Smenamides A and B,Chlorinated Peptide/Polyketide Hybrids Containing a Dolapyrrolidinone Unit from the Caribbean Sponge Smenospongia aurea. Evaluation of Their Role as Leads in Antitumor Drug Research

An in-depth study of the secondary metabolites contained in the Caribbean sponge Smenospongia aurea led to the isolation of smenamide A (1) and B (2), hybrid peptide/polyketide compounds containing a dolapyrrolidinone unit. Their structures were elucidated using high-resolution ESI-MS/MS and homo- and heteronuclear 2D NMR experiments. Structures of smenamides suggested that they are products of the cyanobacterial metabolism, and 16S rRNA metagenomic analysis detected Synechococcus spongiarum as the only cyanobacterium present in S. aurea. Smenamides showed potent cytotoxic activity at nanomolar levels on lung cancer Calu-1 cells, which for compound 1 is exerted through a clear pro-apoptotic mechanism. This makes smenamides promising leads for antitumor drug design.     

Isolation and Characterization of Collagen and Antioxidant Collagen Peptides from Scales of Croceine Croaker (Pseudosciaena crocea)

Acid soluble collagen (ASC) from scales of croceine croaker (ASC-C) was successfully isolated with the yield of 0.37% ± 0.08% (dry weight basis), and characterized as type I collagen on the basis of amino acid analysis and electrophoretic pattern. The antioxidant hydrolysate of ASC-C (ACH) was prepared through a two-stage in vitro digestion (4-h trypsin followed by 4-h pepsin), and three antioxidant peptides (ACH-P1, ACH-P2, and ACH-P3) were further isolated from ACH using ultrafiltration, gel chromatography, and RP-HPLC, and their amino acid sequences were identified as GFRGTIGLVG (ACH-P1), GPAGPAG (ACH-P2), and GFPSG (ACH-P3). ACH-P1, ACH-P2, and ACH-P3 showed good scavenging activities on hydroxyl radical (IC₅₀ 0.293, 0.240, and 0.107 mg/mL, respectively), DPPH radical (IC₅₀ 1.271, 0.675, and 0.283 mg/mL, respectively), superoxide radical (IC₅₀ 0.463, 0.099, and 0.151 mg/mL, respectively), and ABTS radical (IC₅₀ 0.421, 0.309, and 0.210 mg/mL, respectively). ACH-P3 was also effectively against lipid peroxidation in the model system. The antioxidant activities of three collagen peptides were due to the presence of hydrophobic amino acid residues within the peptide sequences. The collagen peptides might be used as antioxidant for the therapy of diseases associated with oxidative stress, or reducing oxidative changes during storage.     

Internal parasites of possums (Trichosurus vulpecula) from Kawau Island,Chatham Island and Stewart Island

As part of a search for pathogens that might be useful agents for biological control of possums, the three largest offshore islands of New Zealand that still have possums were surveyed to determine the pathogens present in these isolated populations. Brushtail possums from Kawau Island (n = 158), Chatham Island (n = 214) and Stewart Island (n = 194) were examined for internal parasites.

Possums from Kawau Island were infected with Eimeria spp. (16.7%), Bertiella trichosuri (5.2%) and Parastrongyloides trichosuri (15.5%). No Paraustrostrongylus trichosuri or Trichostrongylus spp. were found. Possums from Chatham Island were infected with Eimeria spp. (10.9%). Bertiella trichosuri (3.6%), T. colubriformis (6.6%), T. retortaeformis (1%) and T. vitrinus (0.5%). No Parastrongyloides or Paraustrostrongylus spp. were found. Possums from Stewart Island were infected only with Eimeria spp. (4.6%).

Because of their paucity of some parasites, the opportunity exists to use these offshore islands to study the introduction and spread of a parasite into a possum population, and what technology would be required to bring it to hyperendemicity.     

猪繁殖与呼吸综合征基因标记疫苗株NP49-ELISA鉴别诊断方法的建立

猪繁殖与呼吸综合征病毒（Porcine reproductive and respiratory syndrome virus,PRRSV）rHN4-△25＋NP49株是新型基因标记弱毒疫苗候选株,为了配合对该基因标记疫苗免疫猪血清抗体的鉴别诊断,本研究以标记基因编码的NP49（新城疫病毒NP蛋白C末端49个氨基酸,即NP49）多肽作为包被抗原,建立标记疫苗免疫猪血清中NP49抗体的ELISA鉴别诊断方法。通过对NP49-ELISA工作条件的优化,结果显示NP49-ELISA的多肽抗原最适包被浓度为500ng／孔,被检血清最佳稀释度为1：40。利用ROC曲线法确定S／P临界值为0．2,该方法批内与批间重复试验的变异系数均小于10％,与几种常见猪病阳性血清无交叉反应,具有较好重复性和特异性。本研究建立的NP49．ELISA鉴别诊断方法为猪繁殖与呼吸综合征新型基因标记疫苗的临床应用提供了有力保障。     

热带地区街旁小游园建设特征研究——以湛江为例

城市街旁小游园的可达性和灵活多变性使其在城市景观环境空间中成为具有重要意义的过渡空间。以湛江市为例,选取3个具有代表性的街旁小游园,通过对其区位特点、空间处理、地域性景观体现和游憩特色4个方面的建设特征进行调查分析,提出热带地区街旁小游园的建设应做到以人为本、体现热带园林景观地域性特色、注重地方文化的传承与更新的观点。     

Screening of Neutrophil Activating Factors from a Metagenome Library of Sponge-Associated Bacteria

Marine sponge-associated bacteria are known as bio-active compound produce. We have constructed metagenome libraries of the bacteria and developed a metagenomic screening approach. Activity-based screening successfully identified novel genes and novel enzymes; however, the efficiency was only in 1 out of 10⁴ clones. Therefore, in this study, we thought that bioinformatics could help to reduce screening efforts, and combined activity-based screening with database search. Neutrophils play an important role for the immune system to recognize excreted bacterial by-products as chemotactic factors and are recruited to infection sites to kill pathogens via phagocytosis. These excreted by-products are considered critical triggers that engage the immune system to mount a defense against infection, and identifying these factors may guide developments in medicine and diagnostics. We focused on genes encoding amino acid ligase and peptide synthetase and selected from an in-house sponge metagenome database. Cell-free culture medium of each was used in a neutrophil chemiluminescence assay in luminol reaction. The clone showing maximum activity had a genomic sequence expected to produce a molecule like a phospho-N-acetylmuramyl pentapeptide by the metagenome fragment analysis.     

基塘农业模式下不同饲料养殖草鱼的成效分析

【目的】探究基塘农业模式下,不同饲料养殖草鱼的生长性能、常规营养成分和经济效益的差异。【方 法】设置蛹肽蛋白饲料组、混合料组、普通料组进行养殖对比试验,每组选择初始体重为 770（±11.2）g 的草 鱼 610 尾,分别放入面积相同的试验池塘养殖 180 d,试验期结束后每组随机抽取 4 尾草鱼,采集侧线上方背脊 肌肉,制成 4 个质量均为 50（±3.8）g 的混合样作为每组 4 个重复,另外试验前随机抽取 4 尾初始规格鱼种的 背脊肌肉制成混合样设置为空白对照。【结果】蛹肽蛋白饲料组草鱼增重率最高（134.3%）,肌肉粗脂肪含量 （1.74%）显著高于其他组,从增重率与特定生长率两个指标看,均呈现出蛹肽蛋白饲料组 > 普通料组 > 混合料 组的显著性差异;混合料组的草鱼粗蛋白含量（20.7%）和鲜味氨基酸含量（6.37%）均最高,而脂肪含量最低 （1.27%）,投入产出比最低（0.941）。初始组不饱和脂肪酸含量（71.07%）显著高于 3 个试验组,3 个试验组 草鱼肌肉油酸（C18:1）含量与氨基酸总量均高于初始组,蛹肽蛋白料组与普通料组的鱼肉营养成分无显著差异。【结 论】摄食蛹肽蛋白饲料的草鱼增重率高,但容易沉积体脂,导致体型肥胖;混合料组的草鱼生长速度慢,但鱼 肉粗蛋白含量最高（20.7%）,脂肪含量最低（1.27%）,肉质更鲜美。基塘农业模式下利用闲置区域种青养鱼, 能有效降低饲料成本,改善鱼肉品质。     

玉米肽研究进展

玉米蛋白肽在抗氧化和降血压、血脂、胆固醇方面具有显著效果。根据国内外相关研究进展,介绍玉米肽的主要制备提取方法,以及各提取方法的原理、优势和缺点,展望玉米肽的开发应用前景,为玉米肽的应用和开发研究提供理论参考。