bluuebunny/crossref_metadata_2025 huggingface dataset:
The Resolution of Enantiomeric Ibuprofen on Chiral Stationary Phases Containing N‐Arylcarbamoyl Derivatives of Phenylglycine
Authors: Lin Jer‐Yann , Yang Mei‐Hui
Published: May 2015

A series of fourteen anilide derivatives of ibuprofen were resolved on six chiral stationary phases (CSPs) derived from N‐arylcarbamoyl derivatives of (S)‐phenylglycine. Excellent chiral resolutions were achieved on these CSPs. The ionic‐type CSPs showed better chiral recognition abilities than the corresponding covalent‐type CSPs, and the CSP bearing two chiral centers has better performance than the CSPs bearing only one chiral center. The highest separation factor was achieved using the ionic‐type CSP bearing two chiral centers for the resolution of the 3,5‐dinitroanilide derivative of ibuprofen. This result is better than those reported in literature for the resolution of ibuprofen on the CSPs derived from amino acids, According to the chromatographic behaviors, the hydrogen bonding interaction, the π‐π interactions provided by the phenyl groups in CSPs bearing one chiral center, and the phenylethylcarbamoyl moiety in CSPs bearing two chiral centers dominate the chiral recognition.
Preconcentration and Determination of Copper(II) at a Chemically Modified Electrode Containing Salicylaldehyde Thiosemicarbazone
Authors: Chang Chin‐Hung , Liu Chuen‐Ying
Published: May 2015

A chemically modified electrode (CME) containing salicylaldehyde thiosemicarbazone (TSCsal) was evaluated for the ability to preconcentrate copper(II) prior to quantification by voltammetry. The CME has been used for the very sensitive and selective analysis of trace amounts of copper(II). A detection limit of 0.1 ppb was obtained by applying anodic stripping voltammetry with a flow system. The parameters that affect the sensitivity and possible interference by other ions or chelating agents have been examined in detail. The CME exhibits high stability and the response could be reproduced for four preconcentration‐determination‐renewal cycles [10ppbCu(II)] with a 2.87% relative standard deviation. The proposed method has been applied to the determination of copper(II) in tap water, drinking water, and NASS‐3 standard reference sea water samples. The results gave satisfactory recoveries.
15N NMR Study of Coordinated Amine, Aminocarbyne, and Carboxamido Groups in Triosmium Clusters
Authors: Chen Chun‐Ting , Chen Chi‐Cheng , Lin Su‐Ching , Hong Fung‐E , Lin Ying‐Chih , Lu Kuang‐Lien
Published: May 2015

The 15N NMR spectra of the complexes Os3(CO)10(μ2‐CONHPri)(μ2‐CNHR) (1a, R = Pr; 1b, R = CH2Ph) and Os3(CO)9(NH2Pri)(μ2‐CONHPri)(μ2‐CNHR) (2a, R = Pr; 2b, R = CH2Ph) are studied by using the 1H detected (inverse) 1H‐15N correlated spectroscopy. The 15N chemical shifts and the 1H‐15N coupling constants fall in characteristic regions for each of the coordinated amine, aminocarbyne, and carboxamido ligands and these values are related to their bonding types. The NMR data are discussed in terms of the influence of the paramagnetic term which is the major factor determining the chemical shifts. A comparison is made to understand the 15N chemical‐shift differences between the coordinated nitrogen‐containing ligands and the corresponding free organic molecules.
Reinvestigation of the Reaction of Sodium Borohydrate with Benzhydryl Halides under Solvolytic Conditions
Authors: Liu Kwang‐Ting , Huang Huei‐Chin
Published: May 2015

Solvolysis of benzhydryl halides in aqueous diglyme containing sodium borohydride was studied. Contrary to the literature, sodium borohydride was found not to be a convenient trap for benzhydryl carbocations, especially for those containing electron‐withdrawing substituent, and it decomposed appreciably in 80% aqueous diglyme at 45 °C. In addition, significant acceleration of reactions due to the presence of sodium borohydride was realized in the solvolysis of 3‐chloro‐ and 3‐trifluoromethyl‐benzhydryl chlorides.
Synthesis, Reactions, and Structure of 5‐Cyano‐4‐ethoxy‐1‐ethoxycarbonyl‐2‐methylazuleno[1,8‐b,c]pyran
Authors: Wu Chi‐Phi , Cheng Ling‐Yu , Wen Yuh‐Sheng , Hsiao Chwan‐Deng
Published: May 2015

Bicyclic azulene compounds, ethyl 4‐(cyanoethoxycarbonylmethyl)‐2‐methylazulene‐1‐carboxylate (2) and ethyl 4‐(cyanoethoxycarbonylmethyl)azulene‐1‐carboxylate (3) were prepared from ethyl 4‐chloro‐2‐methylazulene‐1‐carboxylate (7) and ethyl 4‐ethoxyazulene‐1‐carboxylate (8), respectively. Oxidation of 2 with DDQ gave the title compound, 5‐cyano‐4‐ethoxy‐1‐ethoxycarbonyl‐2‐methylazuleno[1,8‐b,c]pyran (1) and a minor compound, ethyl 4‐cyanomethyl‐2‐methylazulene‐1‐carboxylate (9). Oxidation of 3 by DDQ produced only ethyl 4‐cyanomethylazulene‐1‐carboxylate (10), Reaction of 1 with 100% H3PO4 at room temperature and 100 °C gave 5‐cyano‐4‐ethoxy‐2‐methylazuleno[1,8‐b,c]pyran (11) and 2‐methyl‐4,5‐dihydrozuleno[1,8‐b,c]pyran‐4‐one (12), respectively. All the new compounds were characterized by IR, UV‐vis, NMR and Mass spectra, and the structure of 1 was determined by X‐ray crystallography. Crystal data for 1; space group P21/n, a = 7.391(1), b = 9.660(5), c = 22.859(1) Å, B = 97.01(1)°, V = 1620.0(3) Å3, Z = 4, with final residuals R = 0.047 and Rw = 0.055.
The Constituents from the Stems of Annona cherimola
Authors: Chen Chung‐Yi , Chang Fang‐Rong , Wu Yang‐Chang
Published: May 2015

Thirty‐five compounds including twenty‐one alkaloids, lysicamine (1), liriodenine (2), atherospermidine (3), oxoxylopine (4), oxoanolobine (5), oxoglaucine (6), (‐)‐anonaine (7), (‐)‐asimilobine (8), (‐)‐xylopine (9), (‐)‐anolobine (10), (‐)‐norisocorydine (11), (+)‐laurotetanine (12), (+)‐isocorydine (13), (‐)‐N‐methylasimilobine (14), (+)‐N‐methyllaurotetanine (15), (‐)‐norushinsunine (16), (‐)‐ushinsunine (17), (‐)‐N‐formylanonaine (18), (+)‐stepharine (19), (+)‐orentaline (20), and (‐)‐kikemanine (21); four kauranes, ent‐kaur‐16‐en‐19‐oic acid (22), 16β‐hydroxy‐17‐acetoxy‐ent‐kauran‐19‐al (23), 17‐acetoxy‐16β‐ent‐kauran‐19‐oic acid (24), and 16β‐hydroxy‐17‐acetoxy‐ent‐kauran‐19‐oic acid (25); two amides, N‐trans‐femloyltyramine (26), and N‐trans‐caffeoyltyramine (27); one purine, adenosine (28); one lactam amide, squamolone (29); and six steroids, β‐sitosterol (30), stigmasterol (31), β‐sitostenone (32), stigmasta‐4,22‐dien‐3‐one (33), 6β‐hydroxy‐β‐sitosterone (34), and 6β‐hydroxystigmasterone (35) are isolated from the stems of Annona cherimola. These compounds were characterized and identified by physical and spectral evidence. Among them, (‐)‐norisocorydine (11) was elucidated as a new enantiomer with a levorotary configuration, which is isolated for the first time.
Base‐Catalyzed Keto‐Enol Tautomerism of Diazepam
Authors: Yang Shen K.
Published: May 2015

The hydrogens at 3‐position of diazepam, a frequently prescribed anxiolytic drug worldwide, undergo an efficient exchange with deuterium atoms in alkaline deuterated methanol. The position of deuterium exchange is confirmed by proton nuclear magnetic resonance and mass spectral analyses. A base‐catalyzed keto‐enol tautomerism is proposed to be responsible for the observed deuterium exchange. This finding has been applied to the preparation of tritium‐labeled diazepam in which only aromatic protons are labeled with tritium atoms. A tritium‐labeled diazepam lacking tritium atoms at 1 and 3 positions is valuable as a substrate for quantitative metabolism studies.
Denaturation of Adenosine Deaminase with Urea and Guanidine Hydrochloride
Authors: Moghaddamnia M. H. , Saboury A. A. , Hakimelahi G. H. , Moosavi‐Moovahedi A. A.
Published: May 2015

The denaturation effect of urea and guanidine hydrochloride on (lie adenosine deaminase has been investigated spectrophotometrically at the two temperatures of 27 °C and 37 °C at pH = 7.50, phosphate buffer (55 mM). A simple, reversible two stale transition, N ⇔︁ D, was used to analyze the denaturation process from which conformational stability was estimated using three different methods, namely, the linear extrapolation method (LEM), Tanford's model (TM), and the denaturant binding method (DBM). A good agreement was observed among these methods. The results from free energy of denaturation at zero concentration of denaturant, ΔG°H2O, show the fragile conformation for adenosine deaminase molecule.
Electrochemical Characterizations of NaY Zeolite‐Entrapped Copper Dicyanoanthraquinone Diimines
Authors: Chang Jun‐Shang , Liu Lilian‐Kao , Wang Chong‐Mou
Published: May 2015

Intrazeolite copper dicyanoanthraquinone diimines (NaY/Cu(DCNAQI) were synthesized within NaY zeolite using a “ship‐in‐a‐bottle” technique. These particles were subjected to CV and EIS characterizations based on their associated particulate electrodes. Analysis of the EIS over a wide range of frequency and at potentials around the formal potential of DCNAQI0/− showed that the charge transfer resistance and the double layer capacitance in the equivalent circuit based on the Fletcher transmission lines were sensitive to the probing potential and the concentration of the free DCNAQI coexisting in the electrolyte solutions. Although CV does not provide much information about the influence of hydrogen on NaY/Cu(DCNAQI), the EIS characterizations suggested hydrogen can significantly accelerate the charge transfer kinetics for most NaY/Cu(DCNAQI) particles.
The Generalized Parameterization Procedure for Semiempirical MO Method and Calculation of ionization Potentials for the Fourth‐Period Element Molecules
Authors: Lu Li‐Hwa , Chen Cheng , Sun Kuang‐Chung
Published: May 2015

This study presents a set of the generalized parameters from a unique resource for the elements which are from the first‐period to the fourth‐period (H to Xe). In addition, these series of parameters are used to examine forty‐five compounds consisting of the fourth‐period elements and the second‐period transition metal elements. Herein, the major calculation theory applied is the s‐p‐d INDO MO method.

To verify the reliability of the molecular calculations, similar calculations of the STO‐3G and STO‐3G* ab inito methods, along with the semiempirical PM3 and AM1 methods are also compared. Results in this study demonstrate that the s‐p‐d INDO MO computed with the generalized parameter is the best available method.
Theoretical Studies of Proton Transfer Reactions—Energy Barriers and the Marcus Equation
Authors: Chu Chih‐Hung , Ho Jia‐Jen
Published: May 2015

The reactants, ion‐dipole complexes, transition states, and products for the proton transfer reactions HBCOH+ + OCXH → HBCO + +HOCXH optimized at the SCF/4–31G* level of theory for B, X = F, Cl, H, CH3, CH2Cl, CHCl2 and CCl3 are studied. The intrinsic barrier ΔE*BX correlates with the degree of the O‐O bond contraction in the transition structure. Both intrinsic and overall barriers can be predicted with the aid of Marcus theory. Progressive degrees of chlorination of the alkyl group in B produce decreases in the barrier to proton transfer from HBCOH+ to OCXH and increases in the reverse transfer barriers. These changes can be quantitatively reproduced by the Marcus equation for all systems.
Regio‐ and Stereocontrolled Nucleophilic Addition Reactions of An Unsymmetrically Disbustituted Butadiene η4‐Molybdenum Cationic Complex
Authors: Chou Shang‐Shing P. , Sheng Hui‐Tuo
Published: May 2015

The reactions of a new cationic complex, [Cp(CO)2Mo(η4‐2‐methyl‐3‐SPh‐C4H4)]+ PF−6 (3), with carbon, hydride, and nitrogen nucleophiles were found to give only the C‐1 addition products in good yield. The X‐ray crystal structures of two of the addition products 4a and 4e confirm the regio‐ and stereochemistry of the nucleophilic additions.
Ene Reaction of Pummerer‐Type Reaction Intermediate and Synthesis of Achillea Amide
Authors: Lee Huey‐Jy , Wang Huey‐Min , Chen Ling‐Ching
Published: May 2015

Pummerer‐type reaction intermediate 2 of methyl α‐(methylthio)acetate (1) has been found to react with 1‐alkenes to afford ene adducts 3. Achillea amide 5 was synthesized from the adduct 3g.
Formation Mechanism of Polyaniline: Evidence from the Post‐Reactions of Isolated Intermediates
Authors: Chiou Yeong‐Han , Wu Chun‐Guey
Published: May 2015

The formation mechanism of Polyaniline was derived from the post reactions of the polymerization intermediate. The intermediate, RPAN, (3000 Å thickness film, purplish‐blue in color) was isolated on silane modified substrates after polymerization for 10 minutes. Under air, RPAN converts to emeraldine salt within a couple of seconds. In the inert atmosphere, the conversion occurred at a relatively low speed. In acidic media, the intermediate was believed to be a very reactive radical cation, which oxidized then coupled with aniline oligomers to start the auto‐catalytic chain growing process. When the radical cation was quenched in water or acid, a violet species, IPAN, with a structure composed mostly of pernigraniline units, was formed. IPAN reacts slowly with aniline oligomers in the presence of protons and oxidants to emeraldine. The conversion processes were monitored by IR and Uv/Vis/NIR spectroscopy.
Electron Impact Mass Spectra of Some Arylpyridines
Authors: Lin Shaw‐Tao , Yang Fu‐May , Liang David , Shiao Min‐Jen
Published: May 2015

The mass spectra of 56 arylpyridines were studied under EI conditions. The fragmentations of this series of compounds are relatively simple because of a stable skeleton containing two aromatic rings. The orientations of cleavage of the methoxyl and methoxycarbonyl groups strongly depend on their position on the pyridine ring and can be applied to the differentiation of the isomers.
Chemical Constituents of Neolitsea parvigemma and Neolitsea konishii
Authors: Chen Keh‐Shaw , Chang Fang‐Rong , Chia Yi‐Chen , Wu Tian‐Shung , Wu Yang‐Chang
Published: May 2015

Twenty‐four compounds including three flavonoids, kaempferol‐3‐O‐rhamnoside (1), quercetin‐3‐O‐rhamnoside (2), and taxifolin‐3‐O‐rhamnoside (3); three ferulates, docosanylferulate (4), tetracosanylferulate (5), and hexacosanylferulate (6); two cyclohex‐2‐en‐1‐ones, blumenol A (7), and roseoside (8); two sesquiterpenes, zeylanidine (9), and zeylanicine (10); four triterpenes, lupeol (11), lupenone (12), taraxerol (13), and taraxerone (14); one steroid, β‐sitosterol (15); one amide, N‐trans‐feruloylmethoxytyramine (16); eight alkaloids, roemerine (17), actinodaphnine (18), N‐methylactinodaphnine (19), glaucine (20), and oxoglaucine (21), boldine (22), corydine (23) and methoxyannomontine (24) were isolated from Neolitsea parvigemma and N. konishii. These compounds were characterized and identified by physical and spectral evidence. Among them, compounds 1, 2, 3, 4, 5, 6, 7, 8, 13, 14, 16, 20, 21, 23, and 24, were isolated for the first time from this genus. This finding is useful as a basis for chemotaxonomy.
Electrocatalytic Oxidation of Amines to Nitriles on a TEMPO‐modified Graphite Felt Electrode (TEMPO = 2,2,6,6‐tetramethylpiperidin‐1‐yloxyl)
Authors: Kashiwagi Yoshitomo , Kurashima Futoshi , Kikuchi Chikara , Anzai Jun‐Ichi , Osa Tetsuo , Bobbin James M.
Published: May 2015

Preparative electrocatalytic oxidation of amines to nitriles was successfully achieved on a poly (acrylic acid)‐coated graphite felt electrode immobilizing 4‐ammo‐2,2,6,6‐tetramethylpiperidin‐1‐yloxyl in high selectivity (> 95%) and high current efficiency (> 92%).
Intramolecular Cycloaddition of Nitrones and Nitrile Oxides with Sulfur‐Substituted Dienes and Its Synthetic Applications
Authors: Chou Shang‐Shing P. , Yu Yu‐Ju
Published: May 2015

A series of sulfur‐substituted dienyl nitrones and oximes were conveniently prepared from the 3‐sulfolene precursors. Regiospecific intramolecular 1,3‐dipolar cycloadditions of nitrones and nitrile oxides with sulfur‐substituted dienes have been efficiently carried out from the suitable 3‐sulfolene precursors. The stereochemistry of the cycloaddition of nitrones depends on the structure of the substituent (sulfide or sulfone) on the diene as well as on the chain length connecting the diene and nitrone. The fused bicyclic products obtained from these reactions have been converted to some interesting heterocyclic compounds which have the useful structure of vinyl sulfide or sulfone.
Laser Desorption Ionization of Melamine and Identification of Fragmentation Channels from Ion Velocity Distribution Measurements
Authors: Han Chau‐Chung , Wang Ru‐Wen , Lee Tieh‐Sheng
Published: May 2015

Fragmentation frequently accompanies intact laser desorption ionization of a parent non‐volatile compound, desorption and dissociation dynamics has been a subject of intense studies over the past decade. As a preliminary lest system for future laser desorption study of energetic compounds such as explosives and propellents, we studied UV laser desorption ionization of melamine at a laser power density of approximately 4.4 MW/cm2. Several gas‐phase dissociation channels of the parent and fragment ions formed in UV laser desorption ionization of melamine films can be identified from their velocity distributions. A phenomenological desorption temperature of the order of 20000 K is estimated from fitting the experimental velocity distributions to Maxwellian functions.
Chaperone Function of Rat Lens α‐Crystallin
Authors: Ho Yuh , Hsu Ming‐Ching , Huang Fu‐Yung
Published: May 2015

A solution of γ‐crystallin became turbid upon beating at 65 °C for 30 minutes; however, addition of α‐crystallin suppressed this thermal aggregation. It was found the effective chaperone function could be achieved with the molar ratio of α/γ greater than 1/20. In terms of crystallin subunit, five molecular α‐crystallin subunits could afford chaperone for one molecular γ‐crystallin. The gel filtration profile of the sample solution, containing α‐ and γ‐crystallins and preincubation at 65 °C for 30 minutes, showed complex formation between α‐ and γ‐crystallins, indicating α‐crystallin was bound to thermally denatured γ‐crystallin. A 1‐anilinonaphthalene‐8‐sulfonic acid (ANS) fluorescence study showed that α‐crystallin has more hydrophobic regions exposed after thermal incubation. In the presence of urea, both the α‐crystallin chaperone activity and the ANS fluorescence intensity decreased. Accordingly, hydrophobic regions of α‐crystallin play an indispensible role in its chaperone activity.
Diastereoselective Cyclopropanation Utilizing a New Chiral N,O‐Acetals Prepared by Electrochemical Oxidation of Carbamates
Authors: Matsumura Yoshihiro , Asano Tsuyoshi , Nakagiri Takeshi , Onomura Osamu
Published: May 2015

A new chiral bicyclic tetrahydropyridine derivative was synthesized from L‐lysine derivatives utilizing electrochemical oxidation as a key step. Allyl alcohols were incorporated into the tetrahydropyridine derivative to afford N,O‐acetals, and the reaction of the resulting N,O‐acetals with a carbenoid, which was generated from Et2Zn and CH2l2, yielded cyclopropanated products in moderate diastereoselectivities.
Crystal Structure and Magnetic Properties of Pyridyl‐Substituted Nitronyl Nitroxides
Authors: Lee Chin‐Jhan , Wei Ho‐Hsiang , Lee Gene‐Hsiang , Wang Yu
Published: May 2015

X‐ray crystal structure and cryomagnetic properties of three organic radicals, 2‐(2‐pyridyl)‐4, 4,5,5‐tetramethyl‐4,5‐dihydro‐1‐H‐imidazol‐1‐oxyl‐3‐N‐oxide(NIT‐oPy) 1, 2‐(3‐pyridyl)‐4,4,5,5‐tetramethyl‐4,5‐dihydro‐l‐H‐imidazol‐1‐oxyl‐3‐N‐oxide(NIT‐mPy) 2 and 2‐(6‐methyl‐2‐pyridyl)‐4,4,5,5‐tetramethyl‐4, 5‐dihydro‐1‐H‐imidazol‐1‐oxyl‐3‐N‐oxide(NIT‐6M‐oPy) 3 were investigated. The crystal structures of compounds 1‐3 show the same feature of a P21/c space group of a monoclinic system. Two crystallographically independent molecules were found in the crystals of compounds 1‐3. The temperature dependence of magnetic susceptibility of compounds 1‐3 revealed an intermolecular antiferromagnetic exchange interaction.
The Synthesis and Chemistry of 8‐Substituted Bicyclo[5.1.0]oct‐1(8)‐ene
Authors: Lee Gon‐Ann , Chen Calvin Ping‐Kuang , Chen Mei‐Yun
Published: May 2015

8‐Bromobicyclo[5.1.0]oct‐1(8)‐cne (7), an intermediate for the preparation of 8‐substituted bicyclo[5.1.0]oct‐1(8)‐enes, was synthesized by denomination of 1,8,8‐tribromobicyclo[5.1.0]octane (6). Compound 7 underwent bromo‐lithium exchange followed by nucleophilic substitution reactions to generate bicyclo[5.1.0]oct‐1(8)‐ene (5), 8‐methylbicyclo[5.1.0]oct‐1(8)‐ene (10), and 8‐trimethylsilylbicyclo[5.1.0]oct‐1(8)‐ene (11). The bicyclic cyclopropenes 7, 5, 10, and 11 reacted with cyclopentadiene to form adducts 12, 13, 14, and 15, respectively. All of these Diels‐Alder adducts are endo‐exo isomers (endo‐addition from the view of the cyclopropene and exo‐addition from the view of the cyclooctene).
Preparation of 3‐(3′‐,4′‐Hydroxyphenyl)sydnones
Authors: Tien Hsien‐Ju , Yeh Mou‐Yung , Huang Ded‐Shih , Wu Yi‐Lung , Kuo Wen‐Fa , Chang Wen‐Kuen , Chang Jing‐Chyi
Published: May 2015

3‐(3′‐,4′‐Hydroxyphenyl)sydnones were prepared by dealkylation of 3‐(3′‐,4′‐alkoxyphenyl)sydnones with concentrated sulfuric acid at room temperature in a range of 59 to 86% yield.
“Sock‐Ball” Chromatographic Separation of High Molecular Weight Fullerenes with Sock‐Shaped Stationary Phase
Authors: Chang Cheng‐Shyong , Tsai Hou‐Jen , Den Tschau‐Gan
Published: May 2015

A method for “Sock‐Bail” chromatographic separation of high molecular weight fullerenes is described. A prepared sock‐shaped stationary phase (Sock‐SAF‐phase) was used for HPLC separation of several polycyclic aromatic hydrocarbons (PAHs) and fullerenes. Fullerenes, as ball‐shaped molecules, are much more strongly retained than PAHs on this stationary phase and have the eluted order C50 < C70 < C76 < C78 < C84 in the mobile phase of n‐hexane/dichloromethane (100/0 ∼ 80/20). In contrast, chromatography on the corresponding unmodified silica phase or SC‐3OH‐phase (an intermediate phase of Sock‐SAF‐phase) gave no separation of fullerenes. This fact indicated that the separation of fullerenes on Sock‐SAF‐phase was related to the selective interaction with the sock moiety.
Reactions of (η6‐Arene)tricarbonylchromium Complexes: Hydrogenation, Nitration, and Bromination
Authors: Own Z. Y.
Published: May 2015

In this study, we explore the reactions of coordinated arenes, e.g., hydrogenation, nitration, and bromination, to prepare compounds which are not accessible from conventional organic synthesis. The reaction products formed from reactions with the coordinated and the uncoordinated arenes are compared. The polycyclic aromatic hydrocarbons (PAHs) employed for this study include phenanthrene, methyl‐ and acetyl‐phenanthrene, and benz[a]anthracene (BA), The tricarbonylchromium group demonstrated various characteristics which influence the reactions in this work, such as an electronic effect to deactivate hydrogenation, a steric effect to exhibit, highly positional selective nitration, and a free radical mechanism to direct bromine to attack at the ring coordinated to tricarbonylchromium.
Oxidation‐Induced Structural Alterations and Its Effect on Chaperone Function of Rat Lens α‐Crystallin
Authors: Ho Yuh , Lai Chien‐Lin , Huang Fu‐Yung
Published: May 2015

An ascorbate‐FeCl3‐EDTA‐H2O2 system was used to oxidize rat lens α‐crystallins. Under this oxidative insult, the chaperone activity of α‐crystallin toward γ‐crystallin was shown to decrease significantly, which is quite different from the result reported by Wang and Spector. (Invest. Ophthalmol. Vis. Sci. 1995, 36, 311‐321.) Fluorescence spectroscopy and circular dichroism were employed to characterize the structural changes of oxidized α‐crystallin. It was found that fluorescence intensity of l‐anilinonaphthalene‐8‐sul‐phonate (ANS) bound to oxidized α‐crystallin increased comparing to that bound to normal α‐crystallin, suggesting oxidation causes the exposure of more hydrophobic regions. Further, α‐crystallin's fluorescence intensity in response to tryptophan residues showed a pseudo first order decline. Amino acid analysis of normal versus oxidized α‐crystallin confirmed actual decline in tryptophan levels, showing about 80% of tryptophan being modified after 10‐hour oxidation. Circular dichroism showed both changes in the secondary and tertiary structures of oxidized α‐crystallin, characterized by a large loss of aromatic‐type amino acid interactions and a large loss of β‐sheet structure. In conclusion, modified tryptophan, secondary and tertiary structural changes of α‐crystallin correlate best with the reduction of chaperone function, the curves all showing a linear slope for 10 hours, then plateauing. These results indicate that the decrease of α‐crystallin chaperone activity is attributed to the structural changes.
The Effect of Lithium Ion on the Regioselectivity of Substitution Reactions of Zinc Sulfolenylate
Authors: Chou Ta‐Shue , Chang Chin‐Jyh
Published: May 2015

The addition of lithium cation to zinc sulfolenylates significantly changes the regioselectivity of its reaction toward carbonyl electrophiles. The more lithium salt is added, the more the reactions prefer to take place at the α‐position of the sulfolenylate.
Synthesis and Crystal Structure of (η2‐Olefin)(N‐phenyl‐2,3‐dicarbomethoxy‐7‐azabenzonorbornadiene)Fe(CO)2 Complexes
Authors: Sun Chia‐Hsing , Wu Shiao‐Yu , Liou Lin‐Shu , Wang Ju‐Chun
Published: May 2015

The title compounds 2a‐f were obtained from photochemical substitution of 1 with alkenes as stable solids in moderate yields. X‐ray structure determination of 2c shows a distorted trigonal bipyramidal geometry with two cross iron‐coordinated olefins. Compounds 2a‐f represent a new type of (η2‐monoolefin)2(R3N)Fe(CO)2.
Kinetic and Mechanistic Studies of Intercalation in Lamellar Hosts Using Time‐Resolved X‐Ray Diffraction
Authors: O'Hare Dermot , Evans John S. O. , Price Stephen
Published: May 2015

Energy dispersive X‐ray diffraction (EDXRD) has been used to perform in‐situ kinetic studies on the intercalation of a range of guest molecules in layered lattices. The kinetics of the intercalation of cations {K+, PyH+ (Py = C5H5N), NMe+4} and the long chain ammonium ions C12TMA, C16TMA, C18TMA (C12TMA = dodecyltrimethylammonium, C16TMA = hexadecyltrimethylammonium and C18TMA = octadecyltrimethylammonium) into crystals of MnPS3 have been determined. These reactions are very fast and in some cases novel transient phases are observed. The rate of cobaltocene, Co(η‐C5H5)2, intercalation in layered dichalcogenides ZrS2, 2H‐SnS2, 2H‐SnSe2, 2H‐TaS2, 2H‐NbS3, 1T‐TaS2 and TiS2 has also been investigated. Integrated intensities of the Bragg reflections have been used to determine the extent of reaction, (α), versus time for each of these reactions. A number of kinetic models have been considered, including the Avrami‐Erofeyev (m = 1.5) deceleratory nuclei‐growth model and statistical simulation. The concentration and solvent dependence of the rate of Co(η‐C5H5)2 intercalation into 2H‐SnS2 has also been determined. Surprisingly we find that the rate of intercalation is invariant to the initial Co(η‐C5H5)2 concentration over a wide concentration range.
Novel Water‐Soluble 4,4‐Disubstituted Ruthenium(III)‐Salen Complexes in DNA Stranded Scission
Authors: Cheng Chien‐Chung , Lu Yen‐Ling
Published: May 2015

Salen‐type Ru(III) complexes are found to be capable of reacting with physiologically acceptable oxidants. The water solubility and DNA affinity of these Ru(III)‐salen complexes are enhanced by the utilization of a variety of charged groups through the formation of peptide bonds. In the presence of hydrogen peroxide, modified Ru(III)‐salen complexes are capable of nicking DNA. In addition, the reactivity in DNA cleavage increases along with the total number of positive charges retaining in Ru(III)‐salen complexes and less influence in the electronic effect. Using 32P‐end‐labeled oligonucleotides and high resolution polyacrylamide gel electrophoresis, Ru(III)‐salen complexes are found to randomly cleave DNA regardless of the DNA secondary conformation such as bulge, inter‐loop, or double‐stranded regions. The possible reactive species of Ru(III)‐salen complexes in DNA cleavage is considered as the hydroxyl radical and high valent oxoruthenium(IV) species according to the UV titration, quenching studies, and reaction with varied oxidants.
Ene Reaction with Pummerer‐Type Reaction Intermediate of 1‐[(2‐Methylthio)ethanoyl]pyrrolidine: A Novel Synthesis of Trichonine
Authors: Sun Kuo‐Hui , Wang Huey‐Min , Chen Ling‐Ching
Published: May 2015

Pummerer‐type reaction intermediate 2 of 1‐[(2‐methylthio)ethanoyl]pyrrolidine (1) has been found to react with 1‐alkenes to afford ene adducts 3. Trichonine 4 was synthesized from the adduct 3g.
Meso‐Chloro‐Substituted Indodicarbocyanines: Aggregate Behavior, Electrochemical Properties, Crystal Structure and Photographic Performance
Authors: Dai Zhi‐Fei , Peng Bi‐Xian , Fan Lou‐Zhen , Li Yong‐Fang
Published: May 2015

The correlation of photographic performance of meso‐chloro‐substituted indocarbocyanine dyes having different substituent groups with their electrochemical properties and aggregation behavior in solutions and crystals and on emulsion grains was investigated. The experimental results indicate that the dyes form easily H‐rather than J‐aggregates no matter what they arc on AgBrI emulsions or in solutions and crystals. All the lowest vacant electronic energy level of the dyes, ELV, are much lower than the energy of conduction band of AgBrI (ECB)(‐3.23 ev), so it is very easy for the dyes to trap electrons from the surface of silver halide, leading to strong desensitization by the electron‐trapping process. The desensitization by the dyes depends fundamentally on their amount and structure, especially on the nature of substituents.
Two‐Photon Absorption and Excited‐State Refractions in Anthraquinone Dyes
Authors: Tiao C. J. , Hwang L. C. , Wen T. C.
Published: May 2015

We examine the nonlinear optical properties of solutions of 9,10‐anthraquinone, 1,4‐dihydroxy‐anthraquinone, 5,8‐dichloro‐1,4‐dihydroxy‐anthraquinone and 1,4‐bisethylamino‐anthraquinone by means of the intensity‐dependent transmission and the Z‐scan method with 532 nm 8 ns pulses. The results demonstrated that the 9,10‐anthraquinone displayed a two‐photon absorption (TPA) character. The molecular TPA cross section of this compound is estimated as σ2 = 7.22 × 10−19 cm4/GW or σ2 = 26.96 × 10−48 cm4/photon/s, respectively, and an essential state of ‘m1Ag’, which should be located near the 2ω virtual transition state, is predicted. On the other hand, the effective excited‐state nonlinear refractive coefficients n2eff of these anthraquinones are found to be ∼10−10 esu, which are comparable with those highly conjugated planar molecules of tetrabenzporphyrins and phthalocyanines.
Thermodynamic Studies on the Interaction of Cobalt with Alpha‐Amylase
Authors: Saboury A. A. , Umar Dahot M. , Ghobadi S. , Chamani J. , Moosavi‐Movahedi A. A.
Published: May 2015

The interaction of α‐amylase from Bacillus amyloliquefaciens with divalent cobalt ion was studied by equilibrium dialysis and isothermal titration microcalorimetry methods at 27 °C in neutral solution at pH = 7.0. A new equation with a useful graphical method, very similar to the Scatchard plot was introduced to obtain a dissociation equilibrium constant using microcalorimetric data. The constant is remarkably like that obtained from a normal Scatchard plot, which uses equilibrium dialysis data. The enzyme activity increased significantly with an increasing concentration of cobalt; however, the temperature of denaturation of the enzyme decreased.
Cellulase Activity in Different Buffering Media During Waste Paper Hydrolysis by HPLC
Authors: Cheng Cheanyeh
Published: May 2015

The activity of cellulase has traditionally been described by pH and temperature; however, the buffering medium is also an important factor, Taking plain water as a reference medium, three kinds of buffer including KH2PO4/K5HPO4, citric acid/sodium citrate, and acetic acid/sodium acetate were adopted to survey their effects on the activity of cellulase. Chromatographic assays indicated that xylose, glucose, and cellobiose were the major products and that minor products such as cellotriose and cellotetraose were present in some cases. The activities of cellulase based on glucose production showed that the phosphate buffer acted as a deactivator for cellulase and each of the two organic acid buffers acted as activators for cellulase. The concentration of activation buffer should be high to reach a high cellulase activity; however, this effect would be compensated for by the product inhibition of cellulase. The highest activity obtained was 4.16 ± 0.08 (× 10−3) IU mg−1 for the citric acid/sodium citrate buffer under pH 4.80, 40 °C and an agitation speed of 150 rpm.
Effects of Titania on the Adsorptive and Catalytic Properties of Silica‐Supported Cobalt Catalyst
Authors: Ho Sui‐Wen , Chen Wei‐Ting , Wu Dai‐En
Published: May 2015

A series of Ti‐promoted (6 wt%) Co/SiO2 catalysts with titania content of 0 to 10 wt% were sequentially prepared by incipient wetness impregnation, and characterized with X‐ray diffraction, thermogravimetric analysis, chemisorption, temperature‐programmed desorption and infrared spectroscopy. The influences of Ti addition and reduction temperature (400–700 °C) on the adsorptive behavior and the catalytic properties for CO hydrogenation were investigated. The presence of Ti decreases the adsorption capacity of the cobalt surface for H2, but enhances activity per gram cobalt. In addition, the turnover frequency increases 2–4 times upon Ti addition at reduction temperatures of 400–700 °C. The promotion in activity is accompanied by an enhanced selectivity for higher hydrocarbons and olefins. These modifications can be rationalized by the creation of active sites for CO dissociation. The desorption of CO2 at 100 °C during temperature‐programmed desorption of CO indicates the formation of active sites for CO disproportionation. Infrared spectroscopy indicates an increase in the relative absorbance of 2060–2075 cm−1 bands upon Ti addition, which are attributed to CO adsorbed on the defect sites of the cobalt surface. Therefore, the promotion effect of Ti may be directly related to the formation of defect sites on the cobalt surface induced by the decorated titania moieties.
Kinetics of the Base‐Catalysed Isomerization of trans‐meso‐CH3Co(H2O)L2+ (L = 5,7,7,12,14,14‐Hexamethyl‐1,4,8,11‐tetraazacyclotetradeca‐4,11‐diene)
Authors: Lee Shaoyung , Hung Chia‐Hsi
Published: May 2015

The isomerization of the complex trans‐meso‐CH3Co(H2O)L2+ (L = 5,7,7,12,14,14‐hexamethyl‐1,4,8,11‐tetraazacyclotetradeca‐4,11‐diene) to trans‐primary, rac‐CH3Co(H2O)L2+ has been investigated from pH range 7.11 to 8.09 in aqueous solution. The reaction rate law has been determined as: ‐d[meso‐CH3Co(H2O)L2+]/dt = kOH [OH−][meso‐CH3Co(H2O)L2+], where kOH = 600 ± 10 M−1s−1 at 25 °C and μ = 0.5 M. The activation parameters of the reaction were also studied with ΔH± = 19.1 ± 0.9 Kcal mol−1 and ΔS± = 18.0 ± 0.8 cal K−1mol−1. A mechanism that involves a secondary NH inversion is proposed.
The Constituents from the Leaves of Magnolia coco
Authors: Yu Hsi‐Jung , Chen Chien‐Chih , Shieh Bor‐Jinn
Published: May 2015

Eighteen compounds including fourteen lignans, one coumarin, and three alkaloids were isolated from the leaves of Magnolia coco. Their structures were established by comparison of spectral data with literature values. Among them, N‐acetylanolobine was elucidated as a new compound.
Determination of Antimony in Sediments by Zeeman‐Corrected Electrothermal Atomic Absorption Spectrometry with Ultrasonic Slurry Sampling
Authors: Mierzwa Jerzy , Sun Yuh‐Chang
Published: May 2015

A method was developed for the determination of antimony in slurried sediments (on the basis of samples of three Certified Reference Materials) by electrothermal atomic absorption spectrometry (ETAAS) with Zeeman‐effect background correction. Slurried samples were prepared in 6% nitric acid containing 0.02% of Triton X‐100. A mixed palladium/magnesium chemical matrix modifier, L'vov platform atomization and a temperature‐time program with a relatively short (10 s) sample pyrolysis stage were used.

The results of the determinations by this technique are in very close agreement with certified values and the repeatability of this analytical procedure expressed in terms of relative standard deviation was typically better than 9% at the slurry concentration of approx. 90 mg/2 mL. The characteristic mass of Sb (at the spectral line 231.1 nm) was 25.6 pg and the limit of detection (calculated for 100 mg/2 mL slurry) was about 0. 04 μg/g.
The Synthesis of New Type Bisazo Compounds Using 4‐Hydroxy‐2,2,6,6‐Tetramethyl‐l‐Piperidinyloxyl as The Phase‐Transfer Dehydrogenation Catalyst
Authors: Wang Xiao‐Yang , Wang Yu‐Lu , Zhang Zi‐Yi , Li Jian‐Ping , Wang Cai‐Lan
Published: May 2015

Using 4‐hydroxy‐2, 2, 6, 6‐tetramethyl‐l ‐piperidinyloxyl as the phase‐transfer dehydrogenation catalyst to prepare bisazo compounds is reported for the first time. Nine bisaryl carbodiazones were synthesized in high yields under mild conditions. This method was efficient, convenient and rapid. A possible mechanism was suggested by a nitroxide free radical which acted on aryl substituted carbazides to form azo compounds.
New Approaches for Solving Crystal Structures from Powder Diffraction Data
Authors: Harris Kenneth D. M.
Published: May 2015

The determination of crystal structures from single crystal diffraction data can generally be carried out routinely and straightforwardly. However, many crystalline solids can be obtained only as microcrystalline powders and are not suitable for investigation by conventional single crystal diffraction methods. In the past, this problem has limited the ability to elucidate the structural properties of such materials. For the wide range of materials in this category, there is clearly a pressing need to develop and exploit techniques that allow crystal structures to be solved from powder diffraction data. Although traditional techniques for structure solution from powder diffraction data have been applied successfully in several cases, these techniques have certain intrinsic limitations, and for the case of organic molecular crystals the challenges that must be overcome are particularly severe. For these reasons, our recent research has focused on the development and implementation of new methodologies for structure solution from powder diffraction data, leading to new “direct‐space” techniques for structure solution in which a hypersurface based on the profile R‐factor is searched using Monte Carlo or Genetic Algorithm techniques. This paper presents a brief overview of the problems and challenges associated with structure solution from powder diffraction data. The foundations of the techniques that we have developed are described, and illustrative examples (from the field of organic molecular crystals) are given to highlight the application of these techniques.
Cheritamine, A New N‐Fatty Acyl Tryptamine and Other Constituents from the Stems of Annona cherimola
Authors: Chen Chung‐Yi , Chang Fang‐Rong , Teng Che‐Ming , Wu Yang‐Chang
Published: May 2015

A new N‐fatty acyl tryptamine, cheritamine (30), along with thirty‐two compounds including nineteen benzenoids, p‐hydroxybenzadehyde (1), p‐hydroxybenzoic acid (2), methylparabene (3), 3‐chlorobenzoic acid (4), vanillin (5), isovanillin (6), vanillic acid (7), isovanillic acid (8), methyl vanillate (9), methyl isovanillate (10), syringaldehyde (11), syringic acid (12), 3,4,5‐trimethoxybenzoic acid (13), trans‐methyl p‐coumarate (14), ferulic acid (15), p‐dihydrocoumaric acid (16), 3‐(4‐hydroxy‐3,5‐dimethoxyphenyl)‐1,2‐propanediol (17), 3,4,5‐trimethoxyphenyl‐β‐D‐glucopyranoside (18) and thalictoside (19); one p‐quinone, 2,6‐dimethoxy‐p‐quinone (20); one purine, uridine (21); eight alkaloids, nicotinic acid (22), thalifoline (23), doryphornine (24), (–)‐norstephalagine (25), (‐)‐romucosine (26), (+)‐pronuciferine (27), (+)‐norisocorydine (28) and oxoasimilobine (29) and three steroids, β‐sitosterol‐D‐glucoside (31), stigmasterol‐D‐glucoside (32) and 6′‐(β‐sitosteryl‐3‐O‐β‐glucopyranosidyl)hexadecanoate (33), are isolated from the stems of Annona cherimola. These compounds were characterized and identified by physical and spectral evidence.
A Simple, Efficient and New Method for Preparing N‐Aryl‐2‐Phenyldiazenecarboxamide
Authors: Wang Cailan , Wang Yulu , Wang Xiaoyang , Li Jianping , Wang Hong
Published: May 2015

Using ferric chloride to oxidize aryl substituted semicarbazide for preparing azo compounds has been described for the first time in this paper. Nine azo compounds have been synthesized in a good to excellent yield (≥88%). This method only needs cheap reagents, simple instruments and a short reaction time.
Secolridoids Glycosides from Jasminum amplexicaule
Authors: Shen Ya‐Ching , Lin Tain‐Tsair , Lu Tsung‐Ying , Hung Shu‐Ee , Sheu Jyh‐Horng
Published: May 2015

In addition to jaslanceosides B (1) and E (2), and jasminoside (3), a new secoiridoid glucoside, isojasminoside (4) was isolated from the leaves of Jasminum amplexicaule (Oleaceace). The structure of 4 was determined on the basis of spectral analysis and chemical reactions. Chemotaxonomy for some selected plants in Jasminum is also discussed.
Chemo‐Enzymatic Synthesis of Optically Active Amino Acids and Peptides
Authors: Chen Shui‐Tein , Wang Kung‐Tsung
Published: May 2015

The industrial alkaline protease, alcalase, is stable and active in a high concentration of organic solvents and useful as a biocatalyst for (i) diastereoselective hydrolysis of peptide esters and preparation of racemization‐free peptides; (ii) selective incorporation of esters of D‐amino acid into peptides in t‐butanol via a selective hydrolysis of esters of D,L‐amino acid, followed by using the unhydrolyzed D‐esters as a nucleophile in a kinetically controlled peptide bond formation; (iii) resolution of esters of amino acid in 95% t‐butanol/5% water, followed by saponification of the unreacted esters to offer both enantiomers with high yield and optical purity; (iv) completely resolve amino‐acid esters with high yield and optical purity via in situ racemization of the unreacted antipode catalyzed by pyridoxal 5‐phosphate; (v) cryobioorganic synthesis of peptides with increased yields 15%–40% of peptide bond formation by reaction at 5 °C instead of 25–30 °C of a kinetically controlled enzymatic reaction in alcohols.
A Correlation between CH Bond Activation Barrier and Singlet‐Tripet Energy Gap of Transition Metal Complex‐Density Functional Study on CpML Insertion into CH4
Authors: Su Ming‐Der , Chu San‐Yan
Published: May 2015

The density functional calculation with B3LYP/LANL2DZ method showed that the singlet‐triplet splitting (ΔE51 = Etriplet – Esinglet) of 16‐electron CpML (M = Rh, Ir; L = CH2, CO, SH2, PH3) correlates well with the activation barrier for its oxidative addition reaction into methane. A qualitative model of the configuration mixing has been used to interpret the correlation.
Theory of Vibrational Predissociation Spectroscopy
Authors: Chang R. , Jiang J. C. , Hsieh P.‐J. , Chang H.C. , Lin S. H.
Published: May 2015

A theory of vibrational predissociation spectroscopy is developed based on the adiabatic approximation that separates the oscillations of the high frequency vibron and low frequency phonon. We find that some properties such as dissociation energy and the number of phonon modes have significant influence on the temperature dependent spectra. Thus a comparison between the present theory and experiment would be a useful approach in determining these properties.
Reactions of Difluorosilylene with Amines, Phosphines and Halomethanes The First Evidence of the Insertion of Difluorosilylene into Tetrafluorosilane
Authors: Chang Chih‐Wei , Liu Chao‐Shiuan , Lee Chi‐Young
Published: May 2015

The reactions of SiF2/SiF4 with amines, phosphines and various halomethanes were studied. The results show that in the presence of strong Lewis base (Et3N, HNEt2, PR3, PR2Cl), SiF2 inserts initially into SiF4 to form Si2F6, which was followed by subsequent reactions leading to products containing SiF3 groups. This is the first report of the insertion of SiF2 into SiF4. When the reactants were a weaker base (such as RPCl2, CX3Br, X=F, Cl), insertion of SiF2 into P‐Cl and C‐Br bonds became predominant.
Polyene Cyclization Promoted by the Cross Conjugated α‐Carbalkoxy Enone System. An Efficient Approach to Highly Functionalized Decalins
Authors: Liu Hsing‐Jang , Sun Daqing , Shia Kak‐Shan
Published: May 2015

The cross conjugated α‐carbalkoxy enone system was found to be an excellent promoter for polyene cyclization. Under mild conditions, the reaction occurred readily with a high degree of regio‐ and stereoselectivity. Based on this facile process, an efficient method for the construction of highly functionalized decalin derivatives has been developed.
The Attempted Generation of 3,4‐Didehydrofuran
Authors: Wu Yong‐Ming , Yang Xiao‐Ping , Xue Feng , Mak Thomas C. W. , Wong Henry N. C.
Published: May 2015

4‐Trimethylsilyl‐3(2H)‐furanone (4) was converted to 4‐trimethylsilyl‐3‐furyl triflate (5). An attempted generation of 3,4‐didehydrofuran (3a) from 5 was unfruitful. On the other hand, 3,4‐bis(trimethylsilyl)furan (6) was also converted to 4‐trimethylsilyl‐3‐furylphenyliodonium triflate (7c) and its fluoride‐promoted elimination pathway might involve a biradical intermediate 3b.
Chemistry of Hypusine Formation on Eukaryotic Initiation Factor 5A in Biological Systems
Authors: Chen Kuang Yu , Jao David L.
Published: May 2015

Hypusine, an unusual amino acid, is derived from the hydrolysis of eukaryotic initiation factor 5 A (eIF‐5A), the only cellular protein known to contain hypusine residue. Hypusine residue is formed through a spermidine‐dependent posttranslational modification of eIF‐5A at a specific lysine residue. Each mature eIF‐5A molecule contains only one hypusine. Hypusine formation on eIF‐5A is essential for cell survival and proliferation. The biochemistry of hypusine formation has been actively investigated in a number of leading laboratories during the past decade. The precise functional role of eIF‐5A remains a mystery. This paper reviews recent progress in the study of the biochemistry of hypusine formation and offers speculation on the possible function of eIF‐5A.
Ion‐Solvent Interaction of Biunivalent Electrolytes in Dioxane‐Water Mixtures from Conductivity Data at Different Temperatures
Authors: Bakr Moustafa Farag , El‐Wahab Mohamed Abd Allah Abd
Published: May 2015

This paper presents the conductivity measurements for some alkaline earth metal salts MgCl2, MgBr2, Mg(NO3)2, CaCl2, CaBr2 and Ca(NO3)2 by which the ion‐solvent interactions are reported in the concentration range in dioxane‐water mixtures at mass fraction of 0, 3, 10, 20 and 30% at 30°, 35°, 40° and 45°C ± 0.01.

The conductance data were analyzed for the limiting molar conductivity, Ao, by the Fuoss‐Edelson conductivity equation for the 2:1 unsymmetrical electrolytes. The results were discussed in terms of the solute‐solvent interaction from the temperature coefficient of Walden product, Λoη of the electrolyte solutions. Moreover, Λoη was found to exhibit a linear relationship with the dielectric constant, ϵ, of the dioxane‐water mixtures. The study gives information regarding the ion‐solvent interactions from the mobilities and Walden product of the ions in the solvent. The ions appear to interact appreciably and the ion‐solvent interaction tends to increase in the order Ca > Mg for the same anion while for the anions, the trend decreases in the order Cl− < Br− < No−3.
Aristolochic Acids as a Defensive Substance for the Aristolochiaceous Plant‐Feeding Swallowtail Butterfly, Pachliopta aristolochiae interpositus
Authors: Wu Tian‐Shung , Leu Yann‐Lii , Chan Yu‐Yi
Published: May 2015

The chemical constituents isolated from every stage of the Taiwanese swallowtail butterfly, Pachliopta aristolochiae interpositus, were studied and compared with the constituents of the insect feeding plant, A. cucurbitifolia. Two aristolochic acid derivatives (1 and 4) and three aristolactam analogues (5, 6, and 7) were isolated from the larval osmeterial fluid and larvae of the insect. In addition, four purines (2, 3, 13, and 14), one indole alkaloid (11), one steroid (10), two benzenoids (8 and 9) and allantoin (12) were also isolated from the insect. Among these compounds, aristolochic acid ‐I (AA‐I, 1) was detected in all life stages of the insect, especially in the larval osmeterial fluid. The studies confirm that the toxic AAs are used as larval feeding stimulants and deterrent allomones against birds.