Production of Multiple Talaroenamines from Penicillium malacosphaerulum via One-Pot/Two-Stage Precursor-Directed Biosynthesis.

Nineteen new talaroenamine derivatives, talaroenamines F1-F19 (1-19), were isolated from the Yellow River wetland derived Penicillium malacosphaerulum HPU-J01 by use of a one-pot/two-stage precursor-directed biosynthesis approach. During this approach, the initial precursor p-methylaniline was first used as a carrier to capture the biologically synthesized cyclohexanedione to produce talaroenamine F, and then the other aniline derivatives were employed to replace the p-methylaniline fragment of talaroenamine F to generate the final products. LC-MS analysis showed that only four compounds (2, 8, 10, and 12) could be produced by the traditional precursor-directed biosynthesis in which the aniline precursors were added simultaneously. Compound 14 was cytotoxic against the K562 cell line with an IC50 value of 2.2 µM. This work demonstrated the one-pot/two-stage precursor-directed biosynthesis could improve substrate acceptance leading to the production of diverse talaroenamines.

New aniline derivatives from the volva of Phallus rubrovolvatus and their anti-inflammatory activity.

Phallus rubrovolvatus is an important commercially cultivated mushroom species in China. However, the volva of P. rubrovolvatus usually discarded as a by-product due to the unpleasant flavor and difficulty in processing. In this study, we investigated the chemical constituents and bioactivities of the volva of P. rubrovolvatus. As a result, fifteen rare aniline derivatives, including twelve new compounds (1-11, 14) and three new natural products (12, 13, 15) were isolated from the volva. Their structures were determined using 1D and 2D NMR data and HR-ESI-MS data, while the relative and absolute configurations were confirmed by NOESY correlations and comparison between experimental and calculated ECD spectra. In addition, compounds 1-15 were tested for anti-inflammatory activity against lipopolysaccharide (LPS)-induced NO production in RAW264.7 macrophages. Compounds 4, 9 and 10 exhibited anti-inflammatory activity with IC50 values ranging from 12.5 to 15.6 µM.

An improved preparation of [18 F]AV-45 by simplified solid-phase extraction purification.

Amyvid (florbetapir f18, [18 F]AV-45, [18 F]5) was the first FDA-approved positron emission tomography imaging agent targeting ß-amyloid (Aß) plaques for assisting the diagnosis of Alzheimer disease. This work aimed to improve the [18 F]AV-45 ([18 F]5) preparation by using solid-phase extraction (SPE) purification. [18 F]AV-45 ([18 F]5) was synthesized by direct nucleophilic radiofluorination of O-tosylated precursor (1 mg) at 120°C in anhydrous dimethyl sulfoxide (DMSO), followed by acid hydrolysis of the N-Boc protecting group. Purification was accomplished by loading the crude reaction mixture to a cartridge (Oasis HLB 3 cc) and eluting with different combinations of solvents. This method removed the chemical impurity while leaving [18 F]AV-45 ([18 F]5) on the cartridge. The final dose was eluted by ethanol. [18 F]AV-45 ([18 F]5) was produced within 51 minutes (radiochemical yield 42.7 ± 5.9%, decay corrected, n = 3), and the radiochemical purity was greater than 95%. Total chemical impurity per batch (24.1 ± 2.7 µg per batch) was below the limit described in the package insert of Amyvid, florbetapir f18 (chemical mass: less than 50 µg/dose). In summary, [18 F]AV-45 ([18 F]5) was produced efficiently and reproducibly using a cartridge-based SPE purification. This method brings the process closer for routine preparation, similar to the commercially used [18 F]FDG.

Separation of brombuterol enantiomers in capillary electrophoresis with cyclodextrin-type chiral selectors and investigation of structure of selector-selectand complexes using nuclear magnetic resonance spectroscopy.

The major goal of this study was to determine the affinity pattern of brombuterol (BB) enantiomers toward various cyclodextrins (CD) and to evaluate the potential of NMR spectroscopy for understanding fine mechanisms of interactions between CDs and BB enantiomers. Separation of BB enantiomers was performed in a fused-silica capillary using a phosphate buffer, pH 2.5, at the room temperature in the normal polarity mode. It was shown once again that CE in combination with NMR spectroscopy represents a very sensitive tool for studies of affinity patterns and structure of CD complexes with chiral guests. Although opposite affinity patterns of BB enantiomers were observed toward native ß- and γ-CDs, no significant differences between the structures of the complexes of these two CDs with BB were detected by NMR spectroscopy. In contrary to this, the opposite affinity pattern of BB enantiomers toward ß-CD and its two sulfated derivatives, heptakis (2,3-O-diacetyl-6-sulfo)-ß-CD (HDAS-ß-CD) and heptakis (2-O-methyl-3,6-di-O-sulfo)-ß-CD (HMDS-ß-CD) was associated with major differences in the structure of the complexes. In addition, it was shown again that HMDS-ß-CD provides separation of enantiomers without formation of inclusion-type complex with the chiral analyte.

Aniline-Tetramic Acids from the Deep-Sea-Derived Fungus Cladosporium sphaerospermum L3P3 Cultured with the HDAC Inhibitor SAHA.

Four new tetramic acids, cladosins H-K (1-4), and a related known compound, cladodionen (5), were isolated from the culture of the Mariana Trench (depth 6562 m) sediment-derived fungus Cladosporium sphaerospermum L3P3 treated with the histone deacetylase inhibitor SAHA (suberanilohydroxamic acid). Interestingly, compounds 1-5 existed as equilibrium E/ Z mixtures and 1-4 were the first cases of tetramic acids containing aniline moieties. Their structures including absolute configurations were elucidated through a combination of NMR, MS, and Mosher's method, together with the consideration of biogenetic origins. Incubation experiments of exogenous aniline and N-phenyloctanamide revealed that the aniline moiety in cladosins H-K (1-4) is probably derived from the degradation of SAHA, indicating that the well-known histone deacetylase inhibitor SAHA could be metabolized by L3P3 and provide aniline as a precursor for biotransformation of chemically reactive polyketides. The cytotoxicity of 1-5 was evaluated against the PC-3, MGC-803, SH-SY5Y, HCT-116, K562, and HL-60 cell lines, and compound 2 showed promising cytotoxicity against the HL-60 cell line with an IC50 value of 2.8 µM.

Characterization and application of a lanthanide-based metal-organic framework in the development and validation of a matrix solid-phase dispersion procedure for pesticide extraction on peppers (Capsicum annuum L.) with gas chromatography-mass spectrometry.

The metal-organic framework [(La0.9 Sm0.1 )2 (DPA)3 (H2 O)3 ]∞ was synthetized and characterized by X-ray diffractometry, differential thermogravimetric analysis, and infrared spectroscopy. The material was tested for the development and validation of a matrix solid-phase dispersion procedure for extraction of atrazine, bifenthrin, bromuconazole, clofentezine, fenbuconazole, flumetralin, procymidone, and pirimicarb, from peppers, with analysis using gas chromatography with mass spectrometry in the selected ion monitoring mode. The method developed was linear over the range tested (50.0-1000.0 µg/kg for procymidone and 200.0-1000.0 µg/kg for all other pesticides), with correlation coefficients ranging from 0.9930 to 0.9992. Experiments were carried out at 250.0, 500.0, and 1000.0 µg/kg fortification levels, and resulted in recoveries in the range of 52.7-135.0%, with coefficient of variation values between 5.2 and 5.4%, respectively, for [(La0.9 Sm0.1 )2 (DPA)3 (H2 O)3 ]∞ sorbent. Detection and quantification limits ranged from 16.0 to 67.0 µg/kg and from 50.0 to 200.0 µg/kg, respectively, for the different pesticides studied. The results were compared with literature data. The developed and validated method was applied to real samples. The analysis detected the presence of residues of pesticides procymidone, fenbuconazole, flumetralin, clofentezine, atrazine, and bifenthrin.

Promotion of catalytic ozonation of aniline with Mn-Ce-Ox/γ-Al2O3.

In this study, Mn-Ce-Ox/γ-Al2O3 supported catalysts were adopted to promote the removal efficiency of aniline in simulated wastewater with ozone. Mn-Ce-Ox/γ-Al2O3 catalysts were prepared by the impregnation-calcination method. Its phase structure, specific surface area, loading amount and distribution of active units were analyzed by XRD, BET, ICP-AES and TEM/SEM respectively. The characterization results demonstrated that the catalysts had a good dispersion of Mn-Ce-Ox active sites and an abundant porous structure from the γ-Al2O3 support. The catalytic ozonation results showed that with Mn3-Ce1-Ox/γ-Al2O3(1.0), the aniline removal efficiency was highly improved, 15.0% higher than that of ozonation without a catalyst. Furthermore, from the variation in loading amounts of Mn and Ce, it can be seen that the molar ratio of Mn and Ce within the Mn-Ce-Ox plays a key role in accelerating the ozonation of aniline in simulated wastewater with ozone, while Mn:Ce = 1.9:1 showed the best performance. More importantly, the catalysts showed high recycling performance and could be reused at least 12 times without obvious loss of activity.

Simultaneous extraction and preconcentration of aniline, phenol, and naphthalene using magnetite-graphene oxide composites before gas chromatography determination.

The coextraction of acidic and basic compounds from different mediums is a significant concept in sample preparation. In this work, simultaneous extraction of acidic, basic, and neutral analytes in a single step was carried out for the first time. This procedure employed the dispersive solid-phase microextraction of analytes with magnetic graphene oxide (graphene oxide/Fe3 O4 ) sorbent followed by gas chromatography with flame ionization detection. After the adsorption of analytes by vortexing and decantation of the supernatant with a magnet, the sorbent was eluted with acetonitrile/methanol (2:1) mixture. The parameters affecting the extraction efficiency were optimized and obtained as follows: sorbent amount 60 mg, desorption time 1 min, extraction time 5 min, pH of the sample 7, sample volume 20 mL, and elution solvent volume 0.3 mL. Under the optimum conditions, linear dynamic ranges were achieved in the range of 0.5-4, 0.25-4, and 0.25-2 µg/mL and limits of detection were 0.341, 0.110, and 0.167 µg/mL for aniline, phenol, and naphthalene, respectively. The relative standard deviations were in the range of 3.3-5.7% in eight repeated extractions. Finally, the applicability of the method was evaluated by the extraction and determination of analytes in stream water and drinking water samples and satisfactory results were obtained.

Optimization of hydraulic shear parameters and reactor configuration in the aerobic granular sludge process.

The hydraulic shear acts as an important selection pressure in aerobic sludge granulation. The effects of the hydraulic shear rate and reactor configuration on structural characteristics of aerobic granule in view of the hydromechanics. The hydraulic shear analysis was proposed to overcome the limitation of using superficial gas velocity (SGV) to express the hydraulic shear stress. Results showed that the stronger hydraulic shear stress with SGV above 2.4 cm s(-1) promoted the microbial aggregation, and favoured the structural stability of the granular sludge. According to the hydraulic shear analysis, the total shear rate reached (0.56-2.31)×10(5) s(-1) in the granular reactor with a larger ratio of height to diameter (H/D), and was higher than that in the reactor with smaller H/D, where the sequencing airlift bioreactor with smaller H/D had a high total shear rate under the same SGV. Results demonstrated that the granular reactor could provide a stronger hydraulic shear stress which promotes the formation and structural stability of aerobic granules.

Rapid removal of aniline from contaminated water by a novel polymeric adsorbent.

Dummy molecularly imprinted polymers (DMIPs) for aniline were synthesized by a thermal polymerization method using acrylamide as a functional monomer, ethylene dimethacrylate as a crosslinker, 2,2-azobisisobutyronitrile as a free radical initiator, acetonitrile as a porogenic solvent, and analogues of aniline, namely sulfadiazine, as the template. The DMIPs that were obtained showed a high affinity to aniline compared to non-imprinted polymers. It was proven that the DMIPs obtained using sulfadiazine as the template were much better than the molecularly imprinted polymers using aniline as the template. The results indicated that the Freundlich model was fit for the adsorption model of DMIP for aniline and the adsorption model of the DMIP for aniline was multilayer adsorption. Furthermore, the results showed that the DMIP synthesized by bulk polymerization could be used as a novel adsorbent for removal of aniline from contaminated water.

The performance of enhanced coagulation for treating slightly polluted raw water combining polyaluminum chloride with variable charge soil.

The feasibility and effectiveness of treating pollutants in slightly polluted raw water by variable charge soil and polyaluminum chloride (PAC) was investigated. Removal efficiencies of turbidity, phenol, aniline, algae and heavy metals (Cu(2+), Zn(2+) and Pb(2+)) were used to evaluate the coagulation performance. The results indicated that the addition of variable charge soil as a coagulant aid is advantageous due to the improvement of removal efficiencies. The tests also demonstrated that the presence of variable charge soil increased the removal of turbidity rather than adding residuary turbidity. The use of variable charge soil produced settleable flocs of greater density and bigger size. The main mechanism involved in the PAC coagulation was supposed to be sweep flocculation as well as charge-neutralization. Variable charge soil played a promoted aid role by adsorption in the enhanced coagulation process. It is concluded that the enhanced coagulation by PAC and variable charge soil, as coagulant and adsorbent, is more effective and efficient than traditional coagulation.

A new antibacterial amino phenyl pyrrolidone derivative from a novel marine gliding bacterium Rapidithrix thailandica.

A recently described marine gliding bacterium Rapidithrix thailandica strain TISTR 1741 was isolated from biofilm specimen collected from the Andaman Sea in Thailand. Four liters fermentation broth of R. thailandica TISTR 1741 cultivated in VY/2 medium were extracted with methanol to yield a novel amino phenyl pyrrolidone derivative compound (1) with antibacterial activities. The chemical structure and physico-chemical properties of 1 were investigated by spectrometry techniques. Compound 1 exhibited selective inhibition against vancomycin-resistant Enterococcus faecalis (VRE) with the MIC of 5.97 mM.

Polyamide nanofiltration membranes to remove aniline in aqueous solutions.

Aniline is commonly used in a number of industrial processes. It is known to be a harmful and persistent pollutant and its presence in wastewater requires treatment before disposal. In this paper, the effectiveness of nanofiltration (NF) to remove aniline from aqueous solutions is studied in a flat membrane test module using two thin-layer composite membranes of polyamide (NF97 and NF99HF). The influence of different operational variables (applied pressure, feed concentration and pH) on the removal of aniline from synthetic aqueous solutions was analysed. The experimental NF results are compared with results previously obtained by reverse osmosis. Based on this comparative study, the effective order for aniline rejection is: HR98PP > NF97 > DESAL3B > SEPA-MS05 > NF99HF.

Sensitive determination of chloroanilines in water samples by hollow fiber-based liquid-phase microextraction prior to capillary electrophoresis with amperometric detection.

A hollow fiber-based liquid-phase microextraction method has been developed for enrichment of trace chloroanilines in water samples. Target analytes including aniline, three mono-chlorinated aniline isomers (o-chloroaniline, m-chloroaniline, and p-chloroaniline) and four mono-chlorinated methylaniline isomers (2-chloro-4-methylaniline, 3-chloro-4-methylaniline, 4-chloro-2-methylaniline, and 5-chloro-2-methylaniline) were determined by CE with amperometric detection after microextraction. Several factors that affect separation, detection, and extraction efficiency were investigated. Under the optimum conditions, eight aniline compounds could be well separated from other components coexisting in water samples within 25 min, exhibiting a linear calibration over three orders of magnitude (r > 0.998); the obtained enrichment factors were between 51 and 239, and the LODs were in the range of 0.01-0.1 ng/mL. The proposed method has been applied for the analyses of real environmental water and sewage samples with relative recoveries in the range of 83-108%.

Application of ultraviolet, ozone, and advanced oxidation treatments to washwaters to destroy nitrosamines, nitramines, amines, and aldehydes formed during amine-based carbon capture.

Although amine-based CO(2) absorption is a leading contender for full-scale postcombustion CO(2) capture at power plants, concerns have been raised about the potential release of carcinogenic N-nitrosamines and N-nitramines formed by reaction of exhaust gas NO(x) with the amines. Experiments with a laboratory-scale pilot unit suggested that washwater units meant to scrub contaminants from absorber unit exhaust could potentially serve as a source of N-nitrosamines via reactions of residual NO(x) with amines accumulating in the washwater. Dosage requirements for the continuous treatment of the washwater recycle line with ultraviolet (UV) light for destruction of N-nitrosamines and N-nitramines, and with ozone or hydroxyl radical-based advanced oxidation processes (AOPs) for destruction of amines and aldehydes, were evaluated. Although <1000 mJ/cm(2) UV fluence was generally needed for 90% removal of a series of model N-nitrosamines and N-nitramines, 280-1000 mJ/cm(2) average fluence was needed for 90% removal of total N-nitrosamines in pilot washwaters associated with two different solvents. While AOPs were somewhat more efficient than ozone for acetaldehyde destruction, ozone was more efficient for amine destruction. Ozone achieved 90% amine removal in washwaters at 5-12 molar excess of ozone, indicating transferred dosage levels of ∼100 mg/L for 90% removal in a first-stage washwater unit, but likely only ∼10 mg/L if applied to a second-stage washwater. Accurate dosage and cost estimates would require pilot testing to capture synergies between UV and ozone treatments.

Separation optimization of aniline and seven 4-substituted anilines in high-submicellar liquid chromatography using empirical retention modeling and Derringer's desirability function.

The separation optimization of aniline and seven 4-substituted derivatives in high-submicellar LC was performed using an interpretive optimization strategy and Derringer's desirability function. Description of the retention of solutes was carried out through several hyperbolic and logarithmic retention models using the retention data of five mobile phases of SDS (0.06-0.12 M) and methanol (50-70% v/v) at pH 3. Among the investigated models, a logarithmic retention model logk=c0+c1φ+c2[S]+c12φ[S]+d12(φ[S])0.5 showed the best prediction capability and was used to predict the solute retention factors. A grid search program was used to calculate the retention times of each solute, based on the best retention model, for all combinations of SDS and methanol concentrations in the factor space. Two different chromatographic goals, analysis time and retention differences between adjacent peaks, were evaluated simultaneously using Derringer's desirability function for each mobile phase conditions in the grid search. Optimal mobile phase composition for separation of eight anilines was found to be 0.119 M SDS and 53% v/v methanol. Under these conditions, full resolutions with a reasonable analysis time (22 min) were obtained. At the optimal condition, a good agreement was observed between predicted and experimental values of the retention times.

Simulation of the chromatographic separation process in HPLC employing suspended-state NMR spectroscopy - comparison of interaction behavior for monomeric and hydride-modified C18 stationary phases.

The interactions of different analytes with monomeric and hydride-modified stationary phases have been investigated employing suspended-state NMR spectroscopy. The suspended-state high-resolution/magic-angle-spinning (1)H-NMR spectrum of an analyte in the presence of C(18) SP material shows a splitting into two sets of signals for the analyte molecule. One state reflects a closer interaction between analyte and C(18) -modified surface that results in an upfield shift and broader signal half-widths. This phenomenon suggests that the analyte exists in two environments. We report a systematic approach upon the investigation on the interaction in the interface of analyte, mobile phase, and modified silica through synthesis of differently modified silica with a gradual increase in surface coverage. The determination of the signal half-widths and chemical shifts revealed a relationship between the modification technique of the C(18) SPs and the chromatographic and NMR spectroscopic behavior. Increasing ligand density results in higher shielding of the NMR signals for the analyte in the "adsorbed" state. The measurement of spin-lattice relaxation times T(1) of the analyte molecule correlate NMR parameter together with separation behavior in HPLC. Furthermore, suspended-state and solid-state NMR measurements revealed different alkyl chain mobilities for the monomeric and hydride-modified SPs.

Removal of aniline and phenol from water using raw and aluminum hydroxide-modified diatomite.

The feasibility of using raw diatomite and aluminum hydroxide-modified diatomite (Al-diatomite) for removal of aniline and phenol from water was investigated. Their physicochemical characteristics such as pHsolution, point of zero charge (pHPZC), surface area, Fourier transform infrared (FT-IR) and scanning electron microscopy was determined. After the raw diatomite was modified, the surface area of Al-diatomite increases from 26.67 to 82.65 m(2) g(-1). The pHPZC and pHsolution (10%) occurred around pH 5.2 and pH 8.6, respectively. The removal rates of aniline and phenol on diatomite and Al-diatomite decreased with increasing solution pH, while surface charge density decreased. The adsorption of aniline and phenol on diatomite presented a good fit to the Langmuir and Freundlich models, but the models are not fit to forecast the adsorption of aniline and phenol on Al-diatomite. The study indicated that electrostatic interaction was a dominating mechanism of aniline and phenol sorption onto Al-diatomite.

Adsorption of chloro-anilines from solution by modified peanut husk in fixed-bed column.

Natural peanut husk (NPH) modified with hexadecyl trimethyl ammonium bromide (CTAB) was used as adsorbent to remove 2,5-dimethoxy-4-chloroaniline (DMCH) from solution in a fixed-bed column. Fourier transform infrared spectroscopy analysis and X-ray fluorescence of NPH and modified peanut husk (MPH) showed that CTAB had been introduced onto the surface of NPH. The effects of flow rate and bed depth on breakthrough curves were studied. The Thomas model and the Yan model were selected to fit the column adsorption data and the results showed that the Yan model was better at predicting the breakthrough curves. The adsorption quantity was up to 6.46 mg/g according to the Yan model. The bed depth service time model was used to calculate the critical bed depth from experimental data and it was directly related to flow rate. As a low-cost adsorbent, MPH is promising for the removal of DMCH from solution.

Preparation and application of hydrophobic hybrid monolithic columns containing polyhedral oligomeric silsesquioxanes for capillary electrochromatography.

Hydrophobic organic-inorganic hybrid monolithic columns were synthesized via thermally initiated free radical polymerization with the confines of 75 µm id capillary using a polyhedral oligomeric silsesquioxane (POSS) reagent containing eight or more methacrylate groups as the crosslinker. Three organic functional monomers, butyl methacrylate (BuMA), lauryl methacrylate (LMA) and methacrylic acid (MAA), were selected and copolymerized with the POSS in the presence of 1-propanol and 1,4-butanediol to prepare the poly(POSS-co-BuMA), poly(POSS-co-LMA), and poly(POSS-co-MAA) monoliths, respectively. The 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) was copolymerized as ionizable monomer into the poly(POSS-co-BuMA) and poly(POSS-co-LMA) for the generation of EOF in capillary electrochromatography (CEC). A hybrid poly(POSS-co-LMA-co-MAA) monolith was also similarly prepared by copolymerizing ternary monomers of POSS, LMA, and MAA, and compared with poly(POSS-co-BuMA), poly(POSS-co-LMA), and poly(POSS-co-MAA) monoliths. The resulting four kinds of POSS-contained hybrid monoliths exhibited good permeability and mechanical stability. Their column efficiencies were evaluated by the separation of alkylbenzene homologues and polar compounds in CEC. The results indicated that the highest efficiencies of 194,100 and 102,100 theoretical plates per meter for thiourea and benzene were obtained on the poly(POSS-co-LMA-co-MAA) monolith. Additionally, the poly(POSS-co-LMA-co-MAA) monolith exhibited better selectivity for separation of polar compounds than those of other hybrid monoliths.