Discovery and structural optimization of pyrazole derivatives as novel inhibitors of Cdc25B

Structural optimization and preliminary structure–activity relationship studies of a series of N-substituted maleimide fused-pyrazole analogues with Cdc25B inhibitory activity, starting from a high-throughput screening hit, are illustrated. A simplified 3,5-diacyl pyrazole analogue was obtained as the most potent compound (118, IC₅₀ = 0.12 μM) with a 270-fold increase in potency.     

Evaluation of free radicals scavenging and immunity-modulatory activities of Purslane polysaccharides

In this study, antioxidant and immunity-modulatory activities of Purslane polysaccharide were estimated. The results revealed that in a dose-dependent manner, Purslane polysaccharides could significantly scavenge superoxide anion, 1,1-diphenyl-2-picrylhydrazyl (DPPH^?), nitric oxide and hydroxyl radicals. Furthermore, the Purslane polysaccharides could still effectively inhibit the red blood cell (RBC) haemolysis, and increase spleen, thymocyte T and B lymphocyte proliferation, it could be concluded that Purslane polysaccharides could be of considerable preventive and therapeutic significance to some free radical associated health problems such as ovarian cancer, by scavenging accumulating free radicals and enhancing immunity functions.     

Preparation and structure of chitosan soluble in wide pH range

Two kinds of chitosans, namely N-acetylated and N-deacetylated chitosan were prepared by the modified processes. They can dissolve in both acid and alkali solution. ¹³C NMR was used to study the basic solution of chitosan, and XRD, FT-IR and SEM were used to study the structure of N-acetylated and N-deacetylated chitosan. The result from X-ray diffraction showed that a transformation of crystal structure occurred during the N-acetylation or N-deacetylation process with the decrease of crystallinity and expansion of crystal lattices. FT-IR spectra revealed that the intermolecular and intramolecular hydrogen bonds were destroyed by both treatments and a looser structure was observed by the SEM. The lower crystallinity, the decreased intermolecular interactions, the more disordered and looser structure were easy for the permeation of LiOH/urea aqueous solution and coordinated with the breakage of intermolecular and intramolecular hydrogen bond by LiOH at low temperature, the prepared chitosans dissolved in LiOH/urea/H₂O mixture.     

玉米重金属铅含量的配合力分析与育种对策

选择有代表性的12个玉米自交系,按Griffing4模式组配获得66个组合(F1),用温室盆栽,在3个Pb2+污染水平下对叶片和子粒Pb2+含量配合力和遗传参数进行分析。结果表明:玉米叶片和子粒的Pb2+含量一般配合力与特殊配合力差异均达到显著水平,非加性方差大于加性方差,遗传方差大于环境方差,广义遗传率大于狭义遗传率,该性状的变异主要来自遗传因素,遗传力较强。玉米种质筛选过程中,土壤Pb2+浓度在333.32 mg/kg以下,用亲本郑58组配的组合在筛选时不仅注重子粒Pb2+含量未超标而且要注重叶片Pb2+高富集,其主要是兼顾饲料和粮食安全的同时进行土壤Pb2+污染的生物修复;土壤Pb2+浓度高于715.46 mg/kg时,用亲本178组配的组合筛选应注意叶片和子粒低Pb2+积累的种质选育,对今后在不同Pb2+污染土壤中开展玉米品种筛选和规避污染育种策略的选择具有一定的指导意义。     

The alteration in the architecture of a T‐DNA insertion rice mutant osmtd1 is caused by up‐regulation of MicroRNA156f

Plant architecture is an important factor for crop production. Some members of microRNA156 (miR156) and their target genes SQUAMOSA Promoter‐Binding Protein‐Like (SPL) were identified to play essential roles in the establishment of plant architecture. However, the roles and regulation of miR156 is not well understood yet. Here, we identified a T‐DNA insertion mutant Osmtd1 (Oryza sativa multi‐tillering and dwarf mutant). Osmtd1 produced more tillers and displayed short stature phenotype. We determined that the dramatic morphological changes were caused by a single T‐DNA insertion in Osmtd1. Further analysis revealed that the T‐DNA insertion was located in the gene Os08g34258 encoding a putative inhibitor I family protein. Os08g34258 was knocked out and OsmiR156f was significantly upregulated in Osmtd1. Overexpression of Os08g34258 in Osmtd1 complemented the defects of the mutant architecture, while overexpression of OsmiR156f in wild‐type rice phenocopied Osmtd1. We showed that the expression of OsSPL3, OsSPL12, and OsSPL14 were significantly downregulated in Osmtd1 or OsmiR156f overexpressed lines, indicating that OsSPL3, OsSPL12, and OsSPL14 were possibly direct target genes of OsmiR156f. Our results suggested that OsmiR156f controlled plant architecture by mediating plant stature and tiller outgrowth and may be regulated by an unknown protease inhibitor I family protein.