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Abstract Biocompatibility and the ability to mediate the appropriate flux of ions, urea, and uremic toxins between blood and dialysate components are key parameters for membranes used in dialysis. Oxone-mediated TEMPO-oxidized cellulose nanomaterials have been demonstrated to be excellent additives in the production and tunability of ultrafiltration and dialysis membranes. In the present study, nanocellulose ionic liquid membranes (NC-ILMs) were tested in vitro and ex vivo. An increase in flux of up to two orders of magnitude was observed with increased rejection (about 99.6%) of key proteins compared to that of polysulfone (PSf) and other commercial membranes. NC-ILMs have a sharper molecular weight cut-off than other phase inversion polymeric membranes, allowing for high throughput of urea and a uremic toxin surrogate and limited passage of proteins in dialysis applications. Superior anti-fouling properties were also observed for the NC-ILMs, including a > 5-h operation time with no systemic anticoagulation in blood samples. Finally, NC-ILMs were found to be biocompatible in rat ultrafiltration and dialysis experiments, indicating their potential clinical utility in dialysis and other blood filtration applications. These superior properties may allow for a new class of membranes for use in a wide variety of industrial applications, including the treatment of patients suffering from renal disease.

Introduction: An active metabolite of buprenorphine (BUP), called norbuprenorphine (NorBUP), is implicated in neonatal opioid withdrawal syndrome when BUP is taken during pregnancy. Therefore, reducing or eliminating metabolism of BUP to NorBUP is a novel strategy that will likely lower total fetal exposure to opioids and thus improve offspring outcomes. Precision deuteration alters pharmacokinetics of drugs without altering pharmacodynamics. Here, we report the synthesis and testing of deuterated buprenorphine (BUP-D2).Methods: We determined opioid receptor affinities of BUP-D2 relative to BUP with radioligand competition receptor binding assays, and the potency and efficacy of BUP-D2 relative to BUP to activate G-proteins via opioid receptors with [35S]GTPγS binding assays in homogenates containing the human mu, delta, or kappa opioid receptors. The antinociceptive effects of BUP-D2 and BUP were compared using the warm-water tail withdrawal assay in rats. Blood concentration versus time profiles of BUP, BUP-D2, and NorBUP were measured in rats following intravenous BUP-D2 or BUP injection.Results: The synthesis provided a 48% yield and the product was ≥99% deuterated. Like BUP, BUP-D2 had sub-nanomolar affinity for opioid receptors. BUP-D2 also activated opioid receptors and induced antinociception with equal potency and efficacy as BUP. The maximum concentration and the area under the curve of NorBUP in the blood of rats that received BUP-D2 were over 19- and 10-fold lower, respectively, than in rats that received BUP.Discussion: These results indicate that BUP-D2 retains key pharmacodynamic properties of BUP and resists metabolism to NorBUP and therefore holds promise as an alternative to BUP.

Chronic, low-grade inflammation has been implicated in aging and age-dependent conditions, including Alzheimer’s disease, cardiomyopathy, and cancer. One of the age-associated processes underlying chronic inflammation is protein aggregation, which is implicated in neuroinflammation and a broad spectrum of neurodegenerative diseases such as Alzheimer’s, Huntington’s, and Parkinson’s diseases. We screened a panel of bioactive thiadiazolidinones (TDZDs) from our in-house library for rescue of protein aggregation in human-cell and C. elegans models of neurodegeneration. Among the tested TDZD analogs, PNR886 and PNR962 were most effective, significantly reducing both the number and intensity of Alzheimer-like tau and amyloid aggregates in human cell-culture models of pathogenic aggregation. A C. elegans strain expressing human Aβ1–42 in muscle, leading to AD-like amyloidopathy, developed fewer and smaller aggregates after PNR886 or PNR962 treatment. Moreover, age-progressive paralysis was reduced 90% by PNR886 and 75% by PNR962, and “healthspan” (the median duration of spontaneous motility) was extended 29% and 62%, respectively. These TDZD analogs also extended wild-type C. elegans lifespan by 15–30% (p < 0.001), placing them among the most effective life-extension drugs. Because the lead drug in this family, TDZD-8, inhibits GSK3β, we used molecular-dynamic tools to assess whether these analogs may also target GSK3β. In silico modeling predicted that PNR886 or PNR962 would bind to the same allosteric pocket of inactive GSK3β as TDZD-8, employing the same pharmacophore but attaching with greater avidity. PNR886 and PNR962 are thus compelling candidate drugs for treatment of tau- and amyloid-associated neurodegenerative diseases such as AD, potentially also reducing all-cause mortality.

Hepatocellular carcinoma (HCC) is both a devastating and common disease. Every year in the United States, about 24,500 men and 10,000 women are diagnosed with HCC, and more than half of those diagnosed patients die from this disease. Thus far, conventional therapeutics have not been successful for patients with HCC due to various underlying comorbidities. Poor survival rate and high incidence of recurrence after therapy indicate that the differences between the redox environments of normal surrounding liver and HCC are valuable targets to improve treatment efficacy. Parthenolide (PTL) is a naturally found therapeutic with anti-cancer and anti-inflammatory properties. PTL can alter HCC’s antioxidant environment through thiol modifications leaving tumor cells sensitive to elevated reactive oxygen species (ROS). Investigating the link between altered thiol mechanism and increased sensitivity to iron-mediated lipid peroxidation will allow for improved treatment of HCC. HepG2 (human) and McARH7777 (rat) HCC cells treated with PTL with increasing concentrations decrease cell viability and clonogenic efficiency in vitro. PTL increases glutathione (GSH) oxidation rescued by the addition of a GSH precursor, N-acetylcysteine (NAC). In addition, this elevation in thiol oxidation results in an overall increase in mitochondrial dysfunction. To elucidate if cell death is through lipid peroxidation, using a lipid peroxidation sensor indicated PTL increases lipid oxidation levels after 6 h. Additionally, western blotting reveals glutathione peroxidase 4 (GPx4) protein levels decrease after treatment with PTL suggesting cells are incapable of preventing lipid peroxidation after exposure to PTL. An elevation in lipid peroxidation will lead to a form of cell death known as ferroptosis. To further establish ferroptosis as a critical mechanism of death for HCC in vitro, the addition of ferrostatin-1 combined with PTL demonstrates a partial recovery in a colony survival assay. This study reveals that PTL can induce tumor cell death through elevations in intracellular oxidation, leaving cells sensitive to ferroptosis.

Abstract Background Loss of skeletal muscle volume and functional limitations are poor prognostic markers in breast cancer patients. Several molecular defects in skeletal muscle including reduced myoblast determination protein 1 (MyoD) levels and increased protein turn over due to enhanced proteosomal activity have been suggested as causes of skeletal muscle loss in cancer patients. However, it is unknown whether molecular defects in skeletal muscle are dependent on tumour aetiology. Methods We characterized functional and molecular defects of skeletal muscle in mouse mammary tumour virus (MMTV)‐Neu (Neu+) mice (n = 6–12), an animal model that represents HER2 + human breast cancer, and compared the results with well‐characterized luminal B breast cancer model MMTV‐PyMT (PyMT+). Functional studies such as grip strength, rotarod performance, and ex vivo muscle contraction were performed to measure the effects of cancer on skeletal muscle. Expression of muscle‐enriched genes and microRNAs as well as circulating cytokines/chemokines were measured. Because nuclear factor‐kappaB (NF‐κB) pathway plays a significant role in skeletal muscle defects, the ability of NF‐κB inhibitor dimethylaminoparthenolide (DMAPT) to reverse skeletal muscle defects was examined. Results Neu+ mice showed skeletal muscle defects similar to accelerated aging. Compared with age and sex‐matched wild type mice, Neu+ tumour‐bearing mice had lower grip strength (202 ± 6.9 vs. 179 ± 6.8 g grip force, P = 0.0069) and impaired rotarod performance (108 ± 12.1 vs. 30 ± 3.9 s, P

Previous studies have demonstrated that the bone targeting agent BT2-peg2 (BT2-minipeg2, 9), when conjugated to vancomycin and delivered systemically by intravenous (IV) or intraperitoneal (IP) injection accumulates in bone to a greater degree than vancomycin alone, but that this accumulation is associated with severe nephrotoxicity. To determine whether this nephrotoxicity could be attributed to BT2-peg2 itself, we used a rat model to assess the distribution and toxicity of BT2-peg2 after IP injection of 11 mg/kg twice daily for 21 days. The results demonstrated that BT2-peg2 accumulates in bone but there was no evidence of nephrotoxicity or any histopathological abnormalities in the bone. This suggests the nephrotoxicity observed in previous studies is likely due to the altered pharmacokinetics of vancomycin when conjugated to BT2-peg2 rather than to BT2-peg2 itself. Thus, BT2-peg2 may be a safe carrier for the enhanced delivery of antibiotics other than vancomycin to the bone as a means of combating bone infection. However, the data also emphasizes the need to carefully examine the pharmacokinetic characteristics of any BT2-peg2-antibiotic conjugate utilized for treatment of bone infections.

Stimulation of cholinergic efferent neurons innervating the inner ear has profound, well-characterized effects on vestibular and auditory physiology, after activating distinct ACh receptors (AChRs) on afferents and hair cells in peripheral endorgans. Efferent-mediated fast and slow excitation of vestibular afferents are mediated by α4β2*-containing nicotinic AChRs (nAChRs) and muscarinic AChRs (mAChRs), respectively. On the auditory side, efferent-mediated suppression of distortion product otoacoustic emissions (DPOAEs) is mediated by α9α10nAChRs. Previous characterization of these synaptic mechanisms utilized cholinergic drugs, that when systemically administered, also reach the CNS, which may limit their utility in probing efferent function without also considering central effects. Use of peripherally-acting cholinergic drugs with local application strategies may be useful, but this approach has remained relatively unexplored. Using multiple administration routes, we performed a combination of vestibular afferent and DPOAE recordings during efferent stimulation in mouse and turtle to determine whether charged mAChR or α9α10nAChR antagonists, with little CNS entry, can still engage efferent synaptic targets in the inner ear. The charged mAChR antagonists glycopyrrolate and methscopolamine blocked efferent-mediated slow excitation of mouse vestibular afferents following intraperitoneal, middle ear, or direct perilymphatic administration. Both mAChR antagonists were effective when delivered to the middle ear, contralateral to the side of afferent recordings, suggesting they gain vascular access after first entering the perilymphatic compartment. In contrast, charged α9α10nAChR antagonists blocked efferent-mediated suppression of DPOAEs only upon direct perilymphatic application, but failed to reach efferent synapses when systemically administered. These data show that efferent mechanisms are viable targets for further characterizing drug access in the inner ear.

Summary: Diagnosis of neurodegenerative diseases hinges on “seed” proteins detected in disease-specific aggregates. These inclusions contain diverse constituents, adhering through aberrant interactions that our prior data indicate are nonrandom. To define preferential protein-protein contacts mediating aggregate coalescence, we created click-chemistry reagents that cross-link neighboring proteins within human, APPSw-driven, neuroblastoma-cell aggregates. These reagents incorporate a biotinyl group to efficiently recover linked tryptic-peptide pairs. Mass-spectroscopy outputs were screened for all possible peptide pairs in the aggregate proteome. These empirical linkages, ranked by abundance, implicate a protein-adherence network termed the “aggregate contactome.” Critical hubs and hub-hub interactions were assessed by RNAi-mediated rescue of chemotaxis in aging nematodes, and aggregation-driving properties were inferred by multivariate regression and neural-network approaches. Aspirin, while disrupting aggregation, greatly simplified the aggregate contactome. This approach, and the dynamic model of aggregate accrual it implies, reveals the architecture of insoluble-aggregate networks and may reveal targets susceptible to interventions to ameliorate protein-aggregation diseases. : Neuroscience; Molecular Neuroscience; Neural Networks; Proteomics Subject Areas: Neuroscience, Molecular Neuroscience, Neural Networks, Proteomics

The title compound, C21H25NO3 [systematic name: (1aR,4E,7aS,8E,10aS,10bR)-8-(2-aminobenzylidene)-1a,5-dimethyl-2,3,6,7,7a,8,10a,10b-octahydrooxireno[2′,3′:9,10]cyclodeca[1,2-b]furan-9(1aH)-one], was synthesized by the reaction of parthenolide [systematic name (1aR,7aS,10aS,10bS,E)-1a,5-dimethyl-8-methylene-2,3,6,7,7a,8,10a,10b-octahydrooxireno[2′,3′:9,10]cyclodeca[1,2-b]furan-9(1aH)-one] with 2-iodoaniline via Heck reaction conditions. The molecule is composed of fused ten-, five- (lactone), and three-membered (epoxide) rings. The lactone ring shows a flattened envelope-type conformation (r.m.s. deviation from planarity = 0.0477 Å), and bears a 2-aminobenzylidene substituent that is disordered over two conformations [occupancy factors 0.901 (4) and 0.099 (4)]. The ten-membered ring has an approximate chair–chair conformation. The dihedral angle between the 2-aminobenzylidine moiety (major component) and the lactone ring (mean plane) is 59.93 (7)°. There are no conventional hydrogen bonds, but there are a number of weaker C—H...O-type interactions.

Age-progressive neurodegenerative pathologies, including Alzheimer’s disease (AD), are distinguished and diagnosed by disease-specific components of intra- or extra-cellular aggregates. Increasing evidence suggests that neuroinflammation promotes protein aggregation, and is involved in the etiology of neurological diseases. We synthesized and tested analogs of the naturally occurring tubulin-binding compound, combretastatin A-4. One such analog, PNR502, markedly reduced the quantity of Alzheimer-associated amyloid aggregates in the BRI-Aβ1–42 mouse model of AD, while blunting the ability of the pro-inflammatory cytokine IL-1β to raise levels of amyloid plaque and its protein precursors in a neuronal cell-culture model. In transgenic Caenorhabditis elegans (C. elegans) strains that express human Aβ1–42 in muscle or neurons, PNR502 rescued Aβ-induced disruption of motility (3.8-fold, P < 0.0001) or chemotaxis (1.8-fold, P < 0.05), respectively. Moreover, in C. elegans with neuronal expression of Aβ1–42, a single day of PNR502 exposure reverses the chemotaxis deficit by 54% (P < 0.01), actually exceeding the protection from longer exposure. Moreover, continuous PNR502 treatment extends nematode lifespan 23% (P ≤ 0.001). Given that PNR502 can slow, prevent, or reverse Alzheimer-like protein aggregation in human-cell-culture and animal models, and that its principal predicted and observed binding targets are proteins previously implicated in Alzheimer’s, we propose that PNR502 has therapeutic potential to inhibit cerebral Aβ1–42 aggregation and prevent or reverse neurodegeneration.

(Z)-5-[2-(Benzo[b]thiophen-2-yl)-1-(3,5-dimethoxyphenyl)ethenyl]-1H-tetrazole methanol monosolvate, C19H16N4O2S·CH3OH, (I), was prepared by the reaction of (Z)-3-(benzo[b]thiophen-2-yl)-2-(3,5-dimethoxyphenyl)acrylonitrile with tributyltin azide via a [3 + 2]cycloaddition azide condensation reaction. The structurally related compound (Z)-5-[2-(benzo[b]thiophen-3-yl)-1-(3,4,5-trimethoxyphenyl)ethenyl]-1H-tetrazole, C20H18N4O3S, (II), was prepared by the reaction of (Z)-3-(benzo[b]thiophen-3-yl)-2-(3,4,5-trimethoxyphenyl)acrylonitrile with tributyltin azide. Crystals of (I) have two molecules in the asymmetric unit (Z′ = 2), whereas crystals of (II) have Z′ = 1. The benzothiophene rings in (I) and (II) are almost planar, with r.m.s deviations from the mean plane of 0.0084 and 0.0037 Å in (I) and 0.0084 Å in (II). The tetrazole rings of (I) and (II) make dihedral angles with the mean planes of the benzothiophene rings of 88.81 (13) and 88.92 (13)° in (I), and 60.94 (6)° in (II). The dimethoxyphenyl and trimethoxyphenyl rings make dihedral angles with the benzothiophene rings of 23.91 (8) and 24.99 (8)° in (I) and 84.47 (3)° in (II). In both structures, molecules are linked into hydrogen-bonded chains. In (I), these chains involve both tetrazole and methanol, and are parallel to the b axis. In (II), molecules are linked into chains parallel to the a axis by N—H...N hydrogen bonds between adjacent tetrazole rings.

The title compound, C28H32N2, (I), is one of a second generation of compounds designed and synthesized based on a very potent and selective α9α10 nicotinic acetylcholine receptor antagonist ZZ161C {1,1′-[[1,1′-biphenyl]-4,4′-diylbis(prop-2-yne-3,1-diyl)]bis(3,4-dimethylpyridin-1-ium) bromide}, which has shown analgesic effects in a chemotherapy-induced neuropathy animal model. Compound (I) was synthesized by the reaction of 4,4′-bis(3-bromoprop-1-yn-1-yl)-1,1′-biphenyl with piperidine at room temperature in acetonitrile. The single-crystal used for X-ray analysis was obtained by dissolving (I) in a mixture of dichloromethane and methanol, followed by slow evaporation of the solvent. In the crystal of (I), the biphenyl moiety has a twisted conformation, with a dihedral angle of 25.93 (4)° between the benzene rings. Both piperidine head groups in (I) are in the chair conformation and are oriented so that the N-atom lone pairs of each piperidine group point away from the central biphenyl moiety.

A series of novel hybrid 8-hydroxyquinoline-indole derivatives (7a–7e, 12a–12b and 18a–18h) were synthesized and screened for inhibitory activity against self-induced and metal-ion induced Aβ1–42 aggregation as potential treatments for Alzheimer’s disease (AD). In vitro studies identified the most inhibitory compounds against self-induced Aβ1–42 aggregation as 18c, 18d and 18f (EC50 = 1.72, 1.48 and 1.08 µM, respectively) compared to the known anti-amyloid drug, clioquinol (1, EC50 = 9.95 µM). The fluorescence of thioflavin T-stained amyloid formed by Aβ1–42 aggregation in the presence of Cu2+ or Zn2+ ions was also dramatically decreased by treatment with 18c, 18d and 18f. The most potent hybrid compound 18f afforded 82.3% and 88.3% inhibition, respectively, against Cu2+- induced and Zn2+- induced Aβ1–42 aggregation. Compounds 18c, 18d and 18f were shown to be effective in reducing protein aggregation in HEK-tau and SY5Y-APPSw cells. Molecular docking studies with the most active compounds performed against Aβ1–42 peptide indicated that the potent inhibitory activity of 18d and 18f were predicted to be due to hydrogen bonding interactions, π–π stacking interactions and π–cation interactions with Aβ1–42, which may inhibit both self-aggregation as well as metal ion binding to Aβ1–42 to favor the inhibition of Aβ1–42 aggregation.

The 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) oxidation of cellulose, when mediated with Oxone® (KHSO5), can be performed simply and under mild conditions. Furthermore, the products of the reaction can be isolated into two major components: Oxone®-mediated TEMPO-oxidized cellulose nanomaterials Form I and Form II (OTO-CNM Form I and Form II). This study focuses on the characterization of the properties of OTO-CNMs. Nanoparticle-sized cellulose fibers of 5 and 16 nm, respectively, were confirmed through electron microscopy. Infrared spectroscopy showed that the most carboxylation presented in Form II. Conductometric titration showed a two-fold increase in carboxylation from Form I (800 mmol/kg) to Form II (1600 mmol/kg). OTO-CNMs showed cellulose crystallinity in the range of 64–68% and crystallite sizes of 1.4–3.3 nm, as shown through XRD. OTO-CNMs show controlled variability in hydrophilicity with contact angles ranging from 16 to 32°, within or below the 26–47° reported in the literature for TEMPO-oxidized CNMs. Newly discovered OTO-CNM Form II shows enhanced hydrophilic properties as well as unique crystallinity and chemical functionalization in the field of bio-sourced material and nanocomposites.

The title compounds, C26H28N2, (I), and C28H32N2, (II), were designed based on the structure of the potent α9α10 nicotinic acetylcholine receptor antagonist ZZ161C {1,1′-[[1,1′-biphenyl]-4,4′-diylbis(prop-2-yne-3,1-diyl)]bis(3,4-dimethylpyridin-1-ium) bromide}. In order to improve the druglikeness properties of ZZ161C for potential oral administration, the title compounds (I) and (II) were prepared by coupling 4,4′-bis(3-bromoprop-1-yn-1-yl)-1,1′-biphenyl with pyrrolidine, (I), and (S)-2-methylpyrrolidine, (II), respectively, in acetonitrile at room temperature. The asymmetric unit of (I) contains two half molecules that each sit on sites of crystallographic inversion. As a result, the biphenyl ring systems in compound (I) are coplanar. The biphenyl ring system in compound (II), however, has a dihedral angle of 28.76 (11)°. In (I), the two independent molecules differ in the orientation of the pyrrolidine ring (the nitrogen lone pair points towards the biphenyl rings in one molecule, but away from the rings in the other). The torsion angles about the ethynyl groups between the planes of the phenyl rings and the pyrrolidine ring N atoms are 84.15 (10) and −152.89 (10)°. In compound (II), the corresponding torsion angles are 122.0 (3) and 167.0 (3)°, with the nitrogen lone pairs at both ends of the molecule directed away from the central biphenyl rings.

As part of a comprehensive program to discover α9α10 nicotinic acetylcholine receptor antagonists, the title compounds C30H36N2, (I), and C36H48N2, (II), were synthesized by coupling 4,4′-bis(3-bromoprop-1-yn-1-yl)-1,1′-biphenyl with 4-methylpiperidine and 2,2,6,6-tetramethylpiperidine, respectively, in acetonitrile at room temperature. In compound (I), the biphenyl system has a twisted conformation with a dihedral angle of 26.57 (6)° between the two phenyl rings of the biphenyl moiety, while in compound (II), the biphenyl moiety sits on a crystallographic inversion centre so the two phenyl rings are exactly coplanar. The terminal piperidine rings in both compound (I) and compound (II) are in the chair conformation. In compound (I), the dihedral angles about the ethynyl groups between the planes of the phenyl rings and the piperidine ring N atoms are 37.16 (16) and 14.20 (17)°. In compound (II), the corresponding dihedral angles are both 61.48 (17)°. There are no noteworthy intermolecular interactions in (I), but in (II) there is a small π-overlap between inversion-related molecules (1 − x, 1 − y, 1 − z), with an interplanar spacing of 3.553 (3) Å and centroid-to-centroid separation of 3.859 (4) Å.

The title compound, C19H17N3O3S (I), was prepared by a [3 + 2]cycloaddition azide condensation reaction using sodium azide and l-proline as a Lewis base catalyst. N-Methylation of compound (I) using CH3I gave compound (II), C20H19N3O3S. The benzothiophene ring systems in (I) and (II) are almost planar, with r.m.s deviations from the mean plane = 0.0205 (14) in (I) and 0.016 (2) Å in (II). In (I) and (II), the triazole rings make dihedral angles of 32.68 (5) and 10.43 (8)°, respectively, with the mean planes of the benzothiophene ring systems. The trimethoxy phenyl rings make dihedral angles with the benzothiophene rings of 38.48 (4) in (I) and 60.43 (5)° in (II). In the crystal of (I), the molecules are linked into chains by N—H...O hydrogen bonds with R21(5) ring motifs. After the N-methylation of structure (I), no hydrogen-bonding interactions were observed for structure (II). The crystal structure of (II) has a minor component of disorder that corresponds to a 180° flip of the benzothiophene ring system [occupancy ratio 0.9363 (14):0.0637 (14)].

The title compound, C19H22N2O3, {systematic name (1aR,4E,7aS,8E,10aS,10bR)-1a,5-dimethyl-8-[(pyrimidin-5-yl)methylidene]-2,3,6,7,7a,8,10a,10b-octahydrooxireno[2′,3′:9,10]cyclodeca[1,2-b]furan-9(1aH)-one} was obtained from the reaction of parthenolide [systematic name (1aR,7aS,10aS,10bR,E)-1a,5-dimethyl-8-methylene-2,3,6,7,7a,8,10a,10b-octahydrooxireno[2′,3′:9,10]cyclodeca[1,2-b]furan-9(1aH)-one] with 5-bromopyrimidine under Heck reaction conditions, and was identified as an E isomer. The molecule possesses ten-, five- (lactone) and three-membered (epoxide) rings with a pyrimidine group as a substituent. The ten-membered ring displays an approximate chair–chair conformation, while the lactone ring shows a flattened envelope-type conformation. The dihedral angle between the pyrimidine moiety and the lactone ring system is 29.43 (7)°.

Fused ring 3,4-dihydropyrimidin-2(1H)-ones and thiones were synthesized by the one-pot three component condensation of 6-methoxy-1-tetralone, aromatic aldehydes and urea or thiourea under solvent-free conditions at 120 °C utilizing poly(4-vinylpyridinium)hydrogen sulfate as Bronsted acid catalyst. This methodology has an advantage of good yields, shorter reaction times, straight forward workup and reusability of the catalyst over five additional times without losing its activity and product yield.

The title compound, C20H23N3O6·CH3OH, was synthesized by [3 + 2] cycloaddition of (Z)-2,3-bis(3,4,5-trimethoxyphenyl)acrylonitrile with sodium azide and ammonium chloride in DMF/water. The central nitrogen of the triazole ring is protonated. The dihedral angles between the triazole ring and the 3,4,5-trimethoxyphenyl ring planes are 34.31 (4) and 45.03 (5)°, while that between the 3,4,5-trimethoxyphenyl rings is 51.87 (5)°. In the crystal, the molecules, along with two methanol solvent molecules are linked into an R44(10) centrosymmetric dimer by N—H...O and O—H...N hydrogen bonds.

The title compound, C33H35NO6 [systematic name: (Z)-3-(4-{(E)-[(E)-1a,5-dimethyl-9-oxo-2,3,7,7a-tetrahydrooxireno[2′,3′:9,10]cyclodeca[1,2-b]furan-8(1aH,6H,9H,10aH,10bH)-ylidene]methyl}phenyl)-2-(3,4,5-trimethoxyphenyl)acrylonitrile methanol hemisolvate], C33H35NO6·0.5CH3OH, was prepared by the reaction of (Z)-3-(4-iodophenyl)-2-(3,4,5-trimethoxyphenyl)acrylonitrile with parthenolide [systematic name: (E)-1a,5-dimethyl-8-methylene-2,3,6,7,7a,8,10a,10b-octahydrooxireno[2′,3′:9,10]cyclodeca[1,2-b]furan-9(1aH)-one] under Heck reaction conditions. The molecule is built up from fused ten-, five- (lactone) and three-membered (epoxide) rings with a {4-[(Z)-2-cyano-2-(3,4,5-trimethoxyphenyl)ethenyl]phenyl}methylidene group as a substituent. The 4-[(Z)-2-cyano-2-(3,4,5-trimethoxyphenyl)ethenyl]phenyl group on the parthenolide exocyclic double bond is oriented in a trans position to the lactone ring to form the E isomer. The dihedral angle between the benzene ring of the phenyl moiety and the lactone ring mean plane is 21.93 (4)°.

The title monosuccinate derivative of melampomagnolide B [systematic name: 4-(((1aR,7aS,10aS,10bS,E)-1a-methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-decahydrooxireno[2′,3′:9,10]cyclodeca[1,2-b]furan-5-yl)methoxy)-4-oxobutanoic acid], C19H24O7, was obtained from the reaction of melampomagnolide B with succinic anhydride under nucleophilic addition reaction conditions. The molecule is built up from fused ten-, five- (lactone) and three-membered (epoxide) rings. The internal double bond in the ten-membered ring has the cis geometry (i.e. it is the E isomer). The lactone ring has an envelope-type conformation, with the (chiral) C atom opposite the lactone O atoms as the flap atom. In the crystal, O—H...O hydrogen bonds link the molecules into chains parallel to the b-axis direction.

The title compound, C21H23BrO3 [systematic name: (3E,3aS,6Z,9R,9aS,9bS)-3-(2-bromobenzylidene)-9-hydroxy-6,9-dimethyl-3,3a,4,5,7,8,9,9a-octahydroazuleno[4,5-b]furan-2(9bH)-one] was prepared by the reaction of 1-bromo-2-iodobenzene with micheliolide [systematic name: (3aS,R,9aS,9bS,Z)-9-hydroxy-6,9-dimethyl-3-methylene-3,3a,4,5,7,8,9,9a-octahydroazuleno[4,5-b]furan-2(9bH)-one] under Heck reaction conditions. The title compound exhibits intramolecular O—H...O hydrogen bonding between the hydroxy group and the lactone ring O atom, forming a ring of graph-set motif S(6). The 2-bromophenyl group is trans to the lactone ring, indicating that this is the E isomer (geometry of the exocyclic C=C bond). The dihedral angle between the benzene ring of the 2-bromophenyl moiety and the mean plane of the lactone ring is 51.68 (7)°.

The title compound, C18H24N2O4·H2O {systematic name: (1aR,7aS,8R,10aS,10bS,E)-5-hydroxymethyl-8-[(1H-imidazol-1-yl)methyl]-1a-methyl-2,3,6,7,7a,8,10a,10b-octahydrooxireno[2′,3′:9,10]cyclodeca[1,2-b]furan-9(1aH)-one monohydrate}, an imidazole derivative of melampomagnolide B was synthesized under Michael addition conditions. The molecule is built up from fused ten-, five- (lactone) and three-membered (epoxide) rings. The internal double bond of the ten-membered ring identifies it as the cis or E isomer. The lactone ring has an envelope-type conformation, with the (chiral) C atom opposite the lactone O atoms as the flap atom. In the crystal, O—H...O, O—H...N and weak C—H...O hydrogen bonds link the molecules (along with water) into sheets parallel to the bc plane.

The title compound, C17H27NO3·0.08H2O {sytematic name: (3R,3aS,9R,9aS,9bS)-3-[(dimethylamino)methyl]-9-hydroxy-6,9-dimethyl-3,3a,4,5,7,8,9,9a-octahydroazuleno[4,5-b]furan-2(9bH)-one 0.08-hydrate}, exhibits intramolecular O—H...O hydrogen bonding to form a ring of graph-set motif S(6). As well as this intramolecular hydrogen bond with the lactone-ring O atom, the hydroxy H atom forms an O—H...O hydrogen bond to the low-occupancy partial water molecule [occupancy = 0.078 (2)]. The water molecule is correlated with disorder of the N(CH3)2 group [major–minor occupancy factors are 0.922 (2):0.078 (2)]. The dihedral angle between the mean planes of the trans-fused seven-membered ring and the lactone ring is 4.42 (9)°.

The title compound, C21H25NO3 [systematic name: (3aS,9aR,10aR,10bS,E)-3-[(E)-4-(4-aminobenzylidene)-6,9a-dimethyl-3a,4,5,8,9,9a,10a,10b-octahydrooxireno[2′,3′:9,10]cyclodeca[1,2-b]furan-2(3H)-one] was obtained from the reaction of parthenolide [synonym: 4,5-epoxygermacra-1(10),11(13)-dieno-12,6-lactone] with 4-iodoaniline under Heck reaction conditions. It was identified as the E-isomer (conformation about the exocyclic methylidene C=C bond; the conformation about the C=C bond in the ten-membered ring is also E). The molecule is built up from fused ten-, five- (lactone) and three-membered (epoxide) rings with a 4-aminophenyl group as a substituent. The ten-membered ring displays an approximate chair–chair conformation, while the lactone ring has an envelope conformation with the C atom bonded to the ring O atom as the flap. The dihedral angle between the benzene ring of the 4-aminophenyl moiety and the lactone ring mean plane is 23.50 (8)°. In the crystal, molecules are linked via N—H...O hydrogen bonds, between the amine group and the lactone and epoxide ring O atoms, forming chains propagating along the b-axis direction. Adjacent chains are linked via C—H...O interactions, forming an undulating two-dimensional network lying parallel to the plane (001). The absolute structure of the molecule in the crystal was confirmed by resonance scattering [Flack parameter = 0.03 (3)].

In the title compound [systematic name: rac-1-benzyl-5-bromo-3-hydroxy-3-(2-imino-3-methyl-5-oxoimidazolidin-4-yl)-2,3-dihydro-1H-indol-2-one ethanol monosolvate], C19H17BrN4O3·C2H5OH, which crystallized as a racemate (RR and SS), the isatin ring is almost planar, with an r.m.s. deviations from the mean plane of 0.0276 (14) Å. The phenyl ring of the benzyl group makes a dihedral angle with the mean plane of the isatin ring of 87.40 (5)° and the dihedral angle between the imidazole and isatin rings is 58.56 (7)°. In the crystal, molecules are linked into two-dimensional pleated-sheet networks in the ac plane formed by O—H...O, N—H...O and O—H...N hydrogen bonds; within these sheets there are R44(10) rings that involve three molecules of the title compound and a single ethanol solvent molecule. In addition, there are π–π interactions between inversion-related benzyl groups, with an interplanar spacing of 3.444 (3) Å.

The title compound, C19H18N4O3 [systematic name: (RS)-1-benzyl-3-hydroxy-3-(2-imino-3-methyl-5-oxoimidazolidin-4-yl)-2,3-dihydro-1H-indol-2-one], was prepared as a racemate (RR and SS) by the aldol condensation of N-benzylisatin with creatinine in the presence of sodium acetate in acetic acid. The r.m.s. deviation of the isatin ring system is 0.033 Å. The benzyl group is disordered over two orientations, with refined occupancies of 0.847 (7) and 0.153 (7). The dihedral angles between the isatin ring system and the benzene ring (major disorder component) and the imidazole ring are 82.82 (7) and 51.31 (3)°, respectively, In the crystal, molecules are linked into (001) sheets by N—H...O and O—H...N hydrogen bonds, which incorporate R22(9) ring motifs. The crystal was grown from mixed solvents (ethanol, methanol and possibly also ethyl acetate). These solvents are disordered in the crystal and the resulting electron density was found to be uninterpretable. The solvent contribution to the scattering was removed with the SQUEEZE routine in PLATON [Spek (2009). Acta Cryst. D65, 148–155]. The formula mass and density do not take account of the solvent.

Highly efficient, ecofriendly, and improved protocol for the synthesis of 1,8-acridinediones has been developed via one-pot multicomponent condensation of 1,3-cyclohexanedione/dimedone, aromatic aldehydes, and ammonium acetate utilizing poly(4-vinylpyridinium)hydrogen sulfate as catalyst in aqueous medium. Excellent yields in shorter reaction time, simple work-up procedure, easy recovery, and reusability of the catalyst are attractive features of this green protocol.

In the title compound, C20H18N2O3, the C=C bond of the acrylonitrile group that links the indole and the 3,4,5-trimethoxyphenyl rings has Z geometry, with dihedral angles between the plane of the acrylonitrile unit and the planes of the benzene and indole ring systems of 21.96 (5) and 38.94 (7)°, respectively. The acrylonitrile group is planar (r.m.s. deviation from planarity = 0.037 Å). Molecules are linked into head-to-tail chains that propagate along the b-axis direction by bifurcated N—H...O intermolecular hydrogen bonds, which form an R12(5) motif between the indole NH group and the two methoxy O atoms furthest from the nitrile group.

The crystal structure of the title compound, C25H27NO4, shows the presence of a double bond with Z geometry which connects the quinuclidin-3-one ring and the trimethoxyresveratrol moiety. The dihedral angle between the two benzene rings in the stilbene skeleton is 32.80 (8)°.

In the title compound, C20H17NO4, the double bond of the acrylonitrile group separating the 1-benzofuran moiety from the 3,4,5-trimethoxyphenyl ring has Z geometry. The 1-benzofuran groups are π–π stacked with inversion-related counterparts such that the furan ring centroid–centroid distance is 3.804 (5) Å. The dihedral angle between the planes of the trimethoxyphenyl ring and the acrylonitrile group is 24.2 (2)°.

In the title compound, C13H13N3, the cyano groups at the 2- and 5-positions are eclipsed with each other. The phenyl ring is disordered over two sets of sites, with refined occupancies of 0.520 (5) and 0.480 (5). The angles between the mean plane of the pyrrolidine ring and the two cyano groups are 71.7 (9) and 75.0 (12)°.

The crystal structure of the title compound, C12H14ClNO, was determined in order to confirm that the chiral center of the molecule has an S configuration. The cyclohexanone ring adopts a chair conformation. The 2-chlorophenyl ring is slightly twisted from the axial C—N bond, with a N—C—C—C torsion angle of −5.7 (2)°. In the crystal, an intermolecular N—H...O hydrogen bond links adjacent molecules into an infinite chain, which propagates in the b-axis direction.

In the crystal structure of the title compound, C21H20N2O4S·CH3OH, molecules are linked into chains by a series of intermolecular N—H...O, N—H...N and O—H...O hydrogen bonds. The molecular structure shows a double bond with Z geometry, connecting the thiazolone and resveratrol units. The dihedral angle between the thiazolone ring and the nearest dimethoxybenzene ring is 53.02 (7)°.

In the title compound, C22H20N+·I−, the dihedral angles between the central pyridine ring and two outer benzene rings are 15.30 (10) and 11.82 (11)°. There are intermolecular π–π stacking interactions between the nearest phenyl ring over an inversion-related pyridyl ring, the shortest centroid–centroid distance being 3.672 (3) Å. The crystal structure of the compound indicates the 2,6-distyryl substituents have an E configuration.

In the crystal structure of the title compound, C22H26N+·Cl−, the piperidine ring is in a chair conformation and the two styryl groups are in axial and equatorial positions. The molecule has a hydrogen bond between the NH group and the chloride anion.

The complete molecule of the title compound, C22H25N, is generated by crystallographic mirror symmetry, with two C atoms and the N atom lying on the mirror plane. The central ring adopts a chair conformation and the dihedral angle between the aromatic rings is 56.69 (4)°.

In the title compound, C13H13FN4O3·0.5CH3OH, molecules are packed in the crystal structure by a series of O—H...N, N—H...O, N—H...F and O—H...O intermolecular hydrogen bonds. The indole and creatinine units make a dihedral angle of 60.80 (4)°.

In the title compound, C18H16N4O3·C2H5OH, molecules are linked into chains by a series of intermolecular N—H...O, N—H...N and O—H...O hydrogen bonds which stabilize the crystal structure. The indole and creatinine units make a dihedral angle of 56.45 (4)°. The title compound has two chiral centres. The crystal structure indicates the compound is racemic (RR and SS).

In the crystal of the title compound, C12H8N2O4S, molecules are linked into chains by a series of intermolecular O—H...O, N—H...O and N—H...N hydrogen bonds. The ninhydrin and aminothiazolidine units make a dihedral angle of 66.41 (3)°. The crystal structure indicates the presence of equimolar R and S enantiomers in the crystal lattice, due to the presence of a chiral centre in the title compound.

Crystals of the title salt, C17H28NO3+·C4H3O4−, were obtained by reacting parthenolide with dimethylamine followed by conversion of the amine adduct into a water-soluble fumarate salt. Subsequent crystallization of the fumarate salt from water afforded colorless orthorhombic crystals. The amine addition is highly stereospecific yielding exclusively a single diastereomer with R-configuration at the newly formed C-11 chiral carbon. In the crystal, intermolecular O—H...O and N—H...O hydrogen bonds help to establish the packing.

In the title compound, C21H17N3O4, pairs of molecules form a planar[maximum deviation 0.0566 (9) Å] centrosymmetric imidazole dimer via two N—H...O hydrogen bonds. These dimeric units are linked by further N—H...O hydrogen bonds between the ester carbonyl group and the imidazolidine ring, formiing chains parallel to the c-axis direction. In addition, there are π–π stacking interactions between the planar imidazole pairs, with an interplanar spacing of 3.301 (2) Å. There is a double bond with Z geometry connecting the imidazolidine and indole units.

The title compound, C25H24N2O3 was prepared by the reaction of (Z)-2-(1H-indol-3-ylmethylene)-1-azabicyclo[2.2.2]octan-3-one with methyl p-(bromomethyl)benzoate, under phase-transfer catalytic (PTC) conditions using triethylbenzylammonium chloride and 50% w/v aqueous NaOH solution in dichloromethane. The crystal structure indicates the presence of a double bond with Z geometry connecting the azabicyclic and indole groups.

In the title compound, C20H14N4O2, molecules are linked into chains by N—H...O hydrogen bonds, but the cyano group does not participate in the supramolecular aggregation. The crystal structure of the compound indicates the presence of a double bond with Z geometry, connecting the imidazolidine and indole units. The dihedral angle between the imidazole and benzene ring planes is 62.45 (4)°.

The title compound, C24H21N3O, was prepared by the reaction of (Z)-2-(1H-indol-3-ylmethylene)-1-azabicyclo[2.2.2]octan-3-one with α-bromo-p-toluonitrile, under phase-transfer catalytic (PTC) conditions using triethylbenzylammonium chloride and 50% w/v aqueous NaOH solution in dichloromethane. The crystal structure indicates the presence of a double bond with Z geometry connecting the azabicyclic and indole groups.

The title compound [systematic name: (12R)-4,8-dimethyl-12-[(1′R)-1′,2′,3′,4′-tetrahydro-1′-naphthyl)aminomethyl]-3,14-dioxatricyclo[9.3.0.02,4]tetradec-7-en-13-one}, C25H33NO3, was formed from the reaction of (1R)-1-aminotetralin with parthenolide in methanolic solution. X-ray crystal structure analysis determined that the configuration of the new chiral center in the title compound was R.

The title compound (systematic name: 12-{[2-(4-hydroxyphenyl)ethyl]aminomethyl}-4,8-dimethyl-3,14-dioxatricyclo[9.3.0.02,4]tetradec-7-en-13-one monohydrate), C23H31NO4·H2O, was obtained by the reaction of tyramine with parthenolide. The configuration of the new chiral center in the title compound is R, establishing the stereospecificity of the amination reaction. The water molecule is disordered over three positions; the site occupancy factors are 0.45, 0.40 and 0.15.

The title compound, C12H15NO, a degradation product of molindone hydrochloride, was prepared by the reaction of molindone with methyl iodide and subsequent reaction of the resulting quaternary ammonium salt with 2N aqueous sodium hydroxide. The newly formed double bond is exocyclic in nature and the carbonyl group is conjugated with the π-electrons of the pyrrole ring. The six-membered ring is in the half-chair conformation. The H atom attached to the N atom is involved in an intermolecular hydrogen bond with the O atom of a screw-related molecule, thus forming a continuous chain.