Other Derivatives (other + derivative)

Distribution by Scientific Domains


Selected Abstracts


Synthesis, Characterization and Electrochemistry of the Novel Dawson-Type Tungstophosphate [H4PW18O62]7, and First Transition Metal Ions Derivatives

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 2 2004
Israel-Martyr Mbomekalle
Abstract Following the synthesis of pure [H4PW18O62]7, (PW18), its derivatives monosubstituted with M (M = MoVI, VIV, VV, MnII, FeIII, CoII, NiII CuII and ZnII) were obtained. All compounds were characterized by elemental analysis, IR, UV/visible and 31P NMR spectroscopy. Their cyclic voltammetry properties were studied as a function of pH and systematically compared with those of their analogs derived from the symmetrical species, [P2W18O62]6,(P2W18). Comparison of the two unsubstituted precursors revealed that the merging of the first two waves of the monophosphate occurred in a less acidic medium than for the diphosphate. The observations point to the higher basicity of the reduced forms of PW18 compared with those of P2W18. The fingerprint pattern observed for ,2 -P2W17M derivatives in media of pH = 3 consisted of the splitting of the third W redox system into two one-electron closely spaced waves which is in contrast to the same system in ,1 -P2W17M. This peculiarity was also obtained for several of the present ,2 -PW17M systems in media of pH = 3 and confirmed that ,2 -substituted derivatives were indeed formed. The absence of this peculiar behavior in some other derivatives is consistent with smooth variations of acid-base properties from one derivative to the next. The electrocatalytic properties of all the compounds are illustrated by the reduction of nitrite by reduced PW18 and of nitrate by reduced ,2 -PW17Cu. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]


The essential oil of Pectis elongata Kunth occurring in north Brazil

FLAVOUR AND FRAGRANCE JOURNAL, Issue 5 2005
Milton Helio L. da Silva
Abstract The oils of Pectis elongata were hydrodistilled and analysed by GC and GC,MS. The major constituents identified in the oils of fresh and dried samples of a specimen collected in Pará state, Brazil, were perilla aldehyde (51.7% and 64.6%) and limonene (43.7% and 33.7%), respectively. The main compound found in the oil of a dried sample of another specimen collected in Amapá state, Brazil, was perilla aldehyde (81.9%), followed by its oxidation derivatives, perilla alcohol (5.6%) and perilla acid (4.0%). The higher percentage of perilla aldehyde in the dried samples is due to the loss of limonene during the drying stage. Probably, the plant oxidation process is initiated in the 1-methyl group of limonene, converting it to perilla alcohol and thence to the other derivatives. Copyright © 2005 John Wiley & Sons, Ltd. [source]


Pyrimido[4,5- c]pyridazine-5,7(6H, 8H)-diones: Marvelous substrates for study of nucleophilic substitution of hydrogen

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2005
Alexander F. Pozharskii
The data on nucleophilic substitution reactions of hydrogen in 6,8-dimethylpyrimido[4,5- c]pyridazine-5,7(6H,8H)-dione, its 3-chloride, N2 -oxide and some other derivatives are reviewed. All these compounds possess a remarkable ability to undergo not only simple functionalizations but also tandem and cascade transformations leading to annelation of various heterocyclic rings. [source]


Amyloid precursor protein-mediated free radicals and oxidative damage: Implications for the development and progression of Alzheimer's disease

JOURNAL OF NEUROCHEMISTRY, Issue 1 2006
P. Hemachandra Reddy
Abstract Alzheimer's disease (AD) is a late-onset dementia that is characterized by the loss of memory and an impairment of multiple cognitive functions. Advancements in molecular, cellular, and animal model studies have revealed that the formation of amyloid beta (A,) and other derivatives of the amyloid precursor protein (APP) are key factors in cellular changes in the AD brain, including the generation of free radicals, oxidative damage, and inflammation. Recent molecular, cellular, and gene expression studies have revealed that A, enters mitochondria, induces the generation of free radicals, and leads to oxidative damage in post-mortem brain neurons from AD patients and in brain neurons from cell models and transgenic mouse models of AD. In the last three decades, tremendous progress has been made in mitochondrial research and has provided significant findings to link mitochondrial oxidative damage and neurodegenerative diseases such as AD. Researchers in the AD field are beginning to recognize the possible involvement of a mutant APP and its derivatives in causing mitochondrial oxidative damage in AD. This article summarizes the latest research findings on the generation of free radicals in mitochondria and provides a possible model that links A, proteins, the generation of free radicals, and oxidative damage in AD development and progression. [source]


Analysis of interaction modes in calix[4]arene,levofloxacin complexes by quantum methods

JOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 3 2006
Alexandrine Lambert
Abstract Host,guest interactions between chiral calix[4]arenes and the antibiotic levofloxacin are analyzed on the basis of quantum mechanical calculations at the density functional (for model systems) and semi-empirical levels. The calix[4]arene macrocycle carries two (+)-isomenthyl groups attached to opposing phenyl groups at the lower rim and different substituents (R,=,H, CH3, tBu, CH2CHCH2, COCH3 and NO2) are considered at the upper rim. Nitro derivatives are expected to form ionized complexes whereas the other derivatives should form neutral complexes with a very low stability. Copyright © 2006 John Wiley & Sons, Ltd. [source]


HEDGING STRATEGIES AND MINIMAL VARIANCE PORTFOLIOS FOR EUROPEAN AND EXOTIC OPTIONS IN A LÉVY MARKET

MATHEMATICAL FINANCE, Issue 4 2010
Wing Yan Yip
This paper presents hedging strategies for European and exotic options in a Lévy market. By applying Taylor's theorem, dynamic hedging portfolios are constructed under different market assumptions, such as the existence of power jump assets or moment swaps. In the case of European options or baskets of European options, static hedging is implemented. It is shown that perfect hedging can be achieved. Delta and gamma hedging strategies are extended to higher moment hedging by investing in other traded derivatives depending on the same underlying asset. This development is of practical importance as such other derivatives might be readily available. Moment swaps or power jump assets are not typically liquidly traded. It is shown how minimal variance portfolios can be used to hedge the higher order terms in a Taylor expansion of the pricing function, investing only in a risk-free bank account, the underlying asset, and potentially variance swaps. The numerical algorithms and performance of the hedging strategies are presented, showing the practical utility of the derived results. [source]


Stochastic Volatility Corrections for Interest Rate Derivatives

MATHEMATICAL FINANCE, Issue 2 2004
Peter Cotton
We study simple models of short rates such as the Vasicek or CIR models, and compute corrections that come from the presence of fast mean-reverting stochastic volatility. We show how these small corrections can affect the shape of the term structure of interest rates giving a simple and efficient calibration tool. This is used to price other derivatives such as bond options. The analysis extends the asymptotic method developed for equity derivatives in Fouque, Papanicolaou, and Sircar (2000b). The assumptions and effectiveness of the theory are tested on yield curve data. [source]


NMR and UPLC-qTOF-MS/MS characterisation of novel phenylethanol derivatives of phenylpropanoid glucosides from the leaves of strawberry (Fragaria × ananassa cv. Jonsok)

PHYTOCHEMICAL ANALYSIS, Issue 5 2009
Kati Hanhineva
Abstract Introduction Strawberry (Fragaria × ananassa) is rich in polyphenols, particularly anthocyanins, flavonols, condensed tannins and ellagic tannins. In addition to the fruits, the leaves of strawberry also contain a wide range of phenolic compound classes, but have not been investigated to the same extent as the fruit. Objective To characterise a metabolite group present in the leaves of strawberry, that was not amenable for identification based on earlier information available in the literature. Methodology Methanolic extracts of strawberry leaves were analysed by UPLC-qTOF-MS/MS and iterative quantum mechanical NMR spectral analysis. Results The structures of phenylethanol derivatives of phenylpropanoid glucosides Eutigoside A ( F4) and its two isomeric forms 2-(4-hydroxyphenyl)ethyl-[6- O -(Z)-coumaroyl]- ,- d -glucopyranoside ( F6) and 4-(2-hydroxyethyl)phenyl-[6- O -(e)-coumaroyl]- ,- d -glucopyranoside ( F1) were resolved by NMR and UPLC-qTOF-MS/MS. In addition, two other derivatives of phenylpropanoid glucosides similar to Eutigoside A but possessing different phenolic acid moieties, namely Grayanoside A ( F5) and 2-(4-hydroxyphenyl)ethyl-[6- O -(e)-caffeoyl]- ,- d -glucopyranoside ( F14), were similarly identified. Also, accurate characteristic coupling constants for the subunits are reported and their usefulness in structural analysis is highlighted. Conclusion Chemical analysis of the leaves of strawberry (Fragaria × ananassa cv. Jonsok) resulted in the identification of a compound class, phenylethanol derivatives of phenylpropanoid glycosides, not previously found in strawberry. Copyright © 2009 John Wiley & Sons, Ltd. [source]


Luminescence properties of poly- (phenylene vinylene) derivatives

POLYMER INTERNATIONAL, Issue 3 2008
Cuong Ton-That
Abstract BACKGROUND: Conjugated polymers, especially those of the poly(phenylene vinylene) (PPV) family, are promising candidates as emission material in light-emitting devices. The aim of this work was to investigate the dependence of the luminescence properties of PPV-based derivatives on their polymer structure, especially side groups. RESULTS: Three PPV derivatives, BEHPPV, MEHPPV and MEHSPPV, were synthesised and characterised by photoluminescence (PL) and cathodoluminescence (CL) spectroscopies in the temperature range 10,300 K. PL and CL spectra of the polymers exhibit similar luminescence peaks, which undergo a blue shift with increasing temperature. The shift in wavelength is accompanied by variations in the relative intensities of emission peaks. Both BEHPPV and MEHPPV display emission characteristics of the PPV backbone, but the peak of MEHPPV shifts to a longer wavelength in comparison with the corresponding peak of BEHPPV at the same temperature. The luminescence spectra of MEHSPPV, which has a sulfanyl incorporated in the side chain, are considerably different from those of the two other derivatives. CONCLUSIONS: The results demonstrate that the luminescence properties depend strongly on the chain conformations of the conjugated backbone, which are affected by polymer side chains. Copyright © 2007 Society of Chemical Industry [source]


Quinolin-6-ol at 100,K

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 2 2009
Anna Michta
The title compound, C9H7NO, has two symmetry-independent molecules in the asymmetric unit, which have different conformations of the hydroxy group with respect to the quinoline ring. One of the molecules adopts a cis conformation, while the other shows a trans conformation. Each type of independent molecule links into a separate infinite O,H...N hydrogen-bonded chain with the graph-set notation C(7). These chains are perpendicular in the unit cell, one extended in the a -axis direction and the other in the b -axis direction. There is also a weak C,H...O hydrogen bond with graph-set notation D(2), which runs in the c -axis direction and joins the two separate O,H...N chains. The significance of this study lies in the comparison drawn between the experimental and calculated data of the crystal structure of the title compound and the data of several other derivatives possessing the hydroxy group or the quinoline ring. The correlation between the IR spectrum of this compound and the hydrogen-bond energy is also discussed. [source]


Synthesis of New Nonclassical Acridines, Quinolines, and Quinazolines Derived from Dimedone for Biological Evaluation

ARCHIV DER PHARMAZIE, Issue 9 2010
Osama I. El- Sabbagh
Abstract New nonclassical acridines, quinolines, and quinazolines were prepared starting from cyclic , -diketones, namely dimedone, through application of Hantzsch addition, Michael addition, and Mannich reactions, respectively. The antimicrobial activity revealed that decahydroacridin-1,8-dione 2e bearing a 3-nitrophenyl group and hexahydroquinoline 4e having a 2,4-dichlorophenyl moiety were the most active compounds against both Gram-positive and -negative bacteria based upon using the disc diffusion method. Cytotoxic activity studies for decahydroacridin-1,8-diones 2a,e against liver carcinoma cells (HepG2) using the MTT cell viability assay revealed that decahydroacridin-1,8-dione bearing a 4-methylphenyl moiety 2d showed a higher cytotoxic activity (IC50,=,4.42,µg/mL) than the other derivatives. [source]


Identification of flurbiprofen and its photoproducts in methanol by gas chromatography,mass spectrometry

BIOMEDICAL CHROMATOGRAPHY, Issue 5 2007
Su-Hui Chao
Abstract A sample of 10 mm flurbiprofen in methanol (or ethanol) was photoirradiated with sixteen 8 W low-pressure quartz mercury lamps irradiated at 306 nm in a Panchum PR-2000 photochemical reactor. In total, four major photoproducts derived from each sample were observed from the HPLC chromatogram. The photoproducts were separated and their structures elucidated by various spectroscopic methods. Alternatively, using GC-MS, 11 major photoproducts were observed. A reaction scheme of flurbiprofen in methanol is proposed: the photochemical reaction routes occur mainly via esterification and decarboxylation, followed by oxidation with singlet oxygen to produce a ketone, alcohols and other derivatives. Copyright © 2007 John Wiley & Sons, Ltd. [source]