不同理化因子对雨生红球藻CG-11碳酸酐酶活性的影响

以雨生红球藻CG-11为实验藻株,探讨在不同CO2、HCO3-、Zn2＋浓度以及pH和氮磷比例条件下,藻细胞的碳酸酐酶活性对这些理化因子的响应。结果表明,通入空气实验组的碳酸酐酶活性最高,为（75.20±1.53）U·mg-1（Chla）,通入5%CO2条件下的碳酸酐酶活性为（9.96±1.43）U·mg-1（Chla）;高浓度HCO3-对碳酸酐酶活性亦具有明显抑制作用,培养液中可溶性无机碳的浓度与碳酸酐酶活性呈负相关;在实验设置的pH范围内,pH9.0时碳酸酐酶活性最高,为（62.32±3.25）U·mg-1（Chla）;适当的氮磷比与Zn2＋浓度显著提高了雨生红球藻CG-11的生长速率,碳酸酐酶的活性亦有明显提高。     

Resveratrol derivative,trans‐3,5,4′‐trimethoxystilbene,exerts antiangiogenic and vascular‐disrupting effects in zebrafish through the downregulation of VEGFR2 and cell‐cycle modulation

Angiogenesis plays an important role in the development of neoplastic diseases such as cancer. Resveratrol and its derivatives exert antiangiogenic effects, but the mechanisms of their actions remain unclear. The aim of this study was to evaluate the antiangiogenic activity of resveratrol and its derivative trans‐3,5,4′‐trimethoxystilbene in vitro using human umbilical vein endothelial cells (HUVECs) and in vivo using transgenic zebrafish, and to clarify their mechanisms of action in zebrafish by gene expression analysis of the vascular endothelial growth factor (VEGF) receptor (VEGFR2/KDR) and cell‐cycle analysis. trans‐3,5,4′‐Trimethoxystilbene showed significantly more potent antiangiogenic activity than that of resveratrol in both assays. In zebrafish, trans‐3,5,4′‐trimethoxystilbene caused intersegmental vessel regression and downregulated VEGFR2 mRNA expression. Trans‐3,5,4′‐trimethoxystilbene also induced G2/M cell‐cycle arrest, most specifically in endothelial cells of zebrafish embryos. We propose that the antiangiogenic and vascular‐targeting activities of trans‐3,5,4′‐trimethoxystilbene result from the downregulation of VEGFR2 expression and cell‐cycle arrest at G2/M phase. J. Cell. Biochem. 109: 339–346, 2010. © 2009 Wiley‐Liss, Inc.     

Cationic N-confused porphyrin derivative as a better molecule scaffold for G-quadruplex recognition

One N-confused porphyrin derivative was prepared and its first observation that it could stabilize G-quadruplex and possessed high selectivity over duplex DNA was made, furthermore, it was also proved to possess the capacity to induce a structural transition from the antiparallel to the mixed-type hybrid G-quadruplex structure.     

A class of novel Schiff’s bases: Synthesis,therapeutic action for chronic pain,anti-inflammation and 3D QSAR analysis

To discover analgesics for treating chronic pain 17 novel Schiff’s bases, N,N′-(Z-allylidene-1,3-diyl)bisamino acid methyl esters were prepared from 1,1,3,3,-tetramethoxypropane and amino acid methyl esters. On tail-flick mouse model 20 μmol/kg of these Schiff’s bases were orally administered, the analgesic action started 30 min after administration, reached the maximum 120 min after administration, and at 180 min this action was still observed. On a xylene-induced ear edema mouse model 20 μmol/kg of these Schiff’s bases exhibited desirable anti-inflammation. Thus the present Schiff’s bases are able to treat chronic pain from inflammation. The effect of the side chains of the amino acid residues of these Schiff’s bases on the analgesic activity was explained with 3D QSAR.     

Cloning and characterization of acetylcholinesterase 1 genes from insecticide-resistant field populations of Liposcelis paeta Pearman (Psocoptera: Liposcelididae)

The psocid, Liposcelis paeta Pearman, is an increasingly important polyphagous pest of stored products worldwide. Intensive use of organophosphorous insecticides for pest control has facilitated resistance development in psocids in China. Three insecticide-resistant field populations of L. paeta were collected from Nanyang city of Henan Province (NY), and Wuzhou (WZ) and Hezhou (HZ) cities of Guangxi Province, China. Previous studies have shown that psocids have different susceptibilities to insecticides. In addition, their AChE susceptibilities to paraoxon-ethyl and demeton-S-methyl also differed from each other. Acetylcholinesterase 1, which is one of the major targets for organophosphate insecticides, has been fully cloned and sequenced from these populations of L. paeta. Comparison of both nucleotide and deduced amino acid sequences revealed nucleotide polymorphisms among L. paeta ace 1 genes from different populations, but none of these polymorphisms correspond to the active sites in AChE 1 from other insects. The results of comparative quantitative real-time PCR indicated that the relative expression level of HZ ace 1 gene was the highest among three populations, which was 1.20 and 1.02-fold higher than those of NY and WZ populations, respectively. This may due to an epigenetic inheritance phenomenon, which allows organisms to respond to a particular environment through changes in gene expression.     

SAR and molecular mechanism study of novel acylhydrazone compounds targeting HIV-1 CA

We synthesized a series of acylhydrazone compounds bearing naturally occurring amino acids’ side chains as HIV assembly inhibitors. Biological evaluation indicated that the compounds had anti-SIV and capsid assembly inhibitory activities. The structure–activity relationship (SAR) study showed that compounds bearing proper aromatic side chains had potential antiviral activities. The molecular modeling experiments revealed the molecular mechanism that they could bind to CA in the same manner as CAP-1 and occupy two more grooves.     

A class of novel carboline intercalators: Their synthesis,in vitro anti-proliferation,in vivo anti-tumor action,and 3D QSAR analysis

Based on DOCK scores 18 N-(3-benzyloxycarbonylcarboline-1-yl)ethylamino acid benzylesters (6a–r) were synthesized as anti-tumor agents. Their IC₅₀ values against five human carcinoma cell lines ranged from 11.1 μM to more than 100 μM. The in vivo assay identified five derivatives of them had no anti-tumor action, the anti-tumor activity of nine derivatives of them equaled that of cytarabine, and the anti-tumor activity of three derivatives of them was higher than that of cytarabine. The UV and fluorescence spectra, as well as the relative viscosity and melting temperature measurements of calf thymus DNA (CT DNA) with and without the representative compound suggested that DNA intercalation could be their action mechanism. The 3D QSAR analysis of N-(3-benzyloxycarbonylcarboline-1-yl)ethylamino acid benzylesters (6a–r) revealed that their in vivo anti-tumor activity significantly depends on the molecular electrostatic and steric fields of the side chain of the amino acid residue.     

Role of mucilage in the germination of Artemisia sphaerocephala (Asteraceae) achenes exposed to osmotic stress and salinity

Artemisia sphaerocephala (Asteraceae) is one of the pioneer species in moving and semi-stable sand dunes in the deserts of northwest China. The outer surface of A. sphaerocephala achenes contains a pectinaceous mucilage layer that can imbibe a large amount of water when wetted. We hypothesized that the mucilage can aid achene germination in heterogeneous environments. Germination of both intact achenes and those from which the mucilage had been removed (demucilaged) declined with increasing osmotic potential and NaCl concentration. However, the germination percentage of intact achenes was significantly higher than that of demucilaged achenes. The early seedling growth of intact achenes did not differ significantly from that of demucilaged achenes in either osmotic potential or NaCl solutions. Achene mucilage presumably plays an ecologically important role in the life cycle of A. sphaerocephala by aiding germination in osmotically- and saline-stressful habitats of the cold desert environment.