In this study, we synthesized novel benzoxazol-2-ylmethyl-(1H-1,2,3-triazol-4-yl)phenyl)-3-aminopropanamides (6a-d) in high yields by means of the Copper-catalysed Azide-Alkyne Cycloaddition (CuAAC) reaction. The synthetic pathway involves the conversion of 2-aminophenol to 2-(bromomethyl)benzoxazole 1, followed by its transformation into the azide derivative 2. Subsequent reaction with functionalized arylalkynes 5a-d under Sharpless’s reaction conditions yields the desired compounds 6a-d. These benzoxazoles were then evaluated as G-Quadruplex DNA (G4) ligands by UV spectroscopy studies using a telomeric sequence (Tel22) as G4 model. We studied how the absorbance at λmax varies over time for the 6a-d/Tel22 mixtures at different molar ratios. Moreover we carried out melting experiments in order to point out any possible stabilization effects arising by ligand interaction. Our findings indicate that Tel22 is slighlty but significantly stabilized by compound 6b at a 1:1 ratio. Furthermore for 6b, these results align well with in silico predictions suggesting that the ligand acts as groove binder interacting with six guanosine residues of the telomeric model.

Two new chiral "click BOX" ligands have been synthetised with high yields starting from commercially available dimethyl propargylmalonate and optically pure alkanolamines, followed by copper catalysed cycloaddition (CuAAC) and oxazoline ring formation. Catalytic activity of the new ligands has been tested in the copper mediated Henry addition. The model reaction between nitromethane and o-anisaldehyde affords the related 1-(2-methoxyphenyl)-2-nitroethanol in high yields (up to 92%) and moderate enantioselectivities (up to 67% e.e.) under straightforward experimental conditions.

Positive allosteric modulators (PAMs) of the GABAB receptor have emerged as a novel approach to the pharmacological manipulation of the GABAB receptor, enhancing the effects of receptor agonists with few side effects. Here, we identified N-cyclohexyl-4-methoxy-6-(4-(trifluoromethyl)phenyl)pyrimidin-2-amine (SSD114) as a new compound with activity as a GABAB PAM in in vitro and in vivo assays. SSD114 potentiated GABA-stimulated [35S]GTPγS binding to native GABAB receptors, whereas it had no effect when used alone. Its effect on GTPγS stimulation was suppressed when GABA-induced activation was blocked with CGP54626, a competitive antagonist of the GABAB receptor. SSD114 failed to potentiate WIN55,212,2-, morphine- and quinpirole-induced [35S]GTPγS binding to cortical and striatal membranes, respectively, indicating that it is a selective GABAB PAM. Increasing SSD114 fixed concentrations induced a leftward shift of the GABA concentration-response curve, enhancing the potency of GABA rather than its efficacy. SSD114 concentration-response curves in the presence of fixed concentrations of GABA (1, 10, and 20μM) revealed a potentiating effect on GABA-stimulated binding of [35S]GTPγS to rat cortical membranes, with EC50 values in the low micromolar range. Bioluminescence resonance energy transfer (BRET) experiments in Chinese Hamster Ovary (CHO)-cells expressing GABAB receptors showed that SSD114 potentiates the GABA inhibition of adenylyl-cyclase mediated by GABAB receptors. Our compound is also effective in vivo potentiating baclofen-induced sedation/hypnosis in mice, with no effect when tested alone. These findings indicate that SSD114, a molecule with a different chemical structure compared to known GABAB PAMs, is a novel GABAB PAM with potential usefulness in the GABAB-receptor research field.

Hereby we report new reaction conditions to convert benzoic acids and more general (hetero)aromatic carboxylic acids into the corresponding n-heptyl esters by applying Novozym-435 as the biocatalyst in cyclohexane as the solvent. Very good yields are obtained in the esterification of a plethora of substituted acids with mild and straightforward reaction conditions. Direct esterification of the acid is favoured compared to transesterification of methyl benzoate under our reaction conditions in all cases studied. Recycling of the immobilised enzyme is feasible although with some minor limitations.

ChemInformVolume 46, Issue 33 Isocyclic Compounds ChemInform Abstract: Novozym-435 as Efficient Catalyst for the Synthesis of Benzoic and (Hetero)aromatic Carboxylic Acid Esters. Daniela Giunta, Daniela Giunta Inst. Chim. Biomol., CNR-UOS SS, I-07100 Sassari, ItalySearch for more papers by this authorBarbara Sechi, Barbara Sechi Inst. Chim. Biomol., CNR-UOS SS, I-07100 Sassari, ItalySearch for more papers by this authorMaurizio Solinas, Maurizio Solinas Inst. Chim. Biomol., CNR-UOS SS, I-07100 Sassari, ItalySearch for more papers by this author Daniela Giunta, Daniela Giunta Inst. Chim. Biomol., CNR-UOS SS, I-07100 Sassari, ItalySearch for more papers by this authorBarbara Sechi, Barbara Sechi Inst. Chim. Biomol., CNR-UOS SS, I-07100 Sassari, ItalySearch for more papers by this authorMaurizio Solinas, Maurizio Solinas Inst. Chim. Biomol., CNR-UOS SS, I-07100 Sassari, ItalySearch for more papers by this author First published: 28 July 2015 https://doi.org/10.1002/chin.201533110Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume46, Issue33August, 2015 RelatedInformation

We have previously reported the synthesis and the pharmacological characterization of a family of methyl 2-(acylamino) thiophene-3-carboxylates as GABA(B) positive allosteric modulators active both in vitro and in vivo. In the present work, we describe the synthesis of new compounds based on the bioisosteric replacement of the ester moiety with amido or heterocyclic groups as well as of thieno[2,3-d]pyrimidine derivatives as rigid analogues thereof. 4H-Thieno[2,3-d][1,3]oxazin-4-ones were used as synthetic intermediates for the preparation of some of these compounds. The structures of oxazinones 11b, 16, and 17 were assigned by X-ray crystallographic studies, which definitely ruled out the isomeric beta-lactam structure previously hypothesized for these compounds. None of the new molecules exhibited significant activity at the GABA(B) receptor, either as allosteric or orthosteric ligands.

We hereby present the development of new reaction conditions for the CALB catalysed esterification of substituted benzoic acids. Using cyclohexane as the reaction media a number of heptyl benzoates have been easily isolated in good to excellent yields (up to 100% at 80 °C, 20–24 h). Moreover, the catalytic system has been successfully applied to the synthesis of local anaesthetics intermediates also showing good productivity in recycling experiments.

Two recently reported hit compounds, COR627 and COR628, underpinned the development of a series of 2-(acylamino)thiophene derivatives. Some of these compounds displayed significant activity in vitro as positive allosteric modulators of the GABAB receptor by potentiating GTPγS stimulation induced by GABA at 2.5 and 25 μM while failing to exhibit intrinsic agonist activity. Compounds were also found to be effective in vivo, potentiating baclofen-induced sedation/hypnosis in DBA mice when administered either intraperitoneally or intragastrically. Although displaying a lower potency in vitro than the reference compound GS39783, the new compounds 6, 10, and 11 exhibited a higher efficacy in vivo: combination of these compounds with a per se nonsedative dose of baclofen resulted in shorter onset and longer duration of the loss of righting reflex in mice. Test compounds showed cytotoxic effects at concentrations comparable to or higher than those of GS39783 or BHF177.

Scotta is the main by-product in the making of ricotta cheese. It is widely produced in southern Europe and particularly in Italy where it represents a serious environmental pollutant due to its high lactose content. With the aim of evaluating whether scotta bioconversion into lactic acid can be considered as an alternative to its disposal, besides providing it with an added value, here the growth, fermentative performances, and lactic acid productions of pure and mixed cultures of Lactobacillus casei , Lactobacillus helveticus , and Streptococcus thermophilus were evaluated on ovine scotta -based media, without and with the addition of nutritional supplements. The outcomes indicate that ovine scotta can be utilized for the biotechnological production of lactic acid with yields up to 92%, comparable to those obtained on cheese-whey. Indeed, the addition of nutritional supplements generally improves the fermentative performances of lactic acid bacteria leading to about 2 g l −1 h −1 of lactic acid. Moreover, the use of mixed cultures for scotta bioconversion reduces the need for nutritional supplements, with no detrimental effects on the productive parameters compared to pure cultures. Finally, by using L. casei and S. thermophilus in pure and mixed cultures, up to 99% optically pure l -lactic acid can be obtained.

The potential efficacy of GABA(B) receptor agonists in the treatment of pain, drug addiction, epilepsy, cognitive dysfunctions, and anxiety disorders is supported by extensive preclinical and clinical evidence. However, the numerous side effects produced by the GABA(B) receptor agonist baclofen considerably limit the therapeutic use of this compound. The identification of positive allosteric modulators (PAMs) of the GABA(B) receptor may constitute a novel approach in the pharmacological manipulation of the GABA(B) receptor, leading to fewer side effects. The present study reports the identification of two novel compounds, methyl 2-(1-adamantanecarboxamido)-4-ethyl-5-methylthiophene-3-carboxylate (COR627) and methyl 2-(cyclohexanecarboxamido)-4-ethyl-5-methylthiophene-3-carboxylate (COR628), which act as GABA(B) PAMs in 1) rat cortical membranes and 2) in vivo assay. Both compounds potentiated GABA- and baclofen-stimulated guanosine 5'-O-(3-[(35)S]thio)-triphosphate binding to native GABA(B) receptors, while producing no effect when given alone. GABA concentration-response curves in the presence of fixed concentrations of COR627 and COR628 revealed an increase of potency of GABA rather than its maximal efficacy. In radioligand binding experiments [displacement of the GABA(B) receptor antagonist, 3-N-[1-((S)-3,4dichlorophenyl)-ethylaminol]-2-(S)hydroxypropyl cyclo-hexylmethyl phosphinic acid ([(3)H]CGP54626)], both COR627 and COR628 increased the affinity of high- and low-affinity binding sites for GABA, producing no effect when administered alone up to a concentration of 1 mM. In vivo experiments indicated that pretreatment with per se ineffective doses of COR627 and COR628 potentiated the sedative/hypnotic effect of baclofen. In conclusion, COR627 and COR628 may represent two additional tools for use in investigating the roles and functions of positive allosteric modulatory binding sites of the GABA(B) receptor.

Compressed carbon dioxide (liquid or supercritical scCO2) and ionic liquids (ILs) are finding a constant interest as alternative green solvents for chemical reactions. Both systems have been employed alone as replacement of volatile organic compounds (VOCs) in a large number of stoichiometric and catalytic transformations sometimes leading to surprisingly improved results. The non volatility of ionic liquids and the benign nature of carbon dioxide are the major driving forces to their use as reaction media. Moreover, the tunability of their solvent properties by proper design (ILs) or by variation of pressure and temperature (scCO2) is an additional reason to their broader application. Both ionic liquids and carbon dioxide present some challenges but, ever since several researchers started to deeply investigate the phase behaviour of the combined system, it appeared how this may possibly be the way to overcome their limitations. The beneficial combination of the two non-traditional solvents has been confirmed by the numerous examples reported in the literature. With the present review the authors wish to discuss about the combination of ionic liquids and carbon dioxide applied to transition metal catalysed reactions with particular emphasis on the phase behaviour of the system.

An highly stereoselective, flexible and very short synthetic approach to d-ribo-configured ureido monosaccharides of the aldose, aldonic acid and alditol series has been performed starting from the 5-(alditol-1-C-yl)-hydantoin intermediates, obtained via aldol-type addition reaction of hydantoin based building blocks to enantiomerically pure aldehydes. A study to assess the stereoselectivity of this reaction has been undertaken and a very high increase of diastereoselectivity was observed depending on the hydantoin protecting group. The imidazolidinone ring elaboration of 5-(alditol-1-C-yl)-hydantoin intermediates to give ureido sugar derivatives was studied.

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Conjugate additions of [Zn(bpy*)Cl(Et)] (bpy* = 4,4'-di-tert-butyl-2,2'-bipyridine) to cyclohex-2-en-1-one are promoted by ZnMe2 in 88% ee but in moderate yield under CuI phosphoramidite catalysis. In the absence of ZnMe2 the [Zn(bpy*)Cl(Et)] is inactive indicating a Schlenk-type equilibrium. Other derivatives of [Zn(bpy*)Cl(R)] (R = Bu, 4-methylbenzyl), prepared in situ from [ZnCl(R)] and the bipyridine give low yields due to competing chloride abstraction. 13C NMR studies indicate facile organo-ligand exchange between [Zn(bpy*)(Et)2] and [Zn(bpy*)Cl2] complexes. In the presence of the bipyridine, [ZnBr(allyl)] disproportionates into [Zn(bpy*)Br2] and [Zn(bpy*)(allyl)2] species. In separate studies, simple (E)-MeCH=CHCONMeR (R = Me, OMe) α,β-unsaturated amides undergo asymmetric 1,4-addition of EtMgBr in 75-99% yield and 48-79% ee in the presence of the diphosphines JosiPhos or MeDuPhos and copper(I) sources.

The synthesis and characterisation of nonclassical ruthenium hydride complexes containing bidentate PP and tridentate PCP and PNP pincer-type ligands are described. The mononuclear and dinuclear ruthenium complexes presented have been synthesised in moderate to high yields by the direct hydrogenation route (one-pot synthesis) or in a two-step procedure. In both cases [Ru(cod)(metallyl)(2)] served as a readily available precursor. The influences of the coordination geometry and the ligand framework on the structure, binding, and chemical properties of the M--H(2) fragments were studied by X-ray crystal structure analysis, spectroscopic methods, and reactivity towards N(2), D(2), and deuterated solvents.

The carbene-containing non-classical ruthenium hydride complex [(PCy3)Ru(H)(2)(H-2)(2)(IMeS)] 1 (IMes = 1,3-Bis-(2,4,6-trimethylphenyl)imidazol-2-ylidene) is an active catalyst for H/D exchange in aromatic ketones. It is also capable of combining sp(2) C-H bond activation with C-C bond formation. Comparing the chemo- and regio-selectivities of the H/D exchange process and the C-C bond formation clearly indicates that different intermediates are involved in the two processes. High pressure NMR studies provide strong evidence that the key intermediate for the C-C coupling reaction is analogous to that for other ruthenium catalysts reported previously. Catalytic turnover is limited by the instability of this intermediate in the presence of the olefinic coupling partner. (C) 2004 Elsevier B.V. All rights reserved.