中草药提取物对蔬菜两种采后病原真菌的抑菌活性研究

以灰葡萄孢菌和链格孢菌为供试病菌,采用生长速率法和培养板连续稀释法在离体条件下研究了木香、决明子等16种中草药提取物抑菌活性,对其效果较好的中草药提取物最小抑菌浓度(MIC)和最小杀菌浓度(MFC)进行了初步确定。试验结果显示,北豆根与黄柏在质量浓度为10.0mg/mL时,对两种病原真菌菌丝生长的抑制率均高于60%。它们对灰葡萄孢菌的最小抑菌浓度MIC依次是12.5,25mg/mL,最小杀菌浓度浓度MFC分别为:25,50mg/mL;对链格孢菌的MIC分别是6.25,12.5mg/mL,MFC都高于MIC两倍,分别是12.5,25mg/mL。     

茶多酚的抑菌作用研究

对茶多酚对常见致病菌的抑制作用进行了研究,测定了茶多酚对这些致病菌的最低抑制浓度,结果表明,茶多酚对金黄色葡萄球菌、蜡样芽孢杆菌、枯草杆菌的抑制作用特别强,其抑菌圈范围明显,抑制作用强;对变形杆菌和沙门氏菌的抑制作用次之,其抑菌圈较为模糊;对大肠杆菌的抑制作用则欠佳.探讨了茶多酚在鲜肉和鲜牛奶中的防腐效果.     

重组Lv-PEN-3蛋白先天免疫相关功能的研究

以凡纳对虾PEN-3对虾素分子作为研究对象,分别进行了细菌结合功能、蛋白酶活性抑制功能与抑菌作用等研究。结果显示：重组Lv-PEN-3分子可以较强地结合细菌,可以有效抑制分泌型蛋白酶的活性,但是其抑制细菌生长的作用较弱,三者之间的关联需要进一步探索。     

中草药与复方对鲁氏耶尔森菌的体外抑菌作用

采用试管二倍稀释法测定了16种中草药单方及5种复方制剂对鲁氏耶尔森菌（Yersinia ruckeri）的最小抑菌浓度（MIC）。结果表明,黄芩（Radix Scutellariae）和诃子（Fructus Chebulae）对鲁氏耶尔森菌的抑菌作用最强,MIC均为0.028g·mL^-1,可作为防治水产养殖动物耶尔森菌病害的主要备选中草药;大黄（Radix et Rhizoma Rhei）的抑菌作用较强,其MIC值为0.227g·mL^-1,也可作为候选药物;青蒿（Herba Artemisiae）、金樱子（Fructus Rosae Laevigatae）、连翘（Fructus Forsythiae）、茵陈（Herba Artemisiae Scopariae）、五倍子（Galla Chinensis）及金银花（Flos Lonicerae）的抑菌作用较弱,其MIC值均为0.455g·mL^-1。5种复方制剂中,大黄、黄柏（Cortex Phel-lodendri）和黄芩3种中草药以5：3：2的比例配伍对鲁氏耶尔森菌具有最佳抑菌作用,其MIC值为0.057g·mL^-1,抑菌效果弱于黄芩,但远强于大黄单独使用,可为该细菌性疾病的防治提供复方配伍参考。     

Chemistry of the Nudibranch Aldisa andersoni: Structure and Biological Activity of Phorbazole Metabolites

The first chemical study of the Indo-Pacific dorid nudibranch Aldisa andersoni resulted in the isolation of five chlorinated phenyl-pyrrolyloxazoles belonging to the phorbazole series. Two new molecules, 9-chloro-phorbazole D and N1-methyl-phorbazole A, co-occurring with known phorbazoles A, B and D, have been characterized. Phorbazoles were found to be present mainly in the external part of the mollusc. The structures of the new compounds were determined by interpretation of spectroscopic data, mainly NMR and mass spectrometry and by comparison with the literature data. Evaluation of feeding-deterrence activity as well as in vitro growth inhibitory properties in human cancer cells was also carried out.     

Optimization of Hydrolysis Conditions for the Production of the Angiotensin-I Converting Enzyme Inhibitory Peptides from Sea Cucumber Collagen Hydrolysates

The effects of different hydrolysis conditions on the angiotensin-I converting enzyme (ACE) inhibitory properties of giant red sea cucumber (Parastichopus californicus) collagen hydrolysates were investigated. Optimal conditions predicted by central composite rotatable design (CCDR) modeling for producing ACE inhibitory peptides were found to be 54.9°C, 1.76 h and an enzyme to substrate (E/S) ratio of 0.064. Compared with experiments performed under these optimal conditions, the predicted degree of hydrolysis (DH) and ACE inhibitory activities had error rates of 3 to 6%. Under optimum conditions, the molecular weights of collagen hydrolysates were less than 6.5 kDa. Lineweaver-Burk plots suggest that the collagen hydrolysates acted as competitive inhibitors with an inhibition constant (Ki) value of 0.706 mg/mL.     

Inhibitory activity against plant pathogenic fungi of extracts from Myoporum bontioides A. Gray and indentification of active ingredients

BACKGROUND: In order to understand the bioactivity of Myoporum bontioides A. Gray against plant pathogens and determine its active ingredients, the inhibitory activities of methanol extracts from M. bontioides against Fusarium oxysporum f. sp. niveum (E. F. Smith) Snyder & Hansen, Pestalotia mangiferae P. Henn., Thielaviopsis paradoxa (De Seynes) v. Hohnel, Colletotrichum musae (Berk. & M. A. Curtis) v. Arx, Alternaria alternata (Fr.) Keissler, Mycosphaerella sentina (Fr.) Schroter and Sphaceloma fawcettii Jenk. were evaluated using a growth rate method, and the active ingredient was isolated by activity-directed isolation and identified by determination and analysis of IR, (1)H NMR, (13)C NMR and mass spectra and correlative physical constants. RESULTS: The results showed that the extracts from stems and leaves of M. bontioides exhibited inhibitory activity against the seven fungi, with > 58% inhibition at 10 g L(-1) after 72 h. The active compound was isolated and identified as (-)-epingaione, and showed inhibitory activity against the above seven fungi. The inhibitory activity against P. mangiferae was the highest, with an EC(50) value of 77 mg L(-1). The EC(50) values against the other six fungi were 147-245 mg L(-1). (-)-Epingaione also inhibited spore germination of F. oxysporum f. sp. niveum, T. paradoxa and S. fawcettii.CONCLUSION: (-)-Epingaione demonstrated broad-spectrum inhibitory activity against plant pathogenic fungi and is promising for exploitation as a fungicide.     

假色槭种子透水性及内源抑制物质的初步研究

为研究假色槭种子透水性及种子不同部位甲醇浸提液生物活性,初步探讨假色槭种子休眠原因,比较了假色槭完整种子和剪裂种皮种子的吸水率,测定了种子各部位浸提液对小麦种子萌发及幼苗生长的抑制强度。结果表明,种皮透水性良好,对假色槭种子休眠影响较小。假色槭种子的果皮、种皮、胚浸提液处理后,对小麦种子发芽率影响较小,但却严重影响了小麦苗高、苗鲜重、根长、根鲜重的生长,降低了叶绿素含量、淀粉酶活性,抑制了小麦种子对自身淀粉和可溶性糖的吸收利用,而且随着各部位浸提液浓度比例的不断提升,其抑制活性也表现得愈加强烈。在各部位浸提液浓度比例相同的情况下,胚浸提液对小麦种子发芽率、苗高、苗鲜重、根长、根鲜重的生长以及各项生理指标的抑制影响强于种皮和果皮。说明假色槭种子果皮透水性不是其休眠的主要原因,种子各部位存在发芽抑制成分,尤其是胚的抑制活性最强可能是其休眠期较长、不易发芽的主要原因。     

烤烟‘K326’抗TMV防御物质初探

烤烟主栽品种‘K326’在打顶后,随着次生代谢产物的积累,烟草花叶病症状呈减轻趋势。本试验利用半叶枯斑法对‘K326’的全株、根、茎、叶甲醇提取物及根部不同极性溶剂萃取物进行抗烟草普通花叶病毒活性筛选,结果表明:在浓度为1mg/mL时,‘K326’各部位甲醇提取物中,根部甲醇提取物的活性最强,对TMV体外钝化、初侵染和复制增殖作用的抑制率分别为74.50%、68.82%和47.76%;利用不同极性溶剂对根部甲醇提取物萃取处理后,乙酸乙酯萃取物活性增强明显,对TMV体外钝化、初侵染和复制增殖作用的抑制率分别为76.81%、78.02%、61.42%;经普通烟‘K326’进一步验证,根部甲醇提取物的乙酸乙酯萃取物活性最强。综上,‘K326’中抗病毒防御物质可能存在于根部甲醇提取物的乙酸乙酯萃取物中。     

Investigation of lactic acid bacterial strains for meat fermentation and the product's antioxidant and angiotensin‐I‐converting‐enzyme inhibitory activities

In the lactic acid bacteria (LAB) strains screened from our LAB collection, Lactobacillus (L.) sakei strain no. 23 and L. curvatus strain no. 28 degraded meat protein and tolerated salt and nitrite in vitro. Fermented sausages inoculated strains no. 23 and no. 28 showed not only favorable increases in viable LAB counts and reduced pH, but also the degradation of meat protein. The sausages fermented with these strains showed significantly higher antioxidant activity than those without LAB or fermented by each LAB type strain. Angiotensin‐I‐converting‐enzyme (ACE) inhibitory activity was also significantly higher in the sausages fermented with strain no. 23 than in those fermented with the type strain. Higher ACE inhibitory activity was also observed in the sausages fermented with strain no. 28, but did not differ significantly from those with the type strain. An analysis of the proteolysis and degradation products formed by each LAB in sausages suggested that those bioactivities yielded fermentation products such as peptides. Therefore, LAB starters that can adequately ferment meat, such as strains no. 23 and no. 28, should contribute to the production of bioactive compounds in meat products.