the pain is an intriguing challenge both for several companies and researchers from academia. In this context, since the modulation of the endocannabinoid system with the non selective phytocannabinoid Δ9-THC produces analgesia and potentiates opioid analgesia in animal models, CB2 ligands studies aimed to explore the involvement of endocannabinoid system in management of pain were started. Several selective CB2 receptor agonists exhibited analgesic activity in preclinical models of acute, inflammatory and neuropathic pain, therefore this class of modulators could be useful as analgesic agents for pain, migraine, inflammation and osteoarthritis. This review is an update of our previously manuscript "A survey of recent patents on CB2 agonists in the management of pain" and provides an overview of patents and advances in CB2 agonist studies in the treatment of pain.
    Recent patents on CNS drug discovery. 03/2013;
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    ABSTRACT: A new hydrophilic interaction ultra-performance LC method was established for the whole blood measurement of L-ergothioneine. Chromatographic separation was achieved in a fairly short time, less than 4 min, on a 100 × 2.1 mm Acquity UPLC BEH HILIC 1.7 μm column with a mobile phase consisting of a mixture of 100 mmol/L ammonium acetate/ACN/water (5:85:10, v/v/v) that flowed isocratically at 0.250 mL/min. The LOD and the limit of quantification were 3.85 and 11.67 μmol/L, respectively. The method exhibited linearity in a concentration range of 15.63–1000 μmol/L (R2 > 0.999). Mean recovery was 96.34% whereas intraassay and interassay precision were 1.52 and 1.82% RSD, respectively. On the whole, the developed method is simple, fast, precise, accurate, and sensitive and may be useful for routine analyses.
    Journal of Separation Science 03/2013; 36(6):1002-1006. · 2.59 Impact Factor
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    ABSTRACT: In spite of rimonabant's withdrawal from the European market due to its adverse effects, interest in the development of drugs based on CB(1) antagonists is revamping on the basis of the peculiar properties of this class of compounds. In particular, new strategies have been proposed for the treatment of obesity and/or related risk factors through CB(1) antagonists, i.e. by the development of selectively peripherally acting agents or by the identification of neutral CB(1) antagonists. New compounds based on the lead CB(1) antagonist/inverse agonist rimonabant have been synthesized with focus on obtaining neutral CB(1) antagonists. Amongst the new derivatives described in this paper, the mixture of the two enantiomers (±)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-3-(2-cyclohexyl-1-hydroxyethyl)-4-methyl-1H-pyrazole ((±)-5), and compound 5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-3-[(Z)-2-cyclohexyl-1-fluorovinyl]-4-methyl-1H-pyrazole ((Z)-6), showed interesting pharmacological profiles. According to the preliminary pharmacological evaluation, these novel pyrazole derivatives showed in fact both neutral CB(1) antagonism behaviour and significant in vivo activity towards food intake.
    European journal of medicinal chemistry 01/2013; 62C:256-269. · 3.27 Impact Factor
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    ABSTRACT: In this paper we report the synthesis of new compounds based on the pyrazole and isoxazole framework fused to a cycloalkene unit, and bearing as a substituent the 1-piperidinyl group as new examples of potential antipsychotic molecules. The general synthesis involves the acylation of a chloro-substituted cyclic ketone with a 1-substituted piperidine-4-carboxylate derivative, followed by heterocyclization of the formed 1,3-dioxo compound with a hydrazine or hydroxylamine.
    Molecules 01/2013; 18(7):8147-8159. · 2.43 Impact Factor
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    ABSTRACT: The synthesis of three series of novel 4-alkyl-5-(5'-chlorothiophen-2'-yl)-pyrazole-3-carbamoyl analogues of rimonabant with affinity for the CB1 cannabinoid receptor subtype is reported. Amongst the novel derivatives, compounds 21j, 22a, 22c, and 22f showed affinity values expressed as Ki ranging from 5.5 to 9.0 nM. Derivative 23e revealed a good CB1 affinity (Ki = 11.7 nM) and the highest CB1 selectivity of the whole series (KiCB2/KiCB1 = 384.6). These new compounds appeared to be able to pass the blood brain barrier and to counteract the activity of cannabinoid agonist. According to the results of mice vas deferens assays, as in the case of rimonabant, derivatives 21a, 22a, and 22b showed inverse agonist activity. In contrast, as a preliminary result to be confirmed, compound 23a exhibited neutral antagonist profile. According to the data obtained through an acute animal model, selected compounds 21a, 22a, and 23a evidenced the capability to significantly reduce food intake. At specific conditions, the effect of the novel compounds were higher than that induced by rimonabant. Amongst the novel CB1 antagonist compounds, 23a may represent a useful candidate agent for the treatment of obesity and its metabolic complications, with reduced side effects relative to those instead observed with rimonabant.
    Central Nervous System Agents in Medicinal Chemistry(Formerly Current Medicinal Chemistry - Central Nervous System Agents) 08/2012;
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    ABSTRACT: The present work aims to study the effects induced by a chronic treatment with a novel CB1 antagonist (NESS038C6) in C57BL/6N diet-induced obesity (DIO) mice. Mice treated with NESS038C6 and fed with a fat diet (NESS038C6 FD) were compared with the following three reference experimental groups: DIO mice fed with the same fat diet used for NESS038C6 and treated with vehicle or the reference CB1 antagonist/inverse agonist rimonabant, "VH FD" and "SR141716 FD", respectively; DIO mice treated with vehicle and switched to a normal diet (VH ND). NESS038C6 chronic treatment (30 mg/kg/day for 31 days) determined a significant reduction in DIO mice weight relative to that of VH FD. The entity of the effect was comparable to that detected in both SR141716 FD and VH ND groups. Moreover, if compared to VH FD, NESS038C6 FD evidenced: (i) improvement of cardiovascular risk factors; (ii) significant decrease in adipose tissue leptin expression; (iii) increase in mRNA expression of hypothalamic orexigenic peptides and a decrease of anorexigenic peptides; (iv) expression increase of metabolic enzymes and peroxisome proliferator-activated receptor-α in the liver; (v) normalization of monoaminergic transporters and neurotrophic expression in mesolimbic area. However, in contrast to the case of rimonabant, the novel CB1 antagonist improved the disrupted expression profile of genes linked to the hunger-satiety circuit, without altering monoaminergic transmission. In conclusion, the novel CB1 antagonist compound NESS038C6 may represent a useful candidate agent for the treatment of obesity and its metabolic complications, without or with reduced side effects relative to those instead observed with rimonabant.
    Behavioural brain research 07/2012; 234(2):192-204. · 3.22 Impact Factor
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    ABSTRACT: Pain, a homeostatic and protective mechanism which can go awry in disease states and therefore needs treatment, is a complex and differentiated sensorial perception which may be classified as physiological, inflammatory and neuropathic. Chronic pain represents a major health problem throughout the world, thus several companies and researchers have embarked on the search for new drugs and targets to treat the disease. The different types of receptors in the CNS involved in the mediation of analgesia include the cannabinoid receptors: in particular, CB2 modulators seem to represent a new potential class of analgesic. This review covers recent patents and advances in CB2 agonist studies in the management of pain.
    Recent patents on CNS drug discovery. 04/2012; 7(1):4-24.
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    ABSTRACT: In search of new selective CB2 ligands, the synthesis and preliminary biological evaluation of novel 1,4-dihydroindeno[1,2-c]pyrazole hybrids of the highly potent prototypicals 5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-N-fenchyl-1H-pyrazole-3-carboxamide 1 and 1-(2,4-dichlorophenyl)-6-methyl-N-(piperidin-1-yl)-1,4-dihydroindeno[1,2-c]pyrazole-3-carboxamide 2 are detailed.We postulated that the introduction of those pharmacophoric elements essential for activity of 1 in the tricyclic core of 2 might provide CB2 ligands with further improved receptor selectivity and biological activity. Among the compounds, 6-chloro-7-methyl-1-(2,4-dichlorophenyl)-N-fenchyl-1,4-dihydroindeno[1,2-c]pyrazole-3-carboxamide (22) exhibited low two digit nanomolar affinity for the cannabinoid CB2R and maintained a high level of CB2-selectivity.
    The Open Medicinal Chemistry Journal 01/2012; 6:1-14.
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    ABSTRACT: Different studies, carried out by us and others, have investigated the impact of carbon nanotubes (CNTs) in vitro and in animal models. To date, only a few studies have been performed on human cells ex vivo. There is also a lack of comparison between CNTs with varied functionalization and structural properties and their impact on different cell types. The present ex vivo human study focuses on the impact of a series of functionalized multiwalled CNTs on human T and B lymphocytes, natural killer (NK) cells and monocytes. Smaller diameter nanotubes are internalized more efficiently. Viability assays displayed the absence of cytotoxicity of all multiwalled CNTs used. Activation assay demonstrated a strong effect on monocytes and NK cells. Our results, on human cells ex vivo, confirmed previous studies demonstrating appropriately functionalized CNTs are nontoxic. The effects on cell functionality were significant for the monocytes and NK cells. These findings encourage the possible use of CNTs for biomedical applications either as carriers of therapeutic molecules or as immune modulator systems.
    Nanomedicine 11/2011; 7(2):231-43. · 5.26 Impact Factor
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    ABSTRACT: An unusual reaction involving ninhydrin and aminothiols was exploited to set an indirect method for the chiral recognition of stereoisomers of penicillamine. Separation of diastereoisomers was achieved on a C18 column in isocratic mode by using a mixture of propionic acid (pH 3.0)/acetonitrile/water (10:10:80, v/v/v) as a mobile phase. Diastereoisomers were detected by a fluorescence detector in fairly short times (about 7 min) and with a good resolution. The lowest detectable amount of toxic isomer of penicillamine (l-enantiomer) in samples of the d-enantiomer, was around 0.01%. The method was also suitable for the indirect chiral recognition of other aminothiols such as cysteine and cysteinylglycine.
    Talanta 09/2011; 85(4):1783-5. · 3.50 Impact Factor
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    ABSTRACT: There is, in principle, more than 1 reason to theorize a positive impact of therapy with D-penicillamine on atherosclerosis development. Through its well-known chelating and thiol-disulfide exchange reactions, this thiol-containing drug may, in fact, interfere with some of the recognized pathological events involved in the leading cause of death and major cause of disability worldwide. Here we discuss the mechanistic base of this proposition and provide some experimental evidence that strongly argues for such a hypothesis.
    The Journal of Clinical Pharmacology 11/2010; 51(12):1728-32. · 2.84 Impact Factor
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    ABSTRACT: A series of phenylimidazole-pyrazolo[1,5-c]quinazolines 1a-q was designed, synthesized and characterised as a novel class of potent phophodiesterase 10A (PDE10A) inhibitors. In this series, 2,9-dimethyl-5-(2-(1-methyl-4-phenyl-1H-imidazol-2-yl)ethyl)pyrazolo[1,5-c]quinazoline (1q) showed the highest affinity for PDE10A enzyme (IC(50)=16nM).
    Bioorganic & medicinal chemistry 11/2010; 19(1):642-9. · 2.82 Impact Factor
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    ABSTRACT: A hydrophilic interaction chromatography-based method, in combination with 1.7 microm ethylene bridged hybrid particle packed column (100 mm x 2.1 mm I.D.) and ultraperformance liquid chromatography, has been developed to measure cytosine (C) and methylcytosine (mC) in order to evaluate the extent of DNA methylation. Separation of cytosine and methylcytosine was achieved with good resolution and in fairly short times (5.5 min) by using isocratic elution with a mixture of 97:3 (v/v) acetonitrile/10 mM ammonium acetate as a mobile phase. The determination coefficients of C and mC were high (R(2) > 0.999) within the range tested. The %RSD for intraday and interday were respectively 2.2% and 2.5% for C and 3.5% and 3.8% for mC. The limit of detection was 0.52 microM (0.52 fmol on-column) both for C and mC while the limit of quantification was 1.72 microM (1.72 fmol on-column) both for C and mC. The smallest amount of purified DNA that yielded a measurable level of C and mC was 10 microg. On the whole, this method is simple, rapid, sensitive, and precise.
    Analytical and Bioanalytical Chemistry 03/2010; 396(8):2937-41. · 3.66 Impact Factor
  • G Murineddu, C Murruzzu, G A Pinna
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    ABSTRACT: The therapeutic approach to AIDS is based on the combination of different drugs in the highly active antiretroviral therapy (HAART) regimen. These drugs have a wide variety of side effects, and some strains of HIV can develop resistance: for these reasons new anti-HIV drugs are needed. In the wide field of anti-HIV medicine this review covers different classes of drugs which inhibit viral entry: in particular the classification of main categories, their mode of action and some new candidates for AIDS therapy are contemplated. Also covered in this review are respiratory syncytial virus (RSV) fusion inhibitors.
    Current Medicinal Chemistry 02/2010; 17(11):1067-91. · 4.07 Impact Factor
  • ChemInform 01/2010; 29(42).
  • ChemInform 01/2010; 30(37).

Publication Stats

451 Citations
181.46 Total Impact Points


  • 2013
    • Università degli studi di Cagliari
      Cagliari, Sardinia, Italy
  • 2012–2013
    • National Research Council
      Roma, Latium, Italy
    • Neuroscienze PharmaNess
      Cagliari, Sardinia, Italy
  • 1988–2013
    • Università degli Studi di Sassari
      • • Dipartimento di Chimica e Farmacia
      • • Facoltà di Farmacia
      • • Dipartimento di Scienze Biomediche
      Sassari, Sardinia, Italy
  • 2010
    • University of Milan
      Milano, Lombardy, Italy