Search Results
Results 201 - 250 of 1416
< 1 2 3 4 5 6 7 8 9 10 >
Ravikumar S - - 2012
Five species of Azospirillum isolated from Manakkudi mangrove ecosystem were subjected for their efficiency to find out their growth parameters potential for the successful establishment of mangrove seedlings. Of the isolated five Azospirillum species, Azospirillum lipoferum (60%) was found to be the dominant one. But the level of maximum indole ...
Nguyen Cuong Mai - - 2012
D-lactic acid production from dry biomass of the microalga, Hydrodictyon reticulatum, was carried out in a 5-l jar fermentor (initial pH 6, 34 °C using CaCO(3) as a neutralizing agent) through simultaneous saccharification and co-fermentation using the Lactobacillus coryniformis subsp. torquens. After 36 h, 36.6 g lactic acid/l was produced ...
Jiang Jie - - 2012
In this communication, we report a general strategy for the production of carbon nanodots (CDs) by microwave irradiation of amino acids in the presence of acid or alkali. The resultant CDs exhibit strong photoluminescence and intense chemiluminescence enhancement of the NaIO(4)-H(2)O(2) system.
Gill Vanessa Leah VL Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, United - - 2012
Heparan sulfate (HS) glycosaminoglycans (GAGs) regulate a host of biological functions. To better understand their biological roles, it is necessary to gain understanding about the structure of HS, which requires identification of the sulfation pattern as well as the uronic acid epimerization. In order to model HS structure, it is ...
Caligiani Augusta - - 2013
The occurrence of triterpene pentacyclic acids in plants is extensive, but little is known about their availability in commercial extracts. A simple GC-MS method for the simultaneous determination of betulinic, corosolic, maslinic, oleanolic and ursolic acids was developed and applied to 38 different commercial plant extracts sold as ingredients for ...
San Juan Ronan R - - 2012
We report the formation and characterization of self-assembled monolayers (SAMs) based on dialkyldithiophosphinic acid adsorbates {[CH3(CH2)n]2P(S)SH (n = 5, 9, 11, 13, 15)} on gold substrates. The SAMs were characterized using x-ray photoelectron spectroscopy, reflection-absorption infrared spectroscopy, contact angle measurements, and electrochemical impedance spectroscopy. The data show that there is ...
Kumar Maushmi S - - 2012
The sensitivity, specificity and selectivity of liquid chromatography/mass spectrometry tandem mass spectrometry (LC-MS/MS) make it an essential tool for the characterization and identification of low molecular compounds such as fatty acids, sterols, cholastane derivatives, nucleosides etc. In the current work, the marine sponge Spongosorites halichondriodes (order Halichondrida, Family Halichondriidae); a ...
Pell Reinhard - - 2012
Novel zwitterionic cinchona alkaloid-based chiral selectors (SOs) were synthesized and immobilized on silica gel. The corresponding brush-type chiral stationary phases (CSPs) were characterized as zwitterionic ion-exchange-type materials and exhibited remarkable enantioselectivity for their zwitterionic target analytes, viz. underivatized amino acids and aminosulfonic acids. We rationally designed structural modifications on the ...
Williams David E - - 2012
Two new merohexaprenoids, halicloic acids A (1) and B (2), have been isolated from the marine sponge Haliclona (Halichoclona) sp. collected in the Philippines. The glycolic acids 1 and 2 slowly decomposed during acquisition of NMR data to aldehydes 3 and 4, respectively, via an oxidative decarboxylation. Halicloic acid B ...
Manley David W - - 2012
Under dry, anaerobic conditions TiO2 photocatalysis of carboxylic acid precursors resulted in carbon-carbon bond forming processes.High yields of dimers were obtained from TiO2 treatment of carboxylic acids alone. On inclusion of electron-deficient alkenes, efficient alkylations were achieved with methoxymethyl and phenoxymethyl radicals. In reactions with maleic anhydride or maleimides, phenoxyacetic ...
Li Na - - 2012
Resorcinarene-based deep cavitands alanine methyl resorcinarene acid (), alanine undecyl resorcinarene acid () and glycine undecyl resorcinarene acid (), which contain chiral amino acids, have been synthesized. The upper rim of the resorcinarene host is elongated with four identical substituents topped with alanine and glycine groups. The structures of the ...
Ohkawa Akiko - - 2012
Chemical investigation of the glandular trichome exudate from Ceratotheca triloba (Pedaliaceae) led to the identification of nine 1-O-acetyl-2-O-[(R)-3-acetyloxy-fatty acyl]-3-O-malonylglycerols. Among these, 1-O-acetyl-2-O-[(R)-3-acetyloxyicosanoyl]-3-O-malonylglycerol (7) was the most abundant constituent (41%), followed by 1-O-acetyl-2-O-[(R)-(3-acetyloxyoctadecanoyl)-3-O-malonylglycerol (2; 21%). Compounds having iso- and anteiso-type structures in the 3-acetyloxy-fatty acyl groups in the fatty acyl moiety ...
Jemia Mariem Ben - - 2012
The volatile constituents of the aerial parts of Centaureaformanekii Halacsy and the aerial parts, capitula and roots of C. orphanidea Heldr. & Sart. ex Boiss. ssp. thessala (Hausskn.) Dostál from Greece were extracted by hydrodistillation and analyzed. The main components in C. formanekii were hexadecanoic acid (13.6%), delta-elemene (9.1%), and ...
Spanò Delia - - 2012
A natural rubber was identified and characterized for the first time in the latex of the perennial Mediterranean shrub Euphorbia characias. Four different methods, i.e., acetone, acetic acid, trichloroacetic acid, and Triton® X-100, followed by successive treatments with cyclohexane/ethanol, were employed to extract the natural rubber. The rubber content was ...
Yanai Hikaru - - 2012
(Z)-Selective olefination of several lactones with ketene silyl acetals was achieved by the catalysis of carbon acids (C-H acids) having a bis(triflyl)methyl group as an acidic functionality; in particular, the triple carbon acid having three bis(triflyl)methyl groups in phloroglucinol shows an excellent catalytic performance.
Asai Teigo - - 2012
Fourteen cyclic glycolipids, named glomerasides A-N, have been isolated from the glandular trichome exudate of Cerastium glomeratum (Caryophyllaceae). Their structures were determined by spectroscopic analysis of the glycolipids, as well as by application of the Ohrui-Akasaka method to the fatty acid methyl esters derived from the glycolipids and GCMS studies ...
Nomoto Yuya - - 2012
From the 1-BuOH-soluble fraction of a MeOH extract of Euphorbia hirta, collected in the Okinawa islands, three new megastigmane glucoside gallates, named hirtionosides A-C, 3-hydroxyoctanoic acid glucosides and a phenylpropanoid glucoside were isolated along with 15 known compounds. The structures of the new compounds were elucidated by detailed analysis of ...
Xin Tao - - 2012
Two acidic polysaccharide fractions (PTPa and PTPb) extracted from the roots of Polygala tenuifolia, were obtained by DEAE-Sephacel anion-exchange, and Sephadex G-100 gel-permeation chromatography. High-performance liquid chromatography (HPLC) identified that PTPa and PTPb was composed of Ara, Glc, Gal, Man and GlcUA in the proportion of 2.4:1.2:0.6:0.4:1.1 and 2.1:1.7:0.5:0.6:1.7, respectively. ...
Huang Lili - - 2012
Catharanthus roseus is an important medicinal plant and the sole commercial source of monoterpenoid indole alkaloids (MIA), anticancer compounds. Recently, triterpenoids like ursolic acid and oleanolic acid have also been found in considerable amounts in C. roseus leaf cuticular wax layer. These simple pentacyclic triterpenoids exhibit various pharmacological activities such ...
Wang Cun-Qin - - 2012
Two unusual triterpenes, ilelic acids A (1) and B (2), together with their biosynthetic related compounds ilelic acids C (3) and D (4) were isolated from the leaves of Ilex latifolia. Their structures with absolute configurations were elucidated by spectroscopic analysis and modified Mosher's method. The plausible biogenetic pathway of ...
Silva P V - - 2012
AIM: To evaluate, by scanning electron microscopy (SEM), the efficacy of smear layer removal using chitosan compared with different chelating agents, and to quantify, by atomic absorption spectrophotometry with flame (AASF), the concentration of calcium ions in these solutions after irrigation. METHODOLOGY: The root canals of twenty-five canines were prepared ...
Wei Huijuan - - 2012
The oxidation-resistant acidic resins are of great importance for the catalytic oxidation systems. In this paper, the oxidatively stable acidic resins are obtained from the cation ion exchange resins (CIERs) through the thermal treatment in N(2) atmosphere. The structure and properties of the thermally treated CIERs were characterized by chemical ...
Zhang Li-Jie - - 2012
Six new triterpenoids, euscaphic acids G-L (1-6), along with nine known triterpene acids, and two known lignans were isolated from the ethanolic extract of the twigs of Euscaphis japonica. This is the first report concerning 1α,3β-dihydroxy-12-oleanen-28-oic acid isolated from a natural source. The structures of the new compounds were established ...
Liu Weiguo - - 2012
We report a new approach to identify swill-cooked oils that are recycled from tainted food and livestock waste from commercial vegetable and animal oils by means of carbon isotope values and relative abundance of fatty acids. We test this method using 40 cooking oil samples of different types with known ...
Muhammad Naveed - - 2012
A new cinnamic acid derivative was isolated from the whole plant of Viola betonicifolia as off white needle. On the basis of various modern spectroscopic techniques including HREI-MS and 1D and 2D NMR, its structure was elucidated as 2,4-dihydroxy, 5-methoxy-cinnamic acid. It showed marked inhibition against DPPH (diphenyl-2-picryl hydrazyl) free ...
Ahmed Marawan - - 2012
X-ray photoelectron spectra of the core and valence levels of the fundamental building blocks of β-lactam antibiotics have been investigated and compared with theoretical calculations. The spectra of the compounds, 2-azetidinone and the 2- and 4- isomers of thiazolidine-carboxylic acid are interpreted in the light of theoretical calculations. The spectra ...
Vandersteen Adelle A - - 2012
Elucidation of the mechanism for decarboxylation of indole-carboxylic acids over a wide range of solution acidity reveals the importance of protonated carbonic acid (PCA) as a reaction intermediate. In concentrated acid, the initial addition of water to the carboxyl group of an indole-carboxylic acid leads to a hydrated species that ...
McCook Kayanne P - - 2012
The insecticidal sesquiterpenes cadina-4,10(15)-dien-3-one and aromadendr-1(10)-en-9-one were administered to the fungus Cyathus africanus ATCC 35853. Biotransformation of the former produced (4R)-9α-hydroxycadin-10(15)-en-3-one, while the latter gave 2β-hydroxyaromadendr-1(10)-en-9-one, 2α-hydroxyaromadendr-1(10)-en-9-one and 10α-hydroxy-1β,2β-epoxyaromadendran-9-one. The bioconversion of santonin led to the production of two analogues, 11,13-dihydroxysantonin and the hitherto unreported 8α,13-dihydroxysantonin, while cedrol yielded 3β,8β-dihydroxycedrane ...
Xiang Wen-Juan - - 2012
A phytochemical investigation of a herb tea made from Thamnolia vermicularis led to the isolation of three new β-orcinol-type depsides (1, 2 and 3), along with seven known compounds hypothamnolic acid (4), 3'-methylevenic acid (5), baeomycesic acid (6), squamatic acid (7), methyl 3'-methyllecanorate (8), barbatinic acid (9) and atranorin (10). ...
Larsen Thomas - - 2012
The relative contribution of carbon from terrestrial vs. marine primary producers to mangrove-based food webs can be challenging to resolve with bulk carbon isotope ratios (δ(13) C). In this study we explore whether patterns of δ(13) C values among amino acids (AAs) can provide an additional tool for resolving terrestrial ...
Huang Fei-Xia - - 2012
Biotransformation of ursolic acid by the filamentous fungus Syncephalastrum racemosum (Cohn) Schroter AS 3.264 yielded five metabolites. Their structures were identified as 3β,21β-dihydroxy-urs-11-en-28-oic acid-13-lactone, 3β,7β,21β-trihydroxy-urs-11-en-28-oic acid-13-lactone, 1β,3β-dihydroxy-urs-12-en-21-one-28-oic acid, 1β,3β,21β-trihydroxy-urs-12-en-28-oic acid and 11,26-epoxy-3β,21β-dihydroxy-urs-12-en-28-oic acid based on NMR and MS spectroscopic analyses. The condensation reactions to form 28-oic acid-13-lactone ring and 11,26-epoxy ...
Rezanka Tomáš - - 2012
Occurrence, biosynthesis, and biodegradation of pivalic acid and other compounds, having a quaternary carbon atom by different bacteria, are described. We have summarized the relevant data that have so far been published, presenting them in a graphical form, i.e., as biodegradation pathways including B(12)-dependent isomerization and desaturation that lead to ...
Kosma Dylan K - - 2012
While suberin is an insoluble heteropolymer, a number of soluble lipids can be extracted by rapid chloroform dipping of roots. These extracts include esters of saturated long-chain primary alcohols and hydroxycinnamic acids. Such fatty alcohols and hydroxycinnamic acids are also present in suberin. We demonstrate that alkyl coumarates and caffeates, ...
Vats Archana - - 2012
Glycopeptidolipids (GPLs) are dominant cell surface molecules present in several non-tuberculous and opportunistic mycobacterial species. GPLs from Mycobacterium smegmatis are composed of a lipopeptide core unit consisting of a modified C(26)-C(34) fatty acyl chain that is linked to a tetrapeptide (Phe-Thr-Ala-alaninol). The hydroxyl groups of threonine and terminal alaninol are ...
de Oliveira Julieta Rangel - - 2012
Marine fungi belonging to the genera Aspergillus, Penicillium, Cladosporium, and Bionectria catalyzed the biotransformation of phenylacetonitrile to 2-hydroxyphenylacetic acid. Eight marine fungi, selected and cultured with phenylacetonitrile in liquid mineral medium, catalyzed it quantitative biotransformation to 2-hydroxyphenylacetic acid. In this study, the nitrile group was firstly hydrolysed, and then, the ...
Wang Jing - - 2012
Three new compounds (Gardeniside A-C), 11α,12α-epoxy-3β-[(O-β-D-glucuronopyranoside-6'-O-methly ester)oxy]olean-28,13-olide (1), siaresinolic acid 3-O-β-D-glucuronopyranoside-6'-O-methly ester (2), and 3-O-β-D- glucuronopyranoside-6'-O-methly ester-siaresinolic acid-28-O-β-D- glucopyranoside (3), with seven known compounds oleanolic acid 3-O-β-D- glucuronopyranoside-6'-O-methly ester (4) , oleanolic acid 3-O-β-D- glucuropyranoside (5) , hederagenin 3-O-β-D- glucuronopyranoside-6'-O- methly ester (6) , chikusetsusaponin IVa methyl ester (7) , ...
Cochrane Nj - - 2012
Background:  Dental erosion is an increasingly prevalent problem in Australia, with the consumption of sports beverages suggested as a risk factor. The aim of this study was to compare the erosive potential of Australian sports beverages. Methods:  Ten beverages were selected and analysed to determine their pH, titratable acidity and ...
Lin Jin-Hong - - 2012
CF(3)- or -CF(2)-containing tetrahydroquinolines have been asymmetrically synthesized from the reaction of fluorinated N-arylimines with benzyl N-vinylcarbamate in the presence of a chiral phosphoric acid.
Hoshino Tatsuro - - 2012
Two new sulfated oleanan saponins, sulfachyranthosides B (1) and D (2), were isolated from a water extract of Achyranthes root (root of Achyranthes bidentata). The structures were determined by analyses of spectroscopic data to be sulfates of achyranthosides B and D, respectively, at the 4'-position of the glucose moiety attached ...
Taira Toshiaki - - 2012
ABSTRACT: Encapsulation of ion-pairs in small spaces that are isolated from the medium is expected to result in amplified interactions between the ions. Yet, sequestration of ion pairs in self-assembled capsules is complicated by competition of the acids and bases for binding directly to the assembly compo-nents. We describe here ...
Zhai Xinyun - - 2012
Carbon nanodots (CDs) with a low cytotoxicity have been synthesized by one-step microwave-assisted pyrolysis of citric acid in the presence of various amine molecules. The primary amine molecules have been confirmed to serve dual roles as N-doping precursors and surface passivation agents, both of which considerably enhanced the fluorescence of ...
Wang Cun - - 2012
A novel electrode was developed through electrodepositing gold nanoparticles (GNPs) on overoxidized-polyimidazole (PImox) film modified glassy carbon electrode (GCE). The combination of GNPs and the PImox film endowed the GNPs/PImox/GCE with good biological compatibility, high selectivity and sensitivity and excellent electrochemical catalytic activities towards ascorbic acid (AA), dopamine (DA), uric ...
Morris Eric A - - 2012
This work addresses the discrepancy in the literature regarding the effects of sulfuric acid (H(2)SO(4)) on elemental Hg uptake by activated carbon (AC). H(2)SO(4) in AC substantially increased Hg uptake by absorption particularly in the presence of oxygen. Hg uptake increased with acid amount and temperature exceeding 500 mg-Hg/g-AC after ...
Williams Russell B - - 2012
High-throughput natural products chemistry methods have facilitated the isolation of eight new (1-8) and two known (9 and 10) beilschmiedic acid derivatives from the leaves of a Gabonese species of Beilschmiedia. Compounds 3-10 were isolated in microgram quantities, and the NMR data for structure elucidation and dereplication were acquired utilizing ...
Nowak SÅ‚awomira - - 2012
2D-TLC and RP-HPLC methods were applied to qualitatively determinate free phenolic acids and those liberated by acid and alkaline hydrolysis in the flowers and leaves of G. robusta and G. squarrosa. The presence of eleven phenolic acids, namely: caffeic, chlorogenic, p-coumaric, p-hydroxybenzoic, ferulic, gallic, protocatechuic, vanillic salicylic, p-hydroxyphenylacetic and ellagic ...
Klaiklay Saranyoo - - 2012
Two new succinic acid derivatives, xylacinic acids A (1) and B (2), along with seven known compounds, including one succinic acid derivative (3), three mellein derivatives (4-6), cytochalasin D (7), 2-chloro-5-methoxy-3-methylcyclohexa-2,5-diene-1,4-dione (8) and isosclerone (9), were isolated from the mangrove-derived fungus Xylaria cubensis PSU-MA34. Their structures were established by spectroscopic ...
Verma Subash Chandra - - 2012
Arjunic acid and arjunolic acid are main bioactive components of Terminalia arjuna stem bark and reported for various biological activities. In this study, microwave-assisted extraction (MAE) of arjunic and arjunolic acid from stem bark of T. arjuna was investigated with developed and validated HPLC-PDA method, which resulted in the isolation ...
Minocha Tanuj - - 2012
The purpose of this study was to evaluate and compare the root surface changes subsequent to the application of citric acid, tetracycline, Ethylenediaminetetraacetic acid (EDTA), and the combination of citric acid and tetracycline, and its influence on the adhesion of a fibrin clot with and without mild disruptive forces. A ...
Lee Seung-Mi SM Dept of Food Science and Technology, Pukyong Natl Univ, Daeyeon Campus 45 Yongso-ro, Nam-Gu, Busan 608-737, Republic of - - 2012
Lecithin was isolated and characterized from anchovy (Engraulis japonica) deoiled residues using supercritical carbon dioxide (SC-CO(2)) at a semibatch flow extraction process and an organic solvent (hexane) extraction. SC-CO(2) extraction was carried out to extract oil from anchovy at different temperatures (35 to 45 °C) and pressures (15 to 25 ...
Ye Shengqing - - 2012
A novel and efficient route to aryl N-aminosulfonamides via a palladium-catalyzed three-component coupling of arylboronic acids, sulfur dioxide and hydrazines in the presence of a balloon of dioxygen is reported. The reaction proceeded smoothly under mild conditions and DABCO·(SO(2))(2) was used as the source of sulfur dioxide.
< 1 2 3 4 5 6 7 8 9 10 >