bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence for extended π,n‐participation in solvolysis of some benzyl chlorides
Authors: Jurić Sandra , Filipović Anita , Kronja Olga
Published: October 2003

Chlorides 3 (1‐aryl‐1‐chloro‐4‐methyl‐7‐methoxy‐4‐heptene) and 4 (1‐aryl‐1‐chloro‐4‐methyl‐4‐hexene) with various phenyl substituents were prepared (Y=p‐OCH3, p‐CH3, H and m‐Br) and the solvolysis rates were measured in 80% (v/v) aqueous ethanol. The rate constants of 3 correlate well with σ+, and the ϱ+ value obtained is −1.45±0.15, whereas with 4 breakdown of the Hammett plot occurs, and the ϱ+ value without the p‐anisyl group is −2.55±0.20, indicating extended π,n‐participation in 3 and simple π‐participation in 4. The drastically smaller activation parameters obtained with 3 than with 4 are consistent with the proposed mechanism in which the high degree of order required in the transition state (large negative ΔS‡) is overcompensated by a small ΔH‡. Copyright © 2003 John Wiley & Sons, Ltd.
Unidirectional cis–trans photoisomerization of cis‐3,3′‐bis(diphenylhydroxymethyl)stilbene in inclusion complex crystals
Authors: Tanaka Koichi , Hiratsuka Takaichi , Ohba Shigeru , Naimi‐Jamal M. Reza , Kaupp Gerd
Published: October 2003

When a 1:1 complex of cis‐3,3′‐bis(diphenylhydroxymethyl)stilbene (1) with acetone was irradiated in the solid state at room temperature using a high‐pressure mercury lamp with a Pyrex filter for 6 h, a 1:1 complex of the trans‐isomer (2) with acetone was obtained without losing the guest acetone molecules. Similar results were obtained without a guest or in the presence of other guests. Internal rotation around the double bond bearing the very large triphenylhydroxymethyl substituent is hardly imaginable in the confinement of the crystal. Therefore, the geometrically easier ‘hula‐twist’ (HT) mechanism with its movements primarily in the molecular plane provides a viable mechanistic alternative for the cis–trans isomerization. The solid‐state mechanism of the reaction was studied by x‐ray and atomic force microscopy (AFM) analyses. Face‐selective efflorescence formed a protective cover on (100) and can be related to the crystal structure. Further molecular migration was not detected with the sensitivity of AFM and the crystal of 1ċacetone did not lose its clarity and microscopic shape. The cis–trans conversion profits from cages that are present in the crystal lattice. X‐ray structural analysis confirmed a strong loss of crystallinity upon the photochemical conversion of 1ċacetone which precludes a definitive conformational proof of HT by x‐ray diffraction. The formation of the amorphous phase excludes a topotactic reaction. Copyright © 2003 John Wiley & Sons, Ltd.
Photocationic and radical polymerizations of epoxides and acrylates by novel sulfonium salts
Authors: Takahashi Eiji , Sanda Fumio , Endo Takeshi
Published: October 2003

Novel sulfonium salts [methyl‐, 2‐indany‐, or 1‐ethoxycarbonylethyl methyl‐2‐naphthylsulfonium hexafluorophosphate and 2‐indany‐, 1‐ethoxycarbonylethyl‐, 2‐methyl‐2‐phenylpropyl‐, 2‐phenylpropyl‐, 2‐phenylethyl‐, 2‐(4‐methoxyphenyl)‐ethyl‐, or 3‐(4‐methoxyphenyl)‐2‐propyl methylphenylsulfonium hexafluorophosphates] were synthesized by the reaction of dimethylsulfate and the corresponding sulfides followed by anion exchange with KPF6. These sulfonium salts could polymerize epoxy monomers at lower temperatures than previously reported for benzylsulfonium salt initiators. In particular, sulfonium salts with naphthyl groups showed higher photoactivity than already reported for di(4‐tert‐butylphenyl)iodonium and triphenylsulfonium hexafluorophosphates. These sulfonium salts showed higher activity in photoradical polymerization and photocationic polymerization. The photopolymerization was accelerated by the addition of 4‐methoxy‐1‐naphthol, N‐ethylcarbazole, 2,4‐dimethylthioxanthone, phenothiazine, and 2‐ethyl‐9,10‐dimethoxyanthracene as photosensitizers. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3816–3827, 2003
Synthesis and characterization of novel hyperbranched poly(imide silsesquioxane) membranes
Authors: Liu Chunqing , Naismith Nathaniel , Huang Yongqing , Economy James
Published: October 2003

A new family of hyperbranched polymers with chemical bonds between the hyperbranched polyimide and polysilsesquioxane network was synthesized by the reaction of an amine‐terminated aromatic hyperbranched polyimide with 3‐glycidoxypropyl trimethoxysilane, followed by hydrolysis and polycondensation in the presence of an acid catalyst. The hyperbranched poly(imide silsesquioxane) membranes were fabricated by the casting the aforementioned polymer solution onto a NaCl optical flat, which was followed by heating at 80 °C for 24 h. The membranes were characterized by Fourier transform infrared, X‐ray diffraction, thermogravimetric analysis, scanning electron microscopy, N2 adsorption and desorption, and CO2 adsorption and desorption. The presence of covalent bonds between the hyperbranched polyimide and polysilsesquioxane segments had a significant effect on the properties of the membranes. N2 adsorption–desorption isotherms for these membranes showed surface areas of 6–16 m2/g, whereas CO2 adsorption–desorption isotherms showed much higher surface areas in the range of 106–127 m2/g. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3736–3743, 2003
Anionic iron(II) alkoxides as initiators for the controlled ring‐opening polymerization of lactide
Authors: McGuinness David S. , Marshall Edward L. , Gibson Vernon C. , Steed Jonathan W.
Published: October 2003

Hetero‐bimetallic Fe(II) alkoxide/aryloxides were evaluated as initiators for the ring‐opening polymerization of rac‐lactide. [(THF)NaFe(OtBu)3]2 (1) and [(THF)4Na2Fe(2,6‐diisopropylphenolate)4] (2) (THF = tetrahydrofuran) both polymerized lactide efficiently at room temperature, with complex 1 affording better control over the molecular weight parameters of the resultant polymer. At conversions below 70%, a linear increase in molecular weight with conversion was observed, indicative of a well‐controlled polymerization process. Complex 2 is the first example of a dianionic Fe(II) alkoxide and has been structurally characterized to reveal a distorted square planar FeO4 array in which both Na counterions bridge two aryloxide ligands and are further complexed by two THF ligands. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3798–3803, 2003
Ethylene polymerization over transition‐metal supported catalysts. II. Cr on zeolite, silica, and charcoal: Characterization and activity studies
Authors: Zhang Y. , Matos I. , Lemos M. A. N. D. A. , Freire Filipe , Nunes Teresa G. , Botelho do Rego A. M. , Henriques R. T. , Fonseca I. F. , Marques M. M. , Lemos F.
Published: October 2003

Cr catalysts supported on silica, zeolite NaY, and charcoal were prepared with two different methods. They were characterized and examined in the polymerization of ethene. Cyclic voltammetry, electron spin resonance, X‐ray photoelectron spectroscopy and silicon‐29 magic‐angle spinning nuclear magnetic resonance spectroscopy were used to characterize them, demonstrating that Cr is not in a single oxidation state, that the distribution among the various oxidation states depends on the history of the sample, and that even for a single oxidation state a variety of different environments can occur. In the polymerization of ethene, the supported Cr catalysts exhibited activity values varying from 103 to 105 gPE · molCr−1 · [M]−1 · h−1, depending on the choice of the support and on the method by which the Cr is placed on it. Silica seemed to be the most efficient support for Cr for this reaction. However, the zeolite‐supported catalysts also showed reasonable activity values (Ap ≅ 104 units) and presented the advantage of having a strong interaction between the Cr and the support, which may prevent leaching of the cation into the surrounding environment. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3768–3780, 2003
Modification of the microstructure of emulsion polymers
Authors: Ilundain Pedro , Alvarez Daniel , Da Cunha Louis , Salazar Rafael , Barandiaran María J. , Asua José M.
Published: October 2003

The effect of treating several commercially important emulsion polymers with different initiator systems was investigated. The initiator system producing highly reactive tert‐butoxyl radicals was able to cause polymer modification. This represented an opportunity to extend the range of properties achievable with a given emulsion polymer. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3744–3749, 2003
Biodegradable/biocompatible ABC triblock copolymer bearing hydroxyl groups in the middle block
Authors: Gadzinowski Mariusz , Sosnowski Stanislaw
Published: October 2003

New biodegradable/biocompatible ABC block copolymers, poly(ethylene oxide)‐b‐poly(glycidol)‐b‐poly(L,L‐lactide) (PEO‐PGly‐PLLA), were synthesized. First, PEO‐b‐poly(1‐ethoxyethylglycidol)‐b‐PLLA was synthesized by a successive anionic ring‐opening copolymerization of ethylene oxide, 1‐ethoxyethylglycidyl ether, and L,L‐lactide initiated with potassium 2‐methoxyethanolate. In the second step, the 1‐ethoxyethyl blocking groups of 1‐ethoxyethylglycidyl ether were removed at weakly acidic conditions leaving other blocks intact. The resulting copolymers were composed of hydrophilic and hydrophobic segments joined by short polyglycidol blocks with one hydroxyl group in each monomeric unit. These hydroxyl groups may be used for further copolymer transformations. The PEO‐PGly‐PLLA copolymers with a molecular weight of PLLA blocks below 5000 were water‐soluble. Above the critical micellar concentration (ranging from 0.05 to1.0 g/L, depending on the composition of copolymer), copolymers formed macromolecular micelles with a hydrophobic PLLA core and hydrophilic PEO shell. The diameters of the micelles were about 25 nm. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3750–3760, 2003
Biodegradable polycaprolactone–polyanhydrides blends
Authors: Ben‐Shabat Shimon , Abuganima Elias , Raziel Aliza , Domb Abraham J.
Published: October 2003

Biodegradable polymers based on a blend of polycaprolactone (PCL) and aliphatic polyanhydrides with various monomer lengths were prepared to obtain desired polymer blends for use as drug carriers. The physicochemical, mechanical, and drug‐release properties of these blends were investigated by various techniques to evaluate the uniformity degree of the polymer blends to establish their potential applications in drug delivery. The results demonstrated that the heat of fusion (ΔH) of the polyanhydride or the blend is increased in relation to the length of the aliphatic chain. However, the blends had different properties than pure polyanhydride, and the crystallization degree of the blends, as expressed by the ΔH, decreased in relation to the ΔH of the pure polyanhydride. Drug‐release studies from blends of PCL and aliphatic polyanhydrides demonstrated first‐order kinetics of the release rate. Polymer degradation was independent at the polyanhydride monomer length. On the basis of theoretical calculation of the interaction factor, a blend of PCL and poly(dodecanedeoic anhydride) was chosen for further elucidation of its thermal, mechanical, and degradation properties. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3781–3787, 2003
S. Kumaresan and P. Kannan, "Substituent effect on azobenzene‐based liquid‐crystalline organophosphorus polymers" Journal of Polymer Science Part A: Polymer Chemistry (2003) 41(20) 3188–3196
Authors: Kumaresan S. , Kannan P.
Published: October 2003

The original article to which this Erratum refers was published inJournal of Polymer Science Part A: Polymer Chemistry (2003) 41(20) 3188–3196

No abstract.
Degradation of the sulfonylurea herbicide LGC‐42153 in flooded soil
Authors: Kim Jin , Liu Kwang‐Hyeon , Kang Seung‐Hun , Koo Suk‐Jin , Kim Jeong‐Han
Published: October 2003

LGC‐42153, 2‐fluoro‐1‐[3‐(4,6‐dimethoxypyrimidin‐2‐ylcarbamoylsulfamoyl)pyridin‐2‐yl]propyl methoxyacetate, is a new sulfonylurea herbicide for use in rice. Its breakdown and metabolism were studied in soil under flooded condition using radioactive tracers labelled at either the propyl group or the pyrimidine ring. The half‐life of LGC‐42153 was approximately 3.0 days. The mass balance over 120 days ranged from 94.0 to 104.2% of applied radiocarbon, and no significant amount of volatiles or [14C]carbon dioxide were observed. Solvent non‐extractable radiocarbon reached 11 ∼ 14% of applied radiocarbon at 120 days after treatment. The major metabolic reaction was the cleavage of the carboxyl ester bond to give 1‐(4,6‐dimethoxypyrimidin‐2‐yl)‐3‐[2‐(1‐hydroxy‐2‐fluoropropyl)pyridine‐3‐sulfonyl]urea, which underwent hydrolysis of the sulfonylurea bridge giving 2‐(1‐hydroxy‐2‐fluoro)propyl‐3‐pyridinesulfonamide and 4,6‐dimethoxy‐2‐aminopyrimidine. Copyright © 2003 Society of Chemical Industry
Addition of a monovalent cationic pesticide to improve efficacy of bipyridyl herbicides in Hulah valley soils
Authors: Rytwo Giora , Tavasi Mordechai
Published: October 2003

Bipyridyl herbicides are widely used in agriculture and gardening for non‐selective weed control. Since they are toxic and relatively expensive, it is ecologically and economically desirable to reduce the amounts applied. A decrease in efficacy of these herbicides is caused by dust accumulated on leaves of weeds. This inactivation arises from the adsorption of the herbicides on dust particles, mainly made of clay minerals, lime and soil organic matter. In order to improve the efficacy and so lower the amounts applied, formulations were developed which include cationic pesticides approved for agricultural use, such as mepiquat or difenzoquat. Such addition restored the efficacy of the bipyridyl herbicides by reducing their binding to dust particles. The proposed formulations, which were tested on a number of different dust‐covered plants, allowed the amounts of herbicide applied to be reduced to 50% of the minimum recommended rate. Neither mepiquat or difenzoquat had any herbicidal activity when sprayed alone at the added rates. The results suggest a procedure that may lower the required rates of contact herbicides, reducing costs and toxicity. This procedure, which can be applied immediately, may have broad implications in farming and gardening. Copyright © 2003 Society of Chemical Industry
Fungicidal potential of methoxylated flavones from citrus for in vitro control of Colletotrichum gloeosporioides, causal agent of anthracnose disease in tropical fruits
Authors: Almada‐Ruiz Ernestina , Martínez‐Téllez Miguel Ángel , Hernández‐Álamos Maria M , Vallejo Socorro , Primo‐Yúfera Eduardo , Vargas‐Arispuro Irasema
Published: October 2003

Four polymethoxylated flavones (3,5,6,7,3′,4′‐hexamethoxyflavone, 3,5,6,7,8,3′,4′‐heptamethoxyflavone, 5,6,7,8,4′‐pentamethoxyflavone and 5,6,7,8,3′,4′‐hexamethoxyflavone) were isolated and characterized from cold‐pressed orange oil. Their antifungal activities were evaluated against Colletotrichum gloeosporioides (Penz) Penz & Sacc, a major plant pathogen of fruits that causes significant damage to crops in tropical, sub‐tropical and temperate regions. Methoxylated flavones were effective in inhibiting mycelial growth of the fungus. As flavone concentration increased, mycelial growth decreased. 5,6,7,8,3′,4′‐Hexamethoxyflavone completely inhibited the growth of C gloeosporioides at a concentration of 100 µg ml−1. Copyright © 2003 Society of Chemical Industry
Influence of a short exposure to teflubenzuron residues on the predation of thrips by Iphiseius degenerans (Acari: Phytoseiidae) and Orius laevigatus (Hemiptera: Anthocoridae)
Authors: Scott Brown Alison S , Simmonds Monique SJ , Blaney Wally M
Published: October 2003

A short duration (24 h) leaf‐disc bioassay was used to determine the effects of teflubenzuron residues on the predation levels of two predators, Iphiseius degenerans (Berlese) and Orius laevigatus (Fieber), foraging on nymphs of two species of thrips, Frankliniella occidentalis (Pergande) and Heliothrips haemorrhoidalis (Bouché), on a range of different species of plant. Teflubenzuron did cause thrips mortality during the 24‐h bioassay; it was more active against H haemorrhoidalis than F occidentalis. Teflubenzuron did not cause significant mortality to either species of predator, although on some plants the effectiveness of both predators was reduced in the presence of teflubenzuron. Copyright © 2003 Society of Chemical Industry
Inhibition of egg development by phosphine in the cosmopolitan pest of stored products Liposcelis bostrychophila (Psocoptera: Liposcelididae)
Authors: Nayak Manoj K , Collins Patrick J , Pavic Hervoika , Kopittke Rosemary A
Published: October 2003

Phosphine‐induced delay in development of eggs was investigated as a mechanism of resistance to this fumigant in Liposcelis bostrychophila Badonnel. One‐day‐old eggs of a susceptible and a strongly resistant strain of L bostrychophila were exposed to a range of phosphine concentrations for 6 days at 30 (±1) °C and 70 (±2)% RH. Delay in mean hatching period occurred in both susceptible and resistant eggs, although it was more pronounced in the latter. A maximum delay of 2.65 days was recorded for eggs of the susceptible strain at 0.01 mg litre−1 (the highest concentration at which eggs survived) and 13.39 days for the resistant strain at 1 mg litre−1 (the highest concentration tested). Delay in egg development time was positively correlated with increasing phosphine concentration. Our results reveal that the most successful strategy to control resistant L bostrychophila is to apply relatively low concentrations of phosphine for extended exposure times (eg 0.05 mg litre−1 for 16 days) that allow all eggs to hatch to the much less tolerant nymph stage. Copyright © 2003 Society of Chemical Industry
Toxicity and kinetics of methoxyfenozide in greenhouse‐selected Spodoptera exigua (Lepidoptera: Noctuidae)
Authors: Smagghe Guy , Pineda Samuel , Carton Bert , Estal Pedro Del , Budia Flor , Viñuela Elisa
Published: October 2003

Methoxyfenozide (RH‐2485) was found to be 7.5‐fold less toxic in terms of LD50 values against last‐instar larvae of a greenhouse‐selected strain of the beet armyworm Spodoptera exigua (Hübner) that was collected in July 2001 in an experimental greenhouse for resistance at Murcia in southern Spain, in comparison with a laboratory susceptible strain. To date, the compound is the newest member of this new group of moulting hormone accelerating IGRs to reach the marketplace against Lepidoptera. To understand this different potency in the greenhouse‐selected S exigua, oxidative metabolism and acetylcholinesterase activities were measured in last‐instar larvae and adults. In addition, we determined, by the use of 14C‐labelled methoxyfenozide, the pattern of absorption in body tissues and excretion via faeces in last‐instar larvae of the greenhouse‐selected strain and compared the results with those from the laboratory susceptible strain. It was striking that the rate of excretion was about twice as high in the greenhouse‐selected strain, resulting in a more rapid clearance of insecticide amounts from the insect body. Data are discussed in relation to mechanisms of lower toxicities for this new group of IGRs. Copyright © 2003 Society of Chemical Industry
Herbicide resistance in Aster squamatus conferred by a less sensitive form of acetolactate synthase
Authors: Osuna Maria D , Fischer Albert J , De Prado Rafael
Published: October 2003

A biotype of Aster squamatus (Sprengel) Hieronymus with suspected resistance to the ALS‐inhibiting herbicide imazapyr was detected in a chicken farm in the province of Seville, Spain, which had been treated once a year with imazapyr for 10 years. Resistance to imazapyr in this biotype was studied using dose–response experiments, absorption and translocation assays, metabolism studies and ALS activity assays. The rate of imazapyr required to inhibit A squamatus growth by 50% (ED50) was 15 times higher for the R (resistant) than for the S (susceptible) biotype. Cross‐resistance existed for the ALS‐inhibitors imazamox, imazethapyr, amidosulfuron, nicosulfuron, rimsulfuron, triasulfuron and tribenuron, but not for bensulfuron. Control of A squamatus using alternative herbicides was poor with clopyralid, intermediate with quinclorac, amitrole and MCPA, and excellent with 2,4‐D, glufosinate and glyphosate. Absorption of [14C]imazapyr increased over time for both the R and S biotypes, and translocation from the treated leaf to shoots and roots was similar in both biotypes, with most of the radioactivity remaining in the treated leaf. No metabolites of imazapyr were detected in either biotype. Sensitivity of the ALS enzyme (target site) to imazapyr was lower for the R biotype (I50(R) = 4.28 × I50 (S)). The mechanism of imazapyr resistance in this R biotype appears to be an altered ALS conferring decreased sensitivity to imazapyr at the whole‐plant level. Copyright © 2003 Society of Chemical Industry
Persistence of the fungicides thiabendazole, carbendazim and prochloraz‐Mn in mushroom casing soil
Authors: Grogan Helen M , Jukes Andrew A
Published: October 2003

The persistence of the fungicides thiabendazole, carbendazim and prochloraz‐Mn in mushroom casing soil was determined following their application at rates commonly used in the UK mushroom industry. Following drench applications, the concentration of all active ingredients was always higher in the top half of the casing soil layer than in with the bottom half. When carbendazim and prochloraz‐Mn were applied using half the recommended volume of water per unit area, there was a tendency for carbendazim concentrations to be even higher in the top half of the casing soil, compared with the standard treatment, while concentrations of prochloraz‐Mn were similar, irrespective of the volume of water used. Carbendazim and prochloraz‐Mn concentrations in the top half of the casing layer decreased to ≤13 mg kg−1 by day 28/29, following different applications, whereas the thiabendazole concentration was consistently high during the course of the crop, being ≤83 mg kg−1 at day 31. Fungicides that do not persist at high concentrations in mushroom casing soil for the duration of the crop may not give good control of mushroom pathogens, particularly if the fungicide concentration falls to a level which is close to the EC50 value. Copyright © 2003 Society of Chemical Industry
Tank‐mix adjuvants and pesticide residues: some regulatory and quantitative aspects
Authors: Holloway Peter J , Western Nigel M
Published: October 2003

Although it is well known that judicious use of adjuvants can increase the performance of foliage‐applied sprays of many agrochemicals, little information is available in the public domain about their ultimate effects on pesticide residues in treated crops. In the present work, the influence of Agral (polyoxyethylene nonylphenols), Toil (methyl esters of rapeseed fatty acids) and Bond (styrene–butadiene copolymers) on surface and crop residues of diclofop‐methyl/diclofop and propiconazole in wheat and field beans was investigated using a model system simulating field practice. Pesticides were applied as commercial formulations, diclofop‐methyl 378 g litre−1 EC (Hoegrass) and propiconazole 250 g litre−1 EC (Tilt), at their maximum approved rates, 1135 g AI ha−1 and 125 g AI ha−1, respectively, both in the presence or absence of the maximum rate recommended for each candidate adjuvant. No detectable residues of diclofop‐methyl or propiconazole were found in wheat 35 days after any of the four applications. However, residues of diclofop were present in this crop, and those from applications containing Agral (0.07 mg kg−1 fresh weight (FW)) or Bond (0.08 mg kg−1 FW) were significantly lower than those with no adjuvant (0.14 mg kg−1 FW) or Toil (0.16 mg kg−1 FW). Unlike wheat, residues of both diclofop and propiconazole were detected in field beans after harvest. Significantly higher residues of the former were recorded from the applications with Agral or Bond (ca 0.32 mg kg−1 FW) than with those with no adjuvant or Toil (ca 0.15 mg kg−1 FW). All the propiconazole applications containing adjuvants showed a similar significant increase in residues (0.10–0.16 mg AI kg−1 FW) over the no‐adjuvant treatment (0.05 mg kg−1 FW) in this crop. There appeared to be little agreement between the apparent amounts of uptake, as indicated by the rates of decline of surface residues up to 5 days after application, and final residues in either target species. On wheat, surface residues of diclofop‐methyl decreased from initially ca 20 to as little as 0.02 mg kg−1 FW using adjuvants; the corresponding values for propiconazole were ca 2 to ca 0.03 mg kg−1 FW. Recoveries of diclofop‐methyl from the surfaces of field beans were much higher than those from wheat, declining from ca 30 to only ca 6 mg kg−1 FW during the course of 5 days; the corresponding residues for propiconazole were ca 2mg to 0.15mg kg−1 FW. These findings are discussed in relation to uptake results obtained with radiolabelled pesticides and adjuvants in the laboratory, and to the mandatory requirements for pesticide residue data for the authorised use of adjuvants in the UK. Copyright © 2003 Society of Chemical Industry
Seungnoidan increases cerebrocortical ATP and acetylcholine contents in ovariectomized rats
Authors: Ma J. Y. , Choo Y. K. , Lee S. H. , Jeong H. Y. , Keum K. S. , Choi B. K. , Jung K. Y.
Published: October 2003

This study investigated the effects of Seungnoidan (SND), which has been widely used as a remedy for cerebroneuronal diseases in Korean folk medicine, on the cerebrocortical adenosine triphosphate (ATP) and acetylcholine (ACh) contents in ovariectomized (OVX) rats. Female Sprague‐Dawley rats were ovariectomized and maintained for 12 weeks to deplete ovarian steroid hormones, followed by oral administration of SND at 500 mg/kg/day for 14 weeks. SND markedly attenuated the high rate of body weight increase in OVX rats, and also reduced the decline of cerebral weight caused by ovariectomy (p < 0.05). Superfusion of SND at 50 mg/kg signiﬁcantly increased the rate of cerebral blood ﬂow, but did not change the mean arterial blood pressure. Deprivation of ovarian steroid hormones signiﬁcantly decreased the cerebral ATP, choline and ACh contents, and these reductions were reduced by treatment of OVX rats with SND (p < 0.01). Additionally, SND also signiﬁcantly elevated the cerebral choline acetyltransferase activities reduced by OVX (p < 0.01). Taken together, these results suggest that the pharmacological properties of SND may be implicated in the improvement of metabolic pathways of cerebral energy and cholinergic neurotransmitter function induced by deprivation of ovarian steroid hormones, and SND may be a promising herbal remedy for treatment of cerebral dysfunctions including dementia. Copyright © 2003 John Wiley & Sons, Ltd.
Antinociceptive activity of Sempervivum tectorum L. extract in rats
Authors: Kekesi Gabriella , Dobos Ildiko , Benedek György , Horvath Gyöngyi
Published: October 2003

The extract of Sempervivum tectorum L. (Crassulaceae) containing several ﬂavonoids is widely used as an antiinﬂammatory agent in folk medicine. Previous studies have demonstrated that various ﬂavonoids or ﬂavonoid‐containing plant extracts produce signiﬁcant antinociception, but no data are available concerning their antinociceptive effect especially at the spinal level. The purpose of the present study was to investigate the antinociceptive activity of Sempervivum tectorum L. extract on acute and inﬂammatory pain sensitivity in awake rats.

The pain sensitivity was assessed by the acute tail‐ﬂick test in intact rats and by the paw withdrawal test after carrageenan‐induced inﬂammation using heat stimulus. The plant extract was administered intraperitoneally and intrathecally in rats.

The intraperitoneal injection of a high dose of the extract (1000 mg/kg) signiﬁcantly (p < 0.05) increased the paw withdrawal latency of the inﬂamed paw. The intrathecal administration (30–300 µg) caused a small, but signiﬁcant increase (10%–15%) in tail‐ﬂick latency. In the carrageenan‐induced inﬂammatory model, the intrathecally applied extract (30–1000 µg) signiﬁcantly decreased, but did not relieve the thermal hyperalgesia. The results suggest that the spinal cord does not seem to play an important role in the antinociceptive effects of this plant extract. Copyright © 2003 John Wiley & Sons, Ltd.
Composition and antimicrobial activity of Achillea clavennae L. essential oil
Authors: Bezić Nada , Skočibušić Mirjana , Dunkić Valerija , Radonić Ani
Published: October 2003

The volatile constituents of Achillea clavennae L. (Asteraceae), rare plant of Europe, have been analysed using GC/MS. Twenty‐ﬁve components making up 81.6% of the oil were characterized with camphor (29.5%), myrcene (5.5%), 1,8‐cineole (5.3%), β‐caryophyllene (5.1%) and linalool (4.9%) being the major constituents. The essential oil was evaluated for antibacterial and antifungal activities. The screening of the antimicrobial activity of essential oil was conducted by a disc diffusion test against Gram‐positive (Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Streptococcus faecalis), Gram‐negative (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis) and fungal organisms (Aspergillus niger, Aspergillus fumigatus, Candida albicans). The activity was more pronounced against Gram‐negative and fungal organisms than against Gram‐positive bacteria. A. clavennae oil was found to possess antimicrobial activity against Klebsiella pneumoniae, Pseudomonas aeruginosa and all fungal organisms. Copyright © 2003 John Wiley & Sons, Ltd.
In vivo and in vitro studies on the anticancer activity of Copaifera multijuga hayne and its fractions
Authors: Lima Sylvia R. M. , Junior Valdir F. Veiga , Christo Herick B. , Pinto Angelo C. , Fernandes Patricia D.
Published: October 2003

Copaiba oil resin (COR) obtained from Copaifera multijuga Hayne has been used in popular medicine as an antinﬂammatory and for the treatment of bronchitis, ulcers and cancer. The aim of this study was to evaluate the action of COR and its fractions on the inhibition of lung metastasis and tumour growth induced by B16F10 melanoma cells in mice and cytotoxicity in vitro using Trypan Blue exclusion method and MTT conversion.

Mice which have received subcutaneously B16F10 cells developed a solid tumour that reached a peak at 17 days. Together with the increase in tumour growth we also observed an increase in the number of lung nodules. There was a positive correlation between the in vitro cytotoxic assay and in vivo antitumour activity. The oral administration of COR (at 2 g/Kg in the days 3, 5, 7, 10, 12 and 14 after inoculation of tumoral cells) reduced tumour growth by 58% and tumour weight by 76%. At the same dose COR reduced the number of lung nodules by 47.1%. In vitro experiments showed that COR incubated with the melanoma cell line reduced cell viability in a concentration and time‐dependent manner. Diterpenic and sesquiterpenic fractions or reconstituted oil induced cytotoxicity. Our results shows that COR and its fractions have tumouricidal activity in the melanoma cell line in both models in vivo and in vitro. Copyright © 2003 John Wiley & Sons, Ltd.
The effect of a catechin‐rich extract of Cocos nucifera on lymphocytes proliferation
Authors: Kirszberg Clarice , Esquenazi Daniele , Alviano Celuta Sales , Rumjanek Vivian M.
Published: October 2003

Catechins are polyphenols with antioxidant activity. The fruit Cocos nucifera (Palmae) has a ﬁber husk rich in catechins and the local population of northeast Brazil uses it as a medicine against various diseases. An anti‐bacterial and anti‐viral activity has been already observed using this substance. Plant extracts, from other sources, rich in catechins are inhibitory to tumour cells, suppressing their proliferation. The aim of the present work was to verify if catechins isolated from Cocos nucifera were capable of inhibiting cell proliferation. An extract obtained from Cocos nucifera was puriﬁed through adsorption chromatography using the resin XAD‐2. The puriﬁed material was used in cultures of an erythroleukaemia cell line (K562) and on normal human peripheral blood lymphocytes. Cell viability was assessed using MTT. Cellular proliferation was measured by [3H]‐thymidine incorporation and cell cycle analysis in a ﬂow cytometer. A dose‐dependent inhibitory effect was observed on tumour cells and on lymphocytes activated by phytohemaglutinin (PHA) or phorbol ester. For PHA this effect was irreversible being already established on the ﬁrst four hours of culture. Copyright © 2003 John Wiley & Sons, Ltd.
Antioxidant principles from the needles of red pine, Pinus densiﬂora
Authors: Jung Mee Jung , Chung Hae Young , Choi Jin Ho , Choi Jae Sue
Published: October 2003

Antioxidant activity of Pinus densiﬂora Sieb. et Zucc. (Pinaceae) was evaluated for potential to inhibit hydroxyl radicals, inhibit total reactive oxygen species generation in kidney homogenates using 2′,7′‐dichlorodihydroﬂuorescein diacetate (DCHF‐DA) and scavenge authentic peroxynitrites. The methanolic extract of P. densiﬂora showed strong antioxidant activity in the tested model systems and thus fractionated with several solvents. The antioxidant activity potential of the individual fraction was in the order of ethyl acetate > n‐butanol > water > dichloromethane fraction. The ethyl acetate soluble fraction exhibiting strong antioxidant activity was further puriﬁed by repeated silica gel and Sephadex LH‐20 column chromatographies. An active lignan (+)‐isolarisiresinol xylopyranoside, as well as two active ﬂavonoids [kaempferol 3‐O‐β‐galactopyranoside and its 6″‐acetyl derivative], were isolated. Copyright © 2003 John Wiley & Sons, Ltd.
Toxicity and antiviral activity of cinnabarin obtained from Pycnoporus sanguineus (Fr.) Murr
Authors: Smânia A. , Marques C. J. S. , Smânia E. F. A. , Zanetti C. R. , Carobrez S. G. , Tramonte R. , Loguercio‐Leite C.
Published: October 2003

This work describes the cytopathic effect on cells, cytotoxic action on mice, and antiviral activity of cinnabarin. This substance had no effect on mouse neuroblastoma cells (NA cell, ATCC clone C‐1300) at a concentration of 0.31 mg/ml, it was not able to cause toxic effects in mice at concentrations of 1000 mg/kg, and reduced by four times the titers of the rabies virus at concentrations of 0.31 mg/ml. Copyright © 2003 John Wiley & Sons, Ltd.
Effects of Jaoga‐Yukmiwon®, a Korean herbal medicine, on chondrocyte proliferation and longitudinal bone growth in adolescent male rats
Authors: Leem K. , Park S. Y. , Lee D. H. , Boo Y. M. , Cho K. H. , Lim J. , Jeon H. , Park H. J. , Chung J. H. , Kim H.
Published: October 2003

Externally visible growth of the body is the result of proliferation of chondrocytes and longitudinal bone growth. The effects of the Korean herbal medicine, Jaoga‐Yukmiwon®, on the growth of adolescent rats were investigated in the present study. The proliferation ratio of chondrocytes was calculated from 5‐bromo‐2′‐deoxyuridine incorporation during DNA synthesis. The 5‐bromo‐2′‐deoxyuridine incorporation ratio of the control group was 21.1 ± 3.5%, and Jaoga‐Yukmiwon® administration markedly increased the ratio to 34.5 ± 4.6% (p < 0.05). The bone formation rate of longitudinal bone was estimated by labelling with tetracycline, which binds to newly formed bone. The bone formation rate in the tibia of Jaoga‐Yukmiwon®‐administered rats was increased to 405.1 ± 4.3 µm (p < 0.05) from 292.2 ± 11.8 µm (control value). The height of the growth plate in the administrated rats was increased to 614.6 ± 10.0 µm (p < 0.05) from 552.3 ± 17.1 µm. The bone morphogenetic protein‐2 immunostaining in the growth plate was also increased. These results suggest that Jaoga‐Yukmiwon® may promote longitudinal bone growth during the developmental period. Copyright © 2003 John Wiley & Sons, Ltd.
Biological activities of Prunella vulgaris extract
Authors: Psotová Jitka , Kolář Milan , Soušek Jaromír , Švagera Zdeněk , Vičar Jaroslav , Ulrichová Jitka
Published: October 2003

The organic fraction (OF; 25.7% w/w of rosmarinic acid) of Prunella vulgaris (total extract) was found to exhibit the following: scavenging activity on diphenylpicrylhydrazyl radical (DPPH), inhibition of in vitro human LDL Cu(II)‐mediated oxidation, protection of rat mitochondria and rat hepatocytes exposed to either tert‐butyl hydroperoxide, or to Cu(II) and Fe(III) ions. OF also showed a potential to inhibit rat erythrocyte haemolysis and it reduced the production of LTB4 in bovine PMNL generated by the 5‐lipoxygenase pathway. Other observations included antiproliferative effects against HaCaT cells and mouse epidermal ﬁbroblasts and a moderate OF antimicrobial activity on gram‐positive bacteria. Rosmarinic, caffeic and 3‐(3,4‐dihydroxyphenyl)lactic acids exhibited less potent activity than the plant extract in all bioassays. The antioxidative, antimicrobial, together with antiviral effects offer good prospects for the medicinal applications of P. vulgaris. Copyright © 2003 John Wiley & Sons, Ltd.
Antitussive potential of methanol extract of stem bark of Ficus racemosa Linn.
Authors: Bhaskara Rao R. , Murugesan T. , Pal M. , Saha B. P. , Mandal S. C.
Published: October 2003

The methanol extract of Ficus racemosa Linn (Moraceae) (stem bark) (MEFR) was tested for its antitussive potential against a cough induced model by sulphur dioxide gas in mice. The extract demonstrated signiﬁcant (p < 0.001) antitussive activity at all tested dose levels when compared with the control. The antitussive activity of the extract was comparable to that of codeine phosphate (10 mg), a standard antitussive agent. The extract exhibited maximum inhibition of 56.9% at a dose of 200 mg/kg (p.o.) 90 min after administration. Copyright © 2003 John Wiley & Sons, Ltd.
Evaluation of in vitro antiviral activity in methanol extracts against inﬂuenza virus type A from Korean medicinal plants
Authors: Park Kap Joo
Published: October 2003

Methanol extracts from 101 Korean medicinal plants were tested for inhibitory activity against inﬂuenza virus type A by means of a modiﬁed haemagglutination inhibition (HI) test. MM‐57, MM‐72, MM‐104 and MM‐110, four of 101 extracts tested exhibited strong anti‐inﬂuenza virus type A activity at concentration ranges of 0.78–6.25 mg/mL, 0.78–3.13 mg/mL, 0.78–1.56 mg/mL and 0.0975–0.39 mg/mL, respectively. The extracts MM‐57, MM‐72 and MM‐110 showed very strong anti‐inﬂuenza virus type A activity in the range 1.56–6.25 mg/mL, 1.56–3.13 mg/mL and 195–390 µg/mL, respectively. The four methanol extracts were weakly cytotoxic to red blood cells. These results demonstrated that four methanol extracts of Korean medicinal plants exhibit strong anti‐inﬂuenza virus type A activity, and weak cytotoxic effects. They may inhibit attachment of the virus to the cell and may therefore be used for prophylaxis. Copyright © 2003 John Wiley & Sons, Ltd.
Anti‐HIV‐1 limonoid: first isolation from Clausena excavata
Authors: Sunthitikawinsakul Arunrat , Kongkathip Ngampong , Kongkathip Boonsong , Phonnakhu Sida , Daly John W. , Spande Thomas F. , Nimit Yuth , Napaswat Chanita , Kasisit Jittra , Yoosook Chalobon
Published: October 2003

A limonoid, clausenolide‐1‐ethyl ether (1) and two coumarins, dentatin (2) and nor‐dentatin (3), were isolated from Clausena excavata. Limonoid 1 was obtained from the crude ethanol extract of the rhizomes and the roots but had not previously been isolated from C. excavata and exhibited HIV‐1 inhibitory activity. Coumarins 2 and 3, with their structures related to an anti‐HIV‐1 substance, (+)‐calanolide A (4), were obtained from the crude chloroform extract of the rhizomes. Both induced toxicity to cells used in a syncytium assay for anti‐HIV‐1 activity. These compounds, 1–3, did not show any cytotoxic effect against KB and BC‐1 cell lines (IC50 value > 20 µg/mL). Copyright © 2003 John Wiley & Sons, Ltd.
Synergistic interactions among QSAR descriptors
Authors: Peterangelo Stephen C. , Seybold Paul G.
Published: October 2003

Quantitative structure–activity relationships (QSARs) and quantitative structure–property relationships (QSPRs) rely on regression equations containing numerical descriptors of molecular structure. In constructing these models, highly correlated descriptors are sometimes excluded from the regression equations. Although this exclusion seems reasonable, in fact it can lead investigators to overlook significant descriptor combinations, because the small differences between highly correlated descriptors sometimes encode important structural information. Furthermore, the multicollinearity that results from employing correlated descriptors is not as serious a problem as is often assumed. Described are several examples of cases in which pairs of highly correlated, poorly performing single‐parameter descriptors yield highly significant structure–property regression equations. In effect, the descriptors act synergistically and yield regression equations that model the systems examined better than the sum of the individual components. A discussion of practical approaches to this problem is given. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Transformed Dirac equation for the hydrogen atom, comparison with previous approaches in momentum space, and the anomalous Zeeman effect in momentum representation
Authors: Datta Sambhu N.
Published: October 2003

The solution of a unitarily transformed Dirac equation for the hydrogenic electron in zero magnetic field is investigated here. The momentum‐space representation is adopted as a natural recourse. The spinor part of the transformed wavefunction in momentum space can be easily prescribed for a central potential. Hence, for the Coulomb potential, a pair of equations is obtained for the radial components in momentum space. It is shown that starting from these radial equations, one can recover the equations previously derived by Rubinowicz, Lévy, and Lombardi for the problem of the Dirac hydrogen atom in momentum space. This establishes equivalence among different approaches based on the momentum representation, including the current treatment. The recovery of the equations due to Rubinowicz permits the exact eigenvalues to be written down and exact expressions to be derived for the radial components of the transformed wavefunction in momentum space. A new approach is adopted to carry out a reduction to the nonrelativistic regime and the nonrelativistic limit. At first the transformed momentum‐space equation for the hydrogen atom is rewritten in terms of the hyperspherical coordinates. The zeroth‐order solutions of the new equation are recovered in the limit c → ∞ where c is the speed of light. These are manifestly separable into positive‐ and negative‐energy forms. For positive energy, these solutions have nonvanishing upper components that are two‐component spinors. The latter exactly correspond to the single‐component, nonrelativistic, momentum‐space solutions derived by Fock. It is shown that when the upper component is corrected through first order in v2/c2 but the separability is still maintained for the transformed wavefunction, one retrieves the Pauli equation in momentum space. It is also shown that for a hydrogen atom placed in a uniform magnetic field, the nonvanishing momentum‐space matrix elements representing the anomalous Zeeman effect have a simple form, namely, the product of a radial integral and an angular integral. These integrals are equal to the well‐known radial and angular integrals in coordinate representation. The matrix elements can be easily evaluated. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Geminal approach to vibronic models of superconductivity in crystals. I. The Jahn–Teller effect
Authors: Palting Pancracio , Letelier Jorge Ricardo , Chiu Ying Nan
Published: October 2003

Electronic geminals constructed as linear combinations of binary products of site functions are used to formulate a vibronic model of superconductivity in crystals that is based upon the approximation of independent correlated electron pairs obtained variationally from an electron‐pair Hamiltonian and the Jahn–Teller effect. The cyclic symmetry of the system is taken into account and the geminals are sorted into doubly degenerate pairs. The Herzberg–Teller expansion of the pair Hamiltonian in terms of vibrational modes leads directly to the Jahn–Teller effect. A contact transformation of the vibronic Hamiltonian containing only linear terms lowers the energy of the system by a second‐order term associated with the Jahn–Teller stabilization energy. A possible model for superconductivity in solids is proposed on the basis of the Jahn–Teller effect. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Formulation of unrestricted and restricted Hartree–Fock–Bogoliubov equations
Authors: Yamaki Daisuke , Ohsaku Tadafumi , Nagao Hidemi , Yamaguchi Kizashi
Published: October 2003

The Hartree–Fock–Bogoliubov (HFB) method, dealing with Bogoliubov orbitals, which consist of particle and hole part, can provide states with pair correlations associated with Cooper pairs. The dimension of HFB Fock matrices can be reduced by restrictions of spin states of Bogoliubov orbitals similarly to ordinary Hartree–Fock (HF) equations such as restricted HF (RHF), unrestricted HF (UHF), and generalized HF (GHF). However, there are few studies of moderate restricted HFB equations such as UHF‐based HFB equations. In this article, formulation and calculations of restricted HFB equations are described. The solutions of general and restricted HFB equations are compared. Pair correlations taking account of restricted and general HFB equations are discussed. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Comparison of methods for point‐charge representation of electrostatic fields
Authors: Dungsrikaew Virasak , Limtrakul Jumras , Hermansson Kersti , Probst Michael
Published: October 2003

The calculation of the electrostatic potential resulting from an infinite or extended array of charges in the interior of a region of interest is a frequent task in computational chemistry. In case of a periodic potential this can, for example, be done by Ewald summation or by multipole methods. An important alternative are those methods where arrays of auxiliary point charges are optimized with respect to charge and/or position to reproduce the original electrostatic potential. In the literature different variations are reported. We compare the performance of some of these with respect to their ability to reproduce the original potential and the computational effort required. Between (1) surface charges determined by the conductor‐boundary condition, (2) optimized surface charges, and (3) surface charges floating on the surface we find that (2) offers good quality with small computational costs involved. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Hybrid QM/MM studies on energetics of malonaldehyde in condensed phase
Authors: Shigeta Yasuteru
Published: October 2003

Energetics of eight enol isomers of a malonaldehyde (MA) at the ground state in CCl4 solvent environment have been investigated using a hybrid quantum mechanical (QM)/molecular mechanics (MM) method. It is found that relative energies of the isomers slightly change due to interactions between MA and surrounding atoms. In an isolated environment all eight isomers have stable planar structure. On the other hand, most of the isomers have nonplanar structure in CCl4 whose interactions with the solute molecules are, however, weak. Mainly, structural changes are found in the HOCC dihedral angle ϕHOCC, i.e., a hydrogen atom that is connected directly with an oxygen atom, is located at a nonplanar position, and other atoms remain almost planar. Vertical excitation energies of low‐lying excited states at the resultant optimized structure of each isomer are evaluated. The vertical excitation energies in CCl4 are almost the same as those in the isolated environment, but some changes were found in the triplet excitation states. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004