Search

Tantalum pentoxide (Ta2O5) has attracted intensive attention due to their excellent physicochemical properties. Ta2O5 films were synthesized via electron beam evaporation (EBE) and subsequently annealed at different temperatures ranging from 300 to 900 °C. X-ray diffraction (XRD) results show that amorphous Ta2O5 thin films form from 300 to 700 °C and then a phase transition to polycrystalline β-Ta2O5 films occurs since 900 °C. The surface morphology of the Ta2O5 films is uniform and smooth. The resulted Ta2O5 films exhibit excellent transmittance properties for wavelengths ranging from 300 to 1100 nm. The bandgap of the Ta2O5 films is broadened from 4.32 to 4.46 eV by annealing. The 900 °C polycrystalline film electrode has improved electrochemical stability, compared to the other amorphous counterparts.

Wortmannine A (1), a dinor-carbon wortmannin derivative with an unusual five-membered B ring, together with wortmannine B (2), a wortmannin derivative bearing an unusual five-membered B ring and lactam E-ring, and wortmannine C (3), a wortmannin derivative bearing an unusual five-membered B ring and a lactone E-ring, as well as wortmannine D (4), a 4-methyl substituted androstadiene-17-one, were purified from the zeistic culture of Talaromyces wortmannii LGT-4. The structures of 1–4 were elucidated by comprehensive NMR spectroscopy, Mosher’s method and single-crystal X-ray crystallography. Additional known compounds (5–8) were also isolated. The isolates were tested for cytotoxic activities and compound 5, entonaemin A, showed anti-HL60 activity with IC50s of 15.0 μM (24 h) and 12.4 μM (48 h).

Secovironolide (1) was purified from the culture broth of Talaromyces wortmanni and is the first example of a furanosteroid scaffold bearing a five-membered B ring. The structure of 1 was elucidated by comprehensive NMR spectroscopy and single-crystal X-ray crystallography. Additional known viridian derivatives (2–5, 7) were isolated, including the new epoxide containing compound, epoxyvirone (6). Isolates were tested for monoamine oxidase (MAO) inhibitory activity and showed only weak activity.

This study focuses on the application of combining membrane bioreactor (MBR) treatment with reverse osmosis (RO) or nanofiltration (NF) membrane treatment for removal of pharmaceuticals and personal care products (PPCPs) in municipal wastewater. Twenty-seven PPCPs were measured in real influent with lowest average concentration being trimethoprim (7.12 ng/L) and the highest being caffeine (18.4 ng/L). The results suggest that the MBR system effectively removes the PPCPs with an efficiency of between 41.08% and 95.41%, and that the integrated membrane systems, MBR-RO/NF, can achieve even higher removal rates of above 95% for most of them. The results also suggest that, due to the differences in removal mechanisms of NF/RO membrane, differences of removal rates exist. In this study, the combination of MBR-NF resulted in the removal of 13 compounds to below detection limits and MBR-RO achieved even better results with removal of 20 compounds to below detection limits.

Palladium-catalyzed enantioselective dearomative arylalkynylation of N-substituted indoles, through a Heck/Sonogashira sequence, was established using a new BINOL-based phosphoramidite as the chiral ligand. A wide range of 2,3-disubstituted indolines, bearing vicinal quaternary and tertiary stereocenters, were efficiently constructed in one step with excellent enantioselectivities (up to 97 % ee) and diastereoselectivities (>20:1).

A new wortmannine derivative named wortmannine E (1) was isolated from Talaromyces wortmannii LGT-4, an endophytic fungus of Tripterygium wilfordii. Its structure was established by 1D and 2D NMR spectra.

A DNA sequence encoding for the human proinsulin was designed according to the codon bias of Escherichia coli and then chemically synthesized. The synthesized DNA fragment was subcloned into pGEX-3X for expression in E. coli BL21 (DE3) and E. coli BL21 Star (DE3), respectively. Conditions for the highest expression of the GST-proinsulin fusion proteins were optimized. These conditions are that cells of E. coli BL21 star (DE3) are incubated in 100mL of the LB medium with 2 mmol/L IPTG and 60μ?g/mL ampicillin at 26oCfor 4h. After disrupted E. coli cells with ultrasonication, inclusion bodies were precipitated from cell lysis and washed. Fusion proteins from the inclusion bodies were redissolved in 8mmol/L of urea. After dialysed in purified water, fusion proteins were analysed by SDS-PAGE. The purity of the fusion protein is about 80.5% in total. The fusion protein from SDS-PAGE was further identified by mass/mass spectrum. GST in the dyad protein is confirmed by the 9 matched sequences. However, the left part is proved a polypeptide of which is completely different from the human proinsulin.

A palladium-catalyzed indole dearomative bisfunctionalization via a domino arylation/alkynylation sequence has been developed, which provides a reliable approach to a series of structurally diverse tetracyclic indolines bearing vicinal tertiary and quaternary stereocenters in moderate to good yields and excellent diastereoselectivities.

Two novel compounds, secovironolide (I) and epoxyvirone (II), together with five known viridian derivatives are isolated from the title fungus.

AgCl microparticle materials, with novel heart-like morphology, were successfully prepared by means of a simple solution phase route, in which a small amount of hydrochloric acid, ethylene and PVP were introduced to the conventional polyol process. The obtained microparticle materials were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and UV-Vis absorption spectrum. SEM images show that the obtained AgCl microparticle materials have heart-like morphology with an average diameter of 3 um. The influence of different reaction times on size and morphology of the microparticle materials were also investigated. A possible growth mechanism of AgCl microparticle materials has been proposed on the basis of experimental results and analysis. The as-prepared AgCl microparticle materials would find possible potential applications in photocatalytic fields.

Under visible light irradiation, the plasmonic photocatalyst Ag@AgCl crystals were prepared from heart-like AgCl micro-crystals that were synthesized by a simple hydrothermal method firstly. The results indicated that the experimental conditions have a great effect on the morphology of Ag@AgCl crystals. The pure heart-like, and the mixture of heart-like and cubic shape Ag@AgCl crystals were synthesized by controlling the experimental conditions. Scanning electron microscopy, X-ray powder diffraction, and UV–vis spectra were used to characterize the obtained product. The photocatalytic properties of the obtained product were investigated by evaluating on photo-degradation of a model pollutant methyl orange (MO), indicating that the pure heart-like Ag@AgCl crystals exhibit enhanced visible light photocatalytic performance with 95.3% compared with mixed sample of heart-like and cubic ones (71.3%). The strong surface plasmon resonance (SPR) of Ag nanocrystallites can be responsible for the enhanced visible light photocatalytic performance of the as-prepared Ag@AgCl crystals.

A non-active molybdate ester (ME) was synthesized in a batch process. Its tribological performance and its synergistic effect with ZDDP in 5CST were evaluated using a four-ball machine, and the chemistry of tribofilms was analyzed with XANES. The results indicate that ME possesses excellent anti-wear and friction-reducing properties, not load-carrying capacity. Both ME and ZDDP show excellent synergistic tribological behavior in 5CST. According to the XANES results, the tribochemical films generated from ME alone are mainly composed of MoO 3 , and the tribochemical films generated from the oil blends containing ME and ZDDP consist mainly of MoS 2 , sulphate and polyphosphate.

Game-SET-match: Pyrrole aminoimidazole alkaloids (PAIs) are metabiosynthesized from chlorinated analogues of oroidin by cell-free enzyme preparations from PAI-producing sponges. Evidence and implications for the biosynthesis of PAIs include putative single-electron transfers (SETs) that promote C-C bond-forming reactions of precursors.

The aim of this study was to investigate the effect of perfusion computed tomography (PCT) with acetazolamide (ACZ) challenge and compare it to 10% carbon dioxide (CO(2)) challenge in rat C6 glioma.PCT was performed on 32 rats, including 20 with orthotopically implanted C6 gliomas and 12 serving as controls. Ten rats with gliomas and six normal rats underwent PCT with ACZ challenge. The other 10 rats with gliomas and six normal rats underwent PCT with 10% CO(2) challenge. The raw data were processed using Philips computed tomographic brain perfusion software. Perfusion parameters before and after the challenge were recorded. Percentage changes due to ACZ administration and 10% CO(2) challenge were calculated. Pearson's correlation coefficients were used to investigate relationships between percentage changes in perfusion parameters and vascular endothelial growth factor and microvessel density.In C6 gliomas, percentage change in cerebral blood flow was significantly different between ACZ (72.73%) and 10% CO(2) (28.47%) challenge (P.01). Percentage change in cerebral blood volume was 37.85% with ACZ and 24.69% with 10% CO(2) challenge (P = .02). In controls, percentage change in cerebral blood flow was significantly different between ACZ (117.42%) and 10% CO(2) (65.86%) challenge (P.01). For percentage change in cerebral blood volume, there was no significant difference between ACZ (107.51%) and 10% CO(2) (92.95%) challenge. Significant correlations were observed among percentage changes in vascular endothelial growth factor, microvessel density, and cerebral blood volume (P.01). Percentage change in cerebral blood flow correlated well with vascular endothelial growth factor.The results of this study indicate that PCT with ACZ challenge is a more reliable technique compared to 10% CO(2) challenge for the quantitative evaluation of microcirculation in gliomas.

A novel cobalt borophosphate, (NH{sub 4}){sub 2}(C{sub 4}H{sub 12}N{sub 2})[Co{sub 2}B{sub 4}P{sub 6}O{sub 24}(OH){sub 2}].H{sub 2}O with the mixed cations has been synthesized under mild hydrothermal conditions. Its crystal structure was determined by the single-crystal X-ray diffraction (tetragonal, I4{sub 1}/a (no. 88), a=14.207(3) A, c=24.956(6) A, V=5037.09(2) A{sup 3}, Z=8). The crystal structure consists of a new type of three-dimensional borophosphatic anionic partial framework, which is built from the condensation of the fundamental building unit (FBU) [B{sub 2}P{sub 3}O{sub 14}(OH)]. The CoO{sub 6} octahedra are enchased in such borophosphate network to form a complex open framework with a three-dimensional intersecting channel system, the voids of which are occupied by ammonium, dipronated piperazine ions and water molecules, respectively. The magnetic measurement of the title compound has also been investigated. - Graphical abstract: A new organically-templated cobalt borophosphate, (NH{sub 4}){sub 2}(C{sub 4}H{sub 12}N{sub 2})[Co{sub 2}B{sub 4}P{sub 6}O{sub 24}(OH){sub 2}].H{sub 2}O with a novel borophosphate 3D anionic partial framework has been synthesized under mild hydrothermal conditions. Highlights: > The first cobalt borophosphate with the 3D anionic partial borophosphate network. > A porous framework with an intersecting three-dimensional channel system. > The borophosphate compound with the mixed cations.

A water-in-oil microemulsion made up of a cyclohexane/n-hexyl alcohol/Polyethylene glycol tertoctylphenyl/aqueous solution including Bi3+ and VO3+ ions yields the spherical BiVO4 precursors with the size from 5 to 300 nm. Well-crystallized monoclinic scheelite BiVO4 particles with nanometer or micrometer size are fabricated in control by heating microemulsion precursors under various temperatures. The corresponding nucleation and growth process of as-prepared samples has also been investigated via TEM, which demonstrates the detailed morphological evolution of nuclei inside the precursors. As-prepared BiVO4 photocatalysts exhibit enhanced photocatalytic activity under visible-light irradiation in comparison with the bulk BiVO4 prepared by solid-state reaction. The highest RB degrading efficiency of 98% in 180 min under visible-light irradiation is observed for the sample calcined at 600 °C.

Catalytic asymmetric synthesis of various cyclic α-alkyl-amino acid derivatives having a tetrasubstituted α-carbon, such as α-alkylprolines has been accomplished by asymmetric phase-transfer C-alkylation of α-alkyl-amino acid derivatives and subsequent intramolecular N-alkylation.

The high-temperature coal tar sample was separated into 10 narrow oil fractions and one solid-phase pitch product by supercritical fluid extraction and fractionation using n -pentane as solvent at 220°C and pressure from 5 to 15 MPa. Results show that the accumulative yields increase with the extract pressure especially at the lower pressures, and the yield increase rate decrease gradually. The total yield of the oil extract is 78.36%, and the raffinate pitch yield is 21.64%, which is far below that of the conventional distillation. Elemental analysis and chromatograph-mass spectrometer analysis show that with the increase of the extraction pressure, the atomic ratio of carbon to hydrogen, the average ring numbers, as well as the average molecular weight of narrow oil fractions also increase gradually.

Numerous marine-derived pyrrole-imidazole alkaloids (PIAs), ostensibly derived from the simple precursor oroidin, 1a, have been reported and have garnered intense synthetic interest due to their complex structures and in some cases biological activity; however very little is known regarding their biosynthesis. We describe a concise synthesis of 7-(15)N-oroidin (1d) from urocanic acid and a direct method for measurement of (15)N incorporation by pulse labeling and analysis by 1D (1)H-(15)N HSQC NMR and FTMS. Using a mock pulse labeling experiment, we estimate the limit of detection (LOD) for incorporation of newly biosynthesized PIA by 1D (1)H-(15)N HSQC to be 0.96 microg equivalent of (15)N-oroidin (2.4 nmole) in a background of 1500 microg of unlabeled oroidin (about 1 part per 1600). 7-(15)N-Oroidin will find utility in biosynthetic feeding experiments with live sponges to provide direct information to clarify the pathways leading to more complex pyrrole-imidazole alkaloids.

The silica-alumina-pillared montmorillonite materials (SiAl-MMT) were developed by a novel method, which combined several techniques such as ion-exchange, intercalation and surfactant modification. The morphology, composite structure and pore properties of such composite materials, were investigated by X-ray powder diffraction (XRD), Scanning Electronic Microscopy (SEM), Fourier-transform infra-red (FTIR) spectra, as well as Nitrogen Adsorption-Desorption Isotherms. The layer structure of the prepared materials retained and their pore structures were found to be slit-shaped pores located between plate-like particles. The prepared SiAl-MMT materials had a BJH pore volume of 0.63cm3 g-1, a remarkably high BET specific surface area beyond 1000 m2 g-1, and a narrow pore size distribution in the mesoporous region 3.5-4 nm after thermal treatment at 600 °C.

The theoretical and experimental feasibility of direct conversion of CH4 and CO2 to acetic acid by an isothermal step-wise route over Pd/SiO2 and Rh/SiO2 catalysts was investigated. The methyl radical formation from CH4 dissociation and CO2 inserting into the intermediate are regarded as two limiting steps. Preliminary experimental results have shown that the following step-wise route can circumvent the thermodynamic limitation of this direct synthesis at low temperatures. Pd catalysts are more active than Rh catalysts at 170 °C and 200 °C, while formic acid is only produced on Pd catalysts. The optimum contact time of CH4 and CO2 with catalysts is 1 min under the experimental conditions. And there is no apparent deactivation resulting from carbon deposition for catalysts during the successive reaction cycles.

A vinyl group as an acetic acid side chain was attached to the optically active monoacetate of 4-cyclopentene-1,3-diol with CH2 CHMgBr, LiCl, and a CuCN catalyst to produce the SN2-type product, from which the full carbon skeleton of tuberonic acid was constructed through Mitsunobu inversion, Claisen rearrangement, and Wittig reaction. At the last stage, the THP protective group was removed with MgBr2 in Et2O. The diastereomeric ratio of tuberonic acid and the trans isomer was 92:8 by 1H NMR spectroscopy.

Survivin is known to be essential for cell division and to inhibit apoptosis during embryonic development and in adult cancerous tissues. However, the cardiovascular role of survivin is unknown. We observed that in cardiomyocytes cultured under conditions of serum and glucose deprivation (DEPV), the levels of survivin, Bcl-2 and extracellular signal-regulated kinase (ERK) were positively correlated with the anti-apoptotic action of a δ-opioid receptor agonist, [D-Ala2, D-Leu5]-enkephalin acetate (DADLE). By contrast, Bax translocation, mitochondrial membrane damage and reactive oxygen species (ROS) production were inversely correlated with the changes of survivin and Bcl-2. The use of RNA interference (RNAi) targeting survivin increased DEPV-induced cardiomyocyte apoptosis, whereas the anti-apoptotic effect of DADLE was blunted by survivin RNAi. Moreover, survivin transfection and overexpression provided protection against DEPV-induced cardiomyocyte apoptosis. Inhibition of ERK prevented the DADLE-induced decrease in apoptosis and Bax translocation, and increase in survivin and Bcl-2. DADLE-induced increase in survivin was also blunted by phosphoinositol 3-kinase (PI 3-kinase) inhibition. In conclusion, the present study provides the first direct evidence of an anti-apoptotic role of survivin mediating the anti-apoptotic effect of δ-opioid receptor activation in cardiomyocytes. ERK and PI 3-kinase were found to be upstream regulators of survivin. Mitochondrial membranes as well as ROS, Bcl-2 and Bax were also involved in this anti-apoptotic action.

Chiral phase transfer catalysts (S)-1a and (S)-1b with a conformationally fixed biphenyl core were conveniently prepared from the known (S)-6,6‘-dimethylbiphenyl-2,2‘-diol 2 in five steps. These catalysts, (S)-1a and (S)-1b, are readily applicable to asymmetric alkylation of glycine derivatives with excellent enantioselectivity. In particular, catalyst (S)-1b was found to exhibit a unique temperature effect on the enantioselectivity, and asymmetric alkylation of glycine derivatives at room temperature gave a higher ee than that at 0 °C.

Da-Cheng-Qi decoction (DCQD) is composed of dahuang, houpu, zhishi and mangxiao, while Xiao-Cheng-Qi decoction (XCQD) just contains dahuang, houpu, and zhishi. A validated high-performance liquid chromatographic (HPLC) method was developed for the determination and pharmacokinetic comparison of rhein in rats. It was performed on a reversed-phase C(18) column (150 x 4.6 mm) with a mobile phase of methanol and 0.2% acetic acid (89:11, v/v) and ultraviolet detection at 254 nm. The assay was linear over the range 30-3000 ng/mL (r(2) = 0.9991), with mean percentage recovery of 101.4%. The RSD of intra- and inter-day precision were less than 3.0%, with accuracy in the range 96.8-102.5% for each of the concentrations tested. Following oral administration, rhein plasma levels revealed curves characterized by peaks at 20.5 and 30.1 min corresponding to dosages of 15 mg/kg (XCQD) and 20 mg/kg (DCQD) at mean concentrations of 1184.67 and 1814.27 ng/mL, respectively. The half-lives of rhein from XCQD and DCQD were 45.3 and 139.6 min, respectively. AUC(0-12h) of rhein after oral dosage with XCQD and DCQD were 3435.68 and 5382.25 microg/L h, respectively. The pharmacokinetic parameters may be used to guide the clinical prescription compatibility of traditional Chinese prescriptions related to dahuang and mangxiao.

We have demonstrated a self-staring passively continuous-wave mode-locked diode end-pumped Nd:YLF laser with a semiconductor saturable absorber mirror of single-quantum-well (In0.25Ga0.75 As) grown by metal-organic chemical-vapor deposition technique at low temperature. The saturable absorber was used as nonlinear absorber and output coupler simultaneously. Stable pulse duration of 3 ps has been achieved at the repetition rate of 98 MHz. The average output power was 530 mW at 1053 nm under the incident pump power of 10 W, corresponding to the peak power of 1.8 kW and pulse energy of 5.4 nJ

[reaction: see text] Because of the lack of potency binding to the receptors responsible for psychoactivity, cannabidiol has received much attention as a lead compound to develop a nonpsychotropic drug. Herein, we establish a method to access not only cannabidiol but also its analogues. The key reaction is nickel-catalyzed allylation of 2-cyclohexene-1,4-diol monoacetate with a new reagent, (alkenyl)ZnCl/TMEDA, which gives a S(N)2-type product with 94% regioselectivity in good yield.

Disubstituted cyclopentene was prepared from cyclopentene monoacetate and transferred into disubstituted piperidine via oxidative cleavage of the olefin moiety followed by piperidine ring formation. The piperidine was then condensed at the side chain with a quinoline part to afford the olefin precursor of quinine. Finally, the olefin was converted into quinine through the corresponding epoxide. Quinidine was synthesized in a similar way.

Dihydroxylation of 4-aryl-1-azido-2-cyclopentenes 6, in which an aryl group is used as a synthetic equivalent of CH(2)OH, was studied to improve the low to moderate stereoselectivity previously reported for cyclopentenes 3 possessing CH(2)X and nitrogen atom-containing groups. 2-Furyl, Ph, and p-MeOC(6)H(4) groups were chosen as the aryl groups. Compounds 6a-c possessing such aryl groups were prepared by CuCN-catalyzed reaction between 2-cyclopentene-1,4-diol monoacetate 9 and the corresponding Grignard reagents followed by substitution of the hydroxyl group with (PhO)(2)P(=O)N(3). The desired diols 7a-c were obtained with higher selectivities of7:1 when dihydroxylation of 6a-c was carried out at 0 degrees C with OsO(4) (catalyst) and NMO in a mixed solvent of MeCN, THF, t-BuOH, and H(2)O. Among them, the furyl compound recorded the highest selectivity of 14:1. The furyl and azido groups on diol 7a were converted into hydroymethyl and adeninyl groups, respectively, to produce acetonide 2, which upon hydrolysis affords aristeromycin 1.

[reaction: see text] Addition of magnesium anion 4 (M = MgBr, R(1) = TES) to ketone 6 (R(2) = PMB) at -78 degrees C in THF proceeded under chelation control to provide alcohol 7, which possesses the full set of the chiral centers of fostriecin. Subsequently, 7 was transformed successfully to the known key intermediate 2.

Macrosphelide L has been isolated from a strain of Periconia byssoides originally separated from the sea hare Aplysia kurodai, and the absolute stereostructures of this material and macrosphelide H, previously undetermined, have been elucidated on the basis of spectroscopic analyses using 1D and 2D NMR techniques and some chemical transformation. (R)-Methyl 3-p-bromobenzoyloxy-5-oxohexanoate has been synthesized for configurational assignments of macrosphelide H. These macrosphelides inhibited the adhesion of human-leukemia HL-60 cells to HUVEC.

Catalytic asymmetric synthesis of various cyclic alpha-alkyl-amino acid derivatives having a tetrasubstituted alpha-carbon has been accomplished by the utilization of phase-transfer alkylation of alpha-alkyl-amino acid derivatives.

An enantioselective organocatalytic, one-pot synthesis of pyrrolidine, hexahydropyrrolizine, and octahydroindolizine core structures was realized starting from readily available glycine esters by combination with several different organocatalytic reactions.

The title compound, C18H23N2+·I3−, was obtained from the reaction of trans-4-[p-(N,N-diethyl­amino)­styryl]–N-methyl­pyridinium iodide (DEASPI) and 12-tungstophosphate (H3PW12O40) in ethanol. The compound contains the highly π-conjugated cation C18H23N2+, in which the pyridyl ring makes a dihedral angle of 4.14 (3)° with the benzene ring. The I3− counter-ion is roughly linear [I—I—I = 177.50 (2)°] and the I—I distances are 2.9478 (8) and 2.8849 (8) A. Adjacent I3− anions are connected into I62− dimers via an I⋯I contact of 3.852 (8) A, much shorter than the sum of the van der Waals radii of 4.30 A.

A practical anodic and cathodic curve intersection model, which consisted of an apparent anodic curve and an imaginary cathodic line, was proposed to explain multiple corrosion potentials occurred in potentiodynamic polarization curves of Fe-based glassy alloys in alkaline solution. The apparent anodic curve was selected from the measured anodic curves. The imaginary cathodic line was obtained by linearly fitting the differences of anodic curves and can be moved evenly or rotated to predict the number and value of corrosion potentials.

De novo synthesis of the natural products benzosceptrin C (7) and nagelamide H (8) was achieved using cell-free enzyme preparations from the marine sponges Agelas sceptrum and Stylissa caribica employing synthetic 7-(15)N-oroidin. These studies provide direct experimental evidence to support the long-standing, but untested, hypothesis that oroidin is a precursor to more complex pyrrole-aminoimidazole alkaloids, such as the sceptrins, benzosceptrins, and nagelamides. In addition, a new nagelamide, didebromonagelamide A (5b), was isolated from S. caribica, representing the first report of a nagelamide-like compound from the Caribbean.

(NH4)2(C4H12N2) [Co2B4P6O14(OH)2] ·H2O is hydrothermally synthesized from a mixture of CoO, NH4HB4O7, piperazine, H3PO4, and H2O (autoclave, 473 K, 5 d).

A sequence of asymmetric phase-transfer-catalyzed C-alkylation and subsequent intramolecular N-alkylation reaction is used to synthesize cyclic α-amino acid derivatives having a quaternary all-carbon stereocenter, e.g. (III), (V), (VII), (IX) and (XI), in up to 99% optical purity.

epi-Jasmonic acid (epi-JA) and tuberonic acid (TA) were synthesized from the key aldehyde, all cis-2-(2-hydroxy-5-vinylcyclopentyl)acetaldehyde (14), which was in turn prepared stereoselectively from the (1R)-acetate of 4-cyclopentene-1,3-diol (10) through S(N)2-type allylic substitution with CH(2)[double bond, length as m-dash]CHMgBr followed by Mitsunobu inversion, Eschenmoser-Claisen rearrangement, and regioselective Swern oxidation of the corresponding bis-TES ether (13). Wittig reaction of the aldehyde 14 with [Ph(3)P(CH(2))Me](+)Br(-) followed by oxidation afforded epi-JA (3) stereoselectivity over the trans isomer. Similarly, TA (5) was synthesized. Furthermore, the above findings were applied successfully to improve the total efficiency of the previous synthesis of 12-oxo-PDA (1).

A compound with furyl and vinyl groups was designed as an intermediate for synthesis of macrosphelide H. The furyl group was oxidatively transformed into the key C(5)–O(10) part by a two-step conversion of (1) NBS, H2O; (2) NaClO2 without affecting the free hydroxyl group at C(3), thus furnishing the seco acid, while the Wacker oxidation at the final step was used to convert the vinyl group into acetyl group to afford macrosphelide H. This strategy was applied successfully to synthesis of macrosphelide G as well.

Hydrogen sulfide (H2S) is an endogenously generated gaseous transmitter, which has recently been suggested to regulate cardiovascular functions. The present study aims to clarify the mechanisms underlying the cardioprotective effects of H2S. Signaling elements were examined in cardiomyocytes cultured under hypoxia/reoxygenation conditions and in a rat model of ischemia-reperfusion. In cultured cardiomyocytes, sodium hydrosulfide (NaHS; 10, 30, and 50 μmol/l) showed concentration-dependent inhibitory effects on cardiomyocyte apoptosis induced by hypoxia/reoxygenation. These effects were associated with an increase in phosphorylation of glycogen synthase kinase-3β (GSK-3β) (Ser9) and a decrease in Bax translocation, caspase-3 activation, and mitochondrial permeability transition pore (mPTP) opening. Transfection of a phosphorylation-resistant mutant of GSK-3β at Ser9 attenuated the effects of NaHS in reducing cardiomyocyte apoptosis, Bax translocation, caspase-3 activation, and mPTP opening. In a rat model of ischemia-reperfusion, NaHS administration reduced myocardial infarct size and increased the phosphorylation of GSK-3β (Ser9) at a dose of 30 μmol/kg. In conclusion, the H2S donor prevents cardiomyocyte apoptosis by inducing phosphorylation of GSK-3β (Ser9) and subsequent inhibition of mPTP opening.

Monoclinic structured spindly bismuth vanadate microtubes were fabricated on a large scale by a simple ionothermal treatment in the environment-friendly green solvent of urea/choline chloride. The as-prepared samples were characterized by XRD, SEM, TEM, IR and their photocatalytic activity was evaluated by photocatalytic decolorization of rhodamine B aqueous solution under visible-light irradiation. As-obtained BiVO(4) microtubes exhibit the spindly shape with a side length of ca. 800 nm and a wall thickness of ca. 100 nm. The opening of these microtubes presents a saw-toothed structure, which is seldom in other tube-shaped materials. The formation mechanism of the spindly microtubes is ascribed to the complex cooperation of the reaction-crystallization process controlled by BiOCl and the nucleation-growth process of nanosheets induced by solvent molecules attached on the surface of microtubes. Such spindly microtubes exhibit much higher visible-light photocatalytic activity than that of bulk BiVO(4) prepared by solid-state reaction, possibly resulting from their large surface area and improved crystallinity.

Catalytic asymmetric synthesis of various cyclic α-alkyl-amino acid derivatives having a tetrasubstituted α-carbon has been accomplished by the utilization of phase-transfer alkylation of α-alkyl-amino acid derivatives.

Edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one), a newly developed hydroxy radical scavaging agent which has been widely used for protection against ischemia-reperfusion injury is highly effective in preventing cell apoptosis. However, the exact intracellular mechanism(s) underlying the protective action of edaravone is not clear. We observed that in PC12 cells cultured under serum deprivation (DEPV) condition, the levels of survivin were positively correlated with the anti-apoptotic action of edaravone. Survivin RNA interference (RNAi) increased DEPV-induced PC12 cell apoptosis, whereas the anti-apoptotic effect of edaravone was blunted by survivin RNAi. Moreover, survivin overexpression provided protection against DEPV-induced PC12 cell apoptosis. Inhibition of ERK and PI(3)-K/AKT prevented edaravone's ability to decrease apoptosis and increase survivin. In conclusion, the present study provides the first direct evidence that survivin involves in the anti-apoptotic effects of edaravone via a pathway involving ERK and PI(3)-K/AKT.

Chiral phase-transfer catalysts (S)-1a, (S)-1b, and (S)-2 with conformationally fixed biphenyl cores were conveniently prepared from the known, easily available (S)-6,6′-dimethylbiphenyl-2,2′-diol 3 and (S)-4,5,6,4′,5′,6′-hexamethoxybiphenyl-2,2′-dicarboxylic acid 14, respectively, in five steps. The catalysts, (S)-1a and (S)-1b are readily applicable to asymmetric alkylation of N-(diphenylmethylene)glycine tert-butyl ester with excellent enantioselectivity. In particular, catalyst (S)-1b was found to exhibit the unique temperature effect on the enantioselectivity, and asymmetric alkylation of glycine derivatives at room temperature gave higher enantiomeric excess than that at 0 °C. In addition, the catalyst (S)-2 exhibited the high catalytic performance (0.01–1 mol %) in the asymmetric alkylation of N-(diphenylmethylene)glycine tert-butyl ester and N-(p-chlorophenylmethylene)alanine tert-butyl ester compared to the existing chiral phase-transfer catalysts, thereby allowing to realize a general and useful procedure for highly practical enantioselective synthesis of structurally diverse natural and unnatural α-alkyl-α-amino acids as well as α,α-dialkyl-α-amino acids. This approach is successfully applied to the short asymmetric synthesis of cell adhesion BIRT-377.

A validated high-performance liquid chromatography (HPLC) method was developed for simultaneous determination and pharmacokinetic study of aloe emodin and chrysophanol in rats. It was performed on a reverse-phase C(18) column and a mobile phase made up of methanol and 0.2% acetic acid (83:17, v/v). The ultraviolet detection was 254 nm. 1,8-dihydroxyanthraquinone was used as the internal standard. The assay was linear over the range 28-2800 ng/mL (r(2) = 0.9993) for aloe emodin and 25.6-2560 ng/mL (r(2) = 0.9991) for chrysophanol. The average percentage recoveries of three spiked plasmas were 98.8-104.8% and 97.7-103.2% for aloe emodin and chrysophanol, respectively. Their RSD of intra-day and inter-day precision at concentrations of 56, 280 and 1400 ng/mL for aloe emodin and 51.6, 258 and 1290 ng/mL for chrysophanol were less than 3.5%. This method was applied for the first time to simultaneously determinate aloe emodin and chrysophanol in rats following oral administration of traditional Chinese medicine of Da-Cheng-Qi decoction. The pharmacokinetic parameters showed that chrysophanol was better absorbed with higher concentrations in plasma than aloe emodin did. They both eliminated slowly in male rats. The assay is suitable for identifying the plasma and tissue levels of aloe emodin and chrysophanol in preclinical investigations.