Identification of an Asexual Reproduction Inducer of Phytopathogenic and Toxigenic Fusarium

Asexual and sexual reproduction are the most important biological events in the life cycle of phytopathogenic and toxigenic Fusarium and are responsible for disease epidemics. However, the signaling molecules which induce the asexual reproduction of Fusarium are unknown. Herein we describe the structure elucidation, including the absolute configuration, of Fusarium asexual reproduction inducer (FARI), a new sesquiterpene derivative, by spectroscopic analysis, total synthesis, and conidium‐inducing assays of synthetic isomers. We have also uncovered the universality of FARI among Fusarium species. Moreover, a mechanism‐of‐action study suggested that the Gpmk1 and LaeA signaling pathways are required for conidium formation induced by FARI; conversely, the Mgv1 of mitogen‐activated protein kinase is not involved in conidium formation. FARI exhibited conidium‐inducing activity at an extremely low dose and high stereoselectivity, which may suggest the presence of a stereospecific target.     

基于正交试验的诱导轮前置孔板的参数化研究

为明确前置各种参数的孔板对抑制GSB-80/300型的诱导轮离心泵小流量不稳定特性的影响程度,选择孔板离诱导轮前缘的距离L,孔板的孔径D,孔板的厚度B作为3因素,每个因素各取3水平,制定了L9(3~3)正交数值模拟试验方案。数值模拟试验方案采用雷诺时均N-S控制方程和标准κ-ε湍流模型。通过数值模拟,得到了前置各种参数的孔板下诱导轮离心泵流场的分布情况,得到了较佳的三种参数组合,并揭示了各个因素对流场的影响顺序是:孔板的孔径D,孔板的厚度B,孔板离诱导轮前缘的距离L。在此基础上,对三种较佳参数组合下的孔板进行了全工况点的数值模拟,分别得到了它们的扬程流量特性曲线。通过流场,外特性曲线分析比较,得到了有效抑制GSB-80/300型的诱导轮离心泵小流量不稳定特性的最佳参数组合的孔板。     

正丙醇诱导合成WO3粉体与光致变色性质

采用正丙醇为有机诱导剂, 在水热条件下制备了形貌新颖的WO3粉体, 使用XRD, SEM和TEM等手段进行了结构和形貌表征, 并用紫外-可见(UV-Vis)光谱仪及测色计测试了光致变色性能. 结果表明, 正丙醇诱导合成的WO3粉体仍为六方相, 但形成了特殊的海胆状纳米结构, SEM和TEM测试结果表明, 海胆状WO3微球由大量的WO3纳米杆簇集形成. 该诱导产物的纳米杆簇集成的海胆状结构显著地改善了光生质子的传输过程, 提高了合成的WO3粉体的光致变色性能.     

Recent Synthetic Biology Approaches for Temperature- and Light-Controlled Gene Expression in Bacterial Hosts

The expression of genes of interest (GOI) can be initiated by providing external stimuli such as temperature shifts and light irradiation. The application of thermal or light stimuli triggers structural changes in stimuli-sensitive biomolecules within the cell, thereby inducing or repressing gene expression. Over the past two decades, several groups have reported genetic circuits that use natural or engineered stimuli-sensitive modules to manipulate gene expression. Here, we summarize versatile strategies of thermosensors and light-driven systems for the conditional expression of GOI in bacterial hosts.     

Synthetic studies on basidifferquinones: the first synthesis of (±)-basidifferquinone C

Basidifferquinones, isolated from Streptomyces sp., are potent inducers for fruiting-body formation of a basidiomycete Polyporus arcularius. Construction of the basic framework of basidifferquinones and the first synthesis of (±)-basidifferquinone C were accomplished by starting from 3,5-dihydroxy-2-naphthoic acid.     

Pterocarine, a New Diarylheptanoid from Pterocarya tonkinesis, its Cell Cycle Inhibition at G0／G1 Phase and Induction of Apoptosis in HCT-15 and K562 Cells

Pterocarya tonkinesis(Franch.)Dode.(Juglandaceae)forms a typical community ofriverside season rain forest in Xishuangbanna area of Yunnan province1.The same genusplant P.stenoptera C.DC.,has long been used as a traditional Chinese herbal medicine2and P.tonkinesis,itself,is also used as a folk medicine for the treatment of certain cancersin partial area of China.However,no report had so far been seen on the chemicalconstituents and their biological activities of the title plant yet.In the …     

Enantio- and diastereoselective synthesis of 2,5-disubstituted pyrrolidines through a multicomponent Ugi reaction and their transformation into bicyclic scaffolds

A new enantio- and diastereoselective synthesis of 2,5-disubstituted pyrrolidines through a multicomponent approach has been developed, using highly reactive pyrrolines 4 as preformed cyclic imines. The pyrrolidines obtained using protected aspartic acid as acid component in the Ugi condensation have been transformed into two epimeric bicyclic lactones 18, 19, which may find an application as external reverse turn inducers.     

Development of Semisynthetic Apoptosis-Inducing Agents Based on Natural Phenolic Acids Scaffold: Design,Synthesis and In-Vitro Biological Evaluation

A crucial target in drug research is magnifying efficacy and decreasing toxicity. Therefore, using natural active constituents as precursors will enhance both safety and biological activities. Despite having many pharmacological activities, caffeic and ferulic acids showed limited clinical usage due to their poor bioavailability and fast elimination. Therefore, semisynthetic compounds from these two acids were prepared and screened as anticancer agents. In this study, CA and FA showed very potent anticancer activity against Caco-2 cells. Consequently, eighteen derivatives were tested against the same cell line. Four potent candidates were selected for determination of the selectivity index, where compound 10 revealed a high safety margin. Compound 10 represented a new scaffold and showed significant cytotoxic activity against Caco-2. Cell-cycle analysis and evaluation of apoptosis showed that derivatives 10, 7, 11, 15 and 14 showed the highest proportion of cells in a late apoptotic stage.     

Green-synthesized Zinc oxide nanoparticle,an efficient safe anticancer compound for human breast MCF7 cancer cells

There are many types of researches investigating anticancer therapeutics for breast cancer therapy. Zinc oxide nanoparticles (ZnONPs) as an efficient drug delivery system, has been widely being used in various biomedical applications. In the current study, we synthesized ZnONP applying Rheum rhaponticum Waste (RRW) as a novel bio-platform to investigate its anticancer impacts on MCF7 breast cancer cells compared with normal Human HFF and HDF cells. In this regard, RRW was triggered to synthesize the ZnONPs. Then, they were characterized by XRD, FTIR, TEM, and SEM analysis. Next, the MCF-7, HFF, and HDF cell lines were cultured and treated as the following plane: Incubation of all cell lines for 72, 48, and 24 hours at the presence of different ZnONPs doses. Finally, the cell morphology, BCL2- BAX genes expression profile and AO/PI-fluorescent cell staining on the 48-hour incubated cells were analyzed to check the ZnONP apoptotic activity. Moreover, the ZnONP antioxidant activity was analyzed by a DPPH antioxidant test. We produced the 30 nm ZnONPs which significantly increased the BAX and decreased the BCL-2 gene expression. According to the results including the Sub G1 enhancement peaks, apoptotic hallmarks, MTT assay, and the AO/PI-fluorescent stained cells, ZnONPs can specifically induce apoptotic death in MCF7 breast cancer cells compared with normal HFF and HDF cells. The IC₅₀ values of MCF-7 in 72, 48, and 24 hr were measured at 8, 11, and 12 μg/ml in 72, 48, and 24 hr, respectively. This is while the mentioned values in the normal cells (HFF, HDF) were estimated at higher treatment doses. In conclusion, we suggest that the ZnONPs have the potential to be applied as a safe cell-specific apoptosis inducer in breast cancer treatment. However, there are many challenges that need to be clarified for applying them as an efficient anticancer agent.