A novel antifungal anthraquinone from seeds of Aegle marmelos Correa (family Rutaceae)

A new anthraquinone, 1-methyl-2-(3′-methyl-but-2′-enyloxy)-anthraquinone (1) has been isolated from seeds of Aegle marmelos Correa and was characterized on the basis of spectral analysis (UV, IR, ¹H NMR, ¹³C NMR, 2D NMR and mass spectroscopy). The compound exhibited significant antifungal activity against pathogenic strains of Aspergillus species and Candida albicans in disc diffusion assay (MIC value of 6.25 μg/disc), microbroth dilution and percent spore germination inhibition assays (MIC value of 31.25–62.5 μg/ml).     

Antimicrobial activity of Rubus chamaemorus leaves

The antibacterial activity of Rubus chamaemorus leaf butanolic fraction of the methanol extract and ellagic acid was evaluated against some Gram-positive and Gram-negative bacteria. Antimycotic activity was assayed against Candida albicans. MICs and MBCs were determined by broth dilution test and by disc diffusion method.     

杂交竹枯梢病菌的室内杀菌剂筛选

为了筛选防治杂交竹枯梢病的有效药剂,以菌落生长法和孢子萌发率法测定和比较了12种常用杀菌剂对杂交竹枯梢病菌竹长喙壳菌Ceratosphaeria phyllostachydis Zhang TZ01菌株的毒力。试验结果表明：甲基托布津、多菌灵、代森锰锌、炭疽福关这4种杀菌剂对TZ01有较好的抑制作用,能极显著的抑制TZ01的菌丝生长,其EGn分别是1．265,3、567,4．569,26．450mg／L。另外筛选出的药剂对TZ01孢子的萌发均有较强的抑制作用,在EGn浓度下这4种药剂对TZ01孢子萌发的抑制百分率分别为59．5％,67．9％,54．8％,47．8％。综合菌丝生长抑制率和孢子萌发抑制率两方面评定,认为甲基托布津对病菌的抑制作用最强。但因为甲基托布津易引起病菌的抗药性因而在田间试验和推广应用时可与其它筛选出的3种杀菌剂轮换使用。     

Antinociceptive activity of the aerial parts of Solanum xanthocarpum

The methanolic extract of Solanum xanthocarpum aerial parts, given orally at 125, 250 and 500 mg/kg, showed significant antinociceptive activity in mice.     

The sporicidal activity of yellow‐cedar heartwood,essential oil and wood constituents towards Phytophthora ramorum in culture

In this paper, we demonstrate that 140 mg/kg of essential oil from the wood of yellow‐cedar, incense cedar, Port‐Orford‐cedar or western juniper strongly inhibits zoospore germination and hyphal growth of Phytophthora ramorum in culture. Four individual compounds in yellow‐cedar heartwood were also tested. Zoospore germination was reduced to 0% with 10, 100 and 1000 mg/kg of nootkatin, carvacrol and valencene, respectively. Nootkatone was the least active compound, with 3.5% zoospore germination at 1000 mg/kg. Sporangia germination was 0% with 500 mg/kg of nootkatin or carvacrol. The disruption of the zoospore outer membrane and the loss of sporangial contents were often observed and indicative of sporicidal activity. Hyphal growth was inhibited by 99.9% with 50 mg/kg of nootkatin or 500 mg/kg of carvacrol, but growth resumed upon removing the inhibitors. The zoosporicidal activity of yellow‐cedar heartwood shavings stored dry for approximately 10 years was consistent with the quantity of extractable compounds they contained. Thus, spreading fresh shavings or chips of yellow‐cedar heartwood with appreciable higher concentrations of the active compounds, over areas in infection zones where spores might be difficult to control such as trails and parking lots used by hikers and bicyclists, might be useful as part of an integrated program to minimize P. ramorum spore distribution.     

Antibacterial activity of the endemic Hypericum kazdaghensis

The antibacterial activity of the chloroform, acetone and methanol extracts of endemic Hypericum kazdaghensis leaves were evaluated by disc diffusion method. All extracts exhibited antimicrobial activity against all tested bacteria.     

5种药用植物提取液对杨树灰斑病抑菌活性研究

为筛选出对杨树灰斑病菌具有抑制作用的中草药抑菌活性物质,采用3次浸渍提取法对丁香、肉桂、厚朴、毛茛、兴安白芷5种中草药进行提取,采用生长速率法和孢子萌发法,测定了提取液对菌丝生长和孢子萌发的影响。结果表明,5种药用植物提取液对杨树灰斑病原菌均有不同程度的抑制作用,其中丁香、肉桂、兴安白芷提取物对病原菌的菌丝生长抑制效果较好,丁香提取液浓度在16 mg/mL时,对病菌菌丝生长抑制率可达到98.02%,同样浓度的肉桂、兴安白芷提取液抑制率也可达到91%以上;5种药用植物提取液对孢子萌发抑制作用强于对菌丝生长的抑制作用,其中丁香、毛茛对病原菌的孢子萌发抑制效果最好。说明5种药用植物75%乙醇提取液中含有抗菌成分,为生物防治杨树灰斑病提供参考。     

竹焦油用于农用杀菌剂的研究(Ⅰ):室内实验

以竹材热解副产物——竹焦油为活性成分,采用菌落生长速率法和孢子孢子法测定了竹焦油对12种植物病原真菌的抑菌活性,室内实验表明竹焦油是一种良好的天然抑菌剂,对真菌具有较强的抑制作用,该文为竹焦油在植物源农药方面的综合利用提供了重要的应用基础。     

赤水撑绿竹根腐病菌室内药剂筛选

采用生长速率法和悬滴法测定了8种常用杀菌剂对赤水撑绿竹Bambusa pervariabilis×dendrocalamopsis daii根腐病病原菌尖孢镰孢菌Fusarium oxysporum Schlecht菌丝生长和孢子萌发的抑制作用,并测定了杀菌剂对尖孢镰孢菌的毒力。结果表明,各杀菌剂对菌丝生长和孢子萌发有不同程度的抑制作用,其中70%敌磺钠WP、3%广枯灵AS能很好地抑制菌丝生长,而70%敌磺钠WP、3%广枯灵AS、70%甲基硫菌灵WP、10%苯醚甲环唑WG对孢子萌发有较强的抑制作用,抑制率均在80%以上。对菌丝生长与孢子萌发均有明显作用的杀菌剂为70%敌磺钠WP、3%广枯灵AS。毒力测定结果表明,70%敌磺钠WP、3%广枯灵AS对尖孢镰孢菌的毒力最高,其EC50分别为0.072 5,0.112 6μg/mL、其次为70%甲基硫菌灵WP和10%苯醚甲环唑WG,其EC50分别为7.8216,7.318 7μg/mL。其余几种药剂的毒力较差。8种药剂的相关系数均在0.98以上,药剂浓度与抑制作用呈正相关。     

朱砂根种子萌发过程中酶活性的动态变化

测定了50mg／L GA3和200mg／L 6-BA浸种后的朱砂根种子在萌发过程中酶活性的动态变化。结果表明：在萌发过程中,α-淀粉酶活性整体呈上升趋势,50mg／LGA3处理的活性最大;200mg／L 6-BA处理后的过氧化氢酶（CAT）和过氧化物酶（POD）活性最大,CAT活性是先上升后下降,露白到发芽阶段下降;POD活性一直呈上升趋势,在吸胀到露白阶段,其活性上升较平稳,而在种子露白后到发芽阶段开始迅速上升。     

Cytotoxicity and antibacterial activity of extractives from Wedelia calendulacea

The cytotoxicity and antibacterial activity of petroleum ether, chloroform and methanol extracts of Wedelia calendulacea were assayed by brine shrimp lethality bioassay and standardized disk diffusion method against 19 bacterial strains. Three diterpenes isolated from the plant were also evaluated for in vitro antibacterial activities. The LC50 for the crude extracts against the brine shrimp nauplii were found to be 4.59 microg/ml, 7.99 microg/ml and 14.88 microg/ml, respectively, whereas the positive control, vincristine sulfate showed an LC50 of 0.58 microg/ml. Among the crude extracts and pure compounds tested, (-)-kaur-16-en-19-oic acid isolated from the chloroform extract showed the highest inhibitory activity against most of the bacterial strains with mean zone of inhibition of 10-21 mm at 200 microg/disc.     

牡丹轮纹病病原的初步研究

针对发病牡丹进行实验分析,显微鉴定为这是1种真菌性病害,病原为半知菌亚门丝孢纲丝孢目假尾孢属的黑座假尾孢Pseudocercospora variicola。通过农药筛选试验、对比分析,结论为1：500的50%的立枯净,1：1000的2％春雷霉素,1：700的40％禾益2号对孢子萌发与菌丝生长都有良好的抑制作用。最后对牡丹轮纹病的防治提出了合理化建议。     

不同处理对木球卢卡树种子出苗的影响

对木球卢卡树种子分别采用8种不同的方法浸种,促进种子出苗。经方差分析表明,各处理间出苗率存在极显著差异。其中,150mg／L赤霉素浸泡24h效果最好,出苗率最高,达到63％-300g／L烟丝水浸泡24h效果次之,达到56％。两种处理方法整齐度都好,存在极显著差异。     

山核桃外果皮中的抑菌活性成分

用不同溶剂对山核桃外果皮甲醇浸膏进行萃取分离,得石油醚相、氯仿相、乙酸乙酯相、正丁醇相,以番茄早疫病菌、苹果腐烂病菌、小麦赤霉病菌、水稻纹枯病菌、黄瓜菌核病菌等5种病菌进行抑菌活性试验.结果表明:正丁醇相抑菌活性最强,氯仿相和石油醚相次之,乙酸乙酯相最弱.对氯仿相进行初步分离,得到7个单体化合物:乔松酮,黄卡瓦胡椒素,5-羟基-4',7-二甲氧基黄酮,5-羟基-2-甲氧基-1,4-萘醌,5-羟基-6,7-二甲氧基黄烷酮,乔松素,β-谷甾醇,均为首次从山核桃中分离得到,它们对玉米大斑病菌和水稻稻瘟病菌孢子萌发均有不同程度的抑制作用.     

Phytoalexin production by Aspen (Populus tremuloides Michx.) in response to infection by Hypoxylon mammatum (Wahl.) Mill and Alternaria spp.

Freshly wounded stem sections of P. tremuloides Michx. produce phytoalexin when inoculated with mycelium of Hypoxylon mammatum (Wahl.) Mill., and Alternaria sp. These exudates are inhibitory against spore germination of these two fungi and, although inhibitory against mycelial growth of Alternaria sp., have no effect on the mycelial growth of H. mammatum. It was possible to correlate the amount of phytoalexin elicited by different strains with the inhibitory activity.     

淡紫拟青霉T-DNA插入突变体的表型分析

研究淡紫拟青霉T-DNA插入突变体,鉴定突变体的表型特征,为淡紫拟青霉致病机制分析及致病相关的基因克隆奠定基础。PCR检测筛选的14株T-DNA插入突变体,观察和测定菌落形态,菌落生长速率,产孢量,孢子萌发率和菌丝干质量等生物学性状,并比较突变体致病力。结果表明突变体均含有beta-tubulin基因序列,T-DNA已整合进入野生型菌株20-7的基因组中。通过与野生型菌株对比,发现突变体菌落形态发生了不同程度的改变。菌落生长速率明显增大的菌株占全部菌株的85.71%,只有BN-11菌株的菌落生长速率降低。产孢量显著变大的菌株有BN-11和BN-12,为菌株总数的14.29%。孢子萌发率发生改变的菌株占78.57%。菌丝干质量发生明显增大和减少的菌株都占全部突变体的21.43%。筛选获得了1株致病力增强的突变体BN-11和11株致病力显著降低的突变体。     

喜树叶提取物的抗菌活性研究

采用滤纸片法研究喜树叶乙醇提取物和水提物对金黄色葡萄球茼（Staphylococcus aureus）、大肠杆菌（Escherichia coli）、枯草杆茼（Bacillus subtilis）、八叠球菌（Sarcina ventriculi）、黑曲霉（aspergillus niger）、木霉（Trichoderma virid）和青霉（Penicillium chrysogenum）的抗菌活性。结果表明,喜树叶乙醇提取物和水提物对细菌有明显的抑制作用,浓度越大抑制效果越好;喜树叶乙醇提取物对3种霉菌都有抑茼效果,水提物对霉菌没有抑制作用。     

稀土对马占相思和大叶相思种苗的影响

用10～1000 mg/L稀土溶液对马占相思和大叶相思浸种24 h后的试验结果表明：适宜浓度的稀土溶液可促进马占相思和大叶相思种子内含物的转化,从而促进种子的萌发和幼苗生长,但同一稀土溶液对不同树种的适宜浸种浓度不同。马占相思以10 mg/L处理有利于提高种子发芽势并缩短发芽时间;大叶相思10～30 mg/L处理显著提高种子发芽率和发芽势,但没有显著缩短发芽时间。200 mg/L及以上浓度浸种对2种树种种子萌发有抑制作用。考虑指标多重比较差异及经济因素,10 mg/L处理较利于马占相思和大叶相思幼苗高和根系生长。     

不同条件下紫珠种子萌发特征研究

通过设定L9(34)3因素3水平正交试验,探究了萌发温度条件、光照条件和激素(GA3)条件.结果表明:在紫珠发芽率、发芽指数、发芽势和活性指数指标方面,温度是其影响的最主要因子,光照次之,GA3的影响相对最低,综合分析结果显示,紫珠发芽率、发芽指数、发芽势和活性指数指标最优的萌发条件组合为A3 B3 C2,即1000L...     

Growth and spore germination of Cylindrocarpon destructans in associative cultures with bacteria and actinomycetes1

Studies were made on the effect of bacteria and actinomycetes on growth and spore germination of Cylindrocarpon destructans. The effect of bacteria on growth of this fungus as well as on spore germination was statistically not significant. The actinomycetes in general inhibited or had no influence on growth and germination of conidia of C. destructans.