Chemical Composition,Antibacterial Screening and Cytotoxic Activity of Chiliadenus antiatlanticus (Asteraceae) Essential Oil

The chemical composition and in vitro antibacterial and cytotoxic activities of the essential oil (EO) of Chiliadenus antiatlanticus (Emb. & Maire) Gómiz, an asteraceous species endemic to the southwest of Morocco, were investigated. The EO yield was 1.07±0.28 %, twenty-seven metabolites were identified representing more than 96.4 % of the total composition. Camphor (35.7 %) and derivatives, borneol (4.9 %) and camphene (4.2 %) together with intermedeol (19.9 %), α-pinene (15.5 %) and (E)-pinocarveol (4.1 %) were the major constituents. An antibacterial activity was noticed against 24 strains (all Gram-positive) out of 71 at MICs values=100 μg/mL. The EO also showed significant toxicity towards liver HepG2 (55.8 % of cell viability) and melanoma B16 4A5 (41.6 % of cell viability) tumor cell lines at 100 μg/mL.     

Natural terpenes: self-assembly and membrane partitioning

Monoterpenes (MTs) are highly hydrophobic substances present in essential oils. They cover a wide spectrum of biological effects with a membrane interaction as a common point. Here we studied the surface activity of camphor, cineole, thymol, menthol and geraniol, and their ability to reach and incorporate into model membranes affecting some features of their dynamic organization. All the MTs studied self-aggregated in water with critical micellar concentrations (CMC) between 3 and 8 microM. Their octanol-water and membrane-water partition coefficients were correlated with one another. They all penetrated in monomolecular layers of dipalmitoyl-phosphatildylcholine at the air-water interface, even at surface pressures (pi) above the equilibrium lateral pressure of bilayers; thymol exhibited the highest (61.3 mN/m) and camphor the lowest (37 mN/m) pi(cut-off) value. They affected the self-aggregation of Triton X-100, increasing its CMC from 0.16 mM in the absence of MTs up to 0.68 mM (e.g. for geraniol), and the topology of sPC vesicles, increasing its surface curvature, suggesting their location at the polar head group region of the membrane. The latter was supported by their ability to increase differentially the polarity of the membrane environment sensed by two electrochromic dyes. Dipole moment values (between 1.224 and 2.523 D) and solvation areas (between 80 and 97 A(2)) were calculated from their energy-minimized structures. The relative contribution of each experimental, theoretical and structural property to determine MTs' effects on membrane dynamics were evaluated by a principal component analysis.     

香樟害虫——橄绿瘤丛螟的生物学特性

研究发现嘉兴地区危害香樟树的丛螟科害虫为橄绿瘤丛螟Orthaga olivacea(Warren),对该虫的生物学特性和发生规律做了研究。该虫较为喜欢危害5~10年生香樟树,多头幼虫聚集在一起取食叶片,并缀合受害叶片成鸟巢状虫苞。在嘉兴地区1年发生2代。根据计算幼虫可分为7龄,符合Dyer生长规律。     

Formulation design and optimization of mouth dissolve tablets of nimesulide using vacuum drying technique

The purpose of this research was to develop mouth dissolve tablets of nimesulide. Granules containing nimesulide, camphor, crospovidone, and lactose were prepared by wet granulation technique. Camphor was sublimed from the dried granules by exposure to vacuum. The porous granules were then compressed. Alternatively, tablets were first prepared percentage friability, wetting time, and disintegration time. In the investigation, a 3² full factorial design was used to investigate the joint influence of 2 formulation variables: amount of camphor and crospovidone. The results of multiple linear regression analysis revealed that for obtaining a rapidly disintegrating dosage form, tablets should be prepared using an optimum concentration of camphor and a higher percentage of crospovidone. A contour plot is also presented to graphically represent the effect of the independent variables on the disintegration time and percentage friability. A checkpoint batch was also prepared to prove the validity of the evolved mathematical model. Sublimation of camphor from tablets resulted in superior tablets as compared with the tablets prepared from granules that were exposed to vacuum. The systematic formulation approach helped in understanding the effect of formulation processing variables.     

The cytochrome P450 CYP6P4 is responsible for the high pyrethroid resistance in knockdown resistance-free Anopheles arabiensis

Pyrethroid insecticides are the front line vector control tools used in bed nets to reduce malaria transmission and its burden. However, resistance in major vectors such as Anopheles arabiensis is posing a serious challenge to the success of malaria control.Herein, we elucidated the molecular and biochemical basis of pyrethroid resistance in a knockdown resistance-free Anopheles arabiensis population from Chad, Central Africa. Using heterologous expression of P450s in Escherichia coli coupled with metabolism assays we established that the over-expressed P450 CYP6P4, located in the major pyrethroid resistance (rp1) quantitative trait locus (QTL), is responsible for resistance to Type I and Type II pyrethroid insecticides, with the exception of deltamethrin, in correlation with field resistance profile. However, CYP6P4 exhibited no metabolic activity towards non-pyrethroid insecticides, including DDT, bendiocarb, propoxur and malathion. Combining fluorescent probes inhibition assays with molecular docking simulation, we established that CYP6P4 can bind deltamethrin but cannot metabolise it. This is possibly due to steric hindrance because of the large vdW radius of bromine atoms of the dihalovinyl group of deltamethrin which docks into the heme catalytic centre.The establishment of CYP6P4 as a partial pyrethroid resistance gene explained the observed field resistance to permethrin, and its inability to metabolise deltamethrin probably explained the high mortality from deltamethrin exposure in the field populations of this Sudano-Sahelian An. arabiensis. These findings describe the heterogeneity in resistance towards insecticides, even from the same class, highlighting the need to thoroughly understand the molecular basis of resistance before implementing resistance management/control tools.     

促进真菌染色体重组的MCB^L共诱导平板的构建和应用

基于对樟脑（Ｃａｍｐｈｏｒ）和苯菌灵（Ｂｅｎｏｍｙｌ）可能分别诱导细胞核膜融合和染色体不分离性重组的机理认识,设计了ＭＣＢＬ共诱导平板,以察氏（Ｃｚａｐｅｋ）培养基含有１％Ｃａｍｐｈｏｒ及０５μｇ／ｍｌＢｅｎｏｍｙｌ为基础制作平板。以属间融合组合Ａｓｐｅｒｇｉｌｕｓｎｉｇｅｒ×Ｔｒｉｃｈｏｄｅｒｍａｒｅｓｅｉ为例,研究所设计的几种诱导平板处理方法对融合子代群体的基因型和表型变异的影响,结果表明常规分步诱导处理,杂合二倍体阶段缺乏或极短暂难以获得重组单倍体;而经过ＭＣＢＬ共诱导平板处理能够获得类型齐全的分离子,显著提高表观二倍化率和染色体不分离性重组单倍体的比率。显示ＭＣＢＬ共诱导平板能够有效地扩增捕捉到极短暂杂合二倍体的机率,促进不稳定异核体向重组单倍体的转化,扩增染色体不分离性重组频率。再生菌丝菌龄对共诱导效果影响显著。由此对共诱导机制和应用前景提出讨论。     

Sesquiterpene lactones and other constituents from Tanacetum parthenium

A reinvestigation of the aerial parts of Tanacetum parthenium afforded in addition to known compounds three pinene derivatives, two spiroketal enol ether polyines, four germacranolides; and six guaianolides, two of them being endoperoxides, and two secoguaianolides. The structures were elucidated by high field ¹H NMR spectroscopy, mass spectroscopy and a few chemical transformations. The biogenetic relationships are discussed briefly.     

染色体DNA转化原生质球构建解烃工程菌

用供体菌C_(20-11)和D_(36-3)染色体DNA转化受体菌T_3原生质球。采用5mg/ml溶菌酶,37℃水浴1小时制备原生质球。原生质球形成率为99％,再生率为72.5％。在30％、PEG6000和0.1MCaC1_2作用下,供体DNA转化受体原生质球。我们用上述条件构建了能够同时降解以下四种碳源:苯甲酸、萘、樟脑、十六烷的工程菌株TCD32-14-1。     

Study of mixed function oxidase system in <Emphasis Type="Italic">Aspergillus ochraceus</Emphasis> (NCIM 1146)

Aspergillus ochraceus (NCIM-1146) has shown the ability to degrade cholesterol, camphor and naphthalene, when 96 h grown mycelium incubated in medium containing these organic compounds. Presence of higher level of electron transport components and biotransformation enzyme activity were observed in Aspergillus ochraceus, when grown in potato dextrose medium for 96 h. The enzyme activity preferred NADPH as a cofactor and shows inhibition in the presence of CO, indicating cytochrome P-450 mediated reactions. A significant increase in the levels of electron transport components and biotransformation enzyme activity were observed in presence of different inducers (viz. cholesterol, camphor, naphthalene, veratrole, phenobarbital, n-hexane, kerosene and saffola oil) when compared with mycelium incubated in same way with similar conditions for 2 min incubation. Analyses of the products of cholesterol and camphor using HPLC and GCMS confirm the degradation of these compounds.     

Synthesis of Novel Camphor‐Derived Bifunctional Thiourea Organocatalysts

Synthesis and catalyst performance of 2,3‐ (types B and C ) and 2,8‐disubstituted (type D ) thiourea bifunctional organocatalysts was attempted. The synthesis of catalyst of type B has, so far, not been realized, while catalysts of type C , i.e., the 2,3‐exo‐ and the 2‐endo‐3‐exo‐thiourea catalysts, were prepared in six steps starting from (+)‐camphor. The catalysts of type D were prepared from (+)‐camphor in eight steps. All the potential catalysts as well as most of the intermediate products were carefully structurally characterized. The thiourea bifunctional organocatalysts were tested in a model reaction of Michael addition of dimethyl malonate to trans‐β‐nitrostyrene. Chirality 27:39–52, 2015. © 2014 Wiley Periodicals, Inc.