Nuclear Magnetic Resonance Analysis Research Articles

Up-converted white light emission in Er3+ doped MgAl2O4 nanocrystals

This work presents the influence of host defect centers on the photoluminescence characteristics of Mg1−xErxAl2O4 (x = 0.005, 0.01, and 0.03) nanocrystals under UV and near-infrared (NIR) excitations. The spinel-structured nanocrystals are synthesized through the combustion method. The Rietveld refinement and nuclear magnetic resonance analyses estimated the Er3+ ion occupancy at octahedral and other random sites of the MgAl2O4 lattice, and the existence of various lattice defects. Diffuse reflectance spectra showed broad bands attributed to oxygen vacancies as well as antisite defects and sharp peaks attributed to f–f transitions of Er3+ ions. The upconversion luminescence spectra consisted of sharp emission lines, ascribed to Er3+ ions, in the green and red wavelength regions, which overlapped over the broad curve attributed to intrinsic defects. Further, the UV excited downconversion luminescence spectra showed two broad emission bands in blue–violet and red-NIR regions with a very weak Er3+ ion emission feature. This up- and downconversion emission revealed energy transfer between host and Er3+ ions via intrinsic defects. As a result, the emission color changes from bluish purple to white by varying the excitation wavelength from UV to NIR. This rare earth activated luminescence from MgAl2O4 nanocrystals would exhibit potential applications in display devices and solid-state lighting.

Density, viscosity, excess properties, and intermolecular interaction of propylene glycol methyl ether + 1,2-propylenediamine binary system

In this work, the systematic measurements of physicochemical properties, viz., density (ρ) and viscosity (η) values of propylene glycol methyl ether (PGME) + 1,2-propylenediamine (1,2-PDA) binary system, including pure substances, over the entire mole fraction range at the temperatures of T/K = (298.15 to 318.15) under atmospheric pressure of P = 100.5 kPa. The fundamental data were used to calculate several excess properties, including excess molar volume (VmE), viscosity deviation (Δη), and excess activation Gibbs free energy (ΔG∗E). Meanwhile, the work further investigated the values of thermal expansion coefficient (αp), partial molar volume (V¯) and apparent molar volume (Vφ), thereby offering a comprehensive understanding on non-ideal behavior of the binary system. Furthermore, the variations in ρ values with various molar ratios and temperatures were evaluated through Jouyban-Acree model and nonlinear least squares method. Simultaneously, Grunberg-Nissan model, Eyring-Margules model, Heric model, and McAllister model, were used to fit the dependence of η values on the molar ratio. Arrhenius equation was employed to fit the temperature dependency of η values. In addition, Redlich-Kister (R-K) equation was utilized to fit the VmE, Δη, and ΔG∗E values of binary system. Based on spectral analyses of Raman, ultra-violet (UV), and 1H Nuclear Magnetic Resonance (NMR) and density functional theory (DFT) calculation, the intermolecular hydrogen bond (IHB) of PGME with 1,2-PDA was discussed in depth.

Synthesis of phosphate hydrogels with excellent swelling behavior prepared by ascorbic acid -mediated ARGET ATRP

This manuscript explores the synthesis of hydrogels through reversible deactivation radical polymerization (RDRP) methods, specifically, activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) and Cu0-mediated ATRP. These techniques are known to offer improved control over polymer network structures due to their slow polymerization kinetics. However, these methods have historically been challenging to apply to stimuli-responsive polymers, such as those with acidic or basic moieties. In this study, the direct synthesis of poly(2-(methacryloyloxy) ethyl phosphate) (PMOEP), a phosphate-pendant hydrogel, was investigated in aqueous media by both ascorbic acid (AsA)-mediated ARGET ATRP and Cu0-mediated ATRP. 2-(methacryloyloxy) ethyl phosphate (MOEP) was utilized as the active monomer with tris(2-pyridylmethyl) amine (TPMA) as the ligand. A unique feature of this work is that the diene moiety inherently present in the commercial monomer, bis[2-(methacryloyloxy) ethyl] phosphate (BMOEP), served as the crosslinking agent to obtain the novel PMOEP hydrogel. Formulations were tuned to optimize the swelling characteristics of the hydrogels, with the restriction that the hydrogels should swell homogeneously without fracture. Importantly, using AsA as the reducing agent in the ARGET ATRP reaction resulted in improved homogeneity and enhanced swelling properties of the hydrogel. Furthermore, tuning the target degree of polymerization (Dp) ([monomer]:[initiator]) had a significant impact on swelling characteristics. Specifically, PMOEP hydrogels synthesized via ARGET ATRP with a target Dp of 300 and 1 mM CuII catalyst demonstrated outstanding water absorption capacity of more than 2500% (relative to the dry mass) in phosphate buffer solution (PBS) at pH 7.4 and over 6000% in pure water. The morphology of these hydrogels was imaged using field emission environmental scanning electron microscopy (FE-ESEM) and the chemical composition was examined using Fourier transform infrared (FTIR) spectroscopy. Furthermore, nuclear magnetic resonance (NMR) analysis was performed to investigate the conversion rate of monomer during Cu0-mediated ATRP. To the authors’ knowledge, the synthesis of a 100% phosphate-pendant hydrogel using AsA-mediated ARGET ATRP and an internal phosphodiester crosslinking moiety without dilution or comonomer, has not been reported previously. This facile method for synthesizing and controlling phosphate-based hydrogel properties also provides an opportunity to include additional functional groups and holds significant promise for applications in biomedical engineering, agriculture, and membrane separations.

The Effect of Nonterminal Liquid Crystalline Epoxy Resin Structure and Curing Agents on the Glass Transition of Polymer Networks.

Modern science and technology demand a low glass transition temperature, yet one tailored to specific thermoset needs and specific to individual hardener applications. Two novel, nonterminal liquid crystalline epoxy resins (LCER) were synthesised, with their structures characterized via nuclear magnetic resonance (NMR), mass spectrometry (MS), and elemental analysis. Their liquid crystalline nature and thermal properties were determined using polarized optical microscopy (POM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). A set of seven aromatic amines serving as curing agents was used to perform curing in fourteen different systems in order to assess the glass transition temperature (Tg) of the obtained polymer networks using DSC. The liquid crystalline elastomers were obtained with vitrification occurring in a low temperature range (-10-40 °C), with a more predictable outcome for amines with two aromatic rings in the structure than with one. Moreover, the resin with a core consisting of four aromatic rings produces networks with higher Tg than the three-aromatic resin. The use of nonterminal LCER allowed the lowering of the glass transition temperature of the polymers to more than 70 °C compared to a terminal analogue. This brings new possibilities of designing highly elastic yet cured polymers with potential for use in smart applications due to the LC nature of the resin.

Light emitting diode (LED) irradiation of liposomes enhances drug encapsulation and delivery for improved cancer eradication

Liposomes are widely used as drug delivery nanoplatforms because of their versatility and biocompatibility; however, their ability to load certain drugs may be suboptimal. In this study, we generated liposomes using a combination of DSPE and DSPE-PEG-2 k lipids and loaded them with doxorubicin (DOX) and paclitaxel (PTX), to investigate the effects of light emitting diode (LED) irradiation on liposome structure and drug loading efficiency. Scanning and transmission electron microscopy revealed that the surface of liposomes irradiated with blue or near-infrared LEDs (LsLipo) was rougher and more irregular than that of non-LED-irradiated liposomes (NsLipo). Nuclear magnetic resonance analysis showed that the hydrogen peak originating from the lipid head groups was lower in LsLipo than in NsLipo preparations, indicating that LED irradiation changed the chemical and physical properties of the liposome. Structural changes, such as reduced rigidity, induced by LED irradiation, increased the loading efficiency of DOX and PTX. In vitro and in vivo experiments showed that LsLipo were more effective at inhibiting the growth of cancer cells than NsLipo. Our findings suggest that LED irradiation enhances the drug delivery efficacy of liposomes and offer new possibilities for improving drug delivery systems.

Conditions and Mechanism of Formation of the Maillard Reaction Pigment, Furpenthiazinate, in a Model System and in Some Acid Hydrolyzates of Foods and its Biological Properties.

Furpenthiazinate is a yellow pigment formed by the Maillard reaction between cysteine and furfural under strongly acidic conditions. Here, we describe the conditions and mechanism of pigment formation in a model system and in an acid hydrolyzate of food and analyze its biological properties. A reaction solution containing 32 mM cysteine and 128 mM furfural or 64 mM cysteine and 256 mM furfural in the presence of 2-6 M hydrochloric acid that was heated to 110 °C for 1-2 h yielded approximately 3 mM furpenthiazinate. Nuclear magnetic resonance analysis of furpenthiazinate prepared using 1-13C or 5-13C d-ribose suggests that it was formed through the condensation of cysteine and two C5 chains derived from pentose with the dehydration and elimination of formic acid. Furpenthiazinate was detected in mieki, a seasoning, and some acid hydrolyzates of food, and it did not show antibacterial or mutagenic activity.

New Vision of Cell Walls in Aspergillus fumigatus from Solid-State NMR Spectroscopy.

The fungal cell wall plays a critical role in regulating cellular integrity and communication, and serves as a frontline defense against stress. It is also a prime target for the development of antifungal agents. The cell wall is comprised of diverse polysaccharides and proteins and poses a challenging target for high-resolution structural characterization. Recently, the solid-state nuclear magnetic resonance (ssNMR) analysis of intact Aspergillus fumigatus cells has provided atomic-level insights into the structural polymorphism and functional assembly principles of carbohydrate components within the cell wall. This physical perspective, alongside structural information from biochemical assays, offers a renewed understanding of the cell wall as a highly complex and dynamic organelle. Here, we summarize key conceptual advancements in the structural elucidation of A. fumigatus mycelial and conidial cell walls and their responses to stressors. We also highlight underexplored areas and discuss the opportunities facilitated by technical advancements in ssNMR spectroscopy.

Uncovering the antifungal activities of wild apple-associated bacteria against two canker-causing fungi, Cytospora mali and C. parasitica

Cytospora canker has become a devastating disease of apple species worldwide, and in severe cases, it may cause dieback of entire trees. The aim of this study was to characterize the diversity of cultivable bacteria from the wild apple microbiota and to determine their antifungal ability against the canker-causing pathogenic fungi Cytospora mali and C. parasitica. Five bacterial strains belonging to the species Bacillus amyloliquefaciens, B. atrophaeus, B. methylotrophicus, B. mojavensis, and Pseudomonas synxantha showed strong antagonistic effects against pathogenic fungi. Therefore, since the abovementioned Bacillus species produce known antifungal compounds, we characterized the antifungal compounds produced by Ps. synxantha. Bacteria grown on nutritional liquid medium were dehydrated, and the active compound from the crude extract was isolated and analysed via a range of chromatographic processes. High-performance liquid chromatography, mass spectrometry, and nuclear magnetic resonance analyses revealed a bioactive antifungal compound, phenazine-1-carboxylic acid (PCA). The minimum inhibitory concentration (MIC) demonstrated that PCA inhibited mycelial growth, with a MIC of 10 mg mL−1. The results suggested that PCA could be used as a potential compound to control C. mali and C. malicola, and it is a potential alternative for postharvest control of canker disease.

Highly efficient capture of CO2 through the synergy of intramolecular amines within piperazine‐derived alcoholamines

AbstractAmine‐scrubbing‐based chemical absorption remains a prominent CO2 capture process. However, the overall efficiency of conventional amine absorbents is hard to meet the ever‐increasing demands for CO2 capture. Consequently, developing powerful absorbents for efficient and cost‐effective CO2 capture is greatly important but challenging. Here, a new type of amine absorbent with improved solubility and stability was achieved by substituting the secondary amino groups in piperazine (PZ) with aminoethyl and hydroxyalkyl moieties. The developed amine absorbent presents superior CO2 absorption/desorption abilities through the synergy of their intramolecular amines, leading to a low regeneration energy consumption of 2.56 GJ·t−1 CO2. Moreover, the enhancement of CO2 capture and the corresponding mechanism were elucidated using density functional theory calculations and nuclear magnetic resonance analysis. Such newly developed amine absorbent with excellent CO2 capture performance are expected to greatly contribute to ongoing efforts toward carbon neutrality.

Evaluation of antibacterial activity of an experimental dental adhesive containing synthesized quaternary ammonium compound: in vitro study

BackgroundDental adhesives with immobilized antibacterial agents are formulated to combat bacterial invasion along the tooth-restoration interface. This study aims to evaluate the antibacterial effect of synthesized quaternary ammonium compound (QAC) incorporated into commercial dental adhesive.MethodsQAC was synthesized from 2-(Dimethylamino) ethyl methacrylate and 1-Bromobutane and characterized using CHN (Carbon, Hydrogen, Nitrogen), FTIR (Fourier transform infrared) and H+NMR (Proton nuclear magnetic resonance) analyses. The synthesized QAC was assessed for its cytotoxicity and its antibacterial activity against S. mutans using disc diffusion method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), time-kill kinetics test, and TEM imaging. The QAC was added to the primer of a commercially available adhesive (OptiBond XTR) at two concentrations; 20 and 40 mg mL−1 representing the MIC and MBC, respectively. The antibacterial properties of the experimental adhesives, commercial antibacterial adhesive Clearfil SE Protect containing 12-methacryloyloxydodecylpyridinium bromide (MDPB), and commercial vehicle (OptiBond XTR) were compared using time-kill kinetics test. Statistical analysis by ANOVA followed by tukey post-hoc test (P < 0.05).ResultsDisc diffusion and time-kill kinetics tests showed potent antibacterial action of QAC, both in the unpolymerized and the cured forms. MIC and MBC were 20 and 40 mg mL−1 respectively. There was no statistically significant difference between experimental adhesives and Clearfil Protect with more than 99% reduction in bacterial count, while OptiBond XTR showed no bacterial killing up for up to 10 h.ConclusionsThe synthesized QAC added to a commercially available adhesive imparted antibacterial properties, thus providing an affordable adhesive system to the local market.

Facile extraction of lignin-carbohydrate complexes from bamboo with formic acid aqueous solution under moderate conditions

The extraction of lignin-carbohydrate complexes (LCC) while preserving the majority of the interconnecting bonds poses a formidable challenge in characterizing the structure and exploring further applications. In this study, a straightforward approach was proposed to extract LCC from bamboo by precisely adjusting formic acid aqueous solution concentrations (70 % to 100 %) and reaction temperatures (40 to 100 °C) under normal pressure. Notably, employing a 90 % formic acid aqueous solution at 100 °C for 2 h led to an impressive LCC yield of 24.47 %. Moreover, all the LCC samples demonstrated exceptional homogeneity with a polydispersity index ≤ 1.97. Nuclear magnetic resonance analysis revealed the presence of phenyl glycosidic, benzyl ether, benzyl ester, and acetal bonds within the extracted LCC, with phenyl glycosidic bonds serving as the predominant linkages. The LCC samples displayed notable antioxidant capacity, as evidenced by their high DPPH free radical scavenging index of 1.28.

Chemical enhanced oil recovery under Harsh conditions: Investigation of rock permeability and insights from NMR measurements

Injecting surfactant into a hydrocarbon reservoir stands out as a highly effective method for EOR due to its ability to reduce water/oil IFT and alter rock wettability in certain cases. However, the efficiency of this process is compromised in heterogeneous reservoirs, especially carbonates, characterized by significant permeability variations. This study presents findings from three core flooding experiments on heterogeneous carbonate core samples with different permeabilities. The experiments were conducted under representative reservoir conditions of 100 °C, pressures higher than 3000 psi, and seawater salinities and formation water of 57,745 ppm and 213,768 ppm, respectively. In each experiment, seawater was continuously injected followed by continuously injecting a 2500-ppm solution of in-house synthesized Gemini surfactant. Results revealed that the recovery factor was highest in low-permeability rocks and lowest in high-permeability rocks for both seawater and surfactant floods. Surfactant floods yielded additional recoveries of 31%, 23%, and 19% for low, medium, and high-permeability samples, respectively. Nuclear magnetic resonance (NMR) analysis on short analogous core plugs at different flooding stages confirmed these results. Effluent analysis on the produced aqueous phase indicated that dynamic retention was highest (0.467 mg/gm-rock) in the lowest permeability and lowest (0.146 mg/gm-rock) in the highest permeability rock. NMR analysis suggested that the surfactant's recovery performance and dynamic retention were influenced by the larger surface area of low-permeability rocks, facilitating increased contact with the surfactant. Utilizing NMR monitoring in this work enhances EOR insights through integrated studies and coreflooding experiments and establishes a novel framework for complex reservoir conditions.

Synthesis of rGO-reinforced MgAl2O4 spinel composites by solid-state powder route mechanism: A comparative analysis between non-reinforced and rGO-reinforced spinel composites

Reduced Graphene Oxide (rGO)-reinforced MgAl2O4 spinel composite was successfully synthesized by a solid-state powder route mechanism via high-energy planetary ball milling of corresponding metal oxide precursors followed by a high-temperature single-stage sintering process. The effect of rGO on the homogeneity, phase development, morphology, chemical composition, rate of formation of spinel, and cation anti-site formation of the composites was methodically investigated. For comparison, a stoichiometric non-reinforced MgAl2O4 spinel was also synthesized. The addition of 0.2 wt% and 0.4 wt% of rGO as reinforcement increased the homogeneity of the ball-milled composite powder, with Polydispersity Index (PDI) values of 0.19 and 0.15 respectively, as compared to 0.24 obtained in non-reinforced spinel composite. The X-ray diffraction pattern and IR spectrum of 1650 °C sintered composites confirmed the formation of highly crystalline phases with spinel structure. The microstructural analysis revealed that the addition of rGO led to a reduction in porosity and improved the process of sintering. Calorimetric studies showed that spinelization started to occur at 858 °C and 880 °C for 0.2 wt% and 0.4 wt% rGO-reinforced composites respectively, which was faster than non-reinforced composite. 27Al solid-sate nuclear magnetic resonance (SS-NMR) analysis depicted that ceramic composite reinforced with rGO exhibited lesser inversion parameter of 0.09 (for 0.2 wt% rGO) and 0.055 (for 0.4 wt% rGO), as compared to 0.145 obtained in non-reinforced composite, indicating lesser cation anti-sites formation in rGO-reinforced spinel composite.

Akedanones A-C, In Vitro and In Vivo Antiplasmodial 2,3-Dihydronaphthoquinones Produced by Streptomyces sp. K20-0187.

Three new antiplasmodial compounds, named akedanones A (1), B (2), and C (3), were discovered from the cultured material of Streptomyces sp. K20-0187 isolated from a soil sample collected at Takeda, Kofu, Yamanashi prefecture in Japan. The structures of compounds 1-3 were elucidated as new 2,3-dihydronaphthoquinones having prenyl and reverse prenyl groups by mass spectrometry and nuclear magnetic resonance analyses. Compound 1 and the known furanonaphthoquinone I (4) showed potent in vitro antiplasmodial activity against chloroquine-sensitive and chloroquine-resistant Plasmodium falciparum strains, with half-maximal inhibitory concentration values ranging from 0.06 to 0.3 μM. Compounds 1 and 4 also displayed potent in vivo antiplasmodial activity against drug-sensitive rodent malaria Plasmodium berghei N strain, with inhibition rates of 47.6 and 43.1%, respectively, on intraperitoneal administration at a dose of 5 mg kg-1 day-1 for 4 days.

Production of Kinanthraquinone D with Antimalarial Activity by Heterologous Gene Expression and Biotransformation in Streptomyces lividans TK23.

Two new compounds, kinanthraquinone C (1) and kinanthraquinone D (2), were isolated along with two known compounds, kinanthraquinone (3) and kinanthraquinone B (4), produced by the heterologous expression of the kiq biosynthetic gene cluster and its pathway-specific regulator, kiqA, in Streptomyces lividans TK23. The chemical structures of compounds 1 and 2 were determined using mass spectrometry and nuclear magnetic resonance analyses. To examine a biosynthetic pathway of compounds 1 and 2, incubation experiments were conducted using S. lividans TK23 to supply the compounds 3 and 4. These experiments indicated that compounds 3 and 4 were converted to compounds 2 and 1, respectively, by the endogenous enzymes of S. lividans TK23. Compounds 2, 3, and 4 had antimalarial activities at half-maximal inhibitory concentration values of 0.91, 1.2, and 15 μM, respectively, without cytotoxicity up to 30 μM.

A Novel Water-Soluble Polysaccharide from Daylily (Hemerocallis citrina Baroni): Isolation, Structure Analysis, and Probiotics Adhesion Promotion Effect.

The daylily (Hemerocallis citrina Baroni) flower is a traditional raw food material that is rich in a variety of nutrients. In particular, the content of polysaccharides in daylily is abundant and has been widely used as a functional component in food, cosmetics, medicine, and other industries. However, studies on the structure-effective relationship of daylily flower polysaccharides are still lacking. In view of this, daylily flower polysaccharides were isolated and purified, and their physical and chemical properties, structure, antioxidant activity, and adhesion-promoting effect on probiotics were evaluated. The results showed that a novel water-soluble polysaccharide (DPW) with an average molecular weight (Mw) of 2.224 kDa could be successfully isolated using column chromatography. Monosaccharide composition analysis showed that DPW only comprised glucose and fructose, with a molar ratio of 0.242:0.758. Through methylation and nuclear magnetic resonance (NMR) analysis, it was inferred that DPW belonged to the fructans group with a structure of α-D-Glcp-1→2-β-D-Fruf-1→(2-β-D-Fruf-1)n→. Antioxidant analysis showed that DPW showed strong 2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-Oxide (PTIO-scavenging activity with IC50 of 1.54 mg/mL. DPW of 1.25 to 5 mg/mL could significantly increase the adhesion rate of Lactobacillus acidophilu, Lactobacillus casei, Bifidobacterium adolescentis, and Lactobacillus plantarum on Caco-2 cells. Considering the above results, the present study provides a theoretical basis and practical support for the development and application of daylily polysaccharides as a functional active ingredient.

Streamlining regular liquid chromatography with MALDI-TOF MS and NMR spectroscopy using automatic full-contact splitless spotting interface and flash-tap fractioning collection

BackgroundHigh-resolution matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) and nuclear magnetic resonance (NMR) spectroscopy are powerful tools to identify unknown psychoactive substances. However, in complex matrices, trace levels of unknown substances usually require additional fractionation and concentration. Specialized liquid chromatography systems are necessary for both techniques. The small flow rate of nano LC, typically paired with MALDI-TOF MS, often results in prolonged fractionation times. Conversely, the larger flow rate of semi-preparative LC, used for NMR analysis, can be time-consuming and labor-intensive when concentrating samples. To address these issues, we developed an integrated automatic system that integrated to regular LC. ResultAutomatic spot collector (ASC) and automatic fraction collector (AFC) were present in this study. The ASC utilized in-line matrix mixing, full-contact spotting and real time heating (50 °C), achieving great capacity of 5 μL droplet on MALDI plate, high recovery (76–116%) and rapid evaporation in 2 min. The analytes were concentrated 4–8 times, forming even crystallization, reaching the detection limit at the concentration of 50 μg L−1 for 12 psychoactive substances in urine. The AFC utilizes flexible tubing which flash-tapped the microtube's upper rim (3 mm depth) instead of reaching the bottom. This method prevents sample loss and minimizes the robotic arm's movement, providing a high fractionating speed at 6 s 12 psychoactive compounds were fractionated in a single round analysis (recovery: 81%–114%). Methamphetamine and nitrazepam obtained from drug-laced coffee samples were successful analyzed with photodiode array (PDA) after one AFC round and NMR after five rounds. SignificanceThe ASC device employed real-time heating, in-line matrix mixing, and full-contact spotting to facilitate the samples spotting onto the MALDI target plate, thereby enhancing detection sensitivity in low-concentration and complex samples. The AFC device utilized the novel flash-tapping method to achieve rapid fractionation and high recovery rate. These devices were assembled using commercially available components, making them affordable (400 USD) for most laboratories while still meeting the required performance for advanced commercialized systems.

Spectroscopic and microscopic characterization of humic acids from composts made by co-composting of green waste, spent coffee and OMWW sludge

ABSTRACT Due to its important role in the formation of humic acids (HA), improving lignin degradation during composting has usually been considered a challenge. One practice that could stimulate the biodegradation of this recalcitrant molecule is inoculation with exogenous lignolytic fungal strains. Two composts (C1) and (C2) from piles (H1) and (H2) were evaluated. H1 was the control pile and H2 was inoculated at maturity with Trametes trogii, resulting in a 35% increase in lignin degradation rate compared to H1. The aim of this study was to show the main effects of this increase on the humification process in the co-composting of green waste, coffee grounds and olive mill wastewater sludge (OMWWs). Microstructure of HA1 and HA2 extracted from C1 and C2, respectively, was also investigated by scanning electron microscopy (SEM) and SEM coupled with energy-dispersive X-ray spectroscopy (X-EDS). The results showed that there were several similarities between the compost samples tested. These included the mineral content, the degree of polymerization (PD)> 1 and the compact and rigid surface of the extracted HA. However, C2 was characterized by a higher humic content (HC), degree of polymerization (PD), humification index (HI) and percentage of humic acids (PHA) than C1. Carbon-13 nuclear magnetic resonance (13C-NMR) and Fourier transmission-infrared spectroscopy (FTIR) analysis showed that aliphatic groups such as hydroxyls, alcohols and carboxyls were predominant in both composts. SEM analysis in conjunction with X-EDS analysis of HA2 showed a higher proportion of carbon and potassium (18 and 7.93%) than in HA1 (14 and 0.95%).

Synthesis and Morphology Characteristics of New Highly Branched Polycaprolactone PCL.

A simple and efficient method for the synthesis of biodegradable, highly branched polycaprolactone (PCL) is presented. The solvent-free (bulk) reaction was carried out via ring opening polymerization (ROP), catalyzed by tin octanoate Sn(Oct)2, and it employed hyperbranched polyamide (HPPA) as a macro-initiator. The core-shell structure of the obtained products (PCL-HPPA), with the hyperbranched HPPA core and linear PCL chains as shell, was in the focus of the product characterization. 1H nuclear magnetic resonance (1H NMR) and elemental analysis confirmed the covalent incorporation of the HPPA in the products, as well as a high degree of grafting conversion of its amino functional groups. Confocal Raman Micro spectroscopy, and especially Time-of-Flight Secondary Ion Mass Spectrometry, further supported the existence of a core-shell structure in the products. Direct observation of macromolecules by means of cryogenic transmission electron microscopy, as well as gel permeation chromatography (GPC), suggested the existence of a minor 'aggregated' product fraction with multiple HPPA cores, which was attributed to transesterification reactions. Differential scanning calorimetry, as well as X-ray diffraction, demonstrated that the PCL-HPPA polymers displayed a similar degree of crystallinity to linear neat PCL, but that the branched products possessed smaller and less regular crystallites.

Two New Sesquiterpenoids and a New Shikimic Acid Metabolite from Mangrove Sediment-Derived Fungus Roussoella sp. SCSIO 41427.

Two new sesquiterpenoid derivatives, elgonenes M (1) and N (2), and a new shikimic acid metabolite, methyl 5-O-acetyl-5-epi-shikimate (3), were isolated from the mangrove sediment-derived fungus Roussoella sp. SCSIO 41427 together with fourteen known compounds (4-17). The planar structures were elucidated through nuclear magnetic resonance (NMR) and mass spectroscopic (MS) analyses. The relative configurations of 1-3 were ascertained by NOESY experiments, while their absolute configurations were determined by electronic circular dichroism (ECD) calculation. Elgonene M (1) exhibited inhibition of interleukin-1β (IL-1β) mRNA, a pro-inflammatory cytokine, at a concentration of 5 μM, with an inhibitory ratio of 31.14%. On the other hand, elgonene N (2) demonstrated inhibition at a concentration of 20 μM, with inhibitory ratios of 27.57%.