Small Conjugated Organic Ligand-Modified Polyoxometalate-Based Hybrid Materials for Boosting Photocatalytic CO2 Reduction.

Photocatalytic carbon dioxide (CO2) reduction to value-added chemicals is a multielectron transfer process, and the crucial step is the synthesis of photocatalysts. The introduction of small conjugated organic ligands can make the catalytic active site of the compound easier to be exposed in the reaction system and fully contact with the substrate, accelerating the photocatalytic reaction process. In this paper, we synthesized two isomorphic compounds, namely, {[Co(mtrz)3·(H2O)2]2·[SiW12O40]}·6H2O (1) and {[Ni(mtrz)3·(H2O)2]2·[SiW12O40]}·6H2O (2) (mtrz = 1-methyl-1,2,4-triazole). We found that compound 1 has a great photocatalytic performance through a series of experiments, with a CO reduction yield of 7364.92 µmol g-1 h-1 and a CO selectivity of 82.5%. Furthermore, the high catalytic activity can be maintained over four cycle experiments. The catalytic mechanism of its photocatalytic system is also elucidated, which provides an idea for realizing efficient catalytic reduction of CO2 to CO.

Layered Co-O Cluster Applied to Photocatalytic CO2 Reduction.

In the field of recycling CO2, the photocatalytic CO2 reduction reaction (CO2RR) is a typical example, and researchers have designed a variety of photocatalysts to improve the conversion rate of CO2 over the years. In this paper, two metal-oxygen clusters are designed and formulated as [Co3Zn(OH)6(SO4)]·4H2O (1) and [Ni3Zn(OH)6(SO4)]·4H2O (2). As for compound 1, the main structure is composed of {CoO6} octahedra connected by edge-sharing to form a two-dimensional layer, on which {ZnO4} and {SO4} tetrahedra are supported. More interestingly, compound 1 has outstanding photocatalytic activity, which is mainly attributed to the open-framework structure and the cobalt ions as active sites. Upon catalysis for eight hours, its maximum CO generation rate is 9982.13 µmol g-1 h-1, with a selectivity of 81.8%. Additionally, compound 1 takes on weak antiferromagnetic coupling due to Co(II) ions.

A molecular mechanism of UDCA engagement with GPBAR and subsequent G protein interaction revealed by scattered alanine scanning.

As the most known therapeutic component of bear bile acids, ursodeoxycholic acid (UDCA) is an FDA-approved drug for the treatment of primary biliary cirrhosis (PBC), the dissolution of cholesterol gallstones. UDCA produces many beneficial effects on metabolism and immune responses via its interaction with the membrane G protein-coupled bile acid receptor (GPBAR); however, how UDCA interacts with GPBAR and its selective cellular effects remain elusive. In this study, we delineated the interaction of UDCA with GPBAR and activation mechanism of GPBAR by scattered alanine scanning and molecular docking. Our results indicated that transmembrane helix 2 (TM2), TM3, TM5 and TM6 of GPBAR contribute to the interaction of UDCA in GPBAR binding pocket. Moreover, we predicted that the engagement of the 3-OH of UDCA with phenolic oxygen of Y2406.51 in GPBAR plays a key role in GPBAR activation. Unexpectedly, in addition to the well-known roles of intracellular loop2 (ICL2) residues, we identified that ICL3 residues play an important role in G protein coupling to GPBAR in response to UDCA binding. Our study provides a preliminary molecular mechanism of how GPBAR recognizes UDCA and subsequent activation and G protein interaction, which may facilitate the development of new bile acid derivatives as therapeutics.

Mangiferin Attenuates Murine Lupus Nephritis by Inducing CD4+Foxp3+ Regulatory T Cells via Suppression of mTOR Signaling.

BACKGROUND/AIMS: Lupus nephritis (LN) is an autoimmune glomerulonephritis that frequently develops secondary to systemic lupus erythematosus. Patients with LN require extensive treatments with global immunosuppressive agents. However, long-term treatment with conventional immunosuppressants may cause various side effects. Therefore, it's important to seek alternative drugs for treating LN. Here we aimed to investigate the immunoregulatory effects of mangiferin (MG), an ingredient that was originally extracted from natural herbs, including Mangifera Indica Linn. and Rhizoma Anemarrhenae. METHODS: FasL-deficient B6/ gld mice were used as a spontaneous LN model. The serum anti-dsDNA Ab and creatinine levels were analyzed via ELISA. Renal histology and immunopathology were determined using H&E and PAS staining, immunofluorescence (IgG and C3), and IHC staining (CD3 and a-SMA). Cytokine gene expression was measured by RT-PCR assays while effector T cells and Tregs were enumerated by flow analysis. Finally, the proliferation and apoptosis of T cells were measured by CFSE staining and flow analysis while their mTOR signaling was detected through Western blotting. RESULTS: We found that administration of MG ameliorated LN in lupus-prone B6/gld mice by reducing the urinary protein and serum creatinine levels, diminishing T cell infiltration in kidneys and improving renal immunopathology. MG also significantly lowered the percentages of CD44highCD62Llow effector T cells in B6/gld mice. Importantly, treatments with MG augmented CD4+FoxP3+ Treg frequencies in spleens, lymph nodes and kidneys of B6/gld mice. It also induced CD4+FoxP3+ Tregs from CD3+ T cells in vitro and promoted Treg proliferation. Furthermore, it inhibited CD3+ T cell proliferation in vitro and suppressed their phosphorylation of mTOR and its downstream P70S6K. However, MG did not promote T cell apoptosis, implying that it is not cytotoxic. Depletion of CD4+CD25+FoxP3+ Tregs in B6/gld mice abrogated its therapeutic effects on LN. CONCLUSION: MG exerts a novel therapeutic effect on murine LN via upregulating CD4+FoxP3+ Tregs, downregulating mTOR/p70S6K pathway and improving renal immunopathology. It may be useful for treating LN in clinic.

[Meta-analysis on efficacy and safety of Brucea javanica oil emulsion injection combined with chemotherapy for patients with advanced gastric carcinoma].

Eligible studies were searched in Cochrane library, Pubmed, Medline, CBM, CNKI and VIP databases from establishment to June 2014. Two researchers independently identified 7 randomized controlled trials (RCTs) and extracted data of Brucea javanica oil emulsion injection combined with chemotherapy. Based on the published studies, the researchers analyzed them by RevMan 5.2 software and investigated the efficacy and safety of Brucea javanica oil emulsion injection combined with chemotherapy for patients with advanced gastric cancer by Meta analysis. Meta analysis showed that, compared with the simple chemotherapy, Brucea javanica oil emulsion injection combined with chemotherapy could increase objective response rate by 43%(RR=1.43, P<0.001). In addition, the incidence of neutropenia (RR=0.56, P<0.001), thrombocytopenia (RR=0.64, P=0.02), nausea, vomit (RR=0.66, P=0.002) decreased in these patients. However, the quality of life was not improved significantly in gastric carcinoma patients with combined therapy (RR=1.36, P=0.07). The paper suggested Brucea javanica oil emulsion injection combined with chemotherapy could increase efficacy and safety, which might be a promising therapy for patients with advanced gastric cancer.

An iron-containing POM-based hybrid compound as a heterogeneous catalyst for one-step hydroxylation of benzene to phenol.

It is a major challenge to perform one-pot hydroxylation of benzene to phenol under mild conditions, which replaces the environmentally harmful cumene method. Thus, finding highly efficient heterogeneous catalysts that can be recycled is extremely significant. Herein, a (POM)-based hybrid compound {[FeII(pyim)2(C2H5O)][FeII(pyim)2(H2O)][PMoV2MoVI9VIV3O42]}·H2O (pyim = 2-(2-pyridyl)benzimidazole) (Fe2-PMo11V3) was successfully prepared by hydrothermal synthesis using typical Keggin POMs, iron ions and pyim ligands. Single-crystal diffraction shows that the Fe-pyim unit in Fe2-PMo11V3 forms a stable double-supported skeleton by Fe-O bonding to the polyacid anion. Remarkably, due to the introduction of vanadium, Fe2-PMo11V3 forms a divanadium-capped conformation. Benzene oxidation experiments indicated that Fe2-PMo11V3 can catalyze the benzene hydroxylation reaction to phenol in a mixed solution of acetonitrile and acetic acid containing H2O2 at 60 °C, affording a phenol yield of about 16.2% and a selectivity of about 94%.

Research on the Thermal Insulation Properties of Three-Dimensional Spacer Jacquard Fabric Treated with Silica Aerogel.

Three-dimensional (3D) spacer fabric has the characteristics of a light weight and high strength, and its unique three-dimensional structure gives it great potential for development in terms of insulation. For the purpose of further improving the thermal insulation performance of 3D spacer fabric, the fabric was treated with silica aerogel while solving the problem of powdering during use. Firstly, the electronic Jacquard machine was modified for weaving spacer fabrics. The ground warp yarns were controlled by two groups of heald frames with various positions of heald eye, forming a double-shuttle. The longitudinal warp yarns were controlled by the Jacquard healdwine to prepare a spacer Jacquard fabric with a spacing of 5 mm. Secondly, polyurethane foam was applied as a carrier to compound with silica aerogel. The experimental results demonstrate that the strength of the composite fabrics is significantly increased, while the toughness is decreased. With the increase in silica aerogel content, the pore size of foam becomes smaller, and the degree of foam fragmentation increases, showing a trend of increasing thermal insulation performance followed by a decreasing insulation performance. When the aerogel content is 3.3%, the composite fabric has the optimal thermal insulation performance.

MoO42--templated Ln20Ni21 heterometallic clusters with large low-field magnetic entropy.

The anionic template method is an effective strategy for synthesizing high-nuclearity transition-lanthanide (3d-4f) heterometallic clusters. Herein, two lanthanide clusters with formulas [Gd20Ni21(µ3-OH)21(CO3)6(IDA)21(C2H4NO2)6(C2O4)3(MoO4)1.5(µ2-OH)1.5(H2O)9]Cl10.5·79H2O (1) and [Tb20Ni21(µ3-OH)21(CO3)6(IDA)21(C2H4NO2)6(C2O4)3(MoO4)(µ2-OH)2(H2O)10]Cl11·32H2O (2) were synthesized by introducing MoO42- anions as templates. Structural analysis indicates that compounds 1 and 2 are isomorphic, featuring a fascinating triangular-shaped metal framework. Magnetic property investigations illuminate the fact that compound 1 exhibits a large -ΔSm of 37.83 J kg-1 K-1 at 3 K for ΔH = 7 T. In particular, it is worth mentioning that compound 1 has an excellent low-field magnetic entropy (-ΔSm = 23.85 J kg-1 K-1 at 2 K, 2 T).

Two bimetal-doped (Fe/Co, Mn) polyoxometalate-based hybrid compounds for visible-light-driven CO2 reduction.

Two polyoxometalate (POM)-based hybrid compounds have been successfully designed and constructed by the hydrothermal method with molecular formulas [K(H2O)2FeII0.33Co0.67(H2O)2(DAPSC)]2{[FeII0.33Co0.67(H2O)(DAPSC)]2[FeII0.33Co0.67(H2O)4]2[Na2FeIII4P4W32O120]}·21.5H2O (1), and [Na(H2O)2FeII0.33Mn0.67(H2O)2(DAPSC)]2{[FeII0.33Mn0.67(H2O)(DAPSC)]2[FeII0.33Mn0.67(H2O)4]2[Na2FeIII4P4W32O120(H2O)2]}·24H2O (2) (DAPSC = 2,6-diacetylpyridine bis-(semicarbazone)), respectively. Structural analysis revealed that 1 and 2 consisted of metal-organic complexes containing DAPSC ligands with dumbbell-type inorganic clusters, iron-cobalt (iron-manganese) and some other ions. By utilizing a combination of strongly reducing {P2W12} units and bimetal-doped centres the CO2 photoreduction catalytic capacity of 1 and 2 was improved. Notably, the photocatalytic performance of 1 was much better than that of 2. In CO2 photoreduction, 1 exhibited CO selectivity as high as 90.8%. Furthermore, for 1, the CO generation rate reached 6885.1 µmol g-1 h-1 at 8 h with 3 mg, and its better photocatalytic performance was presumably due to the introduction of cobalt and iron elements to give 1 a more appropriate energy band structure. Further recycling experiments indicated that 1 was a highly efficient CO2 photoreduction catalyst, which could still possess catalytic activity after several cycles.

Exploring the law of color presentation of double-sided heterochromatic digital printing for textile.

With the upgrading of production technology and design aesthetic of textile products, the development and application of double-sided digital printing technology have been gradually proposed in recent years. The production of double-sided heterochromatic digital printing requires high accuracy for color management, as in the production process, different input devices, display devices, and output devices each have varying color processing capabilities and color performance characteristics, which leads to the transfer of color between different devices and not being accurately reproduced. However, there is little research involved in the color formation laws in the design and production of double-sided heterochromatic digital printing. The purpose of this paper is to explore the prediction model of color presentation in double-sided heterochromatic digital printing. Due to the influence of the fabric thickness, the gap between the textile structure, and the infiltration rate of the printing pigments, the color of each side in double-sided, heterochromatic printing results often differs from the designed color. In this paper, taking chiffon fabric, which is one of the thinnest and has the strongest permeability in silk fabric, as an example fabric base, 24 colors from six hue angles and four chromas were selected as experimental colors. According to the color gamut of the digital printing machine, 15 out of 24 colors were selected as experimental colors. These 15 colors were printed on two sides in pairs to generate 225 color pairs as double-sided experimental samples. For these experimental samples, this paper conducts experiments from both subjective and objective aspects through the combination of subjective evaluation of psychophysics experiments and objective instrument measurement. Through the analysis of experimental data, the color difference prediction under the subjective model (R2 = 0.74) and objective model (R2 = 0.85) are given, respectively. The dominant color prediction model (R2 = 0.75) during double-sided heterochromatic digital printing has also been built. The combination of the three models can predict the color regularity of double-sided heterochromatic digital printing on silk, which may have a certain significance for the design and development of silk double-sided heterochromatic digital printing products.

[Relationship of motor deficits and imaging features in metastatic epidural spinal cord compression].

OBJECTIVE: To explore the relationship of motor deficits of the lower extremities with the imaging features of malignant spinal cord compression (MESCCs). METHODS: From July 2006 through December 2008, 56 successive MESCC patients were treated at our department. All were evaluated by magnetic resonance imaging and computed tomography and were scored according to motor deficits Frankel grading on admission. Imaging assessment factors of main involved vertebrae were level of vertebral metastatic location, epidural space involvement, vertebral body involvement, lamina involvement, posterior protrusion of posterior wall, pedicle involvement, continuity of main involved vertebrae, fracture of anterior column, fracture of posterior wall, location in upper thoracic spine and/or cervicothoracic junction. RESULTS: Occurrence was the same between paralytic state of MESCCs and epidural space involvement of imaging features. Multiple regression equation showed that paralytic state had a linear regression relationship with imaging factors of lamina involvement (X1), posterior protrusion of posterior wall (X2), location in upper thoracic spine and/or cervicothoracic junction (X7) of main involved vertebrae. The optimal regression equation of paralytic state (Y) and imaging feature (X) was Y = -0.009 +0.639X, + 0.149X, +0.282X. Lamina involvement of main involved vertebrae has a greatest influence upon paralytic state of MESCC patients. CONCLUSIONS: Imaging factors of lamina involvement, posterior protrusion of posterior wall, location in upper thoracic spine and/or cervicothoracic junction of main involved vertebrae can predict the paralytic state of MESCC patients. MESCC with lamina involvement is more easily encroached on epidural space.

Andrade-Oliveira Salvianolic Acid B Modulates Caspase-1-Mediated Pyroptosis in Renal Ischemia-Reperfusion Injury via Nrf2 Pathway.

Acute kidney injury (AKI) is a serious disease characterized by a rapid decline in kidney function. Oxidative stress is the primary pathogenesis of AKI. Salvianolic acid B (SalB), a water-soluble compound extracted from Salvia miltiorrhiza, possesses a potent antioxidant activity. Here, we investigated the protective effect of SalB against renal ischemia-reperfusion injury (I/R) in mice. Briefly, by analyzing renal function, oxidative stress markers and inflammatory biomarkers, we found that SalB could improve kidney damage, reduce oxidative stress and inflammatory factor levels. Interestingly, the expression of the NLR family pyrin domain-containing 3 (NLRP3), caspase-1, pyroptosis related proteins gasdermin D (GSDMD) and interleukin (IL)-1ß, which were significantly upregulated in the kidney tissues of I/R group, was effectively reversed by SalB. Meanwhile, renal tubular epithelial cells hypoxia and reoxygenation model was used to explore pyroptosis of caspase-1-dependent. Further mechanism study showed that the SalB pretreatment could promote the increase of nuclear factor erythroid-2 related factor 2 (Nrf2) nuclear accumulation, which significantly suppressed oxidative stress, proinflammatory cytokines, NLRP3 inflammasome activation and pyroptosis. These results indicate that SalB can inhibit caspase-1/GSDMD-mediated pyroptosis by activating Nrf2/NLRP3 signaling pathway, resulting in alleviating I/R injury in mice.

Zhen-wu-tang attenuates Adriamycin-induced nephropathy via regulating AQP2 and miR-92b.

Nephrotic syndrome (NS) is characterized by proteinuria, hypoalbuminemia and edema. The disorder of sodium and water metabolism is a critical mechanism regulating the origination and progression of NS. Zhen-wu-tang (ZWT) has been traditionally used to treat edema disease in China and Japan. The present study was carried out to assess the protective effect of ZWT in Adriamycin-induced (ADR) NS rats and investigate the potential anti-NS mechanisms of ZWT. We found that ZWT treatment ameliorate impaired kidney function and regulate water balance of kidney. Importantly, ZWT increased the expression of Aquaporin-2 (AQP2) which play key roles in maintaining body water homeostasis. Additionally, we determined miRNAs expression patterns in NS rats. Using bioinformatics prediction and miR-92b mimic or inhibitor in vitro, we identified miR-92b as a possible modulator of AQP2. Also we found that ZWT can decrease the expression of miR-92b and reverse the effect of miR-92b on AQP2 in vitro. We further demonstrated that miR-92b directly regulated AQP2 expression by targeting 3'-UTR of AQP2. These finding suggest that ZWT may reduce renal edema in Adriamycin-induced nephropathy via regulating AQP2 and miR-92b.

Cordyceps militaris polysaccharides exerted protective effects on diabetic nephropathy in mice via regulation of autophagy.

The present study was designed to investigate the protective effects of Cordyceps militaris polysaccharides (CMP) on STZ-treated DN mice. CMP were identified by FT-IR and HPLC. Diabetic nephropathy (DN) was induced in male C57BL/6 mice by the injection of streptozotocin (STZ, 50 mg kg-1) in citrate buffer on 5 consecutive days. Administration of CMP at 200 and 400 mg kg-1 or irbesartan at 60 mg kg-1 in the STZ-treated mice could prevent the damage caused by STZ. CMP significantly reduced the STZ-induced higher expression of the kidney index, TC, TG, MDA, urinary protein, Scr, and BUN, while it markedly increased the STZ-induced decrease in GSH levels compared with the DN group. Histopathology analysis of the kidney by PAS, Masson, and HE staining confirmed the renal injury induced by STZ and the protective effects of CMP. Transmission electron microscopy (TEM) results confirmed the severe foot process effacement induced by STZ, but CMP treatment inhibited the podocytes' structure defects and ameliorated the function of podocytes. Desmin was measured by immunofluorescence and was related to podocyte injury. The results showed that CMP lessened the expression of desmin induced by STZ. CD68 expression was measured by immunohistochemistry analysis, and the expressions of IL-1ß, IL-6, and MCP-1 mRNA were measured by qRT-PCR. The results showed that CMP suppressed the expressions of CD68, IL-1ß, IL-6, and MCP-1 mRNA induced by STZ. The role of autophagy in the treatment of DN mice with CMP was detected by TEM and western blotting. The results showed that the administration of CMP was able to overcome the STZ-treated autophagy deficiency, significantly increase the rate of autophagy in the kidney, promote the expression of Atg5, beclin1 and LC3 protein, and reduce the expression of p62 protein. In conclusion, the present study demonstrates that CMP exert a protective effect on DN in STZ-treated mice possibly via activation of autophagy.

[The effect of cyclovirobuxinum D on myocardial ischemia induced by coronary artery ligation in rats].

OBJECTIVES: To study the cardiac protection of Cyclovirobuxinum D (Cvb-D) in rats model. METHODS: The rats were subjected to left main coronary artery occlusion. The change about S-T segment, the area of myocardial injury (necrotic and ischemic areas), the amount of cardiac tissue malondialdehyde (MDA), the cardiactissue creatine phosphokinase (CPK) and the cardiac tissue superoxide dismutase (SOD) activation were measured. RESULTS: Compared to the model group, Cvb-D (1.1 mg/kg, 2.2 mg/kg dos-age) significantly reduce myocardial damage, reduce myocardial ischemia mode rats' sigma s-t of ECG, significantly reduce cardiac tissue CPK activation and MDA content, raise the cardiac tissue SOD activation in the rats with myocardial ischemia. CONCLUSION: Cvb-D is effective in treatment of myocardial ischemia in rats.

The complete mitochondrial genome of the black field cricket, Teleogryllus oceanicus.

In this study, the complete mitochondrial genome sequence of the black field cricket, Teleogryllus oceanicus, with the total length of 15 660 bp is determined for the first time. This mitochondrial genome harbors 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNA), two ribosomal RNA genes (rRNA), and one control region (D-loop). The overall base composition is A (40.44%), C (17.12%), G (9.84%), and T (32.60%), so the slight A-T bias (73.04%) was detected. Phylogenetic analysis showed that T. oceanicus is closely related to T. emma that is also a member of the genus Teleogryllus.

Cyclovirobuxinum D alleviates cardiac hypertrophy in hyperthyroid rats by preventing apoptosis of cardiac cells and inhibiting the p38 mitogen-activated protein kinase signaling pathway.

OBJECTIVE: To investigate the underlying mechanisms of cyclovirobuxinum D (Cvb-D) on alleviating cardiac hypertrophy in rats. METHODS: Sprague-Dawley rats were randomly divided into 5 groups: control group; levothyroxine-induced cardiac hypertrophy group (model); levothyroxine-induced cardiac hypertrophy + Cvb-D group (Cvb-D); levothyroxine-induced cardiac hypertrophy + captopril group (captopril); levothyroxine-induced cardiac hypertrophy + SB203580 group (SB203580), n=10 for each group. Rats were daily administered the respective drugs continuously for14 days by gastric gavage. A rat model of cardiac hypertrophy was established by intraperitoneal injection of levothyroxine to investigate whether Cvb-D protects against cardiac hypertrophy by inhibiting the p38 mitogen-activated protein kinase (MAPK) signaling pathway and preventing apoptosis of cardiac cells. RESULTS: Treatment with Cvb-D significantly deceased left ventricle hypertrophy, improved the histopathology, hemodynamic conditions, and cardiac function in rats with cardiac hypertrophy. Compared with the normal control group, in rats with cardiac hypertrophy, expression of bax in the heart and phospho-p38 MAPK protein levels were significantly up-regulated (P<0.01 or 0.05), whereas the bcl-2 protein level was down-regulated (P<0.01). In contrast, Cvb-D treatment reversed the changes in bax and phospho-p38 MAPK protein levels but increased the bcl-2 protein level (P<0.01 or 0.05), and these effects were similar to those of captopril and SB203580 (a specific p38MAPK inhibitor) treatment. Furthermore, both Cvb-D, captopril and SB203580 reduced mRNA expression of p38α, p38ß, c-fos, and c-jun mRNA, and Cvb-D had a stronger effect (P<0.01). CONCLUSION: These results demonstrate that Cvb-D protects against cardiac hypertrophy, which is possibly mediated by prevention of cardiac cell apoptosis and inhibition of the p38MAPK signaling pathway.

[A pharmacology study of Cyclovirobuxinum D on curing myocardial ischemia induced by isoprenaline].

OBJECTIVE: To explore the pharmacology actions of Cyclovirobuxinum D (Cvb-D) for the myocardial ischemia and study its possible mechanism. METHODS: The rats were given orally with Cvb-D 0.55 g/kg, 1.1 g/kg and 2.2 g/kg per day, for 21 days. The myocardial ischemia model were induced by isoprenaline. The rats ECG, serum CPK, LDH, FFA and myocardium tissue SOD, MDA level were detected. RESULTS: Cvb-D could significantly reduce myocardial ischemia model induced by isoprenaline rats' sigmaJ of ECG, shorten ECG resume time, reduce serum FFA content, serum CPK, LDH activation, reduce cardiac tissue MDA content, raise the cardiac tissue SOD activation. CONCLUSION: Cvb-D can decrease the release of FFA, CPK, LDH and improve the model rats' myocardium MDA, SOD level. It may be some of mechanisms of its anti-myocardial ischemia effect.

Combretastatin A-4 and Derivatives: Potential Fungicides Targeting Fungal Tubulin.

Combretastatin A-4, first isolated from the African willow tree Combretum caffrum, is a tubulin polymerization inhibitor in medicine. It was first postulated as a potential fungicide targeting fungal tubulin for plant disease control in this study. Combretastatin A-4 and its derivatives were synthesized and tested against Rhizoctonia solani and Pyricularia oryzae. Several compounds have EC50 values similar to or better than that of isoprothiolane, which is widely used for rice disease control. Structure-activity relationship study indicated the the cis configuration and hydroxyl group in combretastatin A-4 are crucial to the antifungal effect. Molecular modeling indicated the binding sites of combretastatin A-4 and carbendazim on fungal tubulin are totally different. The bioactivity of combretastatin A-4 and its derivatives against carbendazim-resistant strains was demonstrated in this study. The results provide a new approach for fungicide discovery and fungicide resistance management.