Short and Sweet: D‐Glucose to L‐Glucose and L‐Glucuronic Acid

The scarcity and expense of access to L ‐sugars and other rare sugars have prevented the exploitation of their biological potential; for example D ‐psicose, only recently available, has been recognized as an important new food. Here we give the definitive and cheap synthesis of 99.4% pure L ‐glucose from D ‐glucose which requires purification of neither intermediates nor final product other than extraction into and removal of solvents; a simple crystallization will raise the purity to >99.8%.     

气相色谱法测定甘蓝中啶虫脒残留量

用气相色谱分析法快速测定啶虫脒。甘蓝预制样品经高速匀浆法提取、弗罗里硅土层析柱净化后用附带ECD检测器的气相色谱仪检测啶虫脒的残留量,外标法定量,回收率为80.2?.8%,最低检出浓度为0.001mg/kg,测定结果的相对标准偏差不大于3.4%。     

Determination of Herbicide Residues in Garlic by GC–MS

A rapid multi-residue method has been developed for the determination of 16 herbicides in garlic. The analytical procedure is based on prior microwave heating prevention of the generation of sulfur-containing compounds. The garlic samples which had been pretreated were extracted with acetonitrile and cleaned up by solid-phase extraction. The herbicide residues were detected by gas chromatography–mass spectrometry with selected ion monitoring. The recoveries of 16 herbicides ranged from 69.0 to 105.4% with the relative standard deviations (RSD) below 10.1%. The limit of quantification (LOQ) ranged from 0.003 to 0.015 mg kg^?1.     

毛细管气相色谱法测定速冻食品中的山梨酸和苯甲酸

建立了速冻食品中山梨酸和苯甲酸的毛细管气相色谱检测方法。样品用石油醚-乙醚高速匀浆的方法提取后,通过改变酸度而改变其在有机相和水相中分配比的方法,去除脂肪等杂质的干扰,用FFAP毛细管色谱柱FID检测器进行检测。该方法测定结果的相对标准偏差为1.4%~6.6%,回收率为90.5%~96.9%,检出限为1mg/kg。     

Evaluation of the potential of Potamogeton crispus and Myriophyllum spicatum on phytoremediation of atrazine

Atrazine is one of the most frequently detected pesticides and poses a great risk to humans and the environment. In this study, the effects of two submerged macrophytes, Potamogeton crispus and Myriophyllum spicatum, on phytoremediation of atrazine were evaluated. The results showed that atrazine decayed faster in the pots where these two plants were cultivated than that of the control without the plants during the 60-day course of the experiment. Metabolite analyses of atrazine indicated that atrazine was mainly converted to diaminochlorotriazine and hydroxyatrazine. Dissipation kinetics and risk assessment of atrazine showed that atrazine was degraded rather fast in maize and generally safe for human consumption at the recommended high dosage of atrazine. The maximum permissible intake (MPI) for atrazine was calculated to be 0.23 μg/person/day for a child and 0.72 μg/person/day for an adult. However, due to the large-scale application of atrazine over the years, the atrazine residue still poses a great threat to the environment. By using submerged macrophytes M. spicatum and P. crispus, atrazine could be absorbed from the sediment, hence remediating contaminated sediment and water. This study established a protocol for evaluating submerged plants in absorption or phytoremediation of pesticides.     

Lithocarpinols A and B,a pair of diastereomeric antineoplastic tenellone derivatives from the deep-sea derived fungus Phomopsis lithocarpus FS508

Lithocarpinols A(1) and B(2), a pair of tenellone diastereoisomers with novel fused skeleton were isolated from the deep-sea derived fungus Phomopsis lithocarpus FS508. Their structures were elucidated by comprehensive spectroscopic analyses, X-ray diffraction and quantum molecular calculation. Their plausible biogenetic pathway featured an intriguing carbonyl-ene cyclization. Lithocarpinol A exhibited moderate inhibitory effect against HepG-2 and A549 tumor cell lines with IC_(50) values of 9.4 μmol/L and10.9 μmol/L,respectively.     

Emerging Two-Dimensional Nanomaterials for Cancer Therapy

Two-dimensional (2D) nanomaterials have drawn tremendous attention due to their unique physicochemical properties and promising applications in the fields of electronics, energy storage, and catalysis. Recently, the biomedicine community has gradually started to recognize the great potential of these nanostructured materials for biomedical applications – in particular those related to cancer therapy. In this review, we provide a brief overview of a few representative 2D nanomaterials, discuss their preparation strategies and physicochemical properties, and highlight their applications in cancer nanomedicine. We expect that this review will shed some light on the new opportunities associated with 2D nanomaterials for biomedical research.     

毛细管气相色谱法检测果蔬中的丙线磷

对高速匀浆、超声波与振荡器3种提取效果进行了比较,表明高速匀浆法高效、节约,用毛细管气相色谱法氮磷检测器测定果蔬中的丙线磷,回收率为87.6%~99.5%,变异系数为1.30%~5.15%。     

毛细管气相色谱法测定食用油中的酚类抗氧化剂BHA、BHT、TBHQ

建立了同时测定植物油中BHA、BHT、TBHQ等3种酚类抗氧化剂的测定方法。样品中的抗氧化剂经石油醚提取、乙腈萃取后采用HP-5毛细管柱分离。样品加标回收率为82.8?.6%,相对标准偏差为1.06%~3.11%,BHA、BHT、TBHQ的最低检出量分别为5、10、5ng。该方法具有快速、灵敏度高、重现性好、前处理简单等优点。     

棉花植株中多杀菌素及其代谢物残留量的检测

建立了同时测定棉花植株中杀菌素及其代谢产物残留量的高效液相色谱法。在碱性条件下用甲醇提取棉花植株中的多杀菌素及其代谢产物,改变pH值与液-液萃取结合固相萃取的方法去除杂质,以甲醇和含乙酸铵的乙腈混合溶液作流动相,ODC-C18柱分离,利用紫外检测器检测。在最佳条件下,棉花植株中各组分的平均加标回收率为76.9%~108.0%,相对标准偏差为1.3%~9.9%,最低检出浓度为0.01mg/kg。