Influence of foliar glucosinolates in oilseed rape and mustard on feeding and growth of the bertha armyworm,Mamestra configurata Walker

The relationship between host plant glucosinolate profile and feeding and growth of the Bertha armyworm,Mamestra configurata Walker was investigated using eight cultivated rape and mustard varieties. Mean larval weights of neonates reared on intact rosette-stage plants were significantly different on the different species in the orderBrassica juncea <Sinapis alba <B. napus <B. campestris. WhileB. juncea was least preferred,S. alba was significantly more attractive to neonate larvae in choice tests. Relative consumption and growth rates of fourth-instar larvae were also reduced onB. juncea foliage. Other differences were dependent on the plant growth stage. Neonate preference was not correlated to total glucosinolate levels, but rather to the concentrations of isothiocyanate-releasing glucosinolates. However, the relationship between consumption and glucosinolate levels was inconsistent. Relative growth rate was negatively correlated to total glucosinolate content for stage 3 and 4 foliage—mainly due to the concentration of isothiocyanatereleasing glucosinolates. The relative importance of isothiocyanate-releasing glucosinolates was verified by rearing neonates on meridic diets containing equimolar concentrations of sinigrin, its metabolite, allyl isothiocyanate, and indole-3-carbinol, metabolite of 3-indolylmethyl glucosinolate. Sinigrin and allyl isothiocyanate in the diet produced virtually identical negative weight vs. concentration regression lines. No such dose-response effect was observed with indole-3-carbinol. The data suggest that foliar isothiocyanate-releasing glucosinolates may provide some degree of plant protection from polyphagous insects.     

Pseudohalogens in atom transfer radical polymerization of methyl methacrylate

In recent advances in controlled radical polymerization, atom transfer radical polymerization (ATRP) has achieved increasing interest. This investigation reports the ATRP of methyl methacrylate (MMA) using pseudohalogens as initiator as well as an anion for copper catalyst. The results were compared with the conventional halide system. Different pseudohalides were used as the initiator for the ATRP of MMA in combination with CuX (X = pseudohalide or halide) as the catalyst. Pseudohalide initiator in combination with Cu(halide) catalyst leads to inefficient ATRP due to slow initiation. Pseudohalide initiator in combination with Cu(pseudohalide) catalyst leads to uncontrolled or no polymerization. The polymers were characterized by using GPC, IR, MALDI‐TOF‐MS, and TGA analysis. IR and MALDI analysis showed that the resultant polymer had pseudohalide as the end group. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3857–3864, 2007     

The influence of durian (Durio zibethinus Murray cv. Monthong) on conditioned taste aversion to ethanol

The adverse reaction to 1.25 g/kg ethanol was monitored in male Fischer rats given durian or cabbage (2.4 g FW/100 g BW/day), administered intragastrically. During the first ethanol challenge, a reduced rate of blood acetaldehyde clearance and hypothermia, which is associated with the disulfiram-ethanol reaction, was observed in rats given durian or cabbage. Blood ethanol levels and rate of acetaldehyde elimination were lowest 30 min after the first ethanol challenge in rats given cabbage, while a similar but more exacerbated trend was observed at 60 min in rats given durian. When subjected to conditioned taste aversion using saccharine solution (0.2% v/v) paired with ethanol administration, the rats given durian or cabbage exhibited aversion, with the former showing the earliest and most pronounced response, persisting through to the last ethanol challenge. Rats given cabbage exhibited delayed aversion, which progressively increased to the same level as that observed in rats given durian.     

应用FRAP技术评价蛋白在聚丙烯酰胺-丙烯酸凝胶中的扩散行为

药物分子从药物载体中的释放行为与载体的结构有密切关系.本实验中采用丙烯酰胺和丙烯酸等材料,运用水相沉淀的方法,制备了4种不同单体配比的聚丙烯酰胺-丙烯酸(P(Am-co-Ac))共聚物水凝胶.运用红外分析方法对P(Am-co-Ac)组成进行表征.使用荧光漂白恢复法(FRAP,fluorescence recovery after photobleaching)观察荧光素FITC标记的牛血清白蛋白(BSA)在聚丙烯酰胺-丙烯酸中的扩散行为,并以激光共聚焦显微镜进行实时成像.实验表明,FITC-BSA在不同单体配比的共聚物中的扩散系数是不同的.通过调节聚合物中单体的配比能够达到控制蛋白释放速率的作用,从而为调控蛋白和多肽类药物的缓控释放提供了可能性.     

Controlled release of allyl isothiocyanate for bacteria growth management

The ordered, mesoporous silica structures MCM-41 and SBA-15 were synthesized as potential vectors for the controlled release of allyl isothiocyanate. The average pore diameter of each silica was 2.45 ± 0.25 nm and 7.28 ± 0.50 nm, however the average pore volume across both samples was 0.817 ± 0.010 mL/g. The maximum loading was 95.3% and 93.9%; the wider pore size of SBA-15 ensured 80% of the available allyl isothiocyanate was released in the first 24 h whereas MCM-41 released approximately 1%/h up to 60 h. Antimicrobial tests were made against 8 microorganisms: Bacillus cereus, Listeria monocytogenes Staphylococcus aureus, Escherichia coli 25922, Salmonella Typhimurium, Vibrio parahaemolyticus, Pichia anomola and Schizosaccharomyce pombe. Controlled release and antibacterial activity from SBA-15 was always superior to those from MCM-41. Overall, allyl isothiocyanate released from the porous vectors was more efficient in controlling yeast and gram-negative bacteria than gram-positive bacteria. In comparison with evaporated liquid allyl isothiocyanate, no apparent loss of activity occurred as a consequence of adsorption and desorption processes in the pore network.     

Effects of abscisic acid on glucosinolate content,isothiocyanate formation and myrosinase activity in cabbage sprouts

Effects of abscisic acid (ABA) on glucosinolate content, isothiocyanate formation and myrosinase activity in cabbage sprouts were investigated. Subsequently, their distributions in different organs were evaluated. ABA (50 μmol L^?1) significantly increased glucosinolate content, isothiocyanate formation and myrosinase activity by 72.65%, 268.15% and 67.69%, respectively, in 5‐day‐old sprouts. Application of ABA alleviated the decrease rate of glucosinolate content and increased the myrosinase activity during germination. Besides, isothiocyanate formation rapidly increased after germinating for 3 days. The glucosinolate content and isothiocyanate formation reduced by 46.51% and 38.01%, respectively, in fluridon (Flu)‐treated sprouts. Cotyledon of ABA‐treated sprouts had the highest glucosinolate content and isothiocyanate formation, indicating that ABA was necessary to enhance the isothiocyanate formation in cabbage sprouts by increasing glucosinolate content and myrosinase activity.     

Oxime-catalyzed formation of functionalized 1,3-oxathiolanes from aryl isothiocyanates and oxiranes

An efficient synthesis of N-(5-alkyl-1,3-oxathiolan-2-ylidene)arylamines via a one-pot reaction between arylisothiocyanates and substituted oxiranes in the presence of catalytic amount of pyridine-2-carbaldehyde oxime is described.