Novel (E)-3-(3-Oxo-4-substituted-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)-N-hydroxypropenamides as Histone Deacetylase Inhibitors: Design,Synthesis and Bioevaluation

Herein, we report the design, synthesis and evaluation of novel (E)-3-(3-oxo-4-substituted-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)-N-hydroxypropenamides ( 4 a – i , 7 a – g ) targeting histone deacetylases. Three human cancer cell lines were used to test the cytotoxicity of the synthesized compounds (SW620, colon; PC-3, prostate; NCI−H23, lung cancer); inhibitory activity towards HDAC; anticancer activity; as well as their impact on the cell cycle and apoptosis. As a result, compounds 4 a – i bearing the alkyl substituents seemed to be less potent than the benzyl-containing compounds 7 a – g in all biological assays. Compounds 7 e – f were found to be the most active HDAC inhibitors with IC₅₀ of 1.498±0.020 μM and 1.794±0.159 μM, respectively. In terms of cytotoxicity and anticancer assay, 7 e and 7 f also showed good activity with IC₅₀ values in the micromolar range. In addition, the cell cycle and apoptosis of SW620 were affected by compound 7 f in almost a similar manner to that of reference compound SAHA. Docking assays were carried out for analysis the binding mode and selectivity of this compound toward 8 HDAC isoforms. Overall, our data confirmed that the inhibition of HDAC plays a pivotal role in their anticancer activity.     

EFFECTS OF HELPER PROTEINS ENCODED BY p19 AND orf1-orf2 GENES ON Cyt1Aa PROTEIN EXPRESSION IN ACRYSTALLIFEROUS STRAIN OF BACILLUS THURINGIENSIS

A series of plasmids were constructed to examine the effects of p19 and orf1‐orf2 genes from Bacillus thuringiensis on Cyt1Aa synthesis and inclusion formation. The plasmids expressed the cyt1Aa gene along with either p19 or orf1‐orf2, or each of them coordinatively with p20 in the acrystalliferous strain of B. thuringiensis subsp. israelensis 4Q7. No effect on the expression of Cyt1Aa protein was found when P19 or Orf1‐Orf2 co‐expressed with Cyt1Aa. However, when including p20 gene, the constructs with p19 or orf1‐orf2 gene produced lower yield of Cyt1Aa proteins than without p19 or orf1‐orf2 gene. Electron microscopy observation and bioassay showed that P19 and Orf1‐Orf2 have no influence on the crystal size and toxicity of Cyt1Aa protein. It is presumed that P19 and Orf1‐Orf2 might have negative effects on Cyt1Aa synthesis in B. thuringiensis.     

Purification, biochemistry and molecular cloning of an insect glycosylasparaginase from Spodoptera frugiperda

Glycosylasparaginase (EC 3.5.1.26 [EC] ) from Sf9 cells (Spodopterafrugiperda) was purified to homogeneity with a specific activityof 2.1 unit/mg. The enzyme is composed of two non-identical     

不同蔬菜防癌抗促活性的比较研究

本研究采用EBV-EA诱导抑制实验的方法,对40种蔬菜,60个品种,共150个样品的防癌抗促作用效果进行了筛选与比较,其中具有中等以上抑制活性的样品117个,占样品总数的78％,尤其以非洲野苋菜、辣椒、羽衣甘蓝、山药芋头、苦瓜及紫苏、罗勒等一些芳香莱的效果较好。不同品种、不同植株部位、不同提取方法以及不同产地,对蔬菜的抗促活性也有影响,值得进一步研究。     

鹅掌楸雌配子体败育对生殖的影响

胚珠和雌配子体败育是限制鹅掌楸生殖成功的一个重要因素。中国东部和西部鹅掌楸种群在雌配子体发育的各阶段上的败育程度有差异,以西部种群的发育较好。西部分布区较合适的生境促进了胚囊的发育,一定温度和湿度的环境可以活化珠心细胞输送营养物质供给雌配子体发育,提高受精和结籽的能力     

良种茶树芽叶中氨基酸研究

本文报导利用日立－ＥＧ型氨基酸自动分析仪测定的六个茶树良种芽叶中十九种氨基酸组成情况,并以此为依据对良好的品质风格进行了探讨。     

Analysis of randomly isolated cDNAs from developing endosperm of rice (Oryza sativa L.): evaluation of expressed sequence tags,and expression levels of mRNAs

Using a cDNA library prepared from poly(A)⁺ RNA from 10-day-old rice endosperm, partial nucleotide sequences of randomly isolated clones were analyzed. A total of 153 (30.6%) out of 500 cDNA clones showed high amino acid identity to previously identified genes. There was significant redundancy in cDNAs encoding prolamine and glutelin. About 21.0% of the cDNA clones were found to code for seed storage protein genes. Consequently, 37 independent genes were identified. Using cDNA clones encoding glutelin, prolamine, seed allergen, -1,4-glucan branching enzyme, glycine-rich RNA binding protein, metallothionein, non-specific lipid-transfer protein and ubiquitin conjugating enzyme the accumulation of mRNA during rice seed development was compared. Genes associated with seed storage protein and starch biosynthesis were expressed according to expected developmental stages. Glycinerich RNA binding protein genes as well as metallothionein-like protein genes were highly expressed in developing seeds, but low in leaves of whole plants.     

Thermotolerance induced by heat shock in Chlorella

Thermotolerance in cultures of Chlorella zofingiensis was induced by heat shock treatment at supraoptimal temperatures (40and 45 °C for 30 min). Thermotolerance was assayed by two methods: the survival of the cells at 70 °C and the growth of diluted cultures at 35 and 45 °C. A culture without heat shock treatment was unable to grow at 45 °C. According to eletrophoretic analyses, the synthesis of proteins of 95, 73, 60, 43 and 27 kDa was induced by heat shock treatment. The large molecular weight proteins (95, 73, 60 and43 kDa) were present in non-heat treated cells, but the heat shock treatment increased their quantity in cells. The synthesis of a low molecular weight protein (27 kDa) was induced by heat shock treatment. The induced thermotolerance could be inhibited by the presence of an 80S ribosomal translation inhibitor, cycloheximide(CHI). The first 12 amino acid residues from the N-terminus of the27 kDa heat shock induced protein are Val-Glu-Trp-Try-Gly-Pro-Asn-Arg-Ala-Lys-Phe-Leu. This revised version was published online in August 2006 with corrections to the Cover Date.     

A Role for the Disintegrin Domain of Cyritestin, a Sperm Surface Protein Belonging to the ADAM Family, in Mouse Sperm–Egg Plasma Membrane Adhesion and Fusion

Sperm–egg plasma membrane fusion is preceded by sperm adhesion to the egg plasma membrane. Cell–cell adhesion frequently involves multiple adhesion molecules on the adhering cells. One sperm surface protein with a role in sperm–egg plasma membrane adhesion is fertilin, a transmembrane heterodimer (α and β subunits). Fertilin α and β are the first identified members of a new family of membrane proteins that each has the following domains: pro-, metalloprotease, disintegrin, cysteine-rich, EGF-like, transmembrane, and cytoplasmic domain. This protein family has been named ADAM because all members contain a disintegrin and metalloprotease domain. Previous studies indicate that the disintegrin domain of fertilin β functions in sperm–egg adhesion leading to fusion. Full length cDNA clones have been isolated for five ADAMs expressed in mouse testis: fertilin α, fertilin β, cyritestin, ADAM 4, and ADAM 5. The presence of the disintegrin domain, a known integrin ligand, suggests that like fertilin β, other testis ADAMs could be involved in sperm adhesion to the egg membrane. We tested peptide mimetics from the predicted binding sites in the disintegrin domains of the five testis-expressed ADAMs in a sperm–egg plasma membrane adhesion and fusion assay. The active site peptide from cyritestin strongly inhibited (80–90%) sperm adhesion and fusion and was a more potent inhibitor than the fertilin β active site peptide. Antibodies generated against the active site region of either cyritestin or fertilin β also strongly inhibited (80–90%) both sperm–egg adhesion and fusion. Characterization of these two ADAM family members showed that they are both processed during sperm maturation and present on mature sperm. Indirect immunofluorescence on live, acrosome-reacted sperm using antibodies against either cyritestin or fertilin β showed staining of the equatorial region, a region of the sperm membrane that participates in the early steps of membrane fusion. Collectively, these data indicate that a second ADAM family member, cyritestin, functions with fertilin β in sperm–egg plasma membrane adhesion leading to fusion.