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Control of the shape and uniformity of colloid particles is essential for realizing their functionality in various applications. Herein, we report a facile approach for the synthesis of narrowly dispersed anisotropic microparticles with well-defined raspberry-like and golf ball-like surface patterns. First, we demonstrate that hybrid raspberry-like particles can be achieved through a one-pot polymerization method using glycidyl polyhedral oligomeric silsesquioxane (GPOSS) and pentaerythritol tetra(3-mercaptopropionate) (PETMP) as monomers. Varying the polymerization parameters such as catalyst loading, monomer concentration, and the molar ratio of monomers, we are able to regulate the sizes and surface protrusion numbers of these raspberry-like microparticles. The formation mechanism is attributed to a competition balance between thiol-epoxy reaction and thiol-thiol coupling reaction. The former promotes rapid formation of large core particles between PETMP and GPOSS droplets (which can serve as core particles), while the latter allows for generation of surface protrusions by PETMP self-polymerization, leading to the formation of raspberry-like surface patterns. Based on the different POSS contents in the surface protrusions and cores of the raspberry-like microparticles, we demonstrate that they can be used as precursors to produce microporous silica (sub)microparticles with golf ball-like morphology via pyrolysis subsequently. Overall, this work provides a facile yet controllable approach to synthesize narrowly dispersed anisotropic microparticles with diverse surface patterns.

The medicinal part of Aucklandia lappa (Asteraceae) is its dried root, which is one of the commonly used Chinese medicinal materials. Here we reviewed sesquiterpene lactones isolated from A. lappa over the past ten years in the following aspects of pharmacological activities, pharmacokinetics, toxicology, structure–activity relationship. Pharmacological activities consist of anti-cancer, anti-inflammatory activity, anti-immunity activity, anti-oxidant activity, antimicrobial activity, spasmolytic activity and so on. The extractive, showing similar pharmacokinetics parameters, may exert their various biological activities by the interaction of their α-methylene-γ-butyrolactone moiety with the thiol groups of biomacromolecules through Michael-addition. However, the poor aqueous solubility, non-selective binding as a Michael acceptor at undesired targets limited clinical translation of this class. In order to evaluate the potential effect of the extractive applied in clinical trial, the present review outlines information on pharmacological activities, pharmacokinetics, toxicology, and structure–activity relationship, as well as the future research directions of the extractive for further development and utilization of A. lappa.

Graphical abstract Permeation mechanisms through the selectivity filter (SF) and helix bundle crossing (HBC) gate of GIRK2 channel. Water and K+ ions co-translocate through the SF in a water-K+ coupled manner from the extracellular matrix into the intracellular side with the aid of an external electric field. A tilt of the SF affects its recognition efficiency. A 4-K+ occupancy in the SF-HBC cavity is required for the permeation through an open HBC; whilst the three K+ ions around E152 help to abolish the unfavorable cation-dipole interactions to overcome the energy barrier; the fourth K+ near HBC gets ready for the inward transport., G protein-gated inwardly rectifying potassium channels (GIRK) are essential for the regulation of cellular excitability, a physiological function that relies critically on the conduction of K+ ions, which is dependent on two molecular mechanisms, namely selectivity and gating. Molecular Dynamics (MD) studies have shown that K+ conduction remains inefficient even with open channel gates, therefore further detailed study on the permeation events is required. In this study, all-atom MD simulations were employed to investigate the permeation mechanism through the GIRK2 selectivity filter (SF) and its open helix bundle crossing (HBC) gate. Our results show that it is the SF rather than the HBC or the G-loop gate that determines the permeation efficiency upon activation of the channel. SF-permeation is accomplished by a water-K+ coupled mechanism and the entry to the S1 coordination site is likely affected by a SF tilt. Moreover, we show that a 4-K+ occupancy in the SF-HBC cavity is required for the permeation through an open HBC, where three K+ ions around E152 help to abolish the unfavorable cation-dipole interactions that function as an energy barrier, while the fourth K+ located near the HBC allows for the inward transport. These findings facilitate further understanding of the dynamic permeation mechanisms through GIRK2 and potentially provide an alternative regulatory approach for the Kir3 family given the overall high evolutionary residue conservation.

Previously, much attention has been paid to prepare porous magnetic silica micro/nanoparticles, but most of the reported methods are limited by sophisticated procedures and strict synthetic conditi...

The production of α-melanocyte-stimulating hormone (α-MSH), a peptide hormone composed of 13 amino acids, is attempted by recombinant expression using E. coli as the host. To achieve this aim, a synthetic gene containing eight tandem repeats of msh gene (8msh) was designed for ribosomal synthesis of 8 α-MSH. The merit of the strategy is to diminish the peptide toxicity against the host cell and to achieve a higher production yield. Pepsin cleavage sites are introduced between the peptides for enzymatic proteolysis to obtain the monomeric peptide of α-MSH. The constructed plasmid was transformed into different strains of E. coli hosts, and E. coli XL1-Blue with gene 8msh revealed the highest yield of 8 α-MSH. Although 8 α-MSH was fractionalized in the insoluble pellets after cell lysis, pepsin cleavage was able to produce soluble α-MSH peptide, as analyzed and confirmed by mass spectrometry and peptide activity assays. The production of α-MSH was quantified using HPLC with a yield of 42.9 mg/L of LB culture. This study demonstrates the feasibility of producing α-MSH using recombinant expression of tandem repeat gene. The production procedure involves minimal post-treatment and processing and can be scaled up for industrial application.

In recent years, an increasing number of studies have shown that lignin nanoparticles (LNPs) are a new kind of green and sustainable material with potential applications in many areas. With the development of nanotechnology, the controllable preparation of nanomaterials is necessary. However, lignin heterogeneity remains a hurdle that must be overcome for the controllable preparation of LNPs. To solve this problem, we applied a traditional fractionation technique to the preparation of LNPs. We prepared LNPs with tunable sizes by using different lignin fractions with different molecular weights and hydrophilic group content values. The lignin fraction with a high molecular weight, low content of hydrophilic groups, and high syringyl/guaiacyl ratio resulted in weak lignin–water interactions and a high degree of aggregation within the lignin fraction, thereby producing small LNPs. The prepared LNPs showed controllable sizes (21–139 nm) with very narrow size distributions. The findings support the development of green materials along with nano- and biorefinery technologies.

Microbial transformation of ursolic acid by Mucor spinosus AS 3.3450 was carried out in this paper. Three new compounds (1-3) were isolated and their structures were identified as 3β, 7β-dihydroxy-ursolic acid-28-ethanone (1), 3β, 7β, 21β-trihydroxy-ursolic acid (2), and 3β, 21β-dihydroxy-ursolic acid-3-O-β-D-glucopyranoside (3) based on extensive spectral analysis including HRESI-MS, 1H-NMR, 13C-NMR, HMQC and HMBC. Compared with the substrate, compound 1 had stronger cytotoxic activity against Hela cell, K562 cell and KB cell lines. Using Mucor spinosus AS 3.3450 to bio-transform ursolic acid for the first time, this study provided possible ways for reforming the chemical structure of UA and the obtained activity-enhanced bio-transformation products may lay a foundation for the development and application of lead compounds in the future.

A new polysaccharide (cDFP-W1) with high immunostimulatory activities was isolated from the stems of Dendrobium fimbriatum Hook. The analysis of the physicochemical properties showed that cDFP-W1 consisted of mannose and glucose in a molar ratio of 1 : 3.84, and its relative molecular weight was 4.0 × 104 Da. Structural analysis implied that the linear backbone of cDFP-W1 was composed of α-1,4-D-Glcp, β-1,4-D-Manp, 3-O-acetyl-α-1,4-D-Glcp and α-1,4,6-D-Glcp, and its branches were the terminal β-D-Manp that was attached to the C-6 position of α-1,4,6-D-Glcp. An in vivo immunostimulatory assay exhibited that cDFP-W1 at 200 mg kg−1 could significantly increase the proportions of CD4+ T-cell subpopulations, B cells, natural killer cells and dendritic cells, decrease the proportion of CD8+ T-cell subpopulations, and upregulate the percentage of activated macrophages (p < 0.01) in the spleen of mice. An in vitro immunostimulatory assay revealed that cDFP-W1 could effectively promote the proliferation of spleen lymphocytes, enhance the proliferation and phagocytosis of macrophage RAW264.7 cells, and stimulate the mRNA expression and extracellular release of NO, TNF-α and IL-1β of RAW264.7 cells. The western blot experiment suggested that the immunostimulatory activities of cDFP-W1 were closely related to the activation of MAPKs, NF-κB and PI3K/Akt signaling pathways.

Colloidal particles are essential components of sun-dried Isatis indigotica Fort. roots (Ban-Lan-Gen in Chinese, BLG) decoction. Nanoparticles (NPs) were isolated from BLG decoction with size exclusion chromatography and characterized. Their average diameter is ∼120 nm, reversibly responding to pH and temperature changes. They promoted the growth of normal cells but suppressed that of cancerogenic cells and macrophages. Two constitutive glycated proteins were identified from the NPs, namely BLGP1 and BLGP2. Their N-terminal amino acid sequences were V-X-R-E-V-V-K-D-I and V-V-R-E-V-V-K-D-I-A-G-A-V-Q-T-N-E-Q-Y. Their full-length cDNA sequences were cloned to obtain the highly homological amino acid sequences of non-glycated proteins, whose theoretical molecular weights are 21831.64 Da and 21841.67 Da. Using pepsin hydrolysis and mass spectrometry, four possible glycation adducts were identified in BLGP1, whereas one in BLGP2. To conclude, bioactive nanoparticles isolated from the herbal decoction are intelligent nanoassemblies composed of a new boiling-stable protein. Glycation plays a critical role in heat-induced formation of these nanoassemblies. The novel, intelligent, safe and stable nano-carriers for drug delivery may be developed using BLG NPs as prototype.

Three new triterpenoid saponins, ardisicrenoside O (1), ardisicrenoside P (2) and ardisicrenoside Q (3) together with three known compounds, 3β,16α-dihydroxy-30-methoxy-28, 30-epoxy-olean-12-en, cyclamiretin A 3-O-β-d-glucopyranosyl-(1→2) -α-l-arabinopyranoside and cyclamiretin A 3-O-β-d-glucopyranosyl-(1→4) -α-l-arabinopyranoside were isolated from the roots of Ardisia crenata Sims. Their structures were determined by one- and two-dimensional NMR techniques, including HSQC, HMBC and TOCSY experiments, as well as acid hydrolysis and GC analysis. All isolates were evaluated for the cytotoxic activities on two human cancer cell lines and compounds 3, 5 and 6 showed significant cytotoxicity.

Oily wastewater has caused serve environmental pollution in nowadays, and it is highly urgent to develop an effective method for disposing of it. The development superhydrophilic and underwater superoleophobic (SUS) membranes bring hope of solving this global challenge. Previously, deformable hydrogels/hydrophilic polymers, brittle and chemically weak inorganic/metal oxides have been widely employed for fabricating SUS membranes, while most of these materials are likely to be corroded under practical severe conditions. In this work, we report a novel SUS membrane with excellent durability as achieved by introducing polyhedral oligomeric silsesquioxane (POSS) nanoparticles on cotton fabric (CF) followed by thiol-ene functionalization to graft hydrophilic carboxyl group. It is found that the prepared SUS membrane can withstand long-term mechanical abrasion, ultrasonic washing, UV light irradiation and corrosive aqueous solutions without reducing the underwater superoleophobicity. This SUS membrane is also able to separate various oil/water and oil/corrosive aqueous solution mixtures, and only water phase is allowed to permeate through it. The measured water fluxes are very high (up to 88,214 L m−2 h−1), the initial separation efficiencies of this membrane for various oil/water mixtures are over 99% and those values are still maintained at high level (around 98%) after 50 separation cycles even in severe conditions. We believe that this work would be helpful for fabrication of advanced SUS membranes with excellent durability.

Polymer dielectrics have been considered as an ideal choice for preparation of advanced power and electronic systems as their good comprehensive performances. However, it remains a challenge to obtain polymer dielectrics with high dielectric constant ( e r ), low dielectric loss (tan δ) and high temperature capability. Although adding high permittivity inorganic nanofillers has become a promising approach to improve the e r of polymers, it usually causes the adverse increment tan δ. Herein, we demonstrate that fluoride ion encapsulated polyhedral oligomeric silsesquioxane (POSS@F−) can be regarded as a novel filler to enhance the e r and reduce the tan δ of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) simultaneously. Compared with the pristine PPO, the e r of PPO/POSS@F− composite can be enhanced from 2.81 to 5.31, while its tan δ is still relatively low (0.0011 at 1 kHz). Meanwhile, the breakdown strength of PPO can also be slightly reinforced from 334.9 kV/mm to 394.0 kV/mm. Owing to the good thermal properties of PPO and POSS@F−, these composites exhibit good dielectric properties and improved dimension stability at high temperature. We believe that these results are particularly important for the preparation of advanced dielectric materials for desirable applications.

A new benzocoumarin derivative, dendrocoumarin (1), along with itolide A were isolated from the stems of Dendrobium nobile. The structure of the new compound 1 elucidated on the basis of NMR and mass spectroscopic data. Compounds 1 and 2 showed broad spectrum antibacterial activity against five terrestrial pathogenic bacteria.

The effects of temperature, agitation and aeration on glycoprotein GP-1 production by Streptomyces kanasenisi ZX01 in bench-scale fermentors were systematically investigated. The maximum final GP-1 production was achieved at an agitation speed of 200 rpm, aeration rate of 2.0 vvm and temperature of 30 °C. By using a dynamic gassing out method, the effects of agitation and aeration on volumetric oxygen transfer coefficient (kLa) were also studied. The values of volumetric oxygen transfer coefficient in the logarithmic phase increased with increase of agitation speed (from 14.53 to 32.82 h−1) and aeration rate (from 13.21 to 22.43 h−1). In addition, a successful scale-up from bench-scale to pilot-scale was performed based on volumetric oxygen transfer coefficient, resulting in final GP-1 production of 3.92, 4.03, 3.82 and 4.20 mg/L in 5 L, 15 L, 70 L and 500 L fermentors, respectively. These results indicated that constant volumetric oxygen transfer coefficient was appropriate for the scale-up of batch fermentation of glycoprotein GP-1 by Streptomyces kanasenisi ZX01, and this scale-up strategy successfully achieved 100-fold scale-up from bench-scale to pilot-scale fermentor.

In order to generate scientifically-based comparative information to improve fertilization efficiency and reduce nutrient loss, 610 samples of 122 soil profiles were collected at the 0–60 cm depth to compare soil nutrient contents including soil organic matter (SOM), total nitrogen (TN), total phosphorus (TP), available phosphorus (AP), and available potassium (AK) among different slope positions in a Mollisol farmland area of Northeast China. The contents of SOM and TN typically decreased with increased soil depth at back and bottom slope. Soil loss and deposition tended to decrease SOM and TN at the 0–20 cm soil depth on both the back slope and the slope bottom. The TP firstly decreased from 0–20 cm to 30–40 cm, and then not constantly increased at the back slope and the bottom slope. Due to the characteristics of soil nutrients and crop absorption, the contents of both AP and AK were typically the highest at the summit, followed by the slope bottom and the back slope in the 0–20 cm layer. Generally, in order to sustain the high soil productivity and protect the environment, attention should be paid to soil conservation on back slope; in addition, additional N and P fertilizer is necessary on the back slope.

Streptomyces kanasensis ZX01 produces some antibiotics and a glycoprotein with antiviral activity. To further evaluate its biosynthetic potential, here we sequenced the 7,026,279 bp draft genome of S. kanasensis ZX01 and analyzed all identifiable secondary gene clusters for controlling natural products. More than 60 putative clusters were found in S. kanasensis ZX01, the majority of these biosynthetic loci are novel. In addition, the regulators for secondary metabolism in S. kanasensis ZX01 were abundant. The global regulator nsdA not only controls biosynthesis of some antibiotics, but also enhances production of glycoprotein GP-1 with antiviral activity. This study importantly reveals the powerful interplay between genomic analysis and studies of traditional natural product purification/production increasing.

Polyhedral oligomeric silsesquioxane (POSS) is an attractive nano-building block for the preparation of organic-inorganic hybrid materials with diverse applications. However, hybrid microparticles based on POSS have rarely been reported as their preparation remains a challenge. In this work, we describe a facile approach for the fabrication of monodispersed organic-inorganic hybrid microparticles based on POSS (MBOPs) through thiol-Michael dispersion polymerization method. By adjusting the polymerization conditions and the monomer combinations, not only the size and uniformity, but also the POSS content of MBOPs can be tuned. The varied POSS content result in the enhanced UV resistance and thermal stability of hybrid MBOPs compared to purely organic microparticles. In addition, MBOPs could be regarded as precursors for formation of the inorganic SiOC ceramic microparticles with uniform size, well-defined micropore and good alkali resistance after high temperature removing the organic components. Considering the vast selection of POSS derivatives and the vast adaptability of chemical conversion that are possible, we believe that this work provides a platform for material chemists to fabrication of advanced microparticles with unique structures and performances from organic to inorganic.

Microbial transformation of ursolic acid (1) was carried out by Alternaria longipes AS 3.2875. Six transformed products (2–7) from 1 were isolated and their structures were identified as 3-carbonyl ursolic acid 28-O-β-D-glucopyranosyl ester (2), ursolic acid 3-O-β-D-glucopyranoside (3), ursolic acid 28-O-β-D-glucopyranosyl ester (4), 2α, 3β-dihydroxy ursolic acid 28-O-β-D-glucopyranosyl ester (5), 3β, 21β dihydroxy ursolic acid 28-O-β-D-glucopyranosyl ester (6), and 3-O-(β-D-glucopyranosyl)- ursolic acid 28-O-(β-D-glucopyranosyl) ester (7) based on the analysis of 1D NMR, 2DNMR and MS data. The product 2 was a new compound among them and showed stronger antibacterial activity against S. aureu, MRSA and MRCA than substrate. In this study, we modified structure of ursolic acid through biotransformation to enhance its activities and preliminarily discussed the transformation way of the products.

The antidiabetic effects of Ge-Gen-Qin-Lian-Tang decoction (GQD) have been proven clinically. In a pharmacological study conducted on STZ-induced diabetic rats, the constitutive aggregates/sediments of Ge-Gen-Qin-Lian-Tang decoction exhibited stronger hypoglycemic and antioxidant activities compared to the soluble compositions. This study aims to demonstrate the pharmacological properties of aggregates derived from GQD by measuring permeability of the active monomer phytochemicals (e.g., baicalin) in a Caco-2 cell monolayer and determine the cellular viability, intracellular redox status (MDA and SOD), and insulin secretion of pancreatic β-cell line, INS-1, following STZ-induced oxidative stress. The aggregates were separated into three fractions, namely, “MA (microaggregates),” “400 g supernatant,” and “MNA (micro-/nanoaggregates),” by centrifugation at 400 ×g and 15000 ×g, respectively. Aggregates in the sediment increased baicalin absorption, showed little toxicity to β-cells, elevated intracellular SOD levels, and significantly suppressed oxidative damage effects on cellular viability and functions. The “MA” fraction had a larger particle size and provided higher antioxidant cellular protection than “MNA” in vitro, implying that the sediments may be the active components in the herbal decoction. The actions of these micro-/nanoaggregates may provide a new perspective for understanding the antidiabetic effects of herbal decoctions and aid in interpretation of synergistic actions between the multiple components.

A fast, sensitive, high-performance liquid chromatography-tandem mass spectrometry method was developed for the determination of voriconazole in human plasma. Carbamazepine was used as the internal standard and the sample pretreatment involved one-step protein precipitation. Chromatographic separation was conducted on an Ultimate C18 column with a mobile phase consisting of acetonitrile-water (containing 0.1% formic acid; 40:60, v/v) at a flow rate of 0.3 mL/min. The detection of voriconazole was performed on a triple-quadrupole tandem mass spectrometer by multiple reaction monitoring with an electrospray ionization source in the positive mode. The standard curve was linear (r(2) ≥ 0.99) within the concentration range of 2.49-293 ng/mL. The intra-day and inter-day precision values were below 5.3%, and the accuracy was within -4.3-5.7%. The method was applicable to the clinical study of the pharmacokinetics of voriconazole in healthy volunteers following oral administration.

Phlorizin ( 1 ) was anaerobically incubated with human intestinal bacteria and five biotransformation products ( 2 – 6 ) were obtained. Their structures were elucidated as phloretin ( 2 ), phloroglucinol ( 3 ), phloretic acid ( 4 ), 2,3,4-trihydroxybenzenepropanoic acid ( 5 ), and phloretic acid methyl ester ( 6 ) on the basis of their spectroscopic data. Using high-performance liquid chromatography equipped with a diode array detector, chromatographic separation of 1 – 4 was performed on an analytical C 18 column. The time course of the biotransformation was studied to probe into the biotransformation mechanism of 1 by human intestinal flora. The abilities of isolated strains to transform 1 were also investigated in order to find an optimal transformation strain. In addition, the inhibitory activity of parent compound 1 and its three main biotransformation products 2 – 4 on mushroom tyrosinase was estimated. The result showed that 2 has better inhibitory effect on tyrosinase activity than 1 .

An improved technique for single nucleotide mismatch discrimination using immobilized double-stranded DNA probes with a shared-stem hairpin (SH) structure is developed. A hairpin-like double-stranded DNA probe without any chromophore was immobilized on an agarose film-coated slide. The base number of the stem area was increased to 9-19 nt and the entire shared-stem area was included in the hybridization area, in which a mutated nucleotide was introduced in the middle. For the perfect match SH probe, we introduced an inner mismatch in the middle positon of the complementary chain. After the introduction of the inner mismatch, the hybridization ability of the SHP probe with a long stem was enhanced significantly. On the other hand, the mismatch probe was not able to hybridize to the perfect matched target. The annealing properties, specificity and hybridization dynamics of this kind of double-stranded DNA probes immobilized on an agarose film are greatly improved in comparison with those for the linear ones and traditional hairpin-like ones. Collectively we demonstrated that this type of immobilized double-stranded DNA probes had an excellent discrimination ratio for single nucleotide mismatches.

Focusing on the variations of chemical constituents in licorice root, influences of exposure to physical factors of spaceflight on licorice (Glycyrrhiza uralensis Fisch.) seeds were investigated. Licorice seeds obtained from two different producing areas were flown on a recoverable satellite for 18 days. After returning to earth, the seeds carried by the satellite and the parallel ground control were cultivated to maturity under the same condition. Chromatographic fingerprint of 1 year licorice root analyzed by high performance liquid chromatography with diode-array detection not only displayed the contents of glycyrrhizic acid and liquiritin increasing in the spaceflight samples but showed the variation of the kinds of chemical constituents. The main components in the root extract were identified by high performance liquid chromatography coupled with electrospray ionization multi-tandem mass spectrometry. The changes in the kind of secondary metabolites of licorice root after spaceflight were firstly reported. A total of 26 components which included 9 flavonoids, 16 triterpene saponins and 1 coumarin were identified according to their mass spectra determined in both negative and positive ion modes. The research provided the scientific data for spaceflight breeding of medicinal plant and indicated that the technology of spaceflight may be a new effective method for the breeding and cultivation of licorice.

Three new triterpenoid saponins, ardisicrenoside I (1), ardisicrenoside J (2), and ardisicrenoside M (3), along with eight known compounds, were isolated from the roots of Ardisia crenataSims. Their structures were elucidated as 16α-hydroxy-30,30-dimethoxy-3β-O-{β-D-xylopyranosyl-(12)-β-D-glucopyranosyl-(14)-[β-D-glucopyranosyl-(12)]-α-L-arabinopyranosyl}-13β,28-epoxyoleanane (1), 16α-hydroxy-30,30-dimethoxy-3β-O-{α-L-rhamnopyranosyl-(12)-β-D-glucopyranosyl-(14)-[β-D-glucopyranosyl-(12)]-α-L-arabinopyranosyl}-13β,28-epoxyoleanane (2), 30,30-dimethoxy-16-oxo-3β-O-{β-D-xylopyranosyl-(12)-β-D-glucopyranosyl-(14)-[β-D-glucopyranosyl-(12)]-α-L-arabinopyranosyl}-13β,28-epoxyoleanane (3), ardisiacrispin A (4), ardisiacrispin B (5), ardisicrenoside B (6), ardisicrenoside A (7), ardisicrenoside H (8), ardisicrenoside G (9), cyclamiretin A-3β-O-β-D-xylopyranosyl-(12)-β-D-glucopyranosyl-(14)-α-L-arabinopyranoside (10), and cyclamiretin A-3β-O-α-L-rhamnopyranosyl-(12)-β-D-glucopyranosyl-(14)-α-L-arabinopyranoside (11) by means of chemical and spectral analysis, and their cytotoxicities were evaluated in vitro.

Two novel matrix metalloproteinase (MMP) inhibitors, myricetin (m) and kaempferol (k), were found and the inhibitory activity is both in decreased order towards MMP-2 and MMP-9. To understand the mechanism during the processes when inhibitors bind to MMP-2 and MMP-9, molecular modeling, docking, and density functional theory (DFT) calculations were performed. The calculated results indicated that the hydroxyls on benzene ring of the inhibitors control the binding modes between inhibitors and MMPs, thus play an important role on the potency and selectivity. Besides coordinating with the N atoms of three His residues, Zn also interacts with a hydroxyl group of inhibitors by O – Zn distances of 2.66–2.78 Å in all of the docked complexes, so that the hydroxyl acts as a weak zinc binding group (ZBG). The DFT calculated results support the above analysis. The binding affinity calculations between inhibitors and MMPs present the total interaction energies in the m-MMP < k-MMP order and the solvation energy of myricetin is less than that of kaempferol, which reflect the experimental inhibitory activity.

Chalcone synthase catalyzes formation of phenylpropanoid chalcone from one p-coumaroyl-coenzyme A (CoA) and three malonyl-CoA molecules. In order to elucidate structural and energetic features of the reaction mechanism, we performed the quantum mechanics calculations and obtained the following results. In loading step, only a tetrahedral intermediate is located without transition state (TS). Our results indicate that His303 acts as a H31 donor, but not a hydrogen bond donor, to stabilize the intermediate formation. In decarboxylation step, the reaction proceeds via a TS and is sensitive to the environment. In elongation step, a tetrahedral TS is located. All of the results above support the reaction mechanism and further complement the proposal of Noel JP et al.

By means of molecular modeling and docking studies, two novel non-peptide inhibitors (pyrogallic acid and myricetin) with a new zinc binding group (ZBG) have been evaluated as inhibitors of MMP-1 and MMP-3. The differences in binding affinities for MMP-1 and MMP-3 have been rationalized, and the results are consistent with the experiments of Fang et al. The density functional theory (DFT) method B3LYP/6-31G ∗ has also been employed to characterize the interactions between ZBG of pyrogallic acid and the catalytic zinc ion in MMP-1. Our results may be useful for further research in the structure-based design of inhibitors with improved potency and selectivity.

An analytical method was developed for the determination of tebufenozide and methoxyfenozide residues in vegetables. The procedure involves the extraction of tebufenozide and methoxyfenozide using alkali acetonitrile before solid-phase purification from the matrices. The tebufenozide and methoxyfenozide residues were subsequently determined by an electrospray mass spectrometer after separated by the reversed-HPLC. Mass Spectrum acquisition applied Selected Reaction Monitoring (SRM) to diagnostic transition reactions. The qualitative results were obtained based on the retention time, the precursor ion and two daughter ions, and the quantitative results were based on the intension of the characteristic m/z 297 ion and m/z 149 ion. The linear range was from 5.0–200 ng ml−1 and the correlation coefficients (r) were higher than 0.996. The average recovery ranges from 90% to 110% for tebufenozide and 70% to 80% for methoxyfenozide in the replicate sets of vegetable samples fortified with drug concentration of 4.0, 10.0 and 20 μg kg−1, and the relative standard deviations (RSD) were less than 8%. The detection limit and the quantification limit of the method were 1.0 and 4.0 μg kg−1, respectively. This method is quite suitable for determining the residues of tebufenozide and methoxyfenozide in vegetables.

Coal liquefaction residue (CLR), coming from a direct coal liquefaction pilot plant, was used to investigate its rheological characteristics and the effects of temperature, oil and asphaltene, as well as solid content on its rheological characteristics. CLR is a kind of non-Newtonian pseudoplastic fluid, whose viscosity index decreases with increasing temperature, and approaches Newtonian fluid behavior at high temperature. The apparent viscosity of CLR drops greatly without peak as it is sensitive to temperature. After adding a little recycled oil (REC) into CLR, its apparent viscosity decreases remarkably. However, after the addition of a little asphaltene into CLR, its apparent viscosity increases at a low temperature and decreases at a high temperature. In addition, solid content is the factor of increasing the apparent viscosity all the time. All the results indicate that the apparent viscosity of CLR has a close relation with oil, asphaltene, and solid contents. The relationship between the apparent viscosity and temperature can be expressed by Arrhenius Equation. But there is a flex point during heating, and the viscous flow activation energy at the low temperature is greater than that at the high temperature.

The Nafion stabilized alcohol-reduction method has been used to prepare Pt–Ru catalysts supported on Vulcan XC-72. The particle size and morphology of catalysts are determined by X-ray diffraction analysis and transmission electron microscopy. Well-dispersed catalysts with particle sizes from 3 to 7 nm are achieved. The catalytic activities of these catalysts towards methanol electro-oxidation are investigated at electrode potentials of interest for fuel cells. The addition of Nafion during catalyst preparation enhances the methanol electro-oxidation activity even for low methanol concentrations. The in-house prepared Pt–Ru/C catalysts (MEC-01 and MEC-03) in 0.5 M H 2 SO 4 with 5% methanol at 40 °C display a higher catalytic activity than a standard Pt–Ru/C (E-TEK 40) catalyst. In 5% methanol, the impedance of the in-house catalyst is lower than that of the standard Pt–Ru/C (E-TEK 40) catalyst, viz., 26.18 mg Ω versus 139.49 mg Ω. The Structure of the in-house prepared MEC-01 catalyst is compared with that of commercial E-TEK 40 by means of X-ray absorption spectroscopy. The X-ray absorption near-edge structure (XANES) of the MEC-01 catalyst at Pt L III -edge shows significant variation in white line intensity compared with that of the commercial E-TEK 40 catalyst.

This article describes the preparation of novolac-type phenolic resin/silica hybrid organic-inorganic nanocomposite, with a sol- gel process. The coupling agent was used to improve the interface between the organic and inorganic phases. The effect of the structure of the nanocomposite on its physical and chemical properties is dis- cussed. The coupling agent reacts with the resin to form covalent bonds. The structure of the modified hybrid nanocomposites was identified with a Fourier transform infrared spectroscope. The silica network was characterized by nuclear magnetic resonance imaging ( 29 Si NMR). Results revealed that Q4 (tetrasubstituted) and T3 (trisubstituted) are the dominant microstructures. The size of the silica in the phenolic resin was characterized with a scanning electron microscope. The size of the particles of inorganic silica in the modified system was less than 100 nm. The nanocomposite exhibited good transparency. Moreover, the thermal and mechanical properties exhibited significant improvement. The modified hybrid composite exhibited favorable thermal properties. The temperature at which a weight loss of 5% occurred increased from 281 to 350 °C. The flexural strength increased by 6 -30%. The limiting oxygen index of the nanocom- posite reached 37, and the Underwriters Laboratory test was 94V-0. Consequently, these materials possess excellent flame-retardant properties. © 2003 Wiley Periodicals

GP-1 is a novel glycoprotein produced by Streptomyces kanasenisi ZX01 that was isolated from soil near Kanas Lake with significant bioactivity against tobacco mosaic virus. However, extremely low fermentation production has largely hindered further research and market applications on glycoprotein GP-1. In this study, response surface methodology was used to optimize fermentation conditions in a shake flask for higher glycoprotein GP-1 production. When the optimized fermentation conditions were inoculum volume of 6%, initial pH of 6.5, and rotating speed of 150 rpm, glycoprotein GP-1 production could reach 0.9253 mg/L, which was increased by 52.14% compared to the original conditions. In addition, scale-up fermentation was conducted in a 5-L bioreactor to preliminarily explore the feasibility for mass production of glycoprotein GP-1 in a large fermentor, obtaining GP-1 production of 2.54 mg/L under the same conditions, which was 2.75 times higher than the production obtained from a shake flask of 0.9253 mg/L. This work will be helpful to improve GP-1 production on a large scale and lay the foundations for developing it as a novel agent against plant virus.

The first Co/Pd-cocatalyzed intramolecular C-H amination and aziridination reactions were developed. Sulfamate esters were converted to oxathiazinanes by using CoPd(OAc)4 as catalyst and PhI(OAc)2 as oxidant. The mutual presence of both Co and Pd is crucial for the catalytic activity. This combination of two metals with simple acetate ligands provides an economical alternative to the Rh-catalyzed insertion of nitrenoids into C-H bonds.

Polyamidoamine (PAMAM) dendrimers have attracted lots of interest as drug carriers. And little study about whether pluronic-attached PAMAM dendrimers could be potential drug delivery systems has been carried on.Pluronic F127 (PF127) attached PAMAM dendrimers were designed as novel drug carriers.Two conjugation ratios of PF127-attached PAMAM dendrimers were synthesized. (1)H nuclear magnetic resonance ((1)H-NMR), Fourier transform infrared spectrum (FTIR), element analysis and ninhydrin assay were used to characterize the conjugates. Size, zeta potential and critical micelle concentrations (CMC) were also detected. And DOX was incorporated into the hydrophobic interior of the conjugates. Studies on their drug loading and drug release were carried on. Furthermore, hemolysis and cytotoxicity assay were used to evaluate the toxicity of the conjugates.PF127 was successfully conjugated to the fifth generation PAMAM dendrimer at two molar ratios of 19% and 57% (PF127 to surface amine per PAMAM dendrimer molecular). The conjugates showed an increased size and a reduced zeta potential. And higher CMC values were obtained than pure PF127. Compared with unconjugated PAMAM dendrimer, PF127 conjugation significantly reduced the hemolytic toxicity and cytotoxicity of PAMAM dendrimer in vitro. The encapsulation results showed that the ability to encapsulate DOX by the conjugate of 19% conjugation ratio was better than that of 57% conjugation ratio. And the maximum is ∼12.87 DOX molecules per conjugate molecule. Moreover, the complexes showed a sustained release behavior compared to pure DOX.Findings from the in vitro study show that the PF127-attached PAMAM dendrimers may be potential carriers for drug delivery.

A new macrolide glycoside, cuneataside F was isolated from the n-butanol extract of the stem of Sargentodoxa cuneata . The structure was elucidated on the basis of extensive 1D and 2D NMR as well as HRESI-MS spectroscopic analysis.

The first Co/Pd-cocatalyzed intramolecular C-H amination and aziridination reactions were developed. Sulfamate esters were converted to oxathiazinanes by using CoPd(OAc)4 as catalyst and PhI(OAc)2 as oxidant. The mutual presence of both Co and Pd is crucial for the catalytic activity. This combination of two metals with simple acetate ligands provides an economical alternative to the Rh-catalyzed insertion of nitrenoids into C-H bonds.

Cellulose-graft-poly (L-lactide) (cellulose-g-PLLA) was prepared under homogeneous mild conditions. Ring-opening polymerization (ROP) was carried out successfully using 4-dimethylaminopyridine (DMAP) as an organic catalyst in an ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl). The structure of the polymer was characterized by GPC, 1H NMR, 13C NMR, FT-IR, TGA, WAXD, and AFM. The results indicated that the grafting rate of the polymer reached 4.44, which was higher than that reported in AmimCl with Sn(oct)2 as a catalyst. In addition, AFM showed that the polymer in solution could aggregate and self-assemble into an approximately spherical structure, which was different from the rod-like structure of cellulose and round-like polylactic acid particles.

BackgroundGlucocorticoid has an important effect on lipid metabolism in muscles, and the type of fatty acid likely affects mitochondrial utilization. Therefore, we hypothesize that the different fatty acid types treatment may affect the glucocorticoid induction of intramuscular lipid accumulation.Methodology/principal findingsThe effect of dexamethasone (DEX) on fatty acid metabolism and storage in skeletal muscle of broiler chickens (Gallus gallus domesticus) was investigated with and without fatty acid treatments. Male Arbor Acres chickens (31 d old) were treated with either palmitic acid (PA) or oleic acid (OA) for 7 days, followed by DEX administration for 3 days (35-37 d old). The DEX-induced lipid uptake and oxidation imbalance, which was estimated by increased fatty acid transport protein 1 (FATP1) expression and decreased carnitine palmitoyl transferase 1 activity, contributed to skeletal muscle lipid accumulation. More sensitive than glycolytic muscle, the oxidative muscle in DEX-treated chickens showed a decrease in the AMP to ATP ratio, a decrease in AMP-activated protein kinase (AMPK) alpha phosphorylation and its activity, as well as an increase in the phosphorylation of mammalian target of rapamycin (mTOR) and ribosomal p70S6 kinase, without Akt activation. DEX-stimulated lipid deposition was augmented by PA, but alleviated by OA, in response to pathways that were regulated differently, including AMPK, mTOR and FATP1.ConclusionsDEX-induced intramuscular lipid accumulation was aggravated by SFA but alleviated by unsaturated fatty acid. The suppressed AMPK and augmented mTOR signaling pathways were involved in glucocortcoid-mediated enhanced intramuscular fat accumulation.

Microbial transformation of oleanolic acid (1) was carried out. Six transformed products (2-7) from 1 by Alternaria longipes and three transformed products (8-10) from 1 by Penicillium adametzi were isolated. Their structures were elucidated as 2α,3α,19α-trihydroxy-ursolic acid-28-O-β-d-glucopyranoside (2), 2α,3β,19α-trihydroxy-ursolic acid-28-O-β-d-glucopyranoside (3), oleanolic acid 28-O-β-d-glucopyranosyl ester (4), oleanolic acid-3-O-β-d-glucopyranoside (5), 3-O-(β-d-glucopyranosyl)-oleanolic acid-28-O-β-d-glucopyranoside (6), 2α,3β,19a-trihydroxy-oleanolic acid-28-O-β-d-glucopyranoside (7), 21β-hydroxyl oleanolic acid-28-O-β-d-glucopyranoside (8), 21β-hydroxyl oleanolic acid (9), and 7α,21β-dihydroxyl oleanolic acid (10) based on the extensive NMR studies. Among them, 10 was a new compound and compounds 5 and 8-10 had stronger cytotoxic activities against Hela cell lines than the substrate. At the same time, it was reported for the first time in this paper that the skeletons of compounds 2 and 3 were changed from oleanane to uranane and seven glycosidation products were obtained by biotransformation.

The first total synthesis of bulbophylol-B (1) has been achieved with the longest linear sequence of 12 steps and an overall yield of 17.9% via a new and practical approach to construct the dihydrodibenz[b,f]oxepin skeleton employing Wittig, selective reduction, and intramolecular Ullmann reactions as key steps.

A total synthetic route for two natural dihydrostilbenes with significant cytotoxicity toward human cancer cell lines, (3-(2-(7-methoxybenzo[d][1,3]dioxol-5-yl)ethyl)phenol 1a and 6-(3-hydroxyphenethyl)benzo[d][1,3]dioxol-4-ol 1b), which were isolated from Bulbophyllum odoratissimum Lindl, was developed via Wittig-Horner reaction. The natural products 1a and 1b were obtained in 28% and 20% overall yield, respectively. Additionally, nine analogues, 1c-1k, of the two natural dihydrostilbenes were synthesized and evaluated for their anti-proliferative activity against human SGC-7901, KB and HT-1080 cell lines by MTT assay. The activities of 1c and 1d were in the same range as those of the natural products 1a and 1b.

A novel method of feature extraction and classification of fluorescence spectra using neural network was developed in order to improve the diagnostic rate of earlier stage colonic carcinomas with laser-induced 5-ALA-PpIX fluorescence spectra. 150 min after trail intravenous injections of 5-ALA dose of 25mg/kg body weight (BW) to 40 rats, 504 fluorescence spectra excited with 370 nm Ti-Laser were collected in vivo, which included 183 normal, 69 dysplasia (DYS), 87 early cancer (EC) and 165 advanced cancer (AC). After preprocessing, 6 principal components were extracted using adaptive principal component extraction (APEX). With BP neural network trained with resilient back-propagation algorithm (RBPNN), all spectra were divided into two categories: normal or abnormal, which included DYS, EC and AC. The sensitivity and specificity were 96.57% and 95.08% respectively. The accuracy of discriminating DYS and EC and AC from normal tissue were 92.75% and 98.85% and 96.36% respectively. The result indicated that this method could effectively diagnose earlier stage colonic carcinomas

The potential for the use of renewable sources of energy in China and India and their cost effectiveness in air pollution abatement in Asia is studied. This is done through an integrated assessment of the costs and the environmental impacts of several types of renewables, in comparison with fossil fuels. Results for different scenarios for fuel use in China and India for the period 1990–2020 are presented. The acidification model RAINS-ASIA is used to analyze environmental impacts (exceedance of critical loads for acidification) and to perform an optimization analysis, aiming at minimizing abatement costs. The costs of sulfur dioxide (SO2) emission-control through the switch to renewable energy sources are analyzed and compared with the costs of controlling the emissions from fossil fuels (e.g. through flue gas desulfurization). For the environmental targets analyzed in this study an increased use of renewable energy could cut SO2 emission-control costs in China by 17–35%, and in India by more than two thirds.

Basil ( Ocimum basilicum ) , an edible and medicinal plant with high nutritional value and therapeutic efficacy, was used as a potential source of total flavonoids in this study. Heat reflux extractions were performed using aqueous ethanol. The optimized extraction conditions of total flavonoids from O. basilicum were determined by Box-Behnken design with response surface methodology. Response surface plots showed that the optional four independent variables significantly influenced the extraction yield of total flavonoids. The extraction parameters for the highest total flavonoids yield were optimized as: extraction temperature of 79.74 °C, ethanol concentration of 77.63%, ratio of liquid to material of 29.72:1 (mL/g), and extraction time of 2.06 h. The average yield of total flavonoids under above optimum parameters was 42.61 mg of rutin equivalents per g of extract dry matter, which was in good agreement with the predicted value of 40.23 mg/g. These optimized conditions could be useful for the extraction of flavonoids from O. basilicum .

An extract from adult Ascaris suum was fractionated on a Sephadex G-200 column and individual elution fractions assessed for their ability to induce or suppress an IgE antibody response in mice immunized simultaneously with a heterologous antigen (ovalbumin). The results showed that, whilst fractions eluted in the first peak suppressed the anti-ovalbumin IgE antibody production, those eluted in the third peak induced a significant anti-Ascaris IgE response. The mixture of the two kinds of fractions resulted in suppression of anti-Ascaris IgE antibodies. The apparent molecular weight (MW) of the first and third peaks was 530,000 and 29,000 daltons, respectively. After delipidation, the extract still retained most of its biological activities. SDS-PAGE of this material showed selective loss of high-MW components when compared to the whole extract. No bands were observed in SDS-PAGE of peak I in contrast to peak III, which displayed several bands. Immunoblots of all these samples showed at least 3 bands above MW 150,000, which reacted with anti-peak I anti-serum, in the unfractionated extracts and in peak I, but not in peak III. When the extract was fractionated by affinity chromatography using anti-peak I antibodies as ligands, the immunogenic components were present in the effluent, whereas the suppressive components were recovered in the eluate.

The correlations between the Raman band intensities, concentrations, refractive indices and the absorption frequency of benzene were studied by measuring the integrated intensities of the Raman band 992 cm -1 of benzene in 8 solutions of different concentrations and the refractive indices of the solutions. It is shown that the intensity deviation is proportional to the difference between the refractive index of the solution and that of pure benzene. The band intensities of different solutions depend linearly on their refractive indices, that is, the intensity does not depend on the nature of the solvent, but on its refractive index. The relationship between the band intensities and the resonance frequency factors of benzene in the solutions is also linear. The experimental results are discussed from the point of view of perturbation of the medium on the electronic absorption band.