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Chemical pesticides often applied to effectively control the long-horned beetles to protect the forests are reported to affect the non-target organisms adversely. Dastarcus helophoroides is an active natural enemy of long-horned beetles. Studying the molecular mechanism of P450 genes will help to elucidate the metabolic mechanism of pesticides in D. helophoroides to better coordinate the use of chemical and biological controls. In this study, two novel genes, CYP6BQ21, and CYP6BQ22 were successfully cloned from D. helophoroides using the rapid amplification of cDNA ends technique. The sequence and homology analyses indicated that CYP6BQ21 was highly similar to CYP6BQ1 from Tribolium castaneum, while CYP6BQ22 was closely related to CYP6BQ13 from T. castaneum. Gene expression patterns showed that CYP6BQ21 and CYP6BQ22 were specifically expressed in the adult stage of D. helophoroides. In addition, CYP6BQ21 and CYP6BQ22 were significantly expressed under the treatment of a high concentration of cypermethrin. Based on these findings, we proposed that CYP6BQ21 and CYP6BQ22 played possible roles in the development and pesticide stress of D. helophoroides. Our findings are an important first step in identifying and characterizing CYP6BQ21 and CYP6BQ22 from D. helophoroides, and lay the groundwork for future research into the role of these novel CYP6s in the regulation of pesticide resistance in D. helophoroides.

In the fields of medicine and health, traditional high-performance liquid chromatography or UV-visible spectrophotometry is generally used for substance quantification. However, over time, nuclear magnetic resonance spectroscopy (NMR) has gradually become more mature. Nuclear magnetic resonance spectroscopy has certain advantages in the quantitative analysis of substances, such as being nondestructive, having a high flux and short analysis time. Nuclear magnetic resonance spectroscopy has been included in the pharmacopoeiae of various countries. In this paper, the principle of nuclear magnetic resonance spectroscopy and the recent progress in the quantitative study of natural products by NMR are reviewed, and its application in the quantitative study of natural products is proposed. At the same time, the problems of using NMR alone to quantify natural products are summarized and corresponding suggestions are put forward.

The development of non-noble metal ions with potential organic phosphor ligands through strong coordination bonds can afford an effective platform for achieving persistent and tunable phosphorescence at room temperature. However, successful examples of coordination polymers (CPs) or metal–organic frameworks (MOFs) exhibiting long-lasting phosphorescence emission are still rarely explored. In this work, a new strategy has been used for the first time to achieve long-lasting phosphorescence via π-type halogen bonding in coordination polymers. By the selection of two isomers 5-BIPA and 4-BIPA with different Br atom substitution positions in isophthalic acid (IPA), two new Zn(II)-based coordination polymers exhibiting long-lasting phosphorescence emission up to the order of magnitude of millisecond (ms) were presented, which were further revealed by theoretical calculations. Optoelectronic measurements indicated that 1 showed a high photoelectron response because the delocalized π-type halogen bonding and long range order of π-conjugated chains afforded large electron channels for efficient charge transport.

Highly dense packing of chromophoric linkers is achieved in a novel pyrene-based metal-organic framework (MOF), [Zn(TBAPy)1/2(H2O)2], induced by an ionic liquid. This MOF displays a quick response to visible-light irradiation (photocurrent density of up to 4.492 μA cm-2) and is capable of repetitive on-off photocurrent switching with a large on-off ratio (37.55).

Mythimna separata Walker (Lepidoptera: Noctuidae) is one of the major pests that can cause severe damage to grain crops. The development of low-toxicity and high-performance botanical insecticides is becoming the focus of new pesticide research to control M. separata. Tutin, a sesquiterpene lactone compound obtained from Coriaria sinica Maxim, a native Chinese poisonous plant, has antifeedant, absorption, and stomach poisoning against a variety of pests. To understand the toxic effect of tutin on M. separata larvae, we set out to determine their antifeedant, mortality, paralysis, weight change, and to examine the spreading of M. separata hemocytes under different concentrations of tutin treatment. Tissue distribution of the immune-associated gene growth-blocking peptide (GBP) and neuroglian peptide (Nrg) was detected by reverse transcription polymerase chain reaction (PCR). Furthermore, real-time quantitative PCR was carried out to determine the expression profiles of GBP and Nrg after different concentrations of tutin stimulation. Our results revealed that tutin exhibited significant antifeedant and insecticidal activities, paralysis, weight loss to M. separata. Besides, tutin significantly influenced on the morphology of hemocytes and enhanced the expression of GBP and Nrg in M. separata.

Diffusion-ordered spectroscopy (DOSY) is a powerful tool for investigating mixtures and identifying peaks of chemical components. However, similar diffusion coefficients of the components, particularly for complex mixtures that contain crowded resonances, limit resolution and restrict application of the DOSY technique. In this paper, matrix-assisted DOSY were used to explore whether the diffusion resolution of a complex model involving indole alkaloid mixtures can be realized. Furthermore, we investigated the influence of different factors on the separation effect. The results showed that the changes in diffusion coefficient differences were achieved more obviously when using sodium dodecyl sulfate (SDS) micelles as the matrix. In addition, we also found that increasing the concentration of SDS can improve the resolution of the DOSY spectrum. Finally, after investigating the influence factors and NMR conditions, we demonstrated the applications of the SDS-assisted DOSY on analyzing the total alkaloid extract of Alstonia Mairei, and the virtual separation of mixtures was achieved.

Rauvolfia vomitoria is widely distributed in the tropical regions of Africa and Asia, and has been used in traditional folk medicine in China. Indole alkaloids were found to be major bioactive components, while the effects of diabetes mellitus on the pharmacokinetic parameters of the components have not been reflected in vivo. In this study, an efficient and sensitive liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous determination of five ingredients of R. vomitoria in rats. Detection was implemented in multiple-reaction-monitoring mode with an electrospray positive-ionization source. Validation parameters were all in accordance with the current criterion. The established method was effectively employed to compare the pharmacokinetic behaviors of five alkaloids (reserpine, yohimbine, ajmaline, ajmalicine, and serpentine) between normal and type 2 diabetic rats. The single-dose pharmacokinetic parameters of the five alkaloids were determined in normal and diabetic rats after oral administration of 100 and 200 mg/kg body weight. The results indicated that diabetes mellitus significantly altered the pharmacokinetic characteristics of yohimbine, ajmaline, and ajmalicine after oral administration in rats. This is an attempt to provide some evidence for clinicians that may serve as a guide for the use of antidiabetic medicine in clinical practice.

A novel porous anionic cobalt(II) coordination framework based on rod-shaped metal-carboxylate chains, [BMI][Co3(L)2(HCOO)(H2O)2] (1) (H3L = 3,4-bi(4-carboxyphenyl)-benzoic acid, [BMI]Br = 1-butyl-...

Absorbable vascular sealing medical glue, which belongs to Class III medical devices, is a special new material for preventing the leakage of cerebrospinal fluid. Medical four-arm poly(ethylene glycol)-N-hydroxysuccinimide-glutarate (4-arm-PEG-SG) with a molecular weight of 20 000 is the main component of the absorbable medical glue. According to its quality standard, the quality control of residues 1,3-dicyclohexylurea (DCU), glutaric acid (GA) and triethylamine (TEA) is required. A rapid analytical method of quantitative 1H nuclear magnetic resonance (1H NMR) for the determination of residues DCU, GA and TEA in medical 4-arm-PEG-SG was established in the present study. The peaks at δ 1.56 (4H, m), δ 2.71 (4H, t, J = 6.7 Hz), and δ 2.42 (6H, q, J = 7.2 Hz) were selected for quantifying DCU, GA and TEA, respectively, with deuterated pyridine as the solvent and tetramethylsilane as the internal standard. The 1H NMR assay was validated by several experimental parameters including specificity, linearity, accuracy, precision, robustness, limit of detection (LOD), limit of quantification (LOQ) and stability. The average recoveries obtained were in the range of 99.48–102.02% for all three residues. Compared with the HPLC and GC approaches, the proposed 1H NMR method proved to be a powerful tool for quantification due to its unique advantages of simplicity, rapidity and high robustness, especially not requiring standard compounds for calibration curve preparation.

Synthetic microbial coculture to express heterologous biosynthetic pathway for de novo production of medicinal ingredients is an emerging strategy for metabolic engineering and synthetic biology. Here, taking efficient production of salidroside as an example of glycosides, we design and construct a syntrophic Escherichia coli-E. coli coculture composed of the aglycone (AG) strain and the glycoside (GD) strain, which convergently accommodate biosynthetic pathways of tyrosol and salidroside, respectively. To accomplish this the phenylalanine-deficient AG strain was engineered to utilize xylose preferentially and to overproduce precursor tyrosol, while the tyrosine-deficient GD strain was constructed to consume glucose exclusively and to enhance another precursor UDP-glucose availability for synthesis of salidroside. The AG and GD strains in the synthetic consortium are obligatory cooperators through crossfeeding of tyrosine and phenylalanine and compatible in glucose and xylose mixture. Through balancing the metabolic pathway strength, we show that the syntrophic coculture was robust and stable, and produced 6.03 g/L of salidroside. It was the de novo production of salidroside for the first time in E. coli coculture system, which would be applicable for production of other important glycosides and natural products.

A new complex, [Zn(5-Br-ip)(1,2-Bie)]n (1), (5-Br-ipH2 = 5-bromoisophthalic acid; 1,2-Bie = 1,2-bis(imidazole)ethane), has been synthesized by hydrothermal reaction. Its crystal structure was characterized by single-crystal X-ray diffraction analysis and IR spectroscopy. The X-ray single-crystal structure shows that complex 1 belongs to the monoclinic system, C2/c space group, a = 22.367(3), b = 8.2224(12), c = 18.615(4) A, β = 126.21(0)°. The complex exhibits a complicated (3, 4)-connected 3D 3-fold interpenetrating network with a Schlafli symbol of (42·6·102·12)(42·6) topology. The adjacent Zn ions were constructed of one-dimensional double chains, having dinuclear [Zn(COO)2] units bridged by 5-Br-ip. Fluorescence measurements show that the complex has fluorescent emissions at 419 nm upon excitation at 361 nm.

An alkali-resistant Zn-MOF directed by [BMI]Br ionic liquid, (BMI)2[Zn3(ptptc)2] (1), based on a π-electron-rich terphenyl-tetracarboxylic acid, has been synthesized under the combination of hydro/solvothermal and ionothermal condition (BMI = 1-butyl-3-methylimidazolium, H4ptptc = p-terphenyl-3,3′′,5,5′′-tetracarboxylic acid). In 1, the trinuclear Zn(II) clusters are linked by the organic moieties of the ptptc ligands, resulting in a 3D anionic framework structure with highly disordered [BMI]+ cations filled in the pores. 1 exhibits good chemical stability in water and NaOH solutions (pH range of 7–12), which allow it to detect antibiotics and nitroaromatic explosives in an aquatic system. 1 represents high fluorescence quenching efficiency toward NFs (furazolidone, FZD; nitrofurazone, NZF; nitrofurantoin, NFT), NMs (ronidazole, RDZ; metronidazole, MDZ; dimetridazole, DTZ; ornidazole, ODZ) and nitrophenol (2-nitrophenol, 2-NP; 3-nitrophenol, 3-NP; 4-nitrophenol, 4-NP; 2,4,6-trinitrophenol, TNP) in water solution, respectively.

Background The liver is the central organ for cholesterol homoeostasis, and its dysfunction might cause liver pathological alterations including hepatocellular carcinomas (HCCs). 3β-hydroxysteroid-Δ24 reductase (DHCR24), a crucial enzyme of cholesterol biosynthetic pathway, is involved in lipid rafts formation. Genkwadaphnin (GD) is a daphnane diterpene isolated from the flower buds of Daphne genkwa Siebold et Zuccarini (Thymelaeaceae). Methods We evaluated in vitro and in vivo effect of GD using HCC cells and BALB/c nude mice. Microarray assays were used to identify the differential genes by GD. DHCR24 expression and activity, cholesterol level, lipid rafts structure and the role of DHCR24 in human HCC specimens were tested by various molecular biology techniques. Results High expression of DHCR24 in human HCC specimens was correlated with poor clinical outcome. Interfering DHCR24 altered growth and migration of HCC cells. GD inhibited growth and metastasis of HCC cells both in vivo and in vitro. GD suppressed DHCR24 expression and activity, as well as DHCR24-mediated cholesterol biosynthesis and lipid rafts formation, then further inhibited HCC cell invasion and migration. Conclusions Our data suggest that DHCR24-mediated cholesterol metabolism might be an effective therapeutic strategy in HCC, and natural product GD might be a promising agent for HCC therapy.

Twelve new flavan derivatives including four pairs of enantiomers, daphnegiralins A1-A4 (1) and daphnegiralins B1-B4 (2), and two pairs of epimers, daphnegiralins C1/C2 (3) and daphnegiralins D1/D2 (4), were isolated from the stem bark and roots of Daphne giraldii. Their structures were elucidated using spectroscopic analyses, computational approaches, and chemical methods. Separation of the enantiomeric mixtures (1a, 1b, 2a, and 2b) was achieved using chiral HPLC. The compounds were evaluated against a small panel of human cancer cell lines, and 1b-2, 2a, and 2b were cytotoxic against Hep3B human hepatoma cells.

1-Deoxy-d-xylulose 5-phosphate reductoisomerase (DXR) is the first committed enzyme in the MEP terpenoid biosynthetic pathway and also a validated antimicrobial target. Green tea which is rich in polyphenolic components such as the catechins, possesses a plenty of pharmacological activities, in particular an antibacterial effect. To uncover the antibacterial mechanism of green tea and to seek new DXR inhibitors from natural sources, the DXR inhibitory activity of green tea and its main antimicrobial catechins were investigated in this study. The results show that the raw extract of green tea and its ethyl acetate fraction are able to suppress DXR activity explicitly. Further determination of the DXR inhibitory capacity of eight catechin compounds demonstrates that the most active compound is gallocatechin gallate that is able to inhibit around 50% activity of DXR at 25μM. Based on these data, the primary structure-activity relationship of the catechins against DXR is discussed. This study would be very helpful to elucidate the antimicrobial mechanism of green tea and the catechins and also would be very useful to direct the rational utilization of them as food additives.

One new Zn(II) based 3D metal-organic framework (MOF) [Zn(IPA) (TBMIM)] (1) (IPA ​= ​isophthalic acid, TBMIM ​= ​1,4-bis(imidazole-1-ylmethyl)benzene) has been synthesized under hydrothermal conditions. X-ray single-crystal diffraction analysis indicates that the title MOF exhibits a 3-fold interpenetrated diamond network with new type of molecular braid. Time-resolved measurements reveal that 1 emissions rare example of near-infrared phosphorescence at room temperature. The density functional theoretical (DFT) calculations indicate complete separation of molecular orbits between IPA and TBMIM ligands, which is in favor of the generation of triplet state excitons. This MOF also shows well photoelectron responds performance owing to the abundant π···π stacking in the entanglement molecular braids, which afford long-range π electrons delocalization for efficient electron transport.

In this work, an NMR analytical procedure based on highly chemical-shift-selective filtration (CSSF) with total correlation spectroscopy (TOCSY) was used for the rapid identification and quantification of trimethoprim, benproperine phosphate, diclofenac sodium, pentoxyverine citrate, diphenhydramine hydrochloride, sulfamethoxazole, dioxopromethazine hydrochloride, chlorphenamine maleate, prednisone acetate, theophylline, and diazepam in antitussive and antiasthmatic herbal medicinal products. This method is advantageous for content determination owing to its specific background-free signals for each chemical adulterant and easy-to-perform pretreatment operations. Satisfactory results in terms of limit of quantification (0.70–1.35 mg/g), precision (relative standard deviation, RSD%: 2.05–7.08), accuracy (bias%: 0.16–6.51), and recovery (85.4%–106.5%) were achieved. Among 28 batches of antitussive and antiasthmatic herbal medicinal products, 27 batches contained illegal adulterants, which differed in terms of the amount and type of compounds. The established method was employed for the qualitative screening and quantitative detection of illegal adulterants in herbal medicinal products because of its strong selectivity and fast analysis.

The rapid emergence of superbugs, or multi-drug resistant (MDR) organisms, has prompted a search for novel antibiotics, beyond traditional small-molecule therapies. Nanotherapeutics are being investigated as alternatives, and recently superoxide-generating quantum dots (QDs) have been shown as important candidates for selective light-activated therapy, while also potentiating existing antibiotics against MDR superbugs. Their therapeutic action is selective, can be tailored by simply changing their quantum-confined conduction-valence band (CB-VB) positions and alignment with different redox half-reactions-and hence their ability to generate specific radical species in biological media. Here, we show the design of superoxide-generating QDs using optimal QD material and size well-matched to superoxide redox potential, charged ligands to modulate their uptake in cells and selective redox interventions, and core/shell structures to improve their stability for therapeutic action. We show that cadmium telluride (CdTe) QDs with conduction band (CB) position at -0.5 V with respect to Normal Hydrogen Electron (NHE) and visible 2.4 eV bandgap generate a large flux of selective superoxide radicals, thereby demonstrating the effective light-activated therapy. Although the positively charged QDs demonstrate large cellular uptake, they bind indiscriminately to cell surfaces and cause non-selective cell death, while negatively charged and zwitterionic QD ligands reduce the uptake and allow selective therapeutic action via interaction with redox species. The stability of designed QDs in biologically-relevant media increases with the formation of core-shell QD structures, but an appropriate design of core-shell structures is needed to minimize any reduction in charge injection efficiency to adsorbed oxygen molecules (to form superoxide) and maintain similar quantitative generation of tailored redox species, as measured using electron paramagnetic resonance (EPR) spectroscopy and electrochemical impedance spectroscopy (EIS). Using these findings, we demonstrate the rational design of QDs as selective therapeutic to kill more than 99% of a priority class I pathogen, thus providing an effective therapy against MDR superbugs.

Thirteen new flavan compounds named daphnegiravans A–M (1–13) and eight known analogues (14–21) were isolated from the stem and root bark of Daphne giraldii. Their structures were established by comprehensive analysis of NMR data and CD spectra. Five human cancer cell lines (MCF-7, Bcap37, HepG2, Hep3B and A549) were used to evaluate the antitumor activity of all the isolates and their structure–activity relationships were also discussed. Interestingly, prenylated and some methoxy flavans exhibited the highest activities against Hep3B compared with the other cell lines, especially 3 and 9–12 with IC50 values ranging from 5.15 to 9.66 μM. Furthermore, flow cytometry analysis indicated that 3 and 9–11 possessing a 2,2-dimethylpyran moiety in ring B induced G2/M phase arrest in Hep3B cells, while 12 with different structural features effectively inhibited cell proliferation by evoking apoptotic cell death. The reactive oxygen species (ROS) generation might be responsible for the induction of arrest and apoptosis.

Single molecule catalysis is very powerful in revealing catalytic mechanism at the single molecule level. But fluorescent molecule is always necessary to take part into the catalysis directly in previous research. In order to study the single molecule electro-catalysis of non-fluorescent molecule (SMECNFM) on nano-catalyst, we couple the SMECNFM with a single molecule fluorescence reaction. A certain number of fluorescent molecules will be generated and detected when the SMECNFM happens. Through this method, we can detect the electro-oxidation reaction of one HCOONa molecule. The stability of Pt nano-catalyst supported on active carbon is studied at the single molecule level by this method. This paper also provides a general way to make ultra-sensitive sensor, and to study the SMECNFM for the molecules, such as formic acid, hydrogen, oxygen, etc. , on single nanoparticle.

Hydrothermal reactions of molybdenum(III) oxide with isoquinoline under different pH values lead to two new octamolybdate-based polyoxometalates (POMs), namely, (C9H7NH)4(C9H7N)2[Mo8O26] (1) and (C9H7NH)4[(Mo8O26)(C9H7N)2]·2(H2O) (2), and their structures were determined by single-crystal X-ray diffraction analysis. The two compounds represent the first report of [Mo8O26]4− based POMs associated with isoquinoline ligand. Compound (1) has 3D supramolecular framework based on hydrogen bonds between [β-Mo8O26]4− fragment and protonated isoquinoline (C9H7NH)+. Compound (2) contains [(γ-Mo8O26)(C9H7N)2]4− units constructed by [γ-Mo8O26]4− units and isoquinoline through Mo–N bonds.

C36H33ErN4O16, monoclinic, C2/c (no. 15), a = 13.828(3) Å, b = 15.892(3) Å, c = 15.634(3) Å, β = 95.687(2)°, V = 3418.7(12) Å3, Z = 4, R gt (F) = 0.0216, wR ref (F 2 ) = 0.0490, T = 296(2) K.

Neogenkwanines A–H (1–8), eight daphnane-type diterpenes possessing new skeletons with 4,7- or 4,6-ether groups, along with seven known ones (10–16), were isolated from Daphne genkwa. Their structures and absolute configurations were established by analysis of their NMR, X-ray crystallography, CD exciton chirality data and hydrolysis experiments. In addition, an MTT assay was used to examine the growth-inhibitory effects of all the new isolates on HL-60, Hep3B, and U87 cells; compounds 3, 4 and 5 exhibited significant inhibitory effects against Hep3B cell lines with IC50 values of 7.61, 8.16 and 8.35 μM, respectively.

Roughing disorder (RD) is a significant quality barrier in citrus fruit, prevalent on easy-peeling mandarins. As RD is not yet well-understood, this study aimed to examine the changes and synergic molecular processes involved in peel RD. Peel with RD was induced by severely defruiting Satsuma mandarin trees. Morphology observations, RNA-sequencing, and targeted and untargeted metabolic analyses were conducted. The results showed that the primary metabolites of sugars, organic acids and amino acids are dramatically changed in RD peel. The RD peel was always characterized by higher magnesium content during development. Comparative transcriptome profiling was performed for CK and RD peels at 30, 80, and 170 days after full bloom (DAFB) which represented fruit at cell division stage, cell enlargement stage and fruit maturity stage, respectively. Physiological and molecular biological evidence suggested that the month after full bloom is a crucial stage for RD initiation. A total of 4,855 differentially expressed genes (DEGs) in RD peel, relative to CK peel were detected at cell division stage, about 2 to 4-fold more than other stages had. Among the differentially expressed transcription factors, the bHLH family were affected most by RD, and six bHLH transcription factors functionally involved in GA metabolism were assessed to associate with RD occurrence. Gene set enrichment analysis suggested that RD significantly altered starch and GA metabolism in peel. Higher starch content and hydrolysed chain status were found in RD peel at cell division stage. RD occurrence on the peel was influenced significantly by GA, especially abundant GA before July. These changes may mean a significant alteration in sink strength of RD peel. The findings of this study provide insights into the emergence, development and molecular mechanisms of RD.

Six new complexes with 3-pytza ligand (3-pytza = 5-(3-pyridyl) tetrazole-2-acetato), [Sr(3-pytza)2(H2O)2]n·nH2O (1), [Zn(3-pytza)2(H2O)2]n·2nH2O (2), [Cu(3-pytza)2(H2O)]n·2nH2O (3), [Pb(3-pytza)2]n (4), [Eu(3-pytza)2Cl(H2O)2]n (5), [Tb(3-pytza)2Cl(H2O)2]n (6) have been synthesized. These compounds were characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The X-ray analysis reveals that these compounds display 1D or 2D structures. Furthermore, the luminescent properties of 1–6 were investigated at room temperature in the solid state.

Two new coordination compounds, namely 1D [Mn(pztza)2(4,4′-bipy)(H2O)2]·2H2O (1) and [Co(4,4′-bipy)(H2O)4]·2pztza·4H2O (2), were synthesized by the reactions of Hpztza [Hpztza = 5-(2-pyrazinyl)tetrazole-2-acetic acid] with 4,4′-bipyridine and MnCl2·4H2O or CoCl2·6H2O in the presence of NaOH. The two compounds were structurally characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The X-ray analysis reveals that the two compounds form 1D chain structure via the bridging 4,4′-bipy. In compound 1, pztza acts as a monodentate ligand to coordinate to Mn(II) center, while in compound 2, pztza ligands are not coordinated to Co(II) centers, instead, they are connected to the 1D chain via hydrogen bonds. Furthermore, the luminescent properties were investigated at room temperature in the solid state. Mn(II) and Co(II) coordination compounds based on Hpztza and 4,4′-bipy were prepared. As 4,4′-bipy acts as a bridging ligand, the two compounds show 1D chain structure. The luminescent properties were investigated at room temperature in the solid state.

Reactions of four different tetrazole-containing carboxylic acids and 4,4′bipyridine with ZnCl 2 ·6H 2 O, produced four new coordination compounds, [Zn(pytza) 2 (4,4′-bipy)(H 2 O) 2 ]·2H 2 O ( 1 ), (pytza = 5-(3-pyridyl)tetrazole-2-acetato), [Zn(tzpya) 2 (4,4′-bipy)(H 2 O) 2 ]·8H 2 O ( 2 ) (tzpya = 4-(5-tetrazolyl)pyridine-1-acetato), [Zn(4,4′-bipy)(H 2 O) 4 ]·2(pztza)·2H 2 O ( 3 ) (pztza = 5-(2-pyrazinyl)tetrazole-2-acetato). [Zn(atza) 2 (4,4′-bipy) 0.5 ·H 2 O] ( 4 ) (atza = 5-aminotetrazole-1-acetato). These compounds were structurally characterized by elemental analysis, IR spectroscopy, UV–Vis spectroscopy, thermogravimetric analysis and single crystal X-ray diffraction. The X-ray diffraction reveals that compounds 1 – 3 display 1D polymeric chains while 4 shows a 2D layer structure. Compounds 1 – 4 are self-assembled to form 3D networks by hydrogen bonding interactions. Furthermore, the luminescent properties were also investigated at room temperature in the solid state.

A core-shell structure RuRh@Pt/C nanoparticles was prepared by using a two-step reduction method under ultrasonic promotion. The catalytic performance was tested in methanol electrooxidation. X-ray diffraction (XRD), scanning electron microscope (SEM) combined with cyclic voltammetry (CV) were used to characterize the obtained catalyst. The results showed that there was no alloy formed between the core RuRh and the shell Pt. The electrocatalytic activity of RuRh@Pt/C varied with the Ru/Rh ratio in the bimetallic core, among which the catalyst with the Ru/Rh ratio 1:2 and the Pt-shell thickness of 1.5 (Ru1Rh2@Pt1.5/C) showed the highest catalytic activity for methanol. With this catalyst, the current density of the oxidation peak for methanol electro-oxidation reached 2.3 times as that of Pt1.5/C while the corresponding peak potential shifted 60 mV negatively in comparing to that of Pt1.5/C. In addition, the catalyst with the core-shell structure of RuRh@Pt/C possessed much higher CO-tolerance for methanol electro-oxidation, indicating its promising application in low temperature fuel cell.

Reactions of three tetrazole containing carboxylic acid ligands, namely, Hpztza, Htzpya, and Hpytza [Hpztza = 5-(2-pyrazinyl)tetrazole-2-acetic acid, Htzpya = 3-(5-tetrazolyl)pyridine-1-acetic acid, Hpytza = 5-(3-pyridyl)tetrazole-2-acetic acid] with NdCl3·6H2O under hydrothermal conditions, afforded the complexes [Nd(pztza)2(H2O)6]·pztza·3H2O (1), [Nd2(tzpya)2(H2O)12]Cl4·2H2O (2), and [Nd(pytza)2Cl(H2O)2] (3). The compounds were structurally characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. X-ray diffraction analyses revealed that compound 1 displays a mononuclear structure, 2 shows a dinuclear structure, and 3 features a 1D polymeric chain structure via pytza as linker. Furthermore, the luminescent properties investigated at room temperature in the solid state show that compound 2 has an obvious decrease in its luminescence, when compared to the ligand.

Long wavelength of near infrared (NIR) room temperature phosphorescence (RTP) emission is a kind of highly desirable materials. In this study, with the self-assembly reaction of D-A-D type semi-rigid 3,5-bis(1-imidazoly)pyridine (BMP) organic ligand and Zn(II) ions, one ionic coordination polymer (CP) {[Zn0.5(BMP)(H2O)]·(NO3)} (1) has been synthesized and characterized. The as-synthesized 1 exhibits highly prolonged phosphorescence lifetime more than 6000 times as long as that of the pristine BMP phosphor ligand. Theory calculation indicates that NO3- counter ions highly affect the electronic structure and energy levels of the cationic CP host. By a facile anionic exchange, Eosin Y (EY) dye guest encapsulated into the CP host can significantly tune the phosphorescence color from yellow to rare example of near infrared emission through an efficient phosphorescence energy transfer. In addition, the optoelectronic performance of 1 and EY@1 have also been studied.

A new complex, [Zn3(nbta)2(bix)2.5·H2O]n (1) [H3nbta = 5-nitro-1,2,3-benzenetricarboxylic acid; bix = 1,4-bis(imidazol-1-ylmethyl)benzene], has been synthesized by hydrothermal reaction with Zn(II) acetate, H3nbta, and bix ligands. It was determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis and IR spectroscopy. The X-ray single-crystal structure shows that complex 1 belongs to the triclinic system, Pī space group, a = 9.919(6), b = 12.997(8), c = 22.679(13) A, and α = 76.087(7), β = 81.429(8), γ = 81.429(8)°. Complex 1 exhibits a (3,4)-connected 3D network with a (4.6.8)2(62.8)(4.104.12)(4.62.82.10) topology, in which binuclear and mononuclear Zn(II) nodes are bridged by the nbta anions and bix ligands. The thermal stabilities of complex 1 have been briefly observed. Supplemental materials are available for this article. Go to the publisher's online edition of Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry to view the suppl...

Three different cadmium(II) coordination polymers, [Cd2(mip)2(1,2-bie)] (1), [Cd(mip)(1,3-bip)] (2), {[Cd(mip)(1,4-bib)(H2O)]·H2O}2 (3), where H2mip = 5-methylisophthalic acid, 1,2-bie = 1,2-bis(imidazole)ethane, 1,3-bip = 1,3-bis(imidazole)propane and 1,4-bib = 1,4-bis(imidazole)butane, were synthesized under hydrothermal conditions. Their structures have been characterized by elemental analysis, IR and single-crystal X-ray crystallography. Complex 1 displays a 3D network with a (4,5)-connected (42.74)(42.62.76) topology. Complex 2 features a 2D layer structure with a (3,5)-connected (42.6)(42.67.8) topology. Complex 3 has two crystallographically distinct 2D (4,4) polymeric motifs, which are further extended by hydrogen-bonding interactions to form a 2D double layer. These structural analyses indicate that the flexible bis(imidazole) ligands with different spacer lengths play important roles in the formation of the final structures. In addition, the photoluminescent properties of 1–3 in the solid state have been investigated.

Four new daphnane-type diterpenes, genkwadanes A-D (1-4), together with 19 known ones, were isolated from ethanol extract of the flower buds of Daphne genkwa. Their structures were determined on the basis of extensive spectroscopic data. Among them, daphnane-type diterpene with a 1,10-double bond (1) was isolated from this plant for the first time. The cytotoxicity of all compounds 1-23 against the 10 selected human cancer cell lines was assayed. A number of compounds exhibited significant activities against the 10 cancer cell lines (IC50

The use of both 4-bromoisophthalic acid (H2Brip)/5-nitroisophthalic acid (H2nip) and 4,4′-dipyridyldisulfide (dpds) with Co(II) ion under hydrothermal conditions has provided two new Co(II) coordination polymers, [Co(dps)(Brip)]n (1) and [Co(H2O)(dpds)(nip)]n (2), respectively. The two compounds have been characterized by elemental analysis, FT-IR spectroscopy, and X-ray single-crystal diffraction. The starting reagent dpds ligand was converted to dps (4,4′-dipyridylsulfide) in 1. For complex 1, it crystallized in monoclinic system, P21/c space group. Two Co ions are linked by carboxylate oxygen atoms to form a 4-membered [Co2O2] ring. The rings are linked by Brip to generate a 1D polymeric motif. These 1D motifs are further connected through dps to generate a 2D network. For complex 2, it crystallized in orthorhombic system, Pbcn space group. The adjacent Co(II) ions are bridged by Brip to form an alternate 1D chain. Such 1D chains are further connected by dpds to generate a 3D twofold interpenetrating d...

A new complex, {[Cd2(tbip)2(1,3-bip)2]·4H2O}n (1) [H2tbip = 5-tert-butyl isophthalic acid; 1,3-bip = 1,3-bis(imidazole-1-yl)propane], has been synthesized by hydrothermal reaction of Cd(II) salt, H2tbip, and 1,3-bip ligands. The crystal structure was determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis and IR spectroscopy. The X-ray single-crystal structure shows that complex 1 belongs to the triclinic system, P space group, a = 10.3211(10), b = 10.5443(10), c = 11.8324(11) A, and α = 80.0660(10), β = 84.6510(10), γ = 71.5590(10)°. Complex 1 exhibits a 1D chain structure resulting from dimeric Cd(II) units bridged by tetradentate tbip and flexible 1,3-bip ligands. These 1D chains are further extended into a 2D supramolecular structure by hydrogen bonding and C-H···π interactions. Moreover, photoluminescence properties of complex 1 were investigated. Supplemental materials are available for this article. Go to the publisher's online edition of Synthesis an...

Astilbin, a major bioactive compound extracted from Rhizoma smilacis glabrae (RSG), has been reported to possess immunosuppressive properties. Our study first evaluated the effect of astilbin on experimental autoimmune myasthenia gravis (EAMG) in Lewis rats. The results showed that astilbin could attenuate the severity of EAMG by decreasing antigen-specific autoantibodies with up-regulation of regulatory T cells and down-regulation of Th17 cells. In addition to, astilbin also reduced the efficiency of the antigen presenting cells on which the expression of MHC class II decreased. These results suggest that astilbin might be a candidate drug for immunoregulation of EAMG, and provide us new treatment ideas for human myasthenia gravis (MG).

Three new ternary copper(II) complexes, [Cu 2 (phen) 2 (PDIMAla)(H 2 O) 2 ](ClO 4 ) 2 ·CH 3 OH ( 1 ), [Cu 2 (dpq) 2 (PDIMAla)(H 2 O) 2 ](ClO 4 ) 2 ·CH 3 OH ( 2 ) and [Cu 2 (dppq) 2 (PDIMAla)(H 2 O) 2 ](ClO 4 ) 2 ·CH 3 OH ( 3 ) (phen = 1,10-phenanthroline, dpq = dipyrido[3,2:2′,3′-f]quinoxaline, dppz = dipyrido[3,2-a:2′,3′-c]phenazine, H 2 PDIMAla = N , N ′-( p -xylylene)di-alanine acid) have been synthesized and the complex 1 has been structurally characterized by single-crystal X-ray crystallography, spectrometric titrations, ethidium bromide displacement experiments, CD (circular dichroism) spectral analysis and viscosity measurements. The results indicate that the three compounds, especially the complex 3 , can strongly bind to calf-thymus DNA (CT–DNA). The intrinsic binding constants K b of the ternary copper(II) complexes with CT–DNA are 0.38 × 10 5 , 1.4 × 10 5 and 7.8 × 10 5 for 1 , 2 and 3 , respectively. Comparative cytotoxic activities of the copper(II) complexes are also determined by acid phosphatase assay. The results show that the ternary copper(II) complexes have significant cytotoxic activity against the human hepatic (HepG2), human promyelocytic leukemia (HL60) and human prostate (PC3) cell lines. Investigation of antioxidation property show that all the copper(II) complexes have strong scavenging effects for hydroxyl radicals.

A new complex, [Cd2(mip)2(1,3-btp)(H2O)2]n [H2mip = 5-methylisophthalic acid; 1,3-btp = 1,3-bis(1,2,4-triazole)propane], has been obtained by hydrothermal reaction of Cd(II) acetate, H2mip and 1,3-btp ligands. Its crystal structure was characterized by elemental analysis, IR spectroscopy and single crystal X-ray diffraction. The X-ray crystal structure shows that the complex belongs to the triclinic system, P space group, a = 10.1350(11) A, b = 12.1708(13) A, c = 12.7495(14) A, and α = 99.3140(10) °, β = 91.0330(10) °, γ = 113.2160(10) °. The dinuclear Cd(II) units are bridged by mip2− ligands to form a 1D chain and then these 1D chains are further bridged by 1,3-btp co-ligands to form a 2D layer. Adjacent 2D layers are linked by weak hydrogen bonding interactions to form a 2D double layer. In addition, the thermal behavior and luminescence properties of the title complex were investigated.

By employing the 5-nitro-1,2,3-benzenetricarboxylate ligand, two Cu(II) coordination polymers with free –COOH groups as Bronsted acid sites are synthesized, and both compounds show high activity and regioselectivity in catalyzing epoxide ring-opening reactions.

In the present phytochemical study on the leaves of Crataegus pinnatifida, a new monoterpene glycoside, (3S,5R,6R,7E,9R)-3,6-epoxy-7-megastigmen-5,9-diol-9-O-β-Dglucopyranoside(6) and a new sesquilignan glycoside, acernikol-4’’-O-β-D-glucopyranoside (15), together with thirteen known compounds were isolated.

Investigations of two Flacourtiaceae plants, Bennettiodendron leprosipes and Flacourtia ramontchi, resulted in the isolation and structural elucidation of six new constituents including two phenolic glycosides ( 1 and 2), one lignan ( 3), two lignan glycosides ( 4 and 5), and a monoterpene glycoside ( 6), together with 22 known compounds ( 7- 28). The structures of the new compounds were elucidated by spectroscopic analysis and chemical methods. The selected isolates 1, 2, 8- 10, 22- 26, and some phenolic glycosides 29- 42 previously isolated from another Flacourtiaceae plant, Itoa orientalis, were tested against snake venom phosphodiesterase I (PDE I) activity. The result indicated that 22, 30, 32, 34, and 40 exhibited moderate inhibitory activities against PDE I with the values ranging from 13.15 to 20.86 %, and 1, 8, 10, 25, 31, 33, 35, 38, 39, and 41 showed weak inhibitory activity.

Genetic improvement of cotton through biotechnology has been limited by lack of an efficient regeneration system. An efficient somatic embryo production and maturation procedure was thus developed to regenerate plantlets from hypocotyls of cotton cultivars Xinluzhong 20, Xinluzao 24, Xinluzao 33, and 03298 grown in Xinjiang. Calli were effectively produced by 0.01 to 0.10 mg L −1 kinetin (KT) and 0.10 mg L −1 2,4-dichlorophenoxyacetic acid (2,4-D), with a better result by 0.02 or 0.10 mg L −1 KT and 0.10 mg L −1 2,4-D. Split hypocotyl segments and double amounts of KNO 3 during induction of calli were beneficial to the emerge of embryogenic calli. Embryogenic calli and globular-stage somatic embryos were effectively initiated with high concentration of KT and low concentration of 2,4-D in ECM media (0.05 or 0.10 mg L −1 KT and 0.01 mg L −1 2,4-D). Embryos were further developed into plantlets in MSBF medium under the conditions of dehydration and ventilation, which were achieved using filter paper on medium and cotton tampon sealing flask. Using this protocol, normal plantlets with strong roots were developed from these cotton cultivars in 6 to 8 months. The successful regeneration protocol established in this study can be used to improve cotton cultivars by genetic engineering.

CuO/ZnO nano-composites were successfully prepared via coordination oxidation homogeneous co-precipitation method. Thermogravimetric and differential thermal analysis (TG–DTA), FT-IR, field-emission scanning electron microscope (FESEM), energy dispersive X-ray spectrometry (EDS), transmission electron microscope (TEM), powder X-ray diffraction (XRD) were used to characterize the microstructure and morphology of the precursor and the products obtained at various temperatures. The research on the growth dynamics of product showed that the dynamic growth index was 5, the growth speed constant K was 4.93 × 10 4 nm 5 /min and the apparent activation energy presented differently in the low-temperature region and high-temperature region with the values of 14.94 kJ/mol and 59.84 kJ/mol, respectively. The results of the photocatalytic degradation of methyl orange (MO) in aqueous solution indicated that, with the calcining temperature increasing, the photocatalytic performance of the product increased first, and then began to decrease when the calcining temperature got to 450 °C because the particle size increased.

Agrobacterium-tumefaciens-mediated transformation of cotton embryogenic calli (EC) was enhanced by choosing appropriate EC and improving efficiency of coculture, selection cultivation, and plant regeneration. After 48-h cocultivation, the number of β-glucuronidase (GUS)-positive calli characterized by yellow, loose, and fine-grained EC was twofold greater than that of gray, brown, and coarse-granule EC. It indicated that efficiency of transient transformation was affected by EC morphology. And transient transformation efficiency was also improved by cocultivation on the medium adding 50 mg l−1 acetosyringone at 19°C for 48 h. Subculturing EC on the selection medium with low cell density was beneficial to production of more kanamycin-resistant (Km-R) calli lines. From an original 0.3-g EC, an average of 20 Km-R calli lines were obtained from a selection dish and the GUS-positive rate of Km-R clones was 81.97%. A large number of normal plants were rapidly regenerated on the differentiation medium with dehydration treatments and the GUS-positive rate of regeneration plants was about 72.60%. Polymerase chain reaction analysis of GUS-positive plantlets revealed a 100% positive detection rate for neomycin phosphotransferase II gene and uidA. Southern blot of transgenic plants regenerated from different Km-R calli lines demonstrated that the target gene, mostly with the low copy number, has been integrated into the cotton genome.

Background 4-Hydroxymandelic acid (4-HMA) is a valuable aromatic fine chemical and widely used for production of pharmaceuticals and food additives. 4-HMA is conventionally synthesized by chemical condensation of glyoxylic acid with excessive phenol, and the process is environmentally unfriendly. Microbial cell factory would be an attractive approach for 4-HMA production from renewable and sustainable resources. Results In this study, a biosynthetic pathway for 4-HMA production was constructed by heterologously expressing the fully synthetic 4-hydroxymandelic acid synthase (shmaS) in our l-tyrosine-overproducing Escherichia coli BKT5. The expression level of shmaS was optimized to improve 4-HMA production by fine tuning of four promoters of different strength combined with three plasmids of different copy number. Furthermore, two genes aspC and tyrB in the competitive pathway were deleted to block the formation of byproduct to enhance 4-HMA biosynthesis. The final engineered E. coli strain HMA15 utilized glucose and xylose simultaneously and produced 15.8 g/L of 4-HMA by fed-batch fermentation in 60 h. Conclusions Metabolically engineered E. coli strain for 4-HMA production was designed and constructed, and efficiently co-fermented glucose and xylose, the major components in the hydrolysate mixture of agricultural biomass. Our research provided a promising biomanufacturing route to produce 4-HMA from lignocellulosic biomass. Electronic supplementary material The online version of this article (doi:10.1186/s12934-016-0489-4) contains supplementary material, which is available to authorized users.

Eight new benzoylated gentisyl alcohol (=2-(hydroxymethyl)benzene-1,4-diol) glucosides, itosides A–H (1–8), together with the new pyrocatechol (=benzene-1,2-diol) glycoside itoside I (9) were isolated from the bark and twigs of Itoa orientalis (Flacourtiaceae). In itosides B–D (2–4), the gentisyl alcohol moiety was esterified by 1-hydroxy-6-oxocyclohex-2-ene-1-carboxylic acid, while itosides E–H (5–8) contained instead an additional 2-hydroxybenzoic acid moiety. The compounds were accompanied by the known derivatives 4-hydroxytremulacin (10), poliothyrsoside (11), poliothyrsin (12), homaloside D (13), tremulacin, and pyrocatechol β-D-glucopyranoside. The structures of the new compounds were elucidated by spectral and chemical methods.

Eight novel daphnane-type ditepenes, neogenkwanines A—H, are isolated along with seven known ones.

Three mononuclear mixed ligand Cu(II) complexes of the type [Cu(L)(DTHA)]H2O⋅CH3OH, where H2DTHA is 2-(3,5-di-tert-butyl-2-hydroxybenzylamino) acetic acid and the co-ligand L is 1,10-phenanthroline (phen, 1), dipyrido[3,2-d:2′,3′-f]quinoxaline (dpq, 2) dipyrido [3,2-a:2′,3′-c]phenazine (dppz, 3) have been isolated and characterized. Absorption and emission spectral studies and viscosity measurements indicated that 3 interacts with DNA more strongly than all of the other complexes through intercalation mode. Furthermore, cytotoxicity studies on the tested four cell line indicated that they can efficiently inhibit the cell proliferation in a time-dependent manner, and the Hoechst 33258 staining assays have also been employed in finding the extent of DNA damage.

Caesium aluminium dizirconium tetrakis[phosphate(V)], CsAlZr(2)(PO(4))(4), has been synthesized by high-temperature reaction and studied by single-crystal X-ray diffraction at room temperature. This represents the first detailed structural analysis of an anhydrous phosphate containing both zirconium and aluminium. The structure features a complicated three-dimensional framework of [AlZr(2)(PO(4))(4)] constructed by PO(4), AlO(4) and ZrO(6) polyhedra interconnected via corner-sharing O atoms, and one-dimensional Cs chains which are located in the infinite tunnels within the [AlZr(2)(PO(4))(4)] framework, which run along the c axis. The Cs, Al, one P and two O atoms lie on a mirror plane, while a second P atom lies on a twofold axis.

One new sesquiterpene, (1α,4aβ,8aα)-1-isopropanol-4a-methyl-8-methylenedecahydronaphthalene (1), with one new phenylpropanoid, threo-2-(4-hydroxy-3,5-dimethoxyphenyl)-3-(4-hydroxy-3-methoxyphenyl)-3-ethoxypropan-1-ol (2), along with four known phenylpropanoids were isolated from Crataegus pinnatifida. The structures of compounds 1 and 2 were elucidated on the basis of 1D, 2D NMR analyses, and HR-ESI-MS. The antithrombotic activity in vitro of all isolates was assayed, and only compound 1 exhibited potent antithrombotic activity by inhibiting platelet aggregation in rat plasma by 81.4% at 1 mg/ml.