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Sanjai Karpagaselvi - - 2012
In routine histopathology, decalcification of bone and teeth is often an essential and important step during tissue processing. Various decalcifying agents have been used in the past. The rate of decalcification and the effect of decalcifying agents on the tissue and its staining characteristics are two important parameters which influence ...
Papagianni Maria - - 2012
ABSTRACT: This paper gives an overview of the recent advances in engineering the central carbon metabolism of the industrially important bacteria Escherichia coli, Bacillus subtilis, Corynobacterium glutamicum, Streptomyces spp., Lactococcus lactis and other lactic acid bacteria. All of them are established producers of important classes of products, e.g. proteins, amino ...
Polavarapu Prasad L - - 2012
Chiroptical spectroscopy is being widely used for determining the three-dimensional molecular structures (i.e., absolute configurations and conformations) of chiral molecules. The general procedure used with any of the chiroptical spectroscopic methods is to analyze the experimental data using corresponding quantum chemical predictions. Such analysis involves multiple steps, including consideration of ...
Liu Li L Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL 33199, - - 2012
Four metabolites of okadaic acid were generated by incubation with human recombinant cytochrome P450 3A4. The structures of two of the four metabolites have been determined by MS/MS experiments and 1D and 2D NMR methods using 94 and 133 μg of each metabolite. The structure of a third metabolite was ...
Wang Yu - - 2012
A filtration-aided acid cleaning method was used to collect biosilica structures from a diatom culture medium, natural seawater, or water bloom. Cell extraction, acid cleaning, and acid removal were all performed on a polytetrafluoroethylene (PTFE) filter cloth, significantly improving the treatment capacity and efficiency of the traditional acid wash method. ...
Li Yaya - - 2012
Single-walled carbon nanotubes (SWCNTs) fabricated by sodium dodecyl sulfate (SDS) (f-SWCNTs) modified glassy carbon electrodes (f-SWCNTs/GCE) for the simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA). The f-SWCNTs/GCE displayed very good electrochemical catalytic activities with respect to GCE. The oxidation over-potentials of DA and UA decreased ...
Sukumaran Pradeesh - - 2012
Bidens biternata, belonging to the family Asteraceae, is an erect annual herb, up to 1 cm in height, and a widespread weed of cultivated areas. This plant is common, particularly in the Western Ghats regions of Kerala state in India. It is used as a leafy vegetable by the Paniya and ...
Liu Wei - - 2012
A portion of hemicelluloses and acetic acid can be pre-extracted with dilute sulfuric acid prior to aspen chemi-thermomechanical pulp (CTMP) process. The streams collected from the second press-impregnation stage after acid pre-extraction contain significant amount of acid pre-extracted hemicelluloses. Most of total sugars obtained from the pressate were xylan, in ...
Li Heng - - 2012
The carbonylation of a 1-lithio-1,3-butadiene derivative with CO gave rise to a butadienyl acyllithio intermediate, which underwent an immediate intramolecular acyllithiation of the C=C double bond affording a lithio cyclopentadienyl enolate. The X-ray structural analysis of the enolate revealed a dimer connected with a "Li2O2" four-membered ring. Subsequent intermolecular acylation ...
Esche Rebecca - - 2012
An approach based on solid-phase extraction for the effective separation of free phytosterols/-stanols and phytosteryl/stanyl fatty acid and phenolic acid esters from cereal lipids was developed. The ester conjugates were analyzed in their intact form by means of capillary gas chromatography. Besides free sterols and stanols, up to 33 different ...
Smith Graham - - 2012
The racemic title compound, C(9)H(11)NO(4)·H(2)O, a tricyclic rearranged amino-norbornane dicarb-oxy-lic acid, is a conformationally rigid analogue of glutamic acid and exists as an ammonium-carboxyl-ate zwitterion, with the bridghead carb-oxy-lic acid group anti-related. In the crystal, N-H⋯O and O-H⋯O hydrogen bonds involving the ammonium, carb-oxy-lic acid and water donor groups with ...
Hu Fan - - 2012
Pseudo-lignin, which can be broadly defined as aromatic material that yields a positive Klason lignin value and is not derived from native lignin, has been recently reported to form during the dilute acid pretreatment of poplar holocellulose. To investigate the chemistry of pseudo-lignin formation, GPC, FT-IR and (13)C NMR were ...
Wang Kun - - 2012
In order to understand the behaviors of hemicelluloses and lignin under the given acidic conditions with increasing severity, the structural characteristics were elucidated in detail by both wet chemistry methods and spectroscopic analyses in this study. Although acidic pretreatment significantly hydrolyzed the glycosidic linkages in xylan backbone and then reduced ...
Cabanillas Billy Joel - - 2012
Two new dihydrochalcones (1, 2), as well as eight known compounds, piperaduncin C (3), 2',6'-dihydroxy-4'-methoxydihydrochalcone (4), 4,2',6'-trihydroxy-4'-methoxydihydrochalcone (5), 4-hydroxy-3,5-bis(3-methyl-2-butenyl)-benzoic acid (6), 3,5-bis(3-methyl-2-butenyl)-4-methoxybenzoic acid (7), 4-hydroxy-3-(3-methyl-2-butenoyl)-5-(3-methyl-2-butenyl)-benzoic acid (8), 2,2-dimethyl-8-(3-methyl-2-butenyl)-2H-1-chromene-6-carboxylic acid (9), and 3-(3',7'-dimethyl-2',6'-octadienyl)-4-methoxybenzoic acid (10) were isolated from the leaves of Piper dennisii Trelease (Piperaceae), using a bioassay-guided fractionation to determine ...
Chaudhuri Prabir K PK Central Institute of Medicinal and Aromatic Plants, Medicinal Plants Chemistry Section, PO CIMAP, Lucknow 226015, Uttar Pradesh, India. - - 2013
A new triterpenoid, 2α,24-diacetoxy-3β-hydroxyolean-12-en-28-oic acid (1), was characterised from the rhizomes of Nelumbo nucifera Gaertn by spectroscopic and chemical methods along with four known compounds, hyptatic acid-A (2α,3β,24-trihydroxyolean-12-en-28-oic acid) (2), maslinic acid (2α,3β-dihydroxyoleane-12-ene-28-oic acid), betulin and lupeol.
Cruz Andre F - - 2012
Fusarium diseases cause major economic losses in wheat-based crop rotations. Volatile organic compounds (VOC) in wheat and rotation crops, such as chickpea, may negatively impact pathogenic Fusarium. Using the headspace GC-MS method, 16 VOC were found in greenhouse-grown wheat leaves: dimethylamine, 2-methyl-1-propanol, octanoic acid-ethyl ester, acetic acid, 2-ethyl-1-hexanol, nonanoic acid-ethyl ...
Liu Jingyi - - 2012
Caffeoylquinic acids and lignans in the crude extracts of both roots and seeds from different burdock ( Arctium lappa L.) genotypes were simultaneously characterized and systematically compared by LC-MS and matrix-assisted laser desorption/ionization quadrupole ion trap time-of-flight mass spectrometry (MALDI-QIT-TOF MS), and their antioxidant activities were also investigated. A total ...
Szakiel Anna - - 2012
ABSTRACT: Triterpenoid compounds extracted from fruits and leaves of lingonberry (Vaccinium vitis-idaea L.) collected in Finland and Poland were identified and quantitated by GC-MS/FID. The main lingonberry triterpenoid profile consisted of α-amyrin, β-amyrin, betulin, campesterol, cycloartanol, erythrodiol, fern-7-en-3β-ol, friedelin, lupeol, sitosterol, stigmasterol, stigmasta-3,5-dien-7-one, swert-9(11)-en-3β-ol, taraxasterol, urs-12-en-29-al, uvaol, oleanolic acid and ...
Momo Itbert Joseph - - 2012
A new pentacyclic triterpenoid and three new derivatives based on the taraxer-14-ene skeleton with a C-28 attached a carboxylic acid group have been isolated from the stem bark of Hypodaphnis zenkeri, together with six known compounds. The new product was identified as 2α,3α-dihydroxytaraxer-14-en-28-oic acid (1). Its derivatives, 2α,3α-diacetyltaraxer-14-en-28-oic acid (2), ...
Massaad Julie - - 2012
The present study quantitatively analyses the gated photochromism and the acidity photomodulation properties of a diacid dithienylethene compound. Photoisomerisation between the open and closed isomers was investigated by UV/visible and (1) H NMR spectroscopy. It was found that the photocyclisation quantum yield of the diacid form was remarkably high (around 90 %). ...
Lakshmi Prasuna M - - 2012
A phototrophic bacterium (Rubrivivax benzoatilyticus JA2) grows at the expense of l-phenylalanine as sole source of nitrogen but not as carbon source. Near stoichiometric yields of l-phenylpyruvic acid (0.4mM) and l-phenyllactate (0.4mM) were observed from l-phenylalanine (0.9mM consumed). Aminotransfarase and dehydrogenase activities involved in the formation of l-phenylpyruvic acid and ...
Fang Ping - - 2012
Catalytic α-allylation of unprotected amino acid esters to produce α-quaternary α-allyl amino acid esters is reported. Catalytic loadings of picolinaldehyde and Ni(II) salts induce preferential reactivity at the enolizable α-carbon of amino acid esters over the free nitrogen with electrophilic palladium π-allyl complexes. Fourteen examples are given. Additionally, the use ...
Ali Abuzer - - 2012
Two lupeol-type pentacyclic triterpenoids characterised as lup-20(29)-en-3β-ol-27-oic acid (moruslupenoic acid A) and lup-12, 20(29)-dien-3β-ol-26-oic acid (moruslupenoic acid B) and lanst-5, 24-dien-3β-yl acetate (moruslanosteryl acetate) along with the known triterpenoidal phytoconstituents α-amyrin acetate, β-amyrin-β-D-glucopyranoside and betulinic acid have been isolated from the stem bark of Morus alba L. (Moraceae). The structures ...
Mai Thi Thoa - - 2012
Frozen: The spontaneous crystallization of an achiral compound in a chiral conformation is used as unique source of chirality in an absolute asymmetric synthesis of tertiary amino acids. The dynamic axial chirality of tertiary aromatic amides is frozen in a crystal and is responsible for the stereoselectivity of the deprotonation/alkylation. ...
Shah Heena J - - 2012
Dioscorea alata var. purpurae (Indian purple yam) is an important source of diosgenin, a triterpenoid that is used as a raw material in the synthesis of corticosteroid hormones. These drugs are used for the treatment of pharmacological conditions such as arthritis. This paper reports in vitro propagation of explants of ...
Zhao Huazhang - - 2012
Electrochemical reduction of carbon dioxide (CO2) to useful chemical materials is of great significance to the virtuous cycle of CO2. However, some problems such as high overpotential, high applied voltage and high energy consumption exist in the course of the conventional electrochemical reduction process. This study presents a new CO2 ...
Wuensch Christiane - - 2012
The enzymatic carboxylation of phenol and styrene derivatives using (de)carboxylases in carbonate buffer proceeded in a highly regioselective fashion: Benzoic acid (de)carboxylases selectively formed o-hydroxybenzoic acid derivatives, phenolic acid (de)carboxylases selectively acted at the β-carbon atom of styrenes forming (E)-cinnamic acids.
Kimura Ken-Ichi - - 2012
A new compound, 15,20-dinor-5,7,9-labdatriene-18-ol (1), named kujigamberol, was isolated from amber, fossilized tree resin from the Kuji area in Japan, has been dated as being 85Ma old (late Cretaceous). Kujigamberol was identified using the hypersensitive mutant yeast (zds1∆ erg3∆ pdr1∆ pdr3∆) with respect to Ca(2+)-signal transduction. The structure was elucidated ...
Kauffman Marcelo Andrés - - 2012
Cerebrotendinous xanthomatosis (CTX) is a treatable disorder of bile acid production caused by mutations in the mitochondrial enzyme sterol 27-hydroxilase. This inborn error of bile acid metabolism results in lipid pathologic accumulation in multiple tissues. Progressive neuropsychiatric disturbances are a frequent manifestation of this disease. Although seizures have been frequently ...
Radhika Parvataneni - - 2012
Phytochemical investigation of the methanolic extract of the leaves of Andrographis paniculata Nees yielded a minor, new diterpene, 21-nor-3,19-isopropylidine-14-deoxy-ent-labda-8(17),13-dien-16,15-olide (1), together with five known labdane type diterpenes, andrographolide 3, 14-deoxyandrographolide 4, 14-deoxy-12-hydroxyandrographolide 5, 14-deoxy-11,12-dihydroandrographolide 6, neoandrographolide 7, and two acids, cinnamic acid 8, and ferulic acid 9. The chemical structures ...
Jariwala Freneil B - - 2012
In the negative-ion collision-induced dissociation mass spectra of most organic sulfonates, the base peak is observed at m/z 80 for the sulfur trioxide radical anion (SO(3) (-·) ). In contrast, the product-ion spectra of a few sulfonates, such as cysteic acid, aminomethanesulfonate, and 2-phenylethanesulfonate, show the base peak at m/z ...
Shao Meng - - 2012
Four new triterpenoids, psiguanins A-D (1-4), along with 13 known ones (5-17), were isolated from the leaves of Psidium guajava. The structures of new compounds were determined as 2α,3β-dihydroxy-taraxer-20-en-28-oic acid (1), 2α,3β,12α,13β-tetrahydroxy-urs-28-oic acid (2), 2α,3β,12β,13β-tetrahydroxy-urs-28-oic acid (3), and 2α,3β,12β,13α-tetrahydroxy-urs-28-oic acid (4), respectively, on the basis of comprehensive spectroscopic methods and ...
Bednarczyk-Cwynar Barbara - - 2012
Amide formation is one of the reactions that can be undertaken within the carboxyl group of oleanolic acid. A simple method for oleanolic acid anilide and toluidides synthesis is presented. The influence of the location of the methyl substituent on the reactivity of the amine group was tested and the ...
Mukherjee Tulika - - 2012
Chemical investigation of the leaves of Putranjiva roxburghii has resulted in the isolation of two new triterpenoids, putralone, a novel 10alpha-hydroxy-25-nor D:A friedo-olean-9(11)-en-3 one and 3beta-acetoxy-cycloart-24-en-23-one, along with a rare hopanoid, adian-5-en-3beta,29-diol. Other known triterpenoids isolated from this plant are 3beta-acetoxy-adian-5-ene, putrol, putrone, putranjivadione, roxburghonic acid, friedelin, friedlan-3alpha-ol, oleanolic acid ...
Fayek Nesrin M - - 2012
Manilkara zapota (L.) Van Royen is an evergreen tree, native to the tropical Americas and introduced to Egypt as a fruiting tree in 2002. No previous study was reported on the plant cultivated in Egypt. In this study, the leaves of the plant cultivated in Egypt were subjected to phytochemical ...
Bevilacqua Lorenzo - - 2012
The aim of this clinical trial was to compare clinical and biochemical healing outcomes following ultrasonic mechanical instrumentation versus ultrasonic mechanical instrumentation associated with topical subgingival application of amino acids and sodium hyaluronate gel. Eleven systemically healthy subjects with moderate-severe chronic periodontitis, who had four sites with pocket probing depth ...
Dos Santos Fernanda M - - 2012
This work describes the phytochemical study of the extracts from aerial parts of Tibouchina candolleana as well as the evaluation of the antimicrobial activity of extracts, isolated compounds, and semi-synthetic derivatives of ursolic acid against endodontic bacteria. HRGC analysis of the n-hexane extract of T. candolleana allowed identification of β-amyrin, ...
Hopkins Todd Anthony - - 2012
The chiral discrimination ability of amino acid based chiral ionic liquids is studied using chiroptical luminescence techniques. A racemic mixture of dissymmetric europium tris 2,6-pyridinedicarboxylate complexes are dissolved in five chiral ionic liquids, including L- and D-alanine methyl ester bis(trifluoromethanesulfonimide), L-leucine methyl ester bis(trifluoromethanesulfonimide), L-proline methyl ester bis(trifluoromethanesulfonimide), and tetrabutylammonium ...
Barros Helena Rudge de Moraes - - 2012
Four Citrus species (C. sinensis, cvs. Pera and Lima; C. latifolia Tanaka cv. Tahiti; C. limettioides Tanaka cv. Sweet lime and C. reticulate, cv. Ponkan) grown in Brazil were characterised in relation to contents of minerals, ascorbic acid, total polyphenols and antioxidant capacity of pulps and peels. In general, the ...
Baslé Olivier - - 2012
Phosphine-boronates R(2)P(o-C(6)H(4))B(OR')(2) have been evaluated as bifunctional organocatalysts for the Michael addition of malonate pronucleophiles to methylvinylketone. The presence of the Lewis acidic boron center adjacent to phosphorus significantly improves catalytic performance. Isolation and complete characterization of a key intermediate, namely a β-phosphonium enolate, substantiate the role of the Lewis ...
Huang Hung-Yi - - 2012
Bioassay-guided fractionation of the roots of Anneslea fragrans var. lanceolata led to the isolation of four dihydrochalcone glucosides, davidigenin-2'-O-(6″-O-4″'-hydroxybenzoyl)-β-glucoside (1), davidigenin-2'-O-(2″-O-4″'-hydroxybenzoyl)-β-glucoside (2), davidigenin-2'-O-(3″-O-4″'-hydroxybenzoyl)-β-glucoside (3), and davidigenin-2'-O-(6″-O-syringoyl)-β-glucoside (4), and 13 known compounds. The structures were identified by means of spectroscopic analysis. Davidigenin-2'-O-(6″-O-syringoyl)-β-glucoside (4), 1-O-3,4-dimethoxy-5-hydroxyphenyl-6-O-(3,5-di-O-methylgalloyl)-β-glucopyranoside (5), lyoniresinol (10), and syringic acid (13) ...
Ferchichi Loubna - - 2012
Advanced glycation end-products (AGEs) are associated with many pathogenic disorders such as Alzheimer's disease, pathogenesis of diabetes, atherosclerosis or endothelial dysfunction leading to cardiovascular events. Clusiaceae and Calophyllaceae families are rich in compounds like polyphenols which are able to inhibit their formation and are therefore of great interest. Calophyllum flavoramulum ...
Duckstein Sarina M - - 2012
INTRODUCTION: Hamamelis virginiana, known for its high level of tannins and other phenolics is widely used for treatment of dermatological disorders. Although reports on hydroalcoholic and aqueous extracts from Hamamelis leaf and bark exist, knowledge on fermented leaf preparations and the underlying conversion processes are still scant. OBJECTIVE: Aqueous Hamamelis ...
Saini Ratni - - 2012
A stereoselective synthesis of (25S)-Δ(1)-, (25S)-Δ(1,4)-, (25S)-Δ(1,7)-, (25S)-Δ(8(14))-, (25S)-Δ(4,6,8(14))-dafachronic acid, methyl (25S)-Δ(1,4)-dafachronate and (25S)-5α-hydroxy-3,6-dioxocholest-7-en-26-oic acid is described. (25S)-Δ(1,4)-Dafachronic acid and its methyl ester are natural products isolated from corals and have been obtained by synthesis for the first time. (25S)-5α-Hydroxy-3,6-dioxocholest-7-en-26-oic acid represents a promising synthetic precursor for cytotoxic marine steroids.
Rattanaburi Suthida - - 2012
A new chromone, 5,7-dihydroxy-2 -(hydroxymethyl)-6,8-dimethyl-chromen-4-one, named melachromone, together with 12 known compounds, including chromones, anthraquinone, flavonoids, flavonoid glycosides, benzene derivatives, ellagic acids and terpenes, were isolated from the leaves of Melaleuca cajuputi Powell. Their structures were characterised by spectroscopic methods.
Scott William G - - 2012
The process of building and refining crystal structures of nucleic acids, although similar to that for proteins, has some peculiarities that give rise to both various complications and various benefits. Although conventional isomorphous replacement phasing techniques are typically used to generate an experimental electron-density map for the purposes of determining ...
McGinty D - - 2012
A toxicologic and dermatologic review of 1,1-dimethyl-2-phenylethyl acetate when used as a fragrance ingredient is presented. 1,1-Dimethyl-2-phenylethyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an Aryl Alkyl Alcohol with a simple carboxylic acid ...
McGinty D - - 2012
A toxicologic and dermatologic review of piperonyl acetate when used as a fragrance ingredient is presented. Piperonyl acetate is a member of the fragrance structural group aryl alkyl alcohol simple acid esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid ...
Karlsson Niclas G - - 2012
The O-linked glycosylation of the main acidic high molecular weight glycoprotein from ascites fluid from patients with ovarian cancer were analysed. The O-linked oligosaccharides were shown to consist of mainly highly sialylated core 1 and core 2 structures with a smaller amount of sulfated core 2 structures. These structures were ...
Hu Youcai - - 2012
Erythrolic acids A-E (1-5) are five unusual meroterpenoids isolated from the bacterium Erythrobacter sp. derived from a marine sediment sample collected in Galveston, TX. The structures were elucidated by means of detailed spectroscopic analysis and chemical derivatization. The erythrolic acids contain a 4-hydroxybenzoic acid appended with a modified terpene side ...
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