多炔类化合物对美洲大蠊的触杀活性及对乙酰胆碱酯酶和腺苷三磷酸酶活性的影响

采用药膜法测定了人工合成的11个多炔类化合物对美洲大蠊Periplaneta americana初孵若虫的触杀活性。结果表明,当化合物处理浓度为20 μg/cm²时,致死率达70%以上的有: 化合物2 (1-叔丁基-4-羟甲基-丁二炔)、化合物9 (1-苯甲基-4-甲基-丁二炔)和化合物10 (O-炔丙基硫代磷酸二乙酯)。经毒力测定,化合物9和化合物10的LC₅₀分别为3.91 μg/cm²和1.50 μg/cm²。化合物2、化合物7 (1-苯基-4-邻硝基苯基-丁二炔)和化合物10对美洲大蠊乙酰胆碱酯酶(AChE)具有抑制活性,抑制率分别为12.00%、27.24%和62.22%。化合物2和化合物10对Na⁺-K⁺-ATPase具有抑制活性,抑制率分别为44.55%和31.44%;而化合物5 (1-苯基-4-（3,4-亚甲基二氧）苯基-丁二炔)和化合物6 (1-苯基-4-间硝基苯基-丁二炔)对该酶具有激活活性,激活率分别为24.98%和20.99%。化合物2、化合物4 （1-苯基-4-对甲氧基苯基-丁二炔）和化合物7对Ca²⁺-Mg²⁺-ATPase具有抑制活性,抑制率分别为49.02%、38.53%和35.32%, 其他化合物对该酶具有激活活性,其中激活活性最高的为化合物5,激活率达81.12%。     

两种光敏化合物对斜纹夜蛾超氧物歧化酶影响的比较研究(英文)

室内测试了斜纹夜蛾Ｓｐｏｄｏｐｔｅｒａ ｌｉｔｕｒａ Ｆ． ４龄幼虫超氧物歧化酶的活性,并就α－三噻吩（α－ｔｅｒｔｈｉｅｎｙｌ）和化合物５,即１－苯基－４－（３,４－亚甲基二氧）苯基－丁二炔等两种光敏化合物对其产生的影响进行了比较研究。结果表明,近紫外光照（３００－４００ｎｍ）基本不影响对照幼虫超氧物歧化酶活体（ｉｎｖｉｖｏ）活力,但对其离休（ｉｎ ｖｉｔｒｏ）活力有抑制作用。经光敏化合物处理后,在紫外光照下,超氧物歧化酶活体活力基本不受化合物５的影响,但能被α－三噻吩抑制。离体情况下,两种化合物均促进其活力,α－三噻吩尤甚。表明无论在离体还是活体情况下,幼虫对α－三噻吩均比化合物５具有更高的光敏性。对两种光敏化合物可能的作用机理进行了探讨。     

14种菊科植物提取物对松材线虫和淡色库蚊的光活化毒杀作用

以甲醇作溶剂,采用超声波提取法对14种菊科植物进行粗提,并采用浓度稀释法、结合紫外光光照处理,测定这些提取物对松材线虫和淡色库蚊的光活化毒性.研究结果表明,大部分提取物具有光活化活性,其中鲤肠、万寿菊活性最高,表现出明显的光活化毒性;500 μg/mL鲤肠提取物处理对淡色库蚊的光照活性比非光照活性高48.96倍,以1 000 μg/mL的浓度处理24 h可100%杀死供试的松材线虫;微甘菊、白花蒲公英、鱼眼草提取物也对松材线虫表现出光活化效应,光照处理的死亡率明显比非光照处理高.     

多炔化合物氧化胁迫下稗草细胞保护酶系的反应

用多炔类化合物1-苯基-4-(3,4-亚甲二氧)-苯基丁二炔(简称化合物5)处理稗草(Echinochloa crusgalli)愈伤组织,经紫外光(320～400nm)照射后,诱导细胞内形成氧化胁迫环境。利用生化酶学方法,测定几种保护酶系在氧化环境下的活性变化。发现经化合物5和照光处理后,可诱导激活细胞内的谷胱甘肽-S-转移酶(GST)、谷胱甘肽过氧化物酶(GSH-Px)和过氧化物酶(POD)的活性,而超氧化歧化酶(SOD)则表现为活性受抑制。以0．1～10mg／L的浓度处理,所测GST、GSH-Px和POD的照光诱导活性明显高于未经照光处理的活性。其中以10mg／L,的浓度处理,照光所提高3种酶活性的百分率分别为10．47％、113．68％和166．68％。以1mg／L和10mg／L的浓度处理,照光对SOD的抑制百分率分别为50．25％和76．46％。测定结果表明：在外源光敏物质引起细胞内的氧化胁迫环境下,可激活细胞内保护酶的活性,用于抵御氧化逆境对细胞的损伤。而SOD则可能是化合物5光活化抑制稗草生长的生化作用靶标酶之一。     

靛红衍生物的合成及其对稻瘟菌的生物活性

以靛红为原料合成了系列3-亚胺基/亚甲基-吲哚-2-酮化合物及其Mannich碱衍生物,研究了它们在抗稻瘟菌方面的活性,发现了这两种类型的若干化合物有较好的抑制稻瘟菌孢子萌发的活性,初步讨论了构效关系。认为1位的羟甲基和胺甲基、3位的亚甲基是药效团,芳基亚甲基苯环上对位取代基、羟基取代基和吸电子取代基不利于活性的提高,邻位的供电子取代基有利于活性的提高。     

血啉甲醚对斜纹夜蛾SL细胞的氧化损伤

通过研究血啉甲醚（hematoporphyrin monomethyl ether, HMME）对斜纹夜蛾Spodoptera litura (SL)细胞的增殖抑制率IC₅₀、处理后细胞内丙二醛（malondialdehyde, MDA）的生成量、细胞内还原型谷胱甘肽（glutathione, GSH）水平和细胞器超微结构的变化,明确血啉甲醚对SL细胞的氧化损伤,并探讨将血啉甲醚及其衍生物拓展应用到农业害虫防治领域的可行性。用MTT法测定血啉甲醚光照处理下对SL细胞24 h和48 h的IC₅₀值分别为8.35 μg/mL和7.66 μg/mL。硫代巴比妥酸（TBA）法测定表明,血啉甲醚光活化后能导致胞内MDA含量明显升高,且MDA的生成量与其浓度呈正相关;当血啉甲醚浓度为50.000 μg/mL,光照处理48 h时,细胞内MDA生成量达到173.08±3.51 nmol/L。5,5′-二硫代双 (2-硝基)苯甲酸（DTNB）法对处理后细胞内GSH水平测定结果表明,光活化后的血啉甲醚处理SL细胞能导致细胞内还原型GSH相对含量随血啉甲醚浓度升高而显著降低;当血啉甲醚浓度为50.000 μg/mL,处理48 h时,光照处理组细胞内GSH相对含量较之同浓度黑暗处理下降了39.59%。扫描电镜观察显示,6.250 μg/mL的HMME处理细胞并光照后,细胞膜表面出现了明显的孔洞,有的细胞出现了花样皱褶和内陷。这些结果表明在血啉甲醚的试验剂量下,SL细胞受到了氧化损伤。     

化学结构与生物活性:取代苯基N-甲氨基甲酸酯的合成与活性

用异氰酸甲酯与适当的酸类反应,合成了一系列的取代苯基N-甲氨基甲酸酯类化合物。生物测定表明,在苯基N-甲氨基甲酸酯的苯环上引入取代基,均能增加对胆碱酯酶活性的抑制作用,在苯环上引入甲基增加对淡色库蚊(Culex pipiens pallens)幼虫的毒性。在苯环酯键的邻位上引入取代基时,除2,3-二甲苯基化合物外,均降低对蚊幼虫的毒性。 在各化合物对蚊幼虫的毒性和其对胆碱酯酶活性的抑制作用间,不能看出任何相互关系。     

长形肉豆蔻Myristica argentea Warb.化学成分研究(英文)

从长形肉豆蔻Myristica argentea乙醇提取物乙酸乙酯部分分离得到12个化合物,经理化和波谱分析分别鉴定为黄樟醚(1)、甲基丁香酚(2)、异甲基丁香酚(3)、3′-羟基异黄樟醚(4)、7-羟基-3′,4′-亚甲二氧基黄烷(5)、1,4-苯二甲酸二甲酯(6)、内消旋-二氢愈创木脂酸(7)、赤式-1-(4-羟基-3-甲氧基苯基)-4-(3,4-亚甲二氧基苯基)-2,3-二甲基丁烷(8)、赤式-1-(4-羟基-3-甲氧基苯基)-2-(2-甲氧基-4-(1(E)-丙烯基)苯氧基)-丙烷-1-醇(9)、nectandrin B(10)、β-谷甾醇(11)和胡萝卜苷(12)。化合物4~6和8~12为首次自该植物中分离得到,化合物4~6为首次从该属植物中分离得到。     

N-（4-甲基-2-氨基苯并噻唑）α-氨基-α-（3-三氟甲基苯基）-0，0-二（2-烷氧基乙基）亚膦酸酯对小麦赤霉病原菌的抑制活性及作用机制的初步探究

实验室条件下采用生长速率法测定化合物N-(4-甲基-2-氨基苯并噻唑)α-氨基-α-(3-三氟甲基苯基)-O,O-二(2-烷氧基乙基)亚膦酸酯对小麦赤霉病原菌(Fusarium graminearum)的离体抑制效果,并初步研究了其抑制小麦赤霉病原菌作用机制.实验结果表明,该化合物对小麦赤霉病原菌的EC_(50)为46.05 μg/mL,当化合物浓度为50 μg/mL时,对该病原菌的抑制率就达到了60.5 %.以浓度为250 μg/mL的该供试化合物处理小麦赤霉病原菌菌丝24 h后,其细胞膜通透性增强,菌体内还原糖、几丁糖和可溶性蛋白含量及几丁质酶活性在短时间内均出现先升高然后下降的趋势.     

N-甲基取代苯基氨基甲酸酯的系列合成及其对家蝇的生物活性

利用酰氯水相简易工艺合成了52个N-甲基取代苯基氨基甲酸酯类化合物, 并测定了它们对家蝇Musca domestica的室内毒力。结果表明：烷基单取代化合物中,间位取代物的活性大于邻、对位;单卤素取代物中,邻位取代活性大于间位和对位,邻溴代物大于邻氯代物;对位硫甲基和邻位硫乙基取代物的活性均较高。对于烷基间位苯环取代化合物,在一定限度内随烷基分子量增大,化合物对家蝇的毒力增高,其次序为异丙基>乙基>甲基>未取代基。     

Evaluations of larvicidal activity of medicinal plant extracts to Aedes aegypti （Diptera： Culicidae） and other effects on a non target fish

A preliminary study was conducted to investigate the effects of the extracts of 112 medicinal plant species, collected from the southern part of Thailand, on Aedes aegypti. Studies on larvicidal properties of plant extracts against the fourth instar larvae revealed that extracts of 14 species showed evidence of larvicidal activity. Eight out of the 14 plant species showed 100% mosquito larvae mortality. The LC50 values were less than 100μg/mL （4.1μg/ mL-89.4μg/mL）. Six plant species were comparatively more effective against the fourth instar larvae at very low concentrations. These extracts demonstrated no or very low toxicity to guppy fish （Poecilia reticulata）, which was selected to represent most common non-target organism found in habitats ofAe. aegypti, at concentrations active to mosquito larvae. Three medicinal plants with promising larvicidal activity, having LC50 and LC50 values being 4.1 and 16.4 μg/mL for Mammea siamensis, 20.2 and 34.7 μg/mL forAnethum graveolens and 67.4 and 110.3μg/mL forAnnona muricata, respectively, were used to study the impact of the extracts on the life cycle ofAe. aegypti. These plants affected pupal and adult mortality and also affected the reproductive potential of surviving adults by reducing the number of eggs laid and the percentage of egg hatchability. When each larval stage was treated with successive extracts at the LC50 value, the first instar larvae were found to be very susceptible to A. muricata and the second instar larvae were found to be susceptible to A. graveolens, while the third and fourth instar larvae were found to be susceptible to M. siamensis. These extracts delayed larval development and inhibited adult emergence and had no adverse effects on P. reticulata at LC50 and LC50 values, except for the M. siamensis extract at its LC50 value.     

番荔枝内酯化合物布拉它辛对斜纹夜蛾的杀虫活性及对SL细胞的致凋亡作用

为了明确番荔枝内酯化合物布拉它辛的杀虫活性和探索杀虫作用机理,本研究采用浸叶法测定该化合物对斜纹夜蛾Spodoptera litura幼虫的生物活性,采用MTT检测法和流式细胞术,研究该化合物对斜纹夜蛾离体培养卵巢细胞（SL细胞）的细胞毒力和致细胞凋亡作用,以及对SL细胞线粒体膜电位的影响。结果表明: 布拉它辛不仅对斜纹夜蛾幼虫具有良好的拒食活性,处理后24 h,对2龄和3龄幼虫的AFC₅₀值分别为60.25 μg/mL和86.73 μg/mL,还对幼虫生长有良好的抑制作用。布拉它辛处理SL细胞后24 h和48 h,IC50值分别为22.32 μg/mL和10.03 μg/mL。流式细胞仪检测结果表明,布拉它辛对SL细胞具有明显的致凋亡作用,可导致SL细胞线粒体膜电位显著下降。本研究表明布拉它辛对斜纹夜蛾幼虫具有良好的拒食活性与生长抑制作用, 并且该化合物能明显抑制SL细胞的增殖,诱导细胞凋亡,降低线粒体膜电位。因此,布拉他辛具有广阔的研究应用前景。     

克罗烷二萜的昆虫拒食活性及构效关系研究

以饲料柱称重法测定25个克罗烷二萜新化合物对亚洲玉米螟Ostrinia furnacalis(Guenee)5龄幼虫的拒食活性,并进行构效关系分析。结果表明：立体效应对拒食活性意义 重大;C₉边链、C₁₈位的酯基对活性具有一定影响;C_{4处的螺环氧结构看来并非活性所必需。且在25μg/mL时选择法测定中,活性最高的化合物拒食率为57.9%,而500/μg/mL时非选择法测定中拒食率为43.2%。}     

闹羊花素Ⅲ对斜纹夜蛾细胞系的活性及作用机理

研究了闹羊花素Ⅲ对斜纹夜蛾Spodoptera litura离体培养细胞（SL细胞）的活性,并测定了对SL细胞Na⁺、K⁺和葡萄糖吸收以及对4龄幼虫血细胞数量的影响。结果表明：以400 µg/mL 和200µg/mL闹羊花素Ⅲ处理SL细胞,24 h后细胞的相对死亡率为79.00% 和56.69%,处理后8 h,16 h,24 h和48 h的LC₅₀分别为240.09 µg/mL,173.45 µg/mL,113.56 µg/mL和73.40 µg/mL;闹羊花素Ⅲ处理SL细胞后10 min,细胞对离子的吸收迅速增加,30 min后吸收作用逐渐减弱;处理后3天内细胞对葡萄糖的吸收迅速增加,4～5 天后,细胞对葡萄糖的吸收基本停止。以叶碟法和注射法处理4龄幼虫,8 h后幼虫血细胞数量显著降低,随处理时间增加,幼虫血细胞数量又逐渐增加。     

球形芽孢杆菌对致倦库蚊的后致死作用

研究了球形芽孢杆菌Bacillus sphaericus C3-41菌株对致倦库蚊Culex quinquefasciatus幼虫的毒力及其后致死作用。生物测定表明,该菌株对目标蚊幼虫具有很高的毒力,其丙酮粉剂对3～4龄幼虫48 h的半致死浓度(LC₅₀)为(6.92±0.22) μg/L。用不同亚致死浓度处理2～3龄致倦库蚊幼虫,存活幼虫在后期发育中存在明显的延续死亡和损伤现象,经LC₃₀、LC₅₀、LC₇₀、LC₉₀和LC₉₈剂量的C3.41粉剂处理的致倦库蚊羽化前的总死亡率分别为84%、91%、95%、97%和100%,同时存活的幼虫、蛹和成蚊的发育和行为也受到一定的影响。这种后致死作用随处理浓度的升高而增强,可能同球形芽孢杆菌毒素蛋白对处理期间蚊幼虫中肠上皮细胞造成的损伤相关。     

Interaction of larval age and antibiotic on the susceptibility of three insect species to Bacillus thuringiensis

The addition of chlortetracycline hydrochloride to bioassay diets increased the LC₅₀S of the HD-1 isolate of Bacillus thuringiensis 2.4–67.1 times when bioassayed against 4-day-old larvae of Trichoplusia ni, Heliothis virescens, and Ostrinia nubilalis. There were no significant differences in LC₅₀s when bioassays were conducted with neonate larvae in the presence or absence of antibiotic, nor were there any highly significant differences between the LC₅₀s for HD-1 when neonate larvae were used in the presence or absence of antibiotic or when 4-day-old larvae were used in the absence of antibiotic. Viable counts of B. thuringiensis did not increase over time in any of three bioassay diets. There were no differences in activity of pure chlortetracycline hydrochloride and veterinary grade Aureomycin. There was a direct correlation between amount of antibiotic and elevation of HD-1 LC₅₀s when 4-day-old larvae were used. LC₅₀ elevation in presence of antibiotic first appeared in 2-day-old larvae.     

松油烯-４-醇对粘虫幼虫的生物活性

测定了杀虫植物砂地柏Sabina vulgaris Ant.的精油中主杀虫成分-松油烯-4-醇（terpinen 4.01）对粘虫Mythimna separata Walker幼虫的生物活性。结果表明,松油烯- 4-醇对粘虫主要表现为熏蒸作用,对粘虫3龄幼虫24 h的熏蒸LC₅₀为5.3473 μL/L ;还具一定触杀作用,对粘虫4龄幼虫24 h的LD₅₀为147.8 μg/虫。试虫的中毒症状可明显地分为兴奋、痉挛、麻痹和死亡4个阶段,而麻痹的部分试虫有复苏现象。可明显抑制Na⁺ ,K⁺ATP酶的活性,在兴奋期、痉挛期、麻痹期和复苏期,抑制率介于21.28%～34.92% 之间。离体条件下对Na⁺,K⁺ATP酶的I₅₀为133.75 μg·mL^-1;对AChE活性有一定的影响;对酯酶,在兴奋期,酶活力为对照的7.0%,在麻痹期则为对照的1.33倍,而复苏期试虫的酯酶活力与对照相当。     

Susceptibility of northern corn rootworm Diabrotica barberi (Coleoptera: Chrysomelidae) to mCry3A and eCry3.1Ab Bacillus thuringiensis proteins

The susceptibility of the northern corn rootworm Diabrotica barberi (Smith & Lawrence) to mCry3A and eCry3.1Ab proteins derived from Bacillus thuringiensis (Bt) was determined using a diet bioassay. Northern corn rootworm neonates were exposed to different concentrations of mCry3A and eCry3.1Ab, incorporated into artificial diet. Larval mortality was evaluated after 7 d. The mCry3A and eCry3.1Ab proteins were found to be toxic to the northern corn rootworm larvae. The LC₅₀ and LC₉₉ values for mCry3A were 5.13 and 2482.31 μg/mL, respectively. For eCry3.1Ab, the LC₅₀ and LC₉₉ values were 0.49 and 213.01 μg/mL. Based on the estimated lethal concentrations, eCry3.1Ab protein was more efficacious to northern corn rootworm larvae than mCry3A. These lethal concentration values will be used as diagnostic doses for routine annual monitoring for change in susceptibility of field collected northern corn rootworm to mCry3A, and eCry3.1Ab toxins.     

Evaluation of an experimental product based on Bacillus thuringiensis sorovar. israelensis against Aedes aegypti larvae (Diptera:Culicidae)

The larvicidal activity of an experimental formulation of Bacillus thuringiensis israelensis (Bti) against Aedes aegypti larvae was evaluated under laboratory and simulated field conditions (SFC). Samples of technical powder (TP) were assayed to establish the LC₅₀ and the potency of the product. The larvicidal activity of the TP and the tablet (T) were evaluated under SFC to assess the efficacy and the residual activity, measured against Ae. aegypti larvae. Either a T or 250 mg of TP were added to 50 L of water in plastic containers. Containers were exposed to sunlight or kept in the shade. Results showed a LC₅₀ of 0.26 mg/L and a potency of 750 ITU/mg. In spite of differences in the toxicity amongst TP and T samples, all of them killed 98–100% of the larvae and the mortality remained high for six months, in the shade. The replacement of 20% or 60% of the water volume did not affect the activity of the product. Seasonal differences influenced the persistence of the product in containers exposed to sunlight. Both formulations showed an excellent performance, especially when kept in the shade. The Bti tablet evaluated in this study is potentially very useful in programs to control dengue vectors.