bluuebunny/crossref_metadata_2025_split huggingface dataset:
Components of Essential Oils Extracted from Leaves and Shoots of Abies Species in Japan
Authors: Satou Tadaaki , Matsuura Mariko , Takahashi Mizuho , Murakami Shio , Hayashi Shinichiro , Sadamoto Kiyomi , Koike Kazuo 
Published: June 2011

AbstractThe essential oils extracted from the leaves and the shoots of five Abies species (Pinaceae) growing in Japan, i.e., A. firma, A. homolepis, A. veitchii, A. mariesii, and A. sachalinensis, were characterized by GC‐FID and GC/MS analyses. The yields of the essential oils extracted from A. sachalinensis were the highest among them. A significant amount of α‐pinene was contained in the essential oils of all the Abies species examined. In A. homolepis and A. veitchii, significant differences in the content of the essential oils were found depending on whether these were extracted from the leaves or from the shoots. Regarding the enantiomeric ratio of α‐pinene, the (+)‐enantiomer was predominant in the oil extracted from the leaves of A. firma, while (−)‐α‐pinene was present in higher amounts in the oils of A. veitchii (leaves and shoots), A. mariesii (leaves and shoots), and A. sachalinensis (shoots). The fact that there may be a quantitative and qualitative difference in the components of the essential oils extracted from the different parts of a plant was investigated by cluster analysis.
Evaluation of the Antimicrobial Potential of Two Flavonoids Isolated from Limnophila Plants
Authors: Brahmachari Goutam , Mandal Narayan C. , Jash Shyamal K. , Roy Rajiv , Mandal Lalan C. , Mukhopadhyay Arijit , Behera Biswajit , Majhi Sasadhar , Mondal Avijit , Gangopadhyay Arindam 
Published: June 2011

AbstractThe antimicrobial potential of two bioflavonoids, i.e., 5,7‐dihydroxy‐4′,6,8‐trimethoxyflavone (1) and 5,6‐dihydroxy‐4′,7,8‐trimethoxyflavone (2), isolated from Limnophila heterophylla Benth. and L. indica (Linn.) Druce (Scrophulariaceae), respectively, were evaluated against the microbial strains Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Alternaria solani, and Candida albicans. Compounds 1 and 2 exhibited moderate but broad antimicrobial activities against both Gram‐positive and Gram‐negative bacteria and also against the fungal pathogens. Moreover, the mechanism of action of 1 and 2 on the cellular functions or structures of some of the microorganisms was studied. Compound 1 showed a bactericidal effect against E. coli and S. aureus (MICs of 200 and 250 μg/ml, resp.), while compound 2 was found to effectively kill B. subtilis by cell lysis. The growth of A. solani and C. albicans was inhibited by compounds 1 and 2, respectively. The effects of the flavonoids on the cellular structures and the carbohydrate metabolic pathways were studied by scanning electron microscopy (SEM) of the treated cells and by assessing the specific activity of key enzymes of the pathways, respectively. At sublethal doses, they enhanced the activity of gluconeogenic fructose bisphosphatase, but decreased the activity of phosphofructokinase and isocitrate dehydrogenase, the key enzymes of the EmbdenMeyerhofParnas pathway and the tricarboxylic acid cycle, respectively.
Reinvestigation of Coenzyme Q10 Isolation from Sporidiobolus johnsonii
Authors: Dixson David D. , Boddy Christopher N. , Doyle Robert P. 
Published: June 2011

AbstractThere is considerable current interest in coenzyme Q10 (CoQ10) from a medical perspective. CoQ10 has been shown to alleviate the side effects of statin drugs, for instance, and so there is a push to find naturally high producers of the compound. Sporidiobolus johnsonii (S. johnsonii) has been reported to produce CoQ10 in studies that used only standards on thin‐layer chromatography (TLC) and also suggested the production of coenzyme Q9 (CoQ9). This work set out to verify CoQ9/CoQ10 production in S. johnsonii and quantify as appropriate. We show that S. johnsonii produces CoQ10 but found no evidence for CoQ9 biosynthesis. The specific production of CoQ10 was noted at 10 mg/g dry cell weight (DCW) in media supplemented with 4‐hydroxybenzoic acid (HBA). This makes S. johnsonii a naturally high CoQ10 producer. New methods for extraction and purification of CoQ10 are also discussed, and identification of a closely eluting side product under normal phase isolation is reported.
In vitro Cytotoxic Activity of Extracts and Isolated Constituents of Salvia leriifoliaBenth. against a Panel of Human Cancer Cell Lines
Authors: Tundis Rosa , Loizzo Monica R. , Menichini Federica , Bonesi Marco , Colica Carmela , Menichini Francesco 
Published: June 2011

AbstractIn the course of recent efforts to identify new potential antiproliferative active principles, Salvia leriifolia extracts and isolated constituents were evaluated for their cytotoxic activity against a panel of human cancer cell lines, including renal adenocarcinoma (ACHN), amelanotic melanoma (C32), colorectal adenocarcinoma (Caco‐2), lung large cell carcinoma (COR‐L23), malignant melanoma (A375), lung carcinoma (A549), and hepatocellular carcinoma (Huh‐7D12) cells. The hexane and CH2Cl2 extracts showed the strongest cytotoxic activity against the C32 cell line with IC50 values of 11.2 and 13.6 μg/ml, respectively, and the AcOEt extract was the most active extract against the COR‐L23 cell line (IC50 of 20.9 μg/ml). Buchariol, a sesquiterpene obtained by biofractionation of the CH2Cl2 extract, exhibited a higher activity than the positive control vinblastine against the C32 and A549 cell lines (IC50 values of 2.1 and 12.6 μM, resp.). Interesting results were also obtained for naringenin, a flavonoid isolated from the AcOEt extract, which exhibited a strong cytotoxic activity against the C32, LNCaP, and COR‐L23 cell lines (IC50 values of 2.2, 7.7, and 33.4 μM, resp.), compared to vinblastine (IC50 values of 3.3, 32.2, 50.0 μM, resp.). None of the tested compounds affected the proliferation of skin fibroblasts (142BR), suggesting a selective activity against tumor cells.
Phylogenetic Relationships of the Genus Chamaecyparis Inferred from Leaf Essential Oil
Authors: Chen Ying‐Ju , Lin Chun‐Ya , Cheng Seng‐Sung , Chang Shang‐Tzen 
Published: June 2011

AbstractThe species differentiation between Chamaecyparis formosensis, C. obtusa var. formosana, and C. obtusa, based on the composition of the leaf essential oils, was studied. The characterization of the oils by GC‐FID and GC/MS analyses showed remarkable differences between these three essential oils. Cluster analysis (CA) and principal‐component analysis (PCA) distinguished three groups of essential oils. The C. formosensis oil was dominated by α‐pinene while those isolated from C. obtusa var. formosana and C. obtusa were characterized by high levels of (−)‐thujopsene and α‐terpinyl acetate, respectively. Moreover, the phylogenetic relationships of the genus Chamaecyparis were in agreement with previous findings based on morphological and molecular evidence. In addition, the essential oils from C. obtusa var. formosana could be classified into three chemical types, according to their different characteristic main compounds (β‐elemol, (−)‐thujopsene, and cis‐thujopsenal). The biochemical correlations between the major constituents of the Chamaecyparis species were examined and their relationship is discussed.
An Image Analysis Method for the Measurement of Mixing Times in Stirred Vessels
Authors: Vega‐Alvarado L. , Taboada B. , Hidalgo‐Millán A. , Ascanio G. 
Published: June 2011

AbstractAn image analysis method has been developed for measuring mixing times in stirred vessels. The method consists of capturing images of the flow patterns observed in the agitated vessel by use of a fast acid‐base indicator reaction technique. These images are analyzed to quantify the color evolution by means of a hue, light, and saturation color model (HLS), which corresponds to mixing evolution. In comparison with other non‐intrusive techniques based on the red, green, and blue channels (RGB), the proposed methodology allows accurate analysis of the mixing evolution irrespective of the tracer color used, while reducing the subjectivity of the estimation of mixing times by the human eye.
Data Preprocessing of In Situ Laser‐Backscattering Measurements
Authors: Heinrich J. , Elter T. , Ulrich J. 
Published: June 2011

AbstractIn situ measurement techniques are promising tools to aid process development. However, they also pose new challenges in evaluating large amounts of recorded data. A new procedure for in situ laser‐backscattering devices has been developed that allows transformation of the raw recorded data, a chord length distribution, into a format suitable for population balance modeling. Emphasis is thereby laid on the influence of the suspension density on the measured data. Experimental data are recorded using a batch laboratory crystallizer equipped with an in situ 3D‐ORM laser backscattering device and an ultrasound probe. The new proposed five‐step procedure for data preprocessing is based on several independently developed tools from literature and is exemplarily illustrated with results on the crystallization of ascorbic acid. The proposed method is a step forward to use in situ laser‐backscattering devices also for quantitative purposes.
Safety‐Considered Proactive Flare Minimization Strategy under Ethylene Plant Upsets
Authors: Yang X. , Xu Q. , Li K. 
Published: June 2011

AbstractEthylene plant upsets usually lead to flaring of off‐spec products, resulting in significant losses of raw material and energy as well as to air emission problems. Under the premise of plant safe operation, establishing process recycles connecting off‐spec streams to their upper‐stream process can help to reduce flaring during plant upsets. Operational strategies for recycling the potential flaring sources, i.e., effluents from the acetylene reactor and ethylene tower overhead, under various process upsets are developed and analyzed based on rigorous plant‐wide dynamic simulations. Safety considerations on the compressor system performance have been addressed by quantitative comparison of the effectiveness of various recycling strategies. Case studies demonstrate that the safety‐considered flare minimization strategies can proactively reduce the flaring emission amount and upset time and thus have great potentials of economical and environmental benefits to ethylene plants.
Stochastic Modeling of Fluidized Bed Granulation: Influence of Droplet Pre‐Drying
Authors: Dernedde M. , Peglow M. , Tsotsas E. 
Published: June 2011

AbstractA stochastic Monte Carlo method was used to solve the population dynamics of fluidized‐bed granulation. Special emphasis was put on the addition of liquid to the process and on the microprocess of droplet pre‐drying. Pre‐drying can occur during the flight of droplets from the tip of the nozzle to the fluidized bed, especially in top‐spray configuration. A single‐droplet drying model that considers the change of droplet diameter and of the radial concentration profile of binder in the droplet was developed and validated by experiments in an acoustic levitator. Combined with spray flow field considerations, this model can be used to retrieve an initial droplet diameter from spray measurements. Integrated in the Monte Carlo simulation, it shows that pre‐drying can significantly decrease the agglomeration rate due to overspray and premature solidification instead of successful droplet deposition.
Preparation of Pt@Fe2O3 Nanowires and their Catalysis of Selective Oxidation of Olefins and Alcohols
Authors: Hong Haiyan , Hu Lei , Li Min , Zheng Junwei , Sun Xuhui , Lu Xinhua , Cao Xueqin , Lu Jianmei , Gu Hongwei 
Published: June 2011

AbstractIron oxide coated platinum nanowires (Pt@Fe2O3 NWs) with a diameter of 2.8 nm have been prepared by the oxygen oxidation of FePt NWs in oleylamine. These “cable”‐like NWs were characterised by transmission electron microscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy and X‐ray absorption fine structure analysis. These Pt@Fe2O3 NWs were used as “non‐support” heterogeneous catalysts in oxidation of olefins and alcohols. The results revealed that it is an active and highly selective catalyst. Styrene derivatives were tested with molecular oxygen as the sole oxidant, with benzaldehyde successfully obtained from styrene in an absolute yield of 31 %, whereas the use of tert‐butyl hydroperoxide as the sole oxidant in the oxidation of alcohols led to yields of more than 80 % of the corresponding ketone or aldehyde. This unsupported catalyst was found to be more active (TOF=96.5 h−1) than other reported Fe2O3 nanoparticle catalysts and could be recycled multiple times without any notable decrease in activity. Our findings will extend the use of such nanomaterial catalysts to new catalytic systems.
Chemical Synthesis, Structural Characterization, Optical Properties, and Photocatalytic Activity of Ultrathin ZnSe Nanorods
Authors: Yao Tingting , Zhao Qing , Qiao Zhengping , Peng Feng , Wang Hongjuan , Yu Hao , Chi Cheng , Yang Jian 
Published: June 2011

AbstractUltrathin ZnSe nanorods in the cubic phase have been synthesized by the reaction of selenium and zinc oleate for 30 min at 240 °C. These nanorods showed an average diameter of 2.4 nm, which is much smaller than the Bohr size of bulk ZnSe. Thus, they exhibited a remarkable quantum size effect in terms of their optical properties. The formation of the ultrathin nanorods could be attributed to the oriented attachment mechanism, which was supported by the structure of the nanorods and the control experiments. The ultrathin nanorods were transferred into an aqueous solution by ligand exchange. The performance of these nanorods as a catalyst was examined, using the photodegradation of methyl orange as a model reaction. It was found that the ultrathin nanorods possessed better photocatalytic activities than conventional ones.
Crown Ether Complex Cation Ionic Liquids: Preparation and Applications in Organic Reactions
Authors: Song Yingying , Jing Huanwang , Li Bo , Bai Dongsheng 
Published: June 2011

AbstractA series of crown ether complex cation ionic liquids (CECILs) were designed, synthesised and characterised by NMR spectroscopy, HRMS, thermogravimetric differential thermal analysis (TG‐DTA) and elemental analysis. Their applications in various organic reactions were investigated: [15‐C‐5Na][OH], [15‐C‐5Na][OAc], [18‐C‐6K][OH] and [18‐C‐6K][OAc] (15‐C‐5=[15]crown‐5; 18‐C‐6=[18]crown‐6) efficiently catalysed the Michael addition of alkenes and relevant nucleophiles; [18‐C‐6K][OH] and [15‐C‐5Na][OH] effectively catalysed the Henry reaction of nitromethane and aromatic aldehydes; [18‐C‐6K][OH] has excellent catalytic efficiency for Knoevenagel condensation of aromatic aldehydes and malononitrile; PdCl2/[18‐C‐6K]3[PO4]/K2CO3 efficaciously catalysed the Heck reaction of olefins and aromatic halides; [18‐C‐6K][BrO3] can be used as both oxidant and solvent in the oxidation reaction of aromatic alcohols. The CECIL catalysts [15‐C‐5Na][OH] (Michael addition) and [18‐C‐6K][OH] (Henry reaction) can be recycled and reused several times without obvious loss of activity and their recovery is very simple.
The Pivotal Role of Symmetry in the Ruthenium‐Catalyzed Ring‐Closing Metathesis of Olefins
Authors: Costabile Chiara , Mariconda Annaluisa , Cavallo Luigi , Longo Pasquale , Bertolasi Valerio , Ragone Francesco , Grisi Fabia 
Published: June 2011

AbstractThe synthesis of Ru‐based precatalysts with N‐heterocyclic carbene (NHC) ligands bearing syn‐ and anti‐methyl groups on the NHC backbone and aryl N‐substituents with differing steric bulk was carried out. The catalytic behavior of the monophospine Ru precatalysts (7 a, 7 b, 8 a, and 8 b) was compared to the corresponding family of phosphine‐free catalysts (9 a, 9 b, 10 a and 10 b) in the ring‐closing metathesis (RCM) of olefins. These catalysts showed high efficiency in RCM reactions and the syn‐isomers 7 a and 9 a, in particular, proved to be among the most active catalysts in the formation of tetrasubstituted olefins through RCM. DFT studies on the entire RCM catalytic cycle of hindered olefins were performed to rationalize the different behaviors of catalysts with syn‐ and anti‐methyl groups on the NHC backbone. Theoretical results not only disclosed how NHC symmetry influences the overall activity of the catalyst, but also gave relevant and more general indications on the crucial steps of the RCM of olefins.
Photoelectrochemistry of Free‐Base‐Porphyrin‐Functionalized Zinc Oxide Nanoparticles and Their Applications in Biosensing
Authors: Tu Wenwen , Lei Jianping , Wang Peng , Ju Huangxian 
Published: June 2011

AbstractThe photoelectrochemical properties of free‐base‐porphyrin‐functionalized zinc oxide nanoparticles were studied. A universal photoelectrochemical biosensing platform was constructed on indium tin oxide (ITO) by using the functional nanohybrid. The nanohybrid was synthesized by means of dentate binding of ZnO nanoparticles with carboxylic groups of 4,4′,4′′,4′′′‐(21H,23H‐porphine‐5,10,15,20‐tetrayl)tetrakis(benzoic acid) (TCPP), and characterized with scanning electron microscopy, contact angle measurement, and spectral techniques. The nanohybrid‐coated ITO electrode showed an efficient photocurrent response under irradiation at a wavelength of 360 nm, which could be greatly improved upon addition of cysteine by its oxidation at +0.3 V. The possible mechanism was that cysteine acts as a sacrificial electron donor to scavenge the photogenerated holes that locate on the excited state of TCPP, which then injects the photoexcitation electrons into the conduction band of ZnO nanoparticles, thereby transferring photoinduced electrons to the ITO electrode. Based on this enhanced photocurrent signal, a novel method for photoelectrochemical detection of cysteine was developed with a linear range of 0.6 to 157 μmol L−1 in physiological media. The detection limit was 0.2 μmol L−1 at a signal‐to‐noise ratio of 3. The novel strategy of cysteine analysis could provide an alternative method for monitoring biomolecules and extend the application of porphyrin‐functionalized semiconductor nanoparticles.
Expanding the Utility of Brønsted Base Catalysis: Biomimetic Enantioselective Decarboxylative Reactions
Authors: Pan Yuanhang , Kee Choon Wee , Jiang Zhiyong , Ma Ting , Zhao Yujun , Yang Yuanyong , Xue Hansong , Tan Choon‐Hong 
Published: June 2011

AbstractAs a result of the low reactivity of simple esters, the use of them as nucleophiles in direct asymmetric transformations is a long‐standing challenge in synthetic organic chemistry. Nature approaches this difficulty through a decarboxylative mechanism, which is used for polyketide synthesis. Inspired by nature, we report guanidine‐catalyzed biomimetic decarboxylative CC and CN bond‐formation reactions. These highly enantioselective decarboxylative Mannich and amination reactions utilized malonic acid half thioesters as simple ester surrogates. It is proposed that nucleophilic addition precedes decarboxylation in the mechanism, which has been investigated in detail through the identification of intermediates by using electrospray ionization (ESI) mass‐spectrometric analysis and DFT calculations.
The Role of Chirality in Directing the Formation of Cup‐Shaped Porphyrins and the Coordination Characteristics of such Hosts
Authors: Wang Bao‐Yu , Turner Daniel A. , Zujović Teodora , Hadad Christopher M. , Badjić Jovica D. 
Published: June 2011

AbstractCup‐shaped porphyrin 1 a has four norbornane rings for encircling space and this type of host could be of interest in supramolecular and catalytic chemistry. We used 1H NMR spectroscopy to investigate the acid‐catalyzed (pTsOH in CHCl3 and TFA in CH3CN) condensation of racemic, enantioenriched (80–85 % enantiomeric excess (ee)), and enantiopure (99 % ee) pyrromethanecarbinol 7 into 1 a. We found that the oligomerization of racemic 7rac would give 1 a–d in the ratio different from the statistical one, though a minuscule quantity of 1 a (<5 %) formed. The oligomerization of enantioenriched 7 (80–85 % ee), however, led to the formation of greater amounts of 1 a (31–47 %) along with other stereoisomers 1 b–d. Importantly, pTsOH catalyzed the conversion of enantiopure 7 (99 % ee) into 1 a (>95 % diastereomeric excess (de), 25 % overall yield) in CHCl3 although prolonged reaction times or greater concentration of the catalytic acid gave rise to 1 b–d at the expense of 1 a. The metallation of 1 a with Zn(OAc)2 led to the formation of ZnII‐1 a and we used computational (DFT: RI‐BP86/SV(P),TZVP) and experimental (1H NMR spectroscopy) methods to study the partitioning of smaller N‐methylimidazole 13 (94 Å3) and bigger 1,5‐dicyclohexylimidazole 14 (268 Å3) between the inner and outer side of the host. We found that bigger 14 was mostly encapsulated (90 %) inside ZnII‐1 a at 298.0 K, whereas smaller 13 would equally partition between the two sides of the host. Furthermore, the out/in equilibrium was, in the case of 14‐ZnII‐1 a, favored by entropy (TΔS°out/in=3.5±0.1 kcal mol−1) indicating that perhaps differential solvation of the coordinated ligand assisted the encapsulation.
Selective Palladium‐Loaded MIL‐101 Catalysts
Authors: Hermannsdörfer Justus , Kempe Rhett 
Published: June 2011

AbstractPalladium nanoparticles (NPs) of different mean particle size have been synthesized in the host structure of the porous coordination polymer (or metal–organic framework: MOF) MIL‐101. The metal–organic chemical vapor deposition method was used to load MIL‐101 with the Pd precursor complex [(η5‐C5H5)Pd(η3‐C3H5)]. Loadings higher than 50 wt. % could be accomplished. Reduction of the Pd precursor complex with H2 gave rise to Pd NPs inside the MIL‐101 (Pd@MIL‐101). The reduction conditions, especially the temperature, allows us to make size‐conform (size of the Pd NPs correlates with the size of the cavities of the host structure of MIL‐101) and undersized Pd NPs. The Pd@MIL‐101 samples were characterized by X‐ray diffraction, IR spectroscopy, Brauner–Emmett–Teller (BET) analysis, elemental analysis, and transmission electron microscopy (TEM). Catalytic studies, hydrogenation of ketones, were performed with selected Pd@MIL‐101 catalysts. Activity, selectivity, and recyclability of the catalyst family are discussed.