bluuebunny/crossref_metadata_2025_split huggingface dataset:
Indispensable structure of solution additives to prevent inactivation of lysozyme for heating and refolding
Authors: Matsuoka Tsuneyoshi , Hamada Hiroyuki , Matsumoto Koji , Shiraki Kentaro 
Published: September 2009

AbstractThis article investigates solution additives that prevent misfolding of lysozyme from heating treatment and during refolding processes. Comparison of heat treatment of native lysozyme and oxidative refolding from the reduced and denatured state of lysozyme in the presence of 44 different additives revealed an indispensable chemical structure for the additives to be effective against heat‐induced misfolding and for refolding. The additives effective against heat treatment of native lysozyme possessed a main chain of the amino acid moiety. Amino acids that have esterificated and amidated carboxy groups prevented heat‐induced misfoldings more effectively than amino acids themselves. On the other hand, the additives effective against oxidative refolding possessed a guanidium or ureido group. The former additives prevented hydrophobic interaction between the main chains of the unfolded polypeptide, while the latter additives increased the solubility of the aromatic and aliphatic side‐chains. These data also support the fact that arginine (Arg) and Arg derivatives are versatile additives for both misfolding processes. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Rediocides A and G as Potential Antitoxins Against Cobra Venom
Authors: Utsintong Maleeruk , Kaewnoi Atchara , Leelamanit Wichet , Olson Arthur J. , Vajragupta Opa 
Published: September 2009

AbstractRediocides A and G, the principle components of Trigonostemon reidioides (Kurz) Craib, which is known as Lotthanong in Thai, were investigated for a detoxification mechanism against Naja kaouthia venom by in silico, in vitro, and in vivo methods. Molecular dockings of α‐cobratoxin with rediocides A and G were performed, and the binding energies were found to be −14.17 and −14.14 kcal/mol, respectively. Rediocides bind to α‐cobratoxin at the same location as α‐cobratoxin binds to the nicotinic acetylcholine receptor (nAChR), i.e., at the Asp27, Phe29, Arg33, Gly34, Lys35, and Val37 residues. α‐Cobratoxin cannot bind to nAChR, because some of its binding sites are occupied with rediocides. From in vitro SDS‐PAGE, it was found that rediocides can diminish the bands of α‐cobratoxin. In the presence of acetylcholine‐binding protein (AChBP), it was apparent that rediocides can bind both α‐cobratoxin and AChBP. From an in vivo test, it was found that injection of rediocides at 0.5 mg/kg immediately after an α‐cobratoxin dose of three times LD50 cannot prolong the survival time of mice. However, rediocide can prolong the survival time, if it is injected 30 min before the injection of α‐cobratoxin. The in vitro SDS‐PAGE and the in vivo results support the in silico detoxification mechanism of rediocides against cobra venom at a molecular level.
Syntheses, Characterizations, and Biological Activities of Tetradeca‐4,8‐dien‐1‐yl Acetates as Sex Attractants of Leaf‐Mining Moth of the Genus Phyllonorycter (Lepidoptera: Gracillariidae)
Authors: Liblikas Ilme , Mozūraitis Raimondas , Santangelo Ellen M. , Noreika Remigijus , Borg‐Karlson Anna‐Karin 
Published: September 2009

AbstractThe four possible isomers of tetradeca‐4,8‐dien‐1‐yl acetate and corresponding alcohols were synthesized stereoselectively by synthetic routes employing Wittig coupling reaction for the preparation of (Z,E)‐ and (Z,Z)‐isomers, and alkylation of terminal alkynes for the preparation of (E,E)‐ and (E,Z)‐isomers as the key steps. Synthetic products were characterized by 13C‐ and 1H‐NMR spectroscopy as well as mass‐spectrometric methods. All four isomers gave distinctive mass spectra where m/z 81 fragments clearly dominated. Elution order, followed by retention index presented in parenthesis, of tetradeca‐4,8‐dien‐1‐ols was determined as (Z,Z) (2082.1), (Z,E) (2082.8), (E,E) (2083.1), and (E,Z) (2083.2) from unpolar SPB‐1 column, and as (E,E) (2210.2), (Z,E) (2222.1), (E,Z) (2223.4), and (Z,Z) (2224.7) from polar DB‐WAX column. The isomers of tetradeca‐4,8‐dien‐1‐yl acetates eluted in the order of (Z,Z) (2176.1), (Z,E) (2178.4), (E,Z) (2185.9), and (E,E) (2186.4) from SPB‐1, and (Z,E) (2124.3), (E,E) (2157.7), (Z,Z) (2128.9), and (E,Z) (2135.9) from DB‐WAX columns. Field‐screening tests for attractiveness of tetradeca‐4,8‐dien‐1‐yl acetates revealed that (4Z,8E)‐tetradeca‐4,8‐dien‐1‐yl acetate significantly attracted Phyllonorycter coryli and Chrysoesthia drurella males. (4E,8E)‐Tetradeca‐4,8‐dien‐1‐yl acetate was the most efficient attractant for Ph. esperella and Ph. saportella males, and (4E,8Z)‐tetradeca‐4,8‐dien‐1‐yl acetate was attractive to Ph. cerasicolella males.
Cytotoxic Grifolin Derivatives Isolated from the Wild Mushroom Boletus pseudocalopus (Basidiomycetes)
Authors: Song Junsik , Manir Md. Maniruzzaman , Moon Surk‐Sik 
Published: September 2009

AbstractActivity‐guided purification of a MeOH extract of the Korean wild mushroom Boletus pseudocalopus afforded three new grifolin derivatives, 1–3, along with four known phenolic compounds 4–7. Their structures were established by a combination of 1H‐ and 13C‐NMR, NOESY, and extensive two‐dimensional NMR spectroscopic experiments such as gCOSY, gHSQC, gHMBC, and ROESY. The major metabolites 4 and 5 were subjected to reduction to provide the side chain‐reduced compounds 8 and 9 for biological testing. All of the compounds except compound 6 showed anticancer activities in the range of IC50 3.5–11.0 μg/ml against human lung carcinoma A549 and mouse melanoma B16F1 cell lines. In addition, all compounds showed moderate radical‐scavenging activities determined by DPPH assay.
Two New Triterpenoid Saponins Cytotoxic to Human Glioblastoma U251MG Cells from Ardisia pusilla
Authors: Tang Hai‐Feng , Yun Jun , Lin Hou‐Wen , Chen Xiao‐Li , Wang Xiao‐Juan , Cheng Guang 
Published: September 2009

AbstractTwo new triterpenoid saponins, ardipusillosides IV and V (1 and 2, resp.), together with one known saponin, ardisiacrispin B (3), were isolated from the whole plants of Ardisia pusilla A. DC. Their structures were deduced by extensive spectral analysis and chemical evidences. Compound 1 contains a glycosylated glycerol residue which is a very rare structural feature among triterpenoid glycosides and has been so far found only in the genus Ardisia. All the saponins exhibited significant cytotoxicity against human glioblastoma U251MG cells, but did not affect the growth of primary cultured human astrocytes.
New (9βH)‐Lanostanes and Lanostanes from Mikania aff. jeffreyi (Asteraceae)
Authors: Mendes Carla C. , Sandes Luciana Q. , Cruz Frederico G. , Roque Nídia F. 
Published: September 2009

AbstractFour new (9βH)‐lanostanes, i.e., (9βH)‐3β‐acetoxylanosta‐7,24‐diene, (9βH)‐3‐oxolanosta‐7,24‐diene, (9βH,24R)‐3β‐acetoxy‐24‐hydroxylanosta‐7,25‐diene, and (9βH,24S)‐3β‐acetoxy‐24‐hydroxylanosta‐7,25‐diene, two new lanostanes, i.e., (24R)‐3β‐acetoxy‐24‐hydroxylanosta‐8,25‐diene and (24S)‐3β‐acetoxy‐24‐hydroxylanosta‐8,25‐diene, and two known lanostanes, i.e., 3β‐acetoxylanosta‐8,24‐diene and 3‐oxolanosta‐8,24‐diene, were obtained from a new Mikania species (Asteraceae) besides pentacyclic triterpenes, steroids, and diterpenes. The structures of the compounds were determined by spectroscopic methods. This is the second study about acetyl‐lanosterols from higher plants. Moreover, (9βH)‐lanostanes are very rare metabolites from dicotyledone angiosperms. The occurrence of these terpenes together in the same plant makes the species a good source for lanostane‐ and (9βH)‐lanostane‐biosynthesis studies.
Adsorption of the PtII Anticancer Drug Carboplatin by Mesoporous Silica
Authors: Di Pasqua Anthony J. , Wallner Silvia , Kerwood Deborah J. , Dabrowiak James C. 
Published: September 2009

AbstractMCM‐41, a mesoporous silica nanomaterial with a high surface area for adsorption of small molecules, is a potential new type of delivery vehicle for therapeutic and diagnostic agents. In this report, we show that MCM‐41 adsorbs the front‐line anticancer drug carboplatin, [Pt(CBDCA‐O,O′)(NH3)2] (CBDCA=cyclobutane‐1,1‐dicarboxylate; 1), which is used to treat ovarian, lung, and other types of cancer. UV/Visible difference absorption spectroscopy shows that MCM‐41 adsorbs 1.8±0.2% of its own weight of carboplatin after a 24 h exposure to 26.9 mM drug in H2O. The pseudo‐first‐order rate constant for adsorption of carboplatin by MCM‐41, measured using [1H,15N] heteronuclear single quantum coherence (HSQC) NMR, and 15N‐labeled carboplatin is k1=2.92±2.17×10−6 s−1 at ca. 25°.
Thermal Wet Decomposition of Prussian Blue: Implications for Prebiotic Chemistry
Authors: Ruiz‐Bermejo Marta , Rogero Celia , Menor‐Salván César , Osuna‐Esteban Susana , Martín‐Gago José Ángel , Veintemillas‐Verdaguer Sabino 
Published: September 2009

AbstractThe complex salt named Prussian Blue, Fe4[Fe(CN)6]3⋅15 H2O, can release cyanide at pH>10. From the point of view of the origin of life, this fact is of interest, since the oligomers of HCN, formed in the presence of ammonium or amines, leads to a variety of biomolecules. In this work, for the first time, the thermal wet decomposition of Prussian Blue was studied. To establish the influence of temperature and reaction time on the ability of Prussian Blue to release cyanide and to subsequently generate other compounds, suspensions of Prussian Blue were heated at temperatures from room temperature to 150° at pH 12 in NH3 environment for several days. The NH3 wet decomposition of Prussian Blue generated hematite, α‐Fe2O3, the soluble complex salt (NH4)4[Fe(CN6)]⋅1.5 H2O, and several organic compounds, the nature and yield of which depend on the experimental conditions. Urea, lactic acid, 5,5‐dimethylhydantoin, and several amino acids and carboxylic acids were identified by their trimethylsilyl (TMS) derivatives. HCN, cyanogen (C2N2), and formamide (HCONH2) were detected in the gas phase by GC/MS analysis.
Hybrid Organic–Inorganic Silica Gel Carriers with Controlled Drug‐Delivery Properties
Authors: Contessotto Laura , Ghedini Elena , Pinna Francesco , Signoretto Michela , Cerrato Giuseppina , Crocellà Valentina 
Published: September 2009

AbstractPure and modified silica materials were synthesised by a sol–gel process and used as carrier for the controlled release of ibuprofen, selected as model drug. A one‐step synthesis was optimised for the preparation of various silica–drug composites by using tetraethoxysilane and 3‐aminopropyltriethoxysilane as precursors at different molar ratios. The presence of aminopropyl groups on the silica surface influences the drug‐delivery rate leading to a high degree the desorption process controlled.
A Panel of Cytochrome P450 BM3 Variants to Produce Drug Metabolites and Diversify Lead Compounds
Authors: Sawayama Andrew M. , Chen Michael M. Y. , Kulanthaivel Palaniappan , Kuo Ming‐Shang , Hemmerle Horst , Arnold Frances H. 
Published: September 2009

AbstractHerein we demonstrate that a small panel of variants of cytochrome P450 BM3 fromBacillus megateriumcovers the breadth of reactivity of human P450s by producing 12 of 13 mammalian metabolites for two marketed drugs, verapamil and astemizole, and one research compound. The most active enzymes support preparation of individual metabolites for preclinical bioactivity and toxicology evaluations. Underscoring their potential utility in drug lead diversification, engineered P450 BM3 variants also produce novel metabolites by catalyzing reactions at carbon centers beyond those targeted by animal and human P450s. Production of a specific metabolite can be improved by directed evolution of the enzyme catalyst. Some variants are more active on the more hydrophobic parent drug than on its metabolites, which limits production of multiply‐hydroxylated species, a preference that appears to depend on the evolutionary history of the P450 variant.
Unstable Supramolecular Structure of [Bmim][BF4] in Aqueous Solution
Authors: Wu Bo , Zhang Li , Zhang Yu Mei , Wang Hua Ping 
Published: September 2009

AbstractTo unravel the exact composition and structure of aggregates in an aqueous solution of 1‐butyl‐3‐methylimidazolium tetrafluoroborate ([Bmim][BF4]), we performed static and dynamic light‐scattering measurements, as well as transmission electron microscopy (TEM). Results from this work show that the aggregates are vesicles and unstable; herein, we discuss the driving force behind the self‐assembly. Apart from the van der Waals forces and repulsive electrostatic interactions between adjacent cation clusters, the hydrogen‐bonding forces as well as counterion effects might also contribute to this driving force. The information obtained here is useful for a better understanding of the vital role that aggregation behavior plays in the field of ionic liquid recovery, and its potential use in controlled release, drug delivery, and petroleum recovery.
The Ambident Reactivity of 2,4,6‐Tris(trifluoromethanesulfonyl)anisole in Methanol: Using the SO2CF3 Group as a Tool to Reach the Superelectrophilic Dimension in σ‐Complexation Processes
Authors: El Guesmi Nizar , Boubaker Taoufik , Goumont Regis , Terrier François 
Published: September 2009

AbstractThe kinetics of σ complexation of 2,4,6‐tris(trifluoromethanesulfonyl)anisole (7 d) have been investigated over a large pH range of 2–13.70 at T=20 °C in methanol. Two competitive processes associated with the initial addition of MeO− at the unsubstituted 3‐position of 7 d to give a 1,3‐dimethoxy adduct (9 d‐Me) and a subsequent and slow conversion of this species into a 1,1‐dimethoxy isomer (8 d‐Me) have been identified. Both adducts 8 d‐Me and 9 d‐Me are 105–106 times more stable than the related adducts 8 a‐Me and 9 a‐Me of 2,4,6‐trinitroanisole (7 a), a conventional reference aromatic electrophile in Meisenheimer complex chemistry. The high stability of 8 d‐Me and 9 d‐Me is shown to derive from greater rates of formation and lower rates of decomposition than previously determined for 8 a‐Me and 9 a‐Me, thereby emphasising the especially high activation of a benzene ring by SO2CF3 group(s). Analysis of the collected rate and equilibrium data for σ complexation in the anisole series 2,4,6‐tris(SO2CF3)‐, 2,6‐bis(SO2CF3)‐4‐nitro‐, 4‐SO2CF3‐2,6‐dinitro‐ and 2,4,6‐trinitro‐ supports the idea that the especially high capacity of resonance stabilisation of the negative charge of the adducts through an Fπ‐type (as defined in ref. 49) polarisation effect is a major factor that accounts for the strong activation provided by SO2CF3 groups. A most significant result is the finding that the 1,1‐dimethoxy adduct 8 d‐Me is by far the most stable benzene σ adduct so far reported. With a p${K{{{\rm MeOH}\hfill \atop {\rm a}\hfill}}}$ value of 7.32, this adduct is formed exclusively through methanol addition up to pH≈10. This is consistent with the location of 7 d in the superelectrophilic region defined by p${K{{{\rm MeOH}\hfill \atop {\rm a}\hfill}}}$≤9.5–10.5. For comparison, the solvent contribution is negligible in the formation of the 1,3‐isomer 9 d‐Me, the p${K{{{\rm MeOH}\hfill \atop {\rm a}\hfill}}}$ (10.59) of which is situated on the upper limit of the boundary. Taking advantage of the simple relationship linking pKa values for σ complexation in methanol and water, a ranking of the triflone 7 d on the general thermodynamic scale constructed for Meisenheimer electrophiles in water is informative. An approximate calibration on the electrophilicity scale kinetically derived by Mayr et al. has also been made.
Retracted: Influence of an orifice on liquid–liquid two phase flow
Authors: Chakrabarti Dhurjati Prasad , Das Gargi , Das Prasanta Kumar 
Published: September 2009

AbstractThe present study aims an in depth investigation of liquid–liquid horizontal flow through an orifice. Initial studies have been directed to observe the influence of the orifice plate on the phase distribution of the two liquids in the pipe. The flow patterns have been identified using an optical probe along with photographic technique. The probability density function (PDF) analysis of the random signals obtained from the optical probe has been adopted to quantify the observations. The cross‐correlation function between the probe signals upstream and downstream of the orifice has been estimated to check the repeatability of the phenomenon. The inception of dispersion in the downstream section has been observed to occur in the stratified region of the upstream. The use of an orifice as a homogenizer as well as a feasible flow‐metering device for liquid–liquid flow has been encouraged by experimental results.
A neural network approach to predict activity coefficients
Authors: Ramírez‐Beltrán Nazario D. , Vallés Harry Rodríguez , Estévez L. Antonio , Duarte Horacio 
Published: September 2009

AbstractArtificial neural networks (ANNs) and a group‐contribution approach were used to develop an algorithm to predict activity coefficients for binary solutions. The Levenberg–Marquardt algorithm was used to train the ANN and to predict the parameters of the Margules equation. The ANN was trained using phase‐equilibrium database from DECHEMA. The selected systems include alcohols, phenols, aldehydes, ketones, and ethers. The trim mean based on 20% data elimination was selected as the best representation of the Margules‐equation parameters. The algorithm was validated with 121 VLE systems and results show that the ANN provides a relative improvement over the UNIFAC method.
Structural and Photophysical Properties of (Phosphane)gold(I)‐Decorated 4,4′‐Diethynyl‐2,2′‐bipyridine Ligands
Authors: Constable Edwin C. , Housecroft Catherine E. , Kocik Marzena K. , Neuburger Markus , Schaffner Silvia , Zampese Jennifer A. 
Published: September 2009

AbstractTreatment of 4,4′‐diethynyl‐2,2′‐bipyridine with R3PAuCl (R = Ph, 4‐Tol, Et, iPr) leads to the formation of a family of (phosphane)gold(I)‐decorated 4,4′‐diethynyl‐2,2′‐bipyridine ligands. The solid‐state structures of the compounds are significantly affected by the change from aryl‐ to alkyl‐substituted phosphanes, whereas the progression from ethyl to isopropyl substituents leads to a subtle change in the packing that results in the propagation of two different polymeric chain motifs, both supported by close Au···Au contacts [3.1239(1) Å for R = Et, and 3.395(1) Å for R = iPr]. In CH2Cl2 solution, each of the compounds 1–4 is a dual emitter at room temperature. When the excitation wavelength is approximately 238 nm, the emission spectra of 1 and 2 exhibit new bands at 288 and 570 nm at the expense of the original emissions. The photodegradation is not inconsistent with the formation of gold nanoclusters. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Aurora A, centrosome structure, and the centrosome cycle
Authors: Lukasiewicz Kara B. , Lingle Wilma L. 
Published: September 2009

AbstractThe centrosome, also known as the microtubule organizing center of the cell, is a membrane‐less organelle composed of a pair of barrel‐shaped centrioles surrounded by electron‐dense pericentriolar material. The centrosome progresses through the centrosome cycle in step with the cell cycle such that centrosomes are duplicated in time to serve as the spindle poles during mitosis and that each resultant daughter cell contains a single centrosome. Regulation of the centrosome cycle with relation to the cell cycle is an essential process to maintain the ratio of one centrosome per new daughter cell. Numerous mitosis‐specific kinases have been implicated in this regulation, and phosphorlyation plays an important role in coordinating the centrosome and cell cycles. Centrosome amplification can occur when the cycles are uncoupled, and this amplification is associated with cancer and with an increase in the levels of chromosomal instability. The aurora kinases A, B, and C are serine/threonine kinases that are active during mitosis. Aurora A is associated with centrosomes, being localized at the centrosome just prior to the onset of mitosis and for the duration of mitosis. Overexpression of aurora A leads to centrosome amplification and cellular transformation. The activity of aurora A is regulated by phosphorlyation and proteasomal degradation. Environ. Mol. Mutagen., 2009. © 2009 Wiley‐Liss, Inc.
High Performance Fuel Cell Operation with a Non‐fluorinated Polyphosphazene Electrode Binder
Authors: Muldoon J. , Lin J. , Wycisk R. , Takeuchi N. , Hamaguchi H. , Saito T. , Hase K. , Stewart F. F. , Pintauro P. N. 
Published: September 2009

AbstractNon‐fluorinated sulphonated polyphosphazene (SPOP) was synthesised and characterised for utilisation as an electrode binder. Polarisation curves were obtained at 80 °C and 95% RH in a H2/air fuel cell. SPOP has the proper properties for a cathode binder in a fuel cell, as its polarisation curve traced that of Nafion® binder for the same operating conditions.
Triumfettosterol Id and Triumfettosaponin, a New (Fatty Acyl)‐Substituted Steroid and a Triterpenoid ‘Dimer’ Bis(β‐D‐glucopyranosyl) Ester from the Leaves of Wild Triumfetta cordifolia A. Rich. (Tiliaceae)
Authors: Pergaud Sandjo Louis , Konga Simo Ingrid , Kuete Victor , Hannewald Paul , Yemloul Mehdi , Rincheval Vincent , Tchaleu Ngadjui Bonaventure , Kirsch Gilbert , Couty François , Schneider Serge 
Published: September 2009

AbstractTwo new triterpenoid derivatives were isolated from the leaves of wild Triumfetta cordifolia A. Rich. and identified to be a (fatty acyl)‐substituted steroid 1 and a triterpenoid saponin ‘dimer’ 2, named (3β)‐stigmasta‐5,22‐diene‐3,29‐diol 3‐propanoate 29‐triacontanoate and (2α,3β,19α)‐2,3,19‐trimethoxyurs‐12‐ene‐24,28‐dioic acid 24‐[(2α,3β)‐24,28‐bis(β‐D‐glucopyranosyloxy)‐2‐hydroxy‐24,28‐dioxours‐12‐en‐3‐yl] ester, respectively. These compounds were obtained together with a mixture of known sterols (stigmasterol/β‐sitosterol=(3β,22E)‐stigmasta‐5,22‐dien‐3‐ol/(3β)‐stigmast‐5‐en‐3‐ol) and trans‐tiliroside (3). The structures 1 and 2 were determined on the basis of NMR data (1H‐, 13C‐, and 2D‐NMR analyses) and mass spectrometry and confirmed by chemical transformations. The antimicrobial activities of trans‐tiliroside (3) against eight bacterial and two fungal strains were evaluated. This compound showed weak activities on some bacterial strains.
Clerodane and ent‐Kaurane Diterpene Glycosyl and Glycoside Derivatives from the Leaves of Casearia sylvestris
Authors: Wang Wei , Ali Zulfiqar , Li Xing‐Cong , Khan Ikhlas A. 
Published: September 2009

AbstractFive new clerodane diterpene glycosyl derivatives, caseariasides A–E (1–5, resp.) and three new ent‐kaurane diterpene glucosides, sylvestrisides C–E (6–8, resp.) were isolated from the leaves of Casearia sylvestris. Their structures were determined on the basis of chemical and spectroscopic analyses.
A New Hydrolyzable Tannin from Balanophora harlandii with Radical‐Scavenging Activity
Authors: Wang Wei , Zeng Shu‐Fen , Yang Chong‐Ren , Zhang Ying‐Jun 
Published: September 2009

AbstractOne new hydrolyzable tannin, 1‐O‐[(E)‐p‐coumaroyl]‐3‐O‐galloyl‐β‐D‐glucopyranose (1), was isolated from the rhizome of Balanophora harlandii, together with 18 known phenolic compounds. Their structures were determined by detailed spectroscopic analysis. Of the known compounds, 3‐O‐caffeoyl‐D‐glucopyranose (6) was obtained as a natural product for the first time, and compounds 2–6 and 8–19 were identified for the first time from this plant. The radical‐scavenging activity of the isolated compounds was tested by a DPPH assay.