Isolation, synthesis and bioactivity evaluation of isoquinoline alkaloids from Corydalis hendersonii Hemsl. against gastric cancer in vitro and in vivo.

Isoquinoline alkaloid displays significant anti-gastric cancer effects due to its unique structure, which is attracting more and more attention for the development of anti-gastric cancer drugs. In this study, we explore the active components against gastric cancer from the Tibetan Medicine Corydalis hendersonii Hemsl, which is rich in isoquinoline alkaloids. 14 compounds including 2 previously undescribed natural products were obtained. Interestingly, an new active compound displays potent anti-gastric cancer activity. After accomplishing the total syntheses of the active compound and its derivatives, the anti-gastric cancer activity of the active compound was further investigated. In vitro experiments revealed that the active compound significantly attenuated the proliferative capacity, caused G2/M phase arrest, inhibited the cell migration and invasion, and induced cell apoptosis. Mechanistically, the active compound could increase the Bax/Bcl-2 ratio, elevate cytochrome c in the cytosol, and activate caspase-9/3, along with inactivating the upstream PI3K/Akt/mTOR signaling pathway. In addition, the active compound could also cause gastric cancer cell death by inhibiting topoisomerase I activity. More importantly, the anti-gastric cancer activity of the active compound was confirmed in MGC-803 xenograft nude mice in vivo. This work not only promotes the exploitation of Corydalis hendersonii Hemsl., but also provides some experience for discovering new entities from natural sources.

Litorilituus lipolyticus sp. nov., isolated from intertidal sand of the Yellow Sea in China, and emended description of Colwellia asteriadis.

A Gram-stain negative, rod-shaped, aerobic, oxidase-positive and catalase-weakly positive bacterial strain with polar or subpolar flagellum, designated RZ04T, was isolated from an intertidal sand sample collected from a coastal area of the Yellow Sea, China. The organism was observed to grow optimally at 25 °C and pH 6.5-7.0 with 2% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain RZ04T was closely related to Colwellia asteriadis (similarity 96.9%) and Litorilituus sediminis (similarity 96.8%), and 94.4-96.4% sequence similarities to other type strains of species of the genera belonged to the family Colwelliaceae. The dominant fatty acids of strain RZ04T were determined to be C17:1ω8c, C15:1ω8c, C16:0 and summed feature 3 (C16:1ω6c and/or C16:1ω7c), and the predominant isoprenoid quinone was determined to be quinone 8 (Q-8). Phosphatidylethanolamine, phosphatidylglycerol, an unidentified aminophospholipid and four unidentified lipids were determined to be the major constituents of the polar lipids. The genome of strain RZ04T is 4.14 Mbp with a G + C content of 37.4 mol%. A total of 3631 genes are predicted, with 3531 protein-coding genes, 75 RNA genes and 25 pseudogenes. Based on phenotypic, genotypic and phylogenetic analysis, strain RZ04T is considered to represent a novel species in the genus Litorilituus, for which the name Litorilituus lipolyticus is proposed. The type strain is RZ04T (= MCCC 1K03616T = KCTC 62835T). An emended description of Colwellia asteriadis is also provided.

Flavivirga rizhaonensis sp. nov., a marine bacterium isolated from intertidal sand.

A bacterial strain designated RZ03T was isolated from an intertidal sand sample from the Yellow Sea in China and characterised using a polyphasic taxonomic approach. Cells of strain RZ03T were observed to be Gram-stain negative, aerobic, and oxidase and catalase positive rods showing gliding motility and forming yellow colonies. Growth was found to occur at 7-30 °C (optimum, 25 °C), at pH 5.5-9.5 (optimum, pH 6.5-7.0) and with 0.5-5% NaCl (optimum, 1.5-2%). Phylogenetic analysis based on 16S rRNA gene sequences indicates that strain RZ03T clusters within members of the genus Flavivirga of the family Flavobacteriaceae and is closely related to the type strains Flavivirga amylovorans JCM 17112T and Flavivirga jejuensis JCM 17113T (97.9% and 97.5% similarity, respectively). The predominant cellular fatty acids are iso-C15:0, iso-C15:1 G, iso-C17:0 3-OH and iso-C15:0 3-OH and the major respiratory quinone is MK-6. Polar lipids include phosphatidylethanolamine, three unidentified aminolipids, an unidentified phospholipid and four unidentified lipids. The genome of strain RZ03T is 4.88 Mbp with a G+C content of 32.2 mol%. A total of 4152 genes are predicted, with 4052 protein-coding genes, 51 RNA genes and 49 pseudogenes. This polyphasic study suggests that strain RZ03T represents a novel species in the genus Flavivirga, for which the name Flavivirga rizhaonensis is proposed. The type strain is RZ03T(= KCTC 62833T = MCCC 1K03615T).

Double 1,4-addition of (thio)salicylamides/thiosalicylic acids with propiolate derivatives: a direct, general synthesis of diverse heterocyclic scaffolds.

A simple and practical ring-closure procedure to prepare a range of diverse heterocycles has been developed. In this transformation, a variety of substituted (thio)salicylamides and thiosalicylic acids undergo a double 1,4-addition reaction with propiolate derivatives in the presence of an inorganic base (K3PO4), as a result benzothiazinones, benzoxazinones and benzoxathiinones were prepared in good to excellent yields, respectively, even in gram scales. In addition, further transformation towards more complex structures and oxicam drug analogues has also been successfully carried out.

Neuroprotective Effects of an N-Salicyloyl Tryptamine Derivative against Cerebral Ischemia/Reperfusion Injury.

Cerebral ischemia/reperfusion (I/R) injury is a key reason for the poor prognosis of ischemic stroke. As only a few neuroprotective medications for cerebral I/R injury have been applied in the clinic, it is necessary to design a new therapeutic strategy to treat cerebral I/R injury. The N-salicyloyl tryptamine derivative LZWL02003, synthesized from melatonin and salicylic acid, exhibits a wide range of biological properties. In this study, we assessed the neuroprotective capabilities of LZWL02003 in vivo and in vitro and investigated its possible mechanisms. Oxygen-glucose deprivation/reoxygenation was utilized to create an in vitro model of cerebral I/R damage. Middle cerebral artery occlusion/reperfusion was employed to imitate cerebral I/R injury in vivo. Neuronal apoptosis, oxidative stress, mitochondrial dysfunction, and neuroinflammation are associated with the pathogenesis of cerebral I/R injury. Our findings demonstrated that LZWL02003 upregulated the expression of Bcl-2 and downregulated the expression of Bax, thus maintaining the homeostasis of Bcl-2/Bax proteins and preventing apoptosis. LZWL02003 also reduced oxidative stress by reducing malondialdehyde and reactive oxygen species levels, increasing the superoxide dismutase activity, and resolving mitochondrial malfunction. LZWL02003 can lower interleukin (IL)-1ß, tumor necrosis factor (TNF)-α, and IL-6 levels, which in turn suppress neuroinflammation. Activation of the nuclear factor-kappa B (NF-κB) pathway is involved in various pathophysiologies, including cerebral I/R injury. We discovered that LZWL02003 suppressed the phosphorylation activation of NF-κB pathway-related proteins and decreased the nuclear translocation of NF-κB p65 subunits. Taken together, our results suggest that LZWL02003 is a neuroprotective drug with pleiotropic effects and may be a candidate for treating cerebral I/R injury.

Analysis of iodinated amino acids by microemulsion electrokinetic chromatography using aliphatic amine as a cosurfactant.

A novel microemulsion electrokinetic chromatography (MEEKC) was established for the separation and determination of iodinated amino acids using n-butylamine as a novel cosurfactant. By optimizing the type of oil phase, the type and concentration of surfactant, the concentration of cosurfactant and the type and concentration of buffer in the microemulsion system, the optimal conditions for the separation of organic iodines were determined to be 0.5% ethyl acetate, 0.6% SDS, 1.2% n-butylamine and 10 mM sodium borate. The efficient and rapid separation of the five analytes (3-iodo-L-tyrosine (MIT), 3, 5-Diiodo-L-tyrosine (DIT), 3, 5-Diiodo-L-thyronine (T2), 3, 3', 5-Triiodo-L-thyronine (T3) and L-Thyroxine (T4)) was achieved under the optimal conditions. The reliability of the method was verified by measuring the precision, LOD, LOQ and recovery. The practicality of the MEEKC method was demonstrated by applying it to the determination of two iodotyrosines, MIT and DIT, in kelp. The analytical method established in this experiment will provide a reference for the study of iodotyrosines in other natural plants and food.

Intra-Tumoral Secondary Follicle-like Tertiary Lymphoid Structures Are Associated with a Superior Prognosis of Overall Survival of Perihilar Cholangiocarcinoma.

Ectopic lymphoid structures termed tertiary lymphoid structures (TLSs) have an immunomodulatory function and positively affect prognosis in certain cancers. However, their clinical relevance and prognostic utility in perihilar cholangiocarcinoma (pCCA) are unknown. Therefore, determining the involvement and prognostic utility of TLSs in pCCA is the aim of this study. Ninety-three patients with surgically resected pCCA were included retrospectively. Hematoxylin and eosin and immunohistochemical staining identified and classified the TLSs, and multiplex immunofluorescence determined the TLS composition in the pCCA sample. The correlations between clinical features and TLSs were analyzed using either Fisher's exact test or the Chi-squared test. Recurrence-free survival (RFS) and overall survival (OS) correlations with TLSs were analyzed using Cox regression and Kaplan-Meier analyses. We identified TLSs in 86% of patients with pCCA, including lymphoid aggregates (6.45%), primary (13.98%) and secondary follicles (65.59%). Patients with intra-tumoral secondary follicle-like TLSs (S-TLSs) had better OS (p = 0.003) and RFS (p = 0.0313). The multivariate analysis identified the presence of S-TLSs as a good independent prognostic indicator for OS but not for RFS. Interestingly, the presence of S-TLS only indicated better 5-year OS in 54 patients without lymph node metastasis (LNM-, p = 0.0232) but not in the 39 patients with lymph node metastasis (LNM+, p = 0.1244). Intra-tumoral S-TLSs predicted longer OS in patients with surgically resected pCCA, suggesting intra-tumoral S-TLSs' contribution to effective antitumor immunity and that S-TLSs hold promise for diagnostic and therapeutic development in pCCA.

[Combined Use of Zirconium-Modified Bentonite Capping and Calcium Nitrate Addition to Control the Release of Phosphorus from Sediments].

In this study, sediment incubation experiments were carried out to investigate the efficiency and mechanism of the control of phosphorus (P) release from sediments. The results showed that under anoxic conditions, P could be released from the sediment into the pore water first and then the dissolved P in the pore water could be transported into the overlying water, leading to high concentrations of soluble reactive P (SRP) and diffusive gradient in thin-films (DGT)-labile P in the overlying water. However, the combined use of calcium nitrate (CN) addition and zirconium-modified bentonite (ZB) capping could effectively control the release of P from sediment, resulting in the low concentrations of SRP and DGT-labile P in the overlying water. Furthermore, the combined use of CN addition and ZB capping could significantly decrease the concentrations of SRP and DGT-labile P in the sediment. In addition, the combined utilization of CN addition and ZB capping also could result in a reduction of redox sensitive P (BD-P) in the uppermost sediment layer. The reduction of pore water SRP, DGT-labile P, and BD-P in sediment solids is of great importance to the control of sediment-P liberation by the combined use of CN addition and ZB capping. The reduction efficiency of overlying water SRP by combined CN addition/ZB capping technology was higher than that of single CN addition technology. Compared to that of single CN addition technology, the reduction efficiencies of pore water SRP, SRP diffusion flux across the sediment/overlying water interface (SWI), and BD-P in the sediment by the combined use of CN addition and ZB capping were also higher. The combined technology based on CN addition and ZB capping had a higher reduction efficiency of overlying water SRP during the late stage of sediment remediation than the single technology based on ZB capping, and the former had higher reduction efficiencies of pore water SRP, DGT-labile P, and SRP diffusion flux across the SWI and apparent P diffusion flux through the SWI than the latter. The results of this work indicate that the combined use of CN addition and ZB capping is a very promising method for the control of P release from sediments.

Effect of Wenxia Changfu Formula Combined With Cisplatin Reversing Non-Small Cell Lung Cancer Cell Adhesion-Mediated Drug Resistance.

Non-small cell lung cancer (NSCLC), the major form of primary lung cancer, is a common cause of cancer-related death worldwide. Cell adhesion-mediated drug resistance (CAM-DR), a form of chemotherapy resistance, has been reported to confer resistance to various chemotherapeutic agents. Integrin ß1 signaling plays an important role in CAM-DR and has been proposed as a potential target for NSCLC. Wenxia Changfu Formula (WCF) is a Traditional Chinese Compound Prescription for the intervention treatment of NSCLC combined with cisplatin (DDP). This study aims to investigate the effect and mechanism of WCF combined with DDP in reversing CAM-DR. Firstly, the chemical profile of WCF was characterized by UPLC/Q-TOF-MS analysis. A total of 237 compounds with mzCloud Best Match of greater than 70 were identified by using the online database mzCloud. Secondly, we established A549 three-dimensional(3D) cells cultured in vitro and nude mice xenografts models of the A549 cell line with Integrin ß1 overexpression. In vitro, the cell viability, migration and adhesion were measured though MTT Assay, Wound Healing Assay and Cell Adhesion Assay, the Integrin ß1 expression of the A549 cells was assessed through immunocytochemistry; in vitro, the transplanted tumor morphology and the colocalization of Integrin ß1 and its ligands were tested by HE staining and immunofluorescence. As a result, we found that the combination effectively reduced cell viability, suppressed migration and adhesion, and downregulated the protein level of Integrin ß1 in three-dimensional cultured A549 cells. And the combination of WCF with DDP significantly inhibited tumor growth, increased organelle vacuolations and decreased colocalization of Integrin ß1 and its ligands including fibulin-2 and laminin. Taken together, our results confirm that the combination of WCF with DDP could reverse the lung cancer CAM-DR through the Integrin ß1 signaling pathway.

Brucea javanica oil emulsion improves the effect of radiotherapy on esophageal cancer cells by inhibiting cyclin D1-CDK4/6 axis.

BACKGROUND: Esophageal cancer is one of the most common cancers around the world, and it has high incidence and mortality rates. The conventional therapy for esophageal cancer is radiotherapy, although its effect is highly limited by the resistance of esophageal cancer cells. Thus, strong radiosensitizers can be very crucial during radiotherapy against esophageal cancer. Brucea javanica oil emulsion (BJOE) is a widely used drug against various cancers, such as liver, colon, and ovarian cancer. However, its anti-cancer effect and mechanism and the use of BJOE as a radiosensitizer have not been explored in esophageal cancer. AIM: To evaluate the anti-cancer effect and mechanism of BJOE and explore the potential use of BJOE as a radiosensitizer during radiotherapy. METHODS: The inhibitory effect of BJOE and its enhancement function with radiation on cell viability were examined with the calculated half-maximal effective concentration and half-maximal lethal concentration. The influence of BJOE on cell migration and invasion were measured with EC109 and JAR cells by wound-healing and transwell assay. Clonogenesis and apoptotic rate, which was measured by Hoechst staining, were investigated to confirm its enhancement function with radiation. To investigate the molecular pathway underlying the effect of BJOE, the expressions of several apoptosis- and cycle-related proteins was detected by western blotting. RESULTS: Our results demonstrated that BJOE inhibited the growth of esophageal cancer cell lines more than normal cell lines, and it markedly reduced migration and invasion in esophageal cancer cells (EC109 and JAR). Moreover, it promoted cell apoptosis and enhanced the effect of radiotherapy against esophageal cancerous cells. In the viability test, the values of half-maximal effective concentration and half-maximal lethal concentration were reduced. Compared to the control, only around 1/5 colonies formed when using BJOE and radiation together in the clonogenic assay. The apoptotic rate in EC109 was obviously promoted when BJOE was added during radiotherapy. Our study suggests that the expression of the apoptosis-proteins Bax and p21 were increased, while the expression of Bcl-2 was stable. Further detection of downstream proteins revealed that the expression of cyclin D1 and cyclin-dependent kinase 4/6 were significantly decreased. CONCLUSION: BJOE has a strong anti-cancer effect on esophageal cancer and can be used as a radiosensitizer to promote apoptosis in cancerous esophageal cells via the cyclin D1-cyclin-dependent kinase 4/6 axis.

Calixarene and ionic liquid assisted matrix solid-phase dispersion microextraction of organic acids from fruit.

A rapid and effective method was successfully established for the extraction and determination of chlorogenic acid, protocatechuic acid, malic acid, caffeic acid and gallic acid in fruit (chaenomeles speciosa) via matrix solid-phase dispersion (MSPD) microextraction combined with ultra-high performance liquid chromatography with quadrupole time-of-flight tandem mass spectrometry (UHPLC-Q-TOF/MS). Several major extraction parameters were investigated and optimized, such as the type of sorbent, the amount of sorbent, the grinding time, the type and concentration of the eluting solvent. The optimal extraction conditions were obtained by using 20 mg of calix[8]arene as dispersing adsorbent, selecting 60 s as the appropriate grinding time and applying 250 mM of 1-dodecyl-3-methylimidazolium bromide as eluent solvent. Moreover, the calibration curves of the analytes were in the range of 0.01-500 µg/mL with the determination coefficients (r2) higher than 0.9995. The limits of detection and limits of quantification were in the range of 0.202-1.056 ng/mL and 0.674-3.521 ng/mL, respectively. The recoveries of the target compounds at two spiked levels were between 82.19 and 113.36%. Furthermore, this method had acceptable reproducibility (RSD ≤ 3.84%). The proposed approach combined the advantages of MSPD microextraction with UHPLC-Q-TOF/MS, and could be applicable for the analysis organic acids in fruit.

A concise synthesis and biological study of evodiamine and its analogues.

Efficient access to evodiamine and its analogues is presented via Lewis acid catalysis. In this reaction, three chemical bonds and two heterocyclic-fused rings are constructed in one step. The reaction shows good functional group tolerance and atom economy, and various heteroatom-containing evodiamine analogues are obtained in moderate to excellent yields even on a gram scale. An anti-tumor study in vitro demonstrates compound 2b possesses potent efficacy against hepatoma cell line (IC50 = 5.7 µM).

[Effect of Magnetic Zirconium/Iron-Modified Bentonite Addition on Phosphorus Mobilization and Species Transformation in River Sediments].

A magnetic zirconium/iron-modified bentonite (ZrFeBT) was prepared, and the effect of ZrFeBT addition on the mobilization and species transformation of P in river sediments was investigated using incubation sediment core experiments. The results showed that, under anoxic conditions, P could be released from river sediments into the pore water, and then P in the pore water could be released into the overlying water. The addition of ZrFeBT into river sediments could greatly suppress the release of P from river sediments into the pore water under anoxic conditions. Therefore, the release of P from the pore water into the overlying water could be significantly suppressed by the addition of ZrFeBT. After the addition of ZrFeBT into river sediments, the transformation of loosely sorbed P (Labile-P) and BD extractable P (BD-P) to NaOH extractable P (NaOH-rP) and residual P (Res-P) in the sediments was observed. The decrease of bioavailable P (BAP) including water soluble P (WSP), readily desorbable P (RDP), NaHCO3 extractable P (Olsen-P), algal available P (AAP), and Fe oxide-paper extractable P (FeO-P) in the sediments was also observed. A certain amount of P in the ZrFeBT after the incubation experiment was present in the form of mobile P (Labile-P and BD-P), Olsen-P, and FeO-P, which could be re-released into the pore water and overlying water when the environmental conditions change in the future. The control of P release from river sediment into the overlying water by the addition of ZrFeBT could be mainly attributed to the reduction of P in the pore water as well as the reduction of mobile P and BAP in the sediments after ZrFeBT amendment. The results of this study inidcated that ZrFeBT is a promising amendment for the regulation of P release from river sediments into the overlying water.

[Influence of Calcium Ion Pre-treatment on Phosphate Adsorption onto Magnetic Zirconium/Iron-modified Bentonite].

Two kinds of magnetic zirconium/iron-modified bentonites (ZrFeBTs), including magnetic zirconium/iron modified raw bentonite (ZrFeRBT) and magnetic zirconium/iron-modified Ca2+-pretreated bentonite, (ZrFeCaBT) were prepared and characterized. Their phosphate adsorption characteristics were compared to determine the effect of the Ca2+ pre-treatment on the adsorption of phosphate onto ZrFeBTs. The results showed that the as-prepared ZrFeBTs contained Fe3O4 and Zr, and the content of exchangeable Ca2+ in ZrFeCaBT was much higher than that in ZrFeRBT. The adsorption isotherm data exhibited good agreement with the Langmuir isotherm model, with maximum monolayer phosphate adsorption capacities of 8.70 mg·g-1 and 11.5 mg·g-1 for ZrFeRBT and ZrFeCaBT, respectively. The isotherm and kinetics studies showed that the adsorption of phosphate on ZrFeBTs was a chemisorption process. The phosphate adsorption capacities for ZrFeBTs decreased with increasing solution pH. The ZrFeBTs exhibited a high selective adsorption for phosphate in the presence of anions and cations, including Cl-, HCO3-, SO42-, NO3-, Na+, K+, Mg2+, and Ca2+. Furthermore, coexisting Ca2+ greatly enhanced the adsorption of phosphate onto ZrFeBTs. The pre-treatment of raw bentonite with Ca2+ significantly improved the adsorption of phosphate onto ZrFeBTs.

NaI-mediated divergent synthesis of isatins and isoindigoes: a new protocol enabled by an oxidation relay strategy.

A new approach for the synthesis of isatins and isoindigoes by an inexpensive and environmentally friendly NaI-mediated transformation is disclosed. The selectivity could be switched by simply varying the solvent, and isatins (using THF) and isoindigoes (using DMSO) could be obtained in moderate to excellent yields.

Development and validation of nomograms for predicting overall and breast cancer-specific survival among patients with triple-negative breast cancer.

PURPOSE: TNBC is generally more aggressive than other BC subtypes and has limited therapeutic options. We aimed to construct comprehensive and reliable nomograms to predict the OS and BCSS of TNBC patients to offer clinicians therapeutic guidance for improving the prognosis of TNBC patients. PATIENTS AND METHODS: We used the SEER 19 Cancer Registry to identify 21,419 eligible TNBC patients diagnosed from January 1, 2010 to December 31, 2015, and divided the database randomly into a training cohort (n=10,709) and a validation cohort (n=10,710). The log-rank test and Cox analysis together with a competing risk model were utilized to identify independent prognostic factors for OS and BCSS, which were then integrated to construct nomograms. RESULTS: According to the training cohort, except for laterality, the following factors were all predictive of OS and BCSS: age at diagnosis, race, tumor size, number of positive lymph nodes, grade, and histological subtype. The 1-, 3-, and 5-year probabilities of BC-specific mortality were 2.7%, 12.5%, and 17.1%, respectively. The precision of the nomograms was assessed by the C-index value and calibration plot diagrams. The C-index value were 0.779 for OS and 0.793 for BCSS in the internal validation and 0.774 for OS and 0.792 for BCSS in the external validation. Both internal and external calibration plot diagrams showed good consistency between the actual and predicted outcomes, especially for 3- and 5-year OS and BCSS. CONCLUSION: These nomograms hold promise as a novel and accurate tool in predicting OS and BCSS of TNBC patients and could be used in clinical practice to assist clinicians in developing more effective therapeutic strategies and to evaluate prognostic personally.

[Adsorption of Phosphate from Aqueous Solutions on Sediments Amended with Magnetite-Modified Zeolite].

Understanding the characteristics of phosphate adsorption onto magnetite-modified zeolite (MZ)-amended sediment is helpful for knowing the exchange behavior and process of phosphorus at the interface between the overlying water and MZ-amended sediment. Furthermore, it is helpful for the application of MZ as an amendment to control phosphorus release from sediment. To achieve this goal, the adsorption of phosphate on unamended and MZ-amended sediments was comparatively investigated using a series of batch experiments, and the fractionation of phosphorus in the phosphate-adsorbed MZ was studied using a sequential extraction process. The kinetic data of phosphate adsorption onto unamended and MZ-amended sediments were more suitably fitted to the Elovich model than to the pseudo-first-order and pseudo-second-order models. The equilibrium adsorption data of phosphate adsorption onto the unamended and MZ-amended sediments were well described by the Langmuir, Freundlich, and Dubinin-Radushkevic isotherm model. The phosphate adsorption performance of the unamended and MZ-amended sediments decreased with increasing solution pH from 4 to 11. The presence of cations, such as K+, Mg2+, and Ca2+, enhanced the adsorption of phosphate on the unamended and MZ-amended sediments, and the promoting effect decreased in the order of Ca2+ > Mg2+ > K+, whereas the presence of HCO3- inhibited the adsorption of phosphate. The mechanisms for phosphate adsorption onto the unamended and MZ-amended sediments involved electrostatic attraction and ligand exchange, while the mechanism for the adsorption of phosphate on MZ in the amended sediment involved ligand exchange. The sequential extraction analysis of phosphate-adsorbed MZ showed that 49.4% of phosphorus in MZ existed in the mobile form (NH4Cl-P, BD-P, and NaOH-nrP), which could be easily released from MZ. Therefore, the used MZ should be recovered from sediment using external magnetic fields after its application. The results of this study indicated that MZ is a promising sediment amendment for the control of internal loading in rivers.

Direct access to α-sulfenylated amides/esters via sequential oxidative sulfenylation and C-C bond cleavage of 3-oxobutyric amides/esters.

An efficient, environmentally benign and unprecedented synthesis of various α-sulfenylated amides/esters has been developed under oxygen atmosphere. The reaction shows good functional group tolerance and excellent chemo/regioselectivity. All the desired products were obtained in moderate to excellent yields, even on the gram scale. Practically, the related α-thiol Weinreb amide can be readily transferred to a series of prospective compounds, and selenium atom can be introduced to the α-sites of the amides in high yields.

[The cloning, expression, purification and immunological identification of wild-type and mutant hepatitis B virus X gene in pGEX-6P-2 system].

To settle the foundation for the future research on the influence of wild and mutant (A1762T/ G1764A) HBV X gene on the progress of chronic HBV infection and hepatic tumorigenicity, wild and mutant (A1762T/G1764A) HBxAgs expression system was constructed. The wild and mutant (A1762T/ G1764A) HBV X genes were amplified with polymerase chain reaction (PCR) from HBV genome were inserted into pGEX-6P-2 and confirmed by sequencing respectively. Prokaryotic expression vectors pGEX-6P-2-hbvx(w) and pGEX-6P-2-hbvx(m) (A1762T/G1764A) were constructed and transformed to Trans1-blue; wild and mutant HBxAgs were expressed through IPTG induction respectively; after refolding of inclusion body, the wild and mutant HBxAgs were purified with GSTrap FF; and analysised by SDS-PAGE, Western blot and ELISA. SDS-PAGE analysis showed that the expression system was able to express target protein efficiently; the concentrations of purified wild HBxAg and mutant HBxAg were 4.88 mg/mL and 5.07 mg/mL respectively; Western blot analysis certified both the wild HBxAg and the mutant HBxAg could be recognized by the same monoclonal antibody against HBxAg; the two expressed fusion antigens coated in microtiter plate were able to react with the sera of HBV infected patients but not with the sera from healthy donors in ELISA. Results demonstrated that we successfully established a system for expression of hepatitis B x antigen and lay the foundation for further research on the role and molecular mechanisms of the mutant HBxAg in the progress of chronic HBV infection and hepatic tumorigenicity.