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RATIONALE Hirsutinolide-type sesquiterpene lactones (SLs) are natural biologically active compounds mainly found in the genus Vernonia. Very few studies have been published about the fragmentation mechanisms of SLs generally and none about hirsutinolides, although they have drawn attention through their biological and taxonomical interest. This work aims to propose a mass spectrometry fragmentation pattern for hirsutinolides in order to detect and to identify them in a botanical extract. METHODS The fragmentation pathways of six pure hirsutinolides isolated from Pseudelephantopus spiralis were established by positive ion electrospray high-resolution linear ion trap Orbitrap tandem mass spectrometry (ESI(+)-HRMS(n) ). A resolutive, hyphenated ultra-high-performance liquid chromatography (UHPLC) coupled to diode array detection (DAD) and ESI(+)-HRMS(n) method was then implemented to separate and analyze them. The ionization behaviour and diagnostic product ions were investigated by both methods. The UHPLC/DAD-ESI-HRMS(n) method was applied for the dereplication of a plant extract. RESULTS For the six standard compounds, the main fragmentation pattern consists first in the loss of the side chain in the C-8 position followed by the loss of the substituent in the C-13 position. UHPLC/HRMS analyses of hirsutinolides mainly produced sodiated molecules or [M+H-H2 O](+) ions. The high-abundance product ions at m/z 299 and 259 were established to be the characteristic diagnostic ions of the hirsutinolide core. The analysis of a P. spiralis extract further led to the identification of two putative hirsutinolides. CONCLUSIONS The UHPLC/DAD-HRMS(n) method combining characteristic fragmentation patterns and the profiles of the product ions generated in the MS and MS/MS spectra is an effective technique for characterizing hirsutinolide-type SLs.

Thiosemicarbazones have become one of the promising compounds as new clinical candidates due to their wide spectrum of pharmaceutical activities. The wide range of their biological activities depends generally on their related aldehyde or ketone groups. Here, we report the pharmacological activities of some thiosemicarbazones synthesized in this work. Benzophenone and derivatives were used with N(4)-phenyl-3-thiosemicarbazide to synthesize corresponding five thiosemicarbazones (1-5). Their structures were characterized by spectrometrical methods analysis IR, NMR (1)H & (13)C and MS. The compounds were then screened in vitro for their antiparasitic activity and toxicity on Trypanosoma brucei brucei and Artemia salina Leach respectively. The selectivity index of each compound was also determined. Four thiosemicarbazones such as 4, 2, 3 and 1 reveal interesting trypanocidal activities with their half inhibitory concentration (IC50) equal to 2.76, 2.83, 3.86 and 8.48 μM respectively, while compound 5 (IC50 = 12.16 μM) showed a moderate anti-trypanosomal activity on parasite. In toxicity test, except compound 1, which showed a half lethal concentration LC50 >281 μM, the others exerted toxic effect on larvae with LC50 of 5.56, 13.62, 14.55 and 42.50 μM respectively for thiosemicarbazones 4, 5, 3 and 2. In agreement to their selectivity index, which is greater than 1 (SI >1), these compounds clearly displayed significant selective pharmaceutical activities on the parasite tested. The thiosemicarbazones 2-5 that displayed significant anti-trypanosomal and cytoxicity activities are suggested to have anti-neoplastic and anti-cancer activities.

Monoacylglycerol lipase (MAGL) is responsible for signal termination of 2-arachidonoylglycerol (2-AG), an endocannabinoid neurotransmitter endowed with several physiological effects. Previously, we showed that the arylthioamide scaffold represents a privileged template for designing MAGL inhibitors. A series of 37 compounds resulting from pharmacomodulations around the arylthioamide template were synthesized and tested to evaluate their inhibitory potential on MAGL activity as well as their selectivity over fatty acid amide hydrolase (FAAH), another endocannabinoid-hydrolyzing enzyme. We have identified 2,4-dinitroaryldithiocarbamate derivatives as a novel class of MAGL inhibitors. Among the synthesized compounds, we identified [2,4-dinitrophenyl-4-(4-tert-butylbenzyl)piperazine-1-carbodithioate] (CK37), as the most potent MAGL inhibitor within this series (IC(50) = 154 nM). We have also identified [2,4-dinitrophenyl-4-benzhydrylpiperazine-1-carbodithioate] (CK16) as a selective MAGL inhibitor. These compounds are irreversible MAGL inhibitors that probably act by interacting with Cys208 or Cys242 and Ser122 residues of the enzyme. Moreover, CK37 is able to raise 2-arachidonoylglycerol (2-AG) levels in intact cells.

Based on a line of evidence (logP, pKa, 1 H-, and 13 C-NMR, and molecular modeling studies), it appears that cocaine undergoes a hydrophobic collapse which may account for its unprecedented ADME properties, in particular, its exceptional capacity to cross biological membranes. Using molecular simulation techniques, the hypothesis of hydrophobic collapse undergone by the protonated form of cocaine was substantiated using semi-empirical quantum calculations (mainly AM1 and PM3) performed as well as ab initio quantum calculations (6-31 G**). A molecular electrostatic potential map of the internally hydrogen-bonded structure was acquired under AM1 and showed a continuum of high electron density in the central part of the molecule around the methyl ammonium and the two ester moieties. This picture is consistent with the picture of the ammonium being locked between the two C=O and forming a strong canonical primary H bond with the methyl ester and a weaker secondary H bond (non-canonical) with the benzoate ester. Cocaine represents the prototypical example of molecular concision because the pharmacophore and the vector are embedded in the same molecular scaffold. © 2012 Springer Science+Business Media, LLC.

A simpler and efficient “green” method using solid sodium hydroxide in a solvent mixture of acetone/water was found to catalyze N-acylation of 2(3H)-benzoxazolones and 2(3H)-benzothiazolones for facile and rapid synthesis of N-acyl derivatives in excellent yields. This method was applied to the synthesis of a series of 132 compounds employing a variety of acyl chlorides.

Introduction: Fatty acid amide hydrolase (FAAH) is part of the endocannabinoid system (ECS) and has been linked to the aetiology of several neurological and neuropsychiatric disorders. So far no useful PET or SPECT tracer for in vivo visualisation of FAAH has been reported. We synthesized and evaluated a carbon-11-labeled URB597 analogue, biphenyl-3-yl [C-11]-4-methoxyphenylcarbamate or [C-11]-1, as potential FAAH imaging agent. Methods: The inhibitory activity of 1 was determined in vitro using recombinant FAAH. Radiosynthesis of [(CH)-C-11]-1 was performed by methylation using [C-11]-CH3I, followed by HPLC purification. Biological evaluation was done by biodistribution studies in wild-type and FAAH knock-out mice, and by ex vivo and in vivo metabolite analysis. The influence of URB597 pretreatment on the metabolisation profile was assessed. Results: [C-11]-1 was obtained in good yields and high radiochemical purity. Biodistribution studies revealed high brain uptake in wild-type and FAAH knock-out mice, but no retention of radioactivity could be demonstrated. Metabolite analysis and URB597 pretreatment confirmed the non-FAAH-mediated metabolisation of [C-11]-1. The inhibition mechanism was determined to be reversible. In addition, the inhibition of URB597 appeared slowly reversible. Conclusions: Although [C-11]-1 inhibits FAAH in vitro and displays high brain uptake, the inhibition mechanism seems to deviate from the proposed carbamylation mechanism. Consequently, it does not covalently bind to FAAH and will not be useful for mapping the enzyme in vivo. However, it represents a potential starting point for the development of in vivo FAAH imaging tools. (C) 2010 Published by Elsevier Inc.

Monoglyceride lipase (MGL) inhibition may offer an approach in treating diseases in which higher 2-arachidonoyglycerol activity would be beneficial. We report here the synthesis and pharmacological evaluation of bis(dialkylaminethiocarbonyl)disulfide derivatives as irreversible MGL inhibitors. Inhibition occurs through interactions with MGL C208 and C242 residues, and these derivatives exhibit high inhibition selectivity over fatty acid amide hydrolase, another endocannabinoid-hydrolyzing enzyme.

Chalcones featuring an analgesic/anti-inflammatory pharmacophore, i.e., the 2(3H)-benzoxazolone heterocycle, on the one hand, and a radical scavenger moiety, i.e., 2,6-di-t-butylphenol, on the other hand were synthesized by condensation of a ketone 2(3H)-benzoxazolone precursor with 3,5-di-t-butyl-4-hydroxybenzaldehyde. Among the various methods explored (acid homogenous or heterogenous catalysis, base catalysis), heterogenous catalysis conditions using KSF Montmorillonite were found to be the most convenient. The E-geometry of the so-obtained chalcones was ascertained both by 1H and 13C-nuclear magnetic resonance (NMR) spectroscopy as well as B3LYP/6-31G** quantum mechanics calculations. Chalcones 1–8 were pharmacologically evaluated in vitro for their ability to prevent human low-density lipoprotein (LDL) copper-induced oxidation using Cu2+ as oxidizing agent. Compound 4 emerged as the most promising agent as it was able to inhibit copper-mediated human LDL oxidation with an activity ten times greater than that of Probucol, a reference antioxidant drug.

Monoglyceride lipase (MGL) is the enzyme responsible for the termination of 2-arachidonoylglycerol (2-AG) signalling, an endogenous ligand for the G-protein coupled cannabinoid receptors CB1 and CB2. Its known abundance and physiological roles emphasize the interest of MGL as an attractive therapeutic target. Search for MGL inhibitors was undertaken by screening an arylthioamide series. The evaluation of arylthioamides derivatives activity as MGL inhibitors measured by the hydrolysis of [H-3]-2-oleoylglycerol by human purified MGL led to the identification of (2-chloro-phenyl)-morpholin-4-yl-methanethione (2) and (3-nitro-phenyl) morpholin-4-yl-methanethione (12), which moreover exhibit good selectivity compared with human fatty acid amide hydrolase inhibition.

This paper reports efforts aimed at tuning up the synthesis of a compound library centered on the general template 2-amino-1-phenyl-2-thioxoethanone taking the condensation of ω-haloacetophenone, octasulfur, and morpholine as pilot reaction. Considerations about atomic economy were found extremely precious in selecting the best starting halo-reagent. A one-pot practical method based on use of 2-bromo-1-phenylethanone as substrate and N,N-dimethylformamide as solvent can be easily scaled up to gram amounts (72% yield). Based on this synthetic approach, some more specific examples are reported.

The known literature methods to provide access to the title derivatives make use of a base-catalyzed acyl transfer process utilizing either acid halides or anhydrides as acylating agents allowing the synthesis of acylated species in fair to good yields, but none of them is judged satisfactorily to elaborate a library of the title compounds.

The purpose of the present work was to determine the identity of the enzymes that synthesize N-acetylaspartylglutamate (NAAG), the most abundant dipeptide present in vertebrate central nervous system (CNS), and β-citrylglutamate, a structural analogue of NAAG present in testis and immature brain. Previous evidence suggests that NAAG is not synthesized on ribosomes but presumably is synthesized by a ligase. As attempts to detect this ligase in brain extracts failed, we searched the mammalian genomes for putative enzymes that could catalyze this type of reaction. Mammalian genomes were found to encode two putative ligases homologous to Escherichia coli RIMK, which ligates glutamates to the C terminus of ribosomal protein S6. One of them, named RIMKLA, is almost exclusively expressed in the CNS, whereas RIMKLB, which shares 65% sequence identity with RIMKLA, is expressed in CNS and testis. Both proteins were expressed in bacteria or HEK293T cells and purified. RIMKLA catalyzed the ATP-dependent synthesis of N-acetylaspartylglutamate from N-acetylaspartate and l-glutamate. RIMKLB catalyzed this reaction as well as the synthesis of β-citrylglutamate. The nature of the reaction products was confirmed by mass spectrometry and NMR. RIMKLA was shown to produce stoichiometric amounts of NAAG and ADP, in agreement with its belonging to the ATP-grasp family of ligases. The molecular identification of these two enzymes will facilitate progress in the understanding of the function of NAAG and β-citrylglutamate.

Montmorillonite K-10 was used in the acid catalysis of the Willgerodt-Kindler’s reaction (WK) under microwave heating for synthesis of thiobenzamides. Yields of 67% and 43% for the synthesis of morpholin- 4- yl (phenyl) methanethione (1) and [4 - (dimethylamino) phenyl] (morpholin-4-yl) methanethione (2) respectively, showed that the mixture (aldehyde, sulfur, morpholine and K-10) is quite suitable for this reaction. This enables to deduct that the conditions of acid catalysis with the K-10 are favourable to the WK’s reaction of carbonyl compounds. Furthermore, yields of 81% and 74% respectively for the synthesis of thioamides 1 and 2 in basic catalysis with 4-methylmorpholine allows to confirm that this reaction is more advantageous in basic catalysis. The structures of thioamides synthesized were characterized and confirmed by spectroscopy Infrared (IR), nuclear magnetic resonance ( 1 H and 13 C NMR) and mass spectrometry (MS). Keywords: Montmorillonite K-10, 4-methylmorpholine, morpholin-4-yl(phenyl)methanethione, [4- (dimethylamino)phenyl](morpholin-4-yl)methanethione