Larvicidal Effect of a Cell-Wall Fraction Isolated from Alder Decaying Leaves

Decaying alder leaves in water from Alpine Aedes breeding sites, particularly their toxicity to larval Culicidae, were investigated and characterized with comparative toxicological and chemical methods. Bioassays that used third-instar Aedes aegypti as a reference species indicated that the larvicidal effect of crude leaf litter varied with decaying age of the litter, while no toxicity was detected from leaching water of the mosquito breeding sites. Ten-month-old leaf litter was the most toxic. Comparison of the different soluble and insoluble fractions obtained after sequential extraction of decomposed litter allowed us to localize the toxicity factor to an insoluble cell-wall fraction. The toxicity seems to be linked to phenolic activity. It is higher than that found for tannic acid solutions used as a reference to mimic the larvicidal effects of the molecules naturally occurring in decaying litter. The pattern of establishing the larvicidal effect of alder leaf litter in water of Alpine Aedes breeding sites is discussed.     

Hot extraction and characterization of a ligninlike fraction involved in larvicidal effects of decomposed leaf litter against mosquito

Hot water-extraction was performed on decomposed leaf litter in order to solubilize the toxic fraction involved in the dietary interaction against mosquito larvae in subalpine breeding sites. The toxic fraction was partially extracted by water with an optimum temperature of 60°C and recovered in an insoluble form. Phytochemical characterization was achieved through differential enzymatic hydrolyses, using the laccase mediator delignifying system, and aluminum chloride chelation monitored by standard bioassays; comparative spectrophotometric analyses in ultraviolet light after solubilization in acetyl bromide; and comparative reversed-phase high-performance liquid chromatography of the phenolic aldehydes after alkaline nitrobenzene oxidation. The results suggested the involvement of ligninlike compounds in the toxicity of the isolated fraction. Toxicity of this fraction appeared far stronger than that of the crude leaf litter. The involvement of this ligninlike fraction in the dietary toxicity of leaf litter against larval mosquito was then investigated.     

Differential Sensitivity of Mosquito Taxa to Vegetable Tannins

The sensitivity of larval Culicidae to vegetable tannins was investigated in different taxa representative of the fauna from alpine hydrosystems (Aedes rusticus, Culex pipiens) and foreign noxious fauna (Aedes aegypti, A. albopictus). Bioassays reveal that tannic acid at concentrations of 0.1–6 mM is significantly more toxic for C. pipiens than for Aedes taxa, and A. aegypti is more sensitive than A. albopictus and A. rusticus. Comparison of the rank order of sensitivity among taxa with the associated levels of cytochrome P-450, esterase, and glutathione-S-transferase activities suggests that cytochrome P-450 and esterases may be involved in the detoxification of tannins. A possible involvement of these detoxifying enzymes is also revealed in vivo by the synergistic effects of S,S,S-tributyl phosphorotrithioate (esterase inhibitor) and piperonyl butoxide (P-450 inhibitor). The differential sensitivity to tannins among taxa is discussed in terms of ecological implications within mosquito communities from alpine hydrosystems, where the acquisition of tannins–detoxifying enzymatic systems may be considered as a key innovation.     

Taste sensitivity of detritivorous mosquito larvae to decomposed leaf litter

Dietary leaf litter chemistry is known to play an important ecotoxicological role in the plant–mosquito interaction in subalpine flooded areas surrounded by vegetation because of differential larvicidal effects of insoluble polyphenols formed during the leaf decaying process. This dietary interaction was investigated through comparative evaluation of the role of toxic/nontoxic leaf litter in both larval foraging and feeding behavior, by using different samples of decomposed alder leaf litter and larval Aedes aegypti as experimental references. Track analysis showed significant differences in larval foraging behavior in the absence or presence of leaf litter. Comparative alimentary preference investigations and further track analysis suggested that larvae are unable to detect leaf litter toxicity. These characteristics of the larval behavioral feeding pattern suggested that: (1) decomposed leaf litter may be involved as an important attractive food source in the habitat selection and evolutionary history of culicids, and (2) preingestive behavioral mechanisms appear to be minimally involved in the differential larval dietary adaptation to toxic leaf litter. These results may have interesting consequences for culicid biological control.     

厚朴叶挥发油的化学成分及对植物病原真菌的抑菌活性研究

用水蒸汽蒸馏法提取厚朴树叶挥发油、采用GC-MS联用技术分析了其挥发油的化学成分,并用生长速率法检测了对五种植物病原真菌的抑菌活性。结果表明,从挥发油中分离鉴定出40种化合物。厚朴树叶挥发油对油菜菌核病菌具有选择性的抑菌活性,在500 ppm抑制率为81.63%。     

离子交换-高效液相色谱法测定化妆品中6种水溶性功效成分

建立了一种同时测定化妆品中6种水溶性功效成分的分析方法。样品经水直接超声提取后经离子交换色谱柱Rezex ROA-Organic Acid H+(8%)(300×7.8 mm)分离,10 mmol/L硫酸水溶液作为流动相,流速为0.5 mL/min,二极管阵列检测器进行检测,检测波长分别254 nm和214 nm,外标法定量。在优化实验条件下,6种水溶性功效成分标准曲线线性关系良好,在空白化妆品中的加标回收率为87.3%~99.4%,相对标准偏差为2.8%~5.7%。     

汽车内部装饰材料醛类物质的HPLC法测定和分析

采用恒温测试箱法加热汽车内部装饰材料1 h,使其释放出醛类物质,利用DNPH(2,4-二硝基苯肼)管对恒温测试箱内气体进行醛类物质的采样,用HPLC法(高效液相色谱法)进行分析。检出限低于2.0μg/m3。选择五种汽车内部装饰材料,进行醛类物质甲醛和乙醛含量的测定,并对结果进行了分析和讨论。     

乙撑硫脲在人参茎叶中的残留动态

[方法]通过田间试验和液相色谱分析技术研究了75％代森锰锌代谢物乙撑硫脲在茎和叶中残留动态和最终残留量.[结果]吉林抚松田间试验结果表明:施药剂量为推荐剂量的2倍(6250 g a.i./hm2)时,乙撑硫脲在茎和叶中原始沉积量分别为0.782、8.23 mg/kg;半衰期分别为4.9、19.5 d.施药1次,测得茎中乙撑硫脲残留量14d后低于欧洲规定的MRL值(0.05 mg/kg),而叶中乙撑硫脲残留量均高于欧洲规定的MRL值(0.05 mg/kg).[结论]综合多方面因素,按照推荐剂量3 125 g a.i./hm2处理,建议我国在茎上乙撑硫脲的MRL值可暂定为0.05 mg/kg,茎安全间隔期为14 d,而叶上的残留量较高,建议MRL值可暂定为0.50 mg/kg,叶安全间隔期无法确定,施药次数为1次.     

72%2,4-滴胺盐水剂防除春麦田阔叶杂草

72%2,4-滴胺盐水剂450～750mL·hm-2,于春小麦4叶期喷雾处理,防除阔叶杂草总控制效果达85%以上,对春小麦安全,增产13%以上。     

Changes in the Phytochemical and Bioactive Compounds and the Antioxidant Properties of Wolfberry during Vinegar Fermentation Processes

Wolfberry (Lycium barbarum L.), as a kind of functional fruit, has various nutritional and bioactive components, which exhibit healthy benefits. However, wolfberry is not easy to preserve, and the intensive processing of wolfberry needs to be developed. In the present study, the changes in the phytochemical and bioactive compounds, as well as the antioxidant properties of wolfberry, were evaluated in the brewed processes. We found that the sugar contents were significantly decreased, and the total acids values were significantly increased during the fermentation processes. The sugar and fat contents were low in the wolfberry fruit vinegar after fermentation, which is of benefit to human health. In addition, amino acids were examined during the fermentation processes, and histidine, proline, and alanine were found to be the main amino acids in vinegar. The total phenolics and flavonoids contents were significantly increased by 29.4% and 65.7% after fermentation. 4-Hydroxy benzoic acid, 3-hydroxy cinnamic acid, and chlorogenic acid were the primary polyphenols in the wolfberry fruit vinegar. Moreover, the antioxidant activity of wolfberry fruit vinegar was significantly increased compared with that of wolfberry fruit after the fermentation processes. Polysaccharides and polyphenolics were strongly correlated with the antioxidant activity during the fermentation processes. The findings suggest that wolfberry fruit vinegar has a high antioxidant capability, and could be a beneficial food in the human diet.     

Influence of Water Deficit in Bioactive Compounds of Olive Paste and Oil Content

The main objective of this study was to evaluate the effect of different deficit irrigation treatments (control, regulated deficit irrigation [RDI]‐1, RDI‐2, and RDI‐3) on the phenolic profile of the olive paste and oil content. Irrigation treatments with more stress water led to a considerable increase in the phenolic compounds of olive paste, especially in oleuropein (60.24%), hydroxytyrosol (82%), tyrosol (195%), and verbascoside (223%) compared to control. A significant increase in the content of total flavonoids and phenolic acids was also observed for these samples. In virgin olive oils (VOO) elaborated from the most stressed olive trees (RDI‐2 and RDI‐3), a noticeable increase in phenolic substances with antioxidant properties (oleuropein, hydroxytyrosol, tyrosol, secoiridoid derivatives, and o‐vanillin) was observed. Consequently, water stress conditions improved antioxidant activity of VOO.     

Discovery of Quinoline‐Derived Trifluoromethyl Alcohols,Determination of Their in vivo Toxicity and Anticancer Activity in a Zebrafish Embryo Model

In this study the rational design, synthesis, and anticancer activity of quinoline‐derived trifluoromethyl alcohols were evaluated. Members of this novel class of trifluoromethyl alcohols were identified as potent growth inhibitors in a zebrafish embryo model. Synthesis of these compounds was carried out with an sp³‐C?H functionalization strategy of methyl quinolines with trifluoromethyl ketones. A zebrafish embryo model was also used to explore the toxicity of ethyl 4,4,4‐trifluoro‐3‐hydroxy‐3‐(quinolin‐2‐ylmethyl)butanoate ( 1 ), 2‐benzyl‐1,1,1‐trifluoro‐3‐(quinolin‐2‐yl)propan‐2‐ol ( 2 ), and trifluoro‐3‐(isoquinolin‐1‐yl)‐2‐(thiophen‐2‐yl)propan‐2‐ol ( 3 ). Compounds 2 and 3 were found to be more toxic than compound 1 ; apoptotic staining assays indicated that compound 3 causes increased cell death. In vitro cell proliferation assays showed that compound 2 , with an LC₅₀ value of 14.14 μm , has more potent anticancer activity than cisplatin. This novel class of inhibitors provides a new direction in the discovery of effective anticancer agents.     

Seasonal Variation in Concentrations of Fiber, Crude Protein, and Phenolic Compounds in Leaves of Red Alder (Alnus Rubra): Nutritional Implications for Cervids

We sought to determine whether changes in chemical composition could be a factor in increased utilization of red alder (Alnus rubra) by the two cervids, the Columbian black-tailed deer (Odocoileus hemionus columbianus) and Roosevelt elk (Cervus elaphus roosevelti), during the fall in parts of the Douglas fir region of the Pacific Northwest. We found that concentrations and astringency of phenolic compounds decreased from spring through fall, while crude protein content remained high. We conclude that red alder leaves provide a significant source of digestible protein for cervids during fall, when availability of nutrients in most forage species is generally declining.     

Identification of New Compounds with Anticonvulsant and Antinociceptive Properties in a Group of 3-substituted (2,5-dioxo-pyrrolidin-1-yl)(phenyl)-Acetamides

We report herein a series of water-soluble analogues of previously described anticonvulsants and their detailed in vivo and in vitro characterization. The majority of these compounds demonstrated broad-spectrum anticonvulsant properties in animal seizure models, including the maximal electroshock (MES) test, the pentylenetetrazole-induced seizure model (scPTZ), and the psychomotor 6 Hz (32 mA) seizure model in mice. Compound 14 showed the most robust anticonvulsant activity (ED₅₀ MES = 49.6 mg/kg, ED₅₀ 6 Hz (32 mA) = 31.3 mg/kg, ED₅₀ scPTZ = 67.4 mg/kg). Notably, it was also effective in the 6 Hz (44 mA) model of drug-resistant epilepsy (ED₅₀ = 63.2 mg/kg). Apart from favorable anticonvulsant properties, compound 14 revealed a high efficacy against pain responses in the formalin-induced tonic pain, the capsaicin-induced neurogenic pain, as well as in the oxaliplatin-induced neuropathic pain in mice. Moreover, compound 14 showed distinct anti-inflammatory activity in the model of carrageenan-induced aseptic inflammation. The mechanism of action of compound 14 is likely complex and may result from the inhibition of peripheral and central sodium and calcium currents, as well as the TRPV1 receptor antagonism as observed in the in vitro studies. This lead compound also revealed beneficial in vitro ADME-Tox properties and an in vivo pharmacokinetic profile, making it a potential candidate for future preclinical development. Interestingly, the in vitro studies also showed a favorable induction effect of compound 14 on the viability of neuroblastoma SH-SY5Y cells.