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Journal articles on the topic 'Derivative of o-aminobenzoic acids'

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Published: 30 May 2022
Last updated: 31 May 2022

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1

Zhao, MJ, D. Robert, and L. Jung. "New agents for cutaneous photoprotection: derivatives of α-amino acids, 4-aminobenzoic and 4-methoxycinnamic acids." European Journal of Medicinal Chemistry 28, no. 12 (January 1993): 949–54. http://dx.doi.org/10.1016/0223-5234(93)90050-o.

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2

Duggan, BM, RL Laslett, and JFK Wilshire. "Studies in Thiohydantoin Chemistry. I. Some Aspects of the Schlack-Kumpf Reaction." Australian Journal of Chemistry 49, no. 5 (1996): 541. http://dx.doi.org/10.1071/ch9960541.

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An investigation has been carried out into the Schlack-Kumpf reaction, i.e., the reaction of amino acids with a mixture of acetic anhydride, acetic acid and sodium thiocyanate (occasionally ammonium thiocyanate was used). Particular emphasis was placed on the reactions with amino acids containing sensitive or functional side chains, i.e., serine, threonine , arginine , proline , lysine, histidine , cysteine , and aspartic and glutamic acids. The reaction of serine, and of certain of its O- and N-substituted derivatives, takes an unusual course to give an acetylated thiohydantoin derivative of cysteine. Correspondingly, threonine gives an acetylated thiohydantoin derivative of β- methylcysteine. Similar reactions occurred with the 3-phenylthiohydantoin derivatives of serine and of threonine to give acetylated thiohydantoin derivatives of cysteine and of β-methylcysteine respectively.
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3

Slavíková, Tereza, Vladimír Pouzar, and Ivan Černý. "Synthesis of Steroid O-(ω-Hydroxyalkyl)oximes by Reduction of Corresponding O-(ω-Carboxyalkyl)oxime Derivatives." Collection of Czechoslovak Chemical Communications 63, no. 4 (1998): 557–76. http://dx.doi.org/10.1135/cccc19980557.

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Steroid O-(ω-hydroxyalkyl)oximes with varying alkyl chain length were prepared from the corresponding carboxylic acids using the reduction of mixed anhydrides with sodium borohydride. An unexpected reaction course was observed with O-(2-carboxyethyl)oximes of 3-oxo-4-ene steroids, where a 4,5-dihydroisoxazol-3(2H)-one derivative was formed as a side product.
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4

Çalış, Ihsan, S. Serap Birincioǧlu, Hasan Kırmızıbekmez, Bernhard Pfeiffer, and Jörg Heilmann. "Secondary Metabolites from Asphodelus aestivus." Zeitschrift für Naturforschung B 61, no. 10 (October 1, 2006): 1304–10. http://dx.doi.org/10.1515/znb-2006-1019.

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Together with ten well known compounds, the quinic acid derivative chlorogenic acid, the nucleoside adenosine, two amino acids, tryptophan and phenylalanine, the anthraquinone derivatives, aloemodin, aloemodin acetate and chyrosphanol 1-O-gentiobioside, the flavon C-glycosides, isovitexin, isoorientin and isoorientin 4’-O-β -glucopyranoside, as well as two new acylated isoorientin derivatives, 6”-O-(malonyl)-isoorientin and 6”-O-[(S)-3-hydroxy-3-methylglutaroyl]-isoorientin, were isolated from the water soluble part of the methanolic extract of the fresh leaves of Asphodelus aestivus. All compounds were structurally identified by spectroscopic methods, including UV, MS, and NMR (1D and 2D) spectroscopy. Among the compounds isolated, chlorogenic acid and isoorientin were found to be the main compounds of the methanolic extract.
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5

Freire, C. S. R., A. J. D. Silvestre, and C. Pascoal Neto. "Oxidized Derivatives of Lipophilic Extractives Formed during Hardwood Kraft Pulp Bleaching." Holzforschung 57, no. 5 (August 20, 2003): 503–12. http://dx.doi.org/10.1515/hf.2003.075.

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Summary The structural changes of E. globulus wood extractives during bleaching with chlorine dioxide (D), oxygen (O), ozone (Z) and hydrogen peroxide (P) were studied. The detailed characterisation of the extractive derivatives detected in the partially bleached D, O, P and Z pulps was achieved by performing reactions of pure reference compounds with the different bleaching agents. The results show that the unsaturated sterols and fatty acids are extensively degraded during chlorine dioxide and ozone bleaching and only partially degraded during oxygen and hydrogen peroxide bleaching. The corresponding saturated extractives as well as the long chain aliphatic alcohols and ω-hydroxyfatty acids were stable during bleaching. The main oxidation products of β-sitosterol and oleic and linoleic acids, including one chlorinated derivative of linoleic acid, were identified here for the first time in E. globulus bleached pulps and bleaching filtrates.
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6

Spassova, Maria K., Antonín Holý, and Milena Masojídková. "Ribonucleosides of 3-amino- and 3,5-diaminopyrazole-4-carboxylic acid and their open-chain analogues: Synthesis and reactions." Collection of Czechoslovak Chemical Communications 51, no. 7 (1986): 1512–31. http://dx.doi.org/10.1135/cccc19861512.

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Bis(trimethylsilyl) derivative of ethyl 3-aminopyrazole-4-carboxylate (VI) and tris(trimethylsilyl) derivative of ethyl 3,5-diaminopyrazole-4-carboxylate (VII) on reaction with 2,3,5-tri-O-benzoyl-D-ribofuranolyl chloride and subsequent debenzoylation afforded the respective β-D-ribofuranosyl derivatives VIIIa and Xa. Their alkaline hydrolysis led to 1-(β-D-ribofuranosyl)-3-aminopyrazole-4-carboxylic acid (VIIIc) and 1-(β-D-ribofuranosyl)-3,5-diaminopyrazole-4-carboxylic acid (Xb). The esters VIIIa and Xa were not ammonolyzed under normal conditions. Contrary to nucleosidation of the silyl derivatives VI and VII, sodium salt of ethyl 3-aminopyrazole-4-carboxylate was alkylated with 4-chloromethyl-2,2-dimethyl-1,3-dioxolane (XI) or 5-(p-toluenesulfonyloxy)-1,3-dioxane (XVIIb) to give a mixture of the N-isomeric derivatives XIIIa, XIXa and XIIa, XVIIIa, respectively; sodium salt of the 3,5-diamino derivative V reacted with these synthons under formation of the corresponding compounds XIIIb and XXa. Subsequent alkaline and acid hydrolysis of XIIa and XIIIb gave the open-chain analogs of nucleosides XV and XVI. The N-(1,3-dioxan-5-yl) derivatives XVIIIc and XXa resisted acid hydrolysis, giving rise only to carboxylic acids XVIIIb and XXb.
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7

Spitaler, Renate, Ernst-P. Ellmerer, Christian Zidorn, and Hermann Stuppner. "A New Eudesmane Derivative from Leontodon tuberosus." Zeitschrift für Naturforschung B 59, no. 1 (January 1, 2004): 95–99. http://dx.doi.org/10.1515/znb-2004-0113.

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Abstract Besides the known compounds 2,4,6-trihydroxyacetophenone 4-O-β -D-glucopyranoside and syringaresinol 4’-O-β -D-glucopyranoside, the novel sesquiterpenoid 1,2-dehydro-3-oxocostic acid β - D-glucopyranoside ester was isolated from Leontodon tuberosus L. and its structure established by mass spectrometry and 1D- and 2D-NMR spectroscopy. Additionally, a number of fatty and phenolic acids was identified in the crude methanolic extract by HPLC-DAD and HPLC-MS. The chemosystematic impact of the new sesquiterpenoid is discussed briefly.
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8

Landaeta Aponte, Roselis A., Andreas Luxenburger, Scott A. Cameron, Alex Weymouth-Wilson, Richard H. Furneaux, Lawrence D. Harris, and Benjamin J. Compton. "Synthesis of Novel C/D Ring Modified Bile Acids." Molecules 27, no. 7 (April 6, 2022): 2364. http://dx.doi.org/10.3390/molecules27072364.

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Bile acid receptors have been identified as important targets for the development of new therapeutics to treat various metabolic and inflammatory diseases. The synthesis of new bile acid analogues can help elucidate structure–activity relationships and define compounds that activate these receptors selectively. Towards this, access to large quantities of a chenodeoxycholic acid derivative bearing a C-12 methyl and a C-13 to C-14 double bond provided an interesting scaffold to investigate the chemical manipulation of the C/D ring junction in bile acids. The reactivity of this alkene substrate with various zinc carbenoid species showed that those generated using the Furukawa methodology achieved selective α-cyclopropanation, whereas those generated using the Shi methodology reacted in an unexpected manner giving rise to a rearranged skeleton whereby the C ring has undergone contraction to form a novel spiro–furan ring system. Further derivatization of the cyclopropanated steroid included O-7 oxidation and epimerization to afford new bile acid derivatives for biological evaluation.
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9

Guimarães, Anderson C., Alvicler Magalhães, Marcos J. Nakamura, Antonio C. Siani, Christina Barja-Fidalgo, and André L. F. Sampaio. "Flavonoids Bearing an O-Arabinofuranosyl-(1→3)-Rhamnoside Moiety from Cladocolea Micrantha: Inhibitory Effect on Human Melanoma Cells." Natural Product Communications 7, no. 10 (October 2012): 1934578X1200701. http://dx.doi.org/10.1177/1934578x1200701014.

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Eleven known triterpenes (α-amyrin, β-amyrin, lupeol, and their respective acetates, 3- O-acetyl derivatives of betulinic, oleanolic, and ursolic acids, cycloartenol, and tirucall-7,24-dienol), two new flavonols presenting an uncommon interglycosidic O-(1→3) linkage (kaempferol 3- O-α-L-arabinofuranosyl-(1→3)-α-L-rhamnoside and quercetin 3- O-α-L-arabinofuranosyl-(1→3)-α-L-rhamnoside), β-sitosterol, stigmasterol, quercetin, and gallic acid were isolated from the Amazonian medicinal mistletoe, Cladocolea micrantha Kuijt (Loranthaceae). Their structures were established by spectral methods and eventual chromatographic comparisons. The quercetin derivative was not cytotoxic to MV3 human melanoma cells, but was able, when administered at 1 μg/mL, to promote a twofold inhibition of the migration of the cells through the transwell system when compared with paclitaxel at 5 μM.
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10

Qi, Xiao Yan, Lin Wu, Jian Guo Wang, and De Lian Yi. "A Novel Synthesis of Acetophenone Benzopyran Derivative." Advanced Materials Research 152-153 (October 2010): 1483–86. http://dx.doi.org/10.4028/www.scientific.net/amr.152-153.1483.

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The development of a novel synthesis of acetophenone benzopyran is reported. A acetophenone benzopyran derivative was prepared from 1-(2,4-dihydroxyphenyl)ethanone (3) through O-prenylation and Lewis acids catalyzed intermolecular cyclization reaction. The structure of product 1-(3,4-dihydro-4,4-dimethyl-7-hydroxy-2H-1- benzopyran -6-yl)- ethanone (1) was characterized by UV, IR, 1H-NMR, 13C-NMR and elemental analysis.
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11

Nguyen, Thi Thu Huong, Jiří Urban, Eva Klinotová, Jan Sejbal, Jiří Protiva, Pavel Drašar, and Miroslav Protiva. "Synthesis of Several Hydroxylated 23-(Benzimidazol-2-yl-, Benzoxazol-2-yl and Benzothiazol-2-yl)norcholanes and Some Related Compounds." Collection of Czechoslovak Chemical Communications 60, no. 2 (1995): 257–75. http://dx.doi.org/10.1135/cccc19950257.

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The bile acids Ia - Id (lithocholic, chenodeoxycholic, deoxycholic, cholic) and their derivatives (O-acetylated acids and O-acetylated acid chlorides) reacted under various conditions with 1,2-diaminobenzene, 2-aminophenol and 2-aminothiophenol and afforded the title benzimidazoles II and VII, benzoxazoles V and benzothiazoles VI. Alkylation of the benzimidazole derivative IIa with 2-dimethylaminoethyl chloride resulted in 3α-hydroxy-23-[1-(2-dimethylaminoethyl)ben zimidazol-2-yl]- norcholane (IVa). The use of 1,2-diamino-4-methylbenzene enabled the preparation of 3α-acetoxy-23-[5(6)-methylbenzimidazol-2-y l]norcholane (VIII). Reactions of the 3α-hydroxy compounds IVa, Va and VIa with succinic anhydride resulted in the hemisuccinates IVi - VIi. The boric acid mediated condensation of O-acetyllithocholic acid (Ie) with 3,4-diaminopyridine gave compound X which was transformed to 3α-acetoxy-23-[1H-imidazo(4,5- c)pyridin-2-yl]norcholane (IX). The structure of the products was corroborated by the mass, IR, 1H NMR and 13C NMR spectra. Some of the compounds were tested for antileukemic and for the anti-HIV activity in vitro.
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12

Begum, Parvin, Yasuyuki Hashidoko, Md Tofazzal Islam, Yuko Ogawa, and Satoshi Tahara. "Zoosporicidal Activities of Anacardic Acids against Aphanomyces cochlioides." Zeitschrift für Naturforschung C 57, no. 9-10 (October 1, 2002): 874–82. http://dx.doi.org/10.1515/znc-2002-9-1020.

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The EtOAc soluble constituents of the unripe fruits of Ginkgo biloba showed motility inhibition followed by lysis of zoospores of the phytopathogenic Aphanomyces cochlioides. We purified 22:1-ω7-anacardic acid (1), 24:1-ω9-anacardic acid (2) and 22:0-anacardic acid (3), together with other related compounds, 21:1-ω7-cardol (4) and 21:1-ω7-cardanol (5) from the crude extracts of Ginkgo fruits. Amongst them, compound 1 was a major active agent in quality and quantity, and showed potent motility inhibition (98% in 30 min) followed by lysis (55% in 3 h) of the zoospores at 1 × 10−7 m. The 2-O-methyl derivative (1−c) of 1 displayed antibacterial activity against Bacillus subtilis, but practically inactive to Escherichia coli. A brief study on structure-activity relationships revealed that a carboxyl group on the aromatic ring and an unsaturated side chain in the anacardic acid derivative are important for strong motility inhibitory and lytic activities against the zoospore
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13

Wanjala, George W., Arnold N. Onyango, David Abuga, Calvin Onyango, and Moses Makayoto. "Evidence for the Formation of Ozone (or Ozone-Like Oxidants) by the Reaction of Singlet Oxygen with Amino Acids." Journal of Chemistry 2018 (September 13, 2018): 1–6. http://dx.doi.org/10.1155/2018/6145180.

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Antibodies or some amino acids, namely, cysteine, methionine, histidine, and tryptophan, were previously reported to catalyse the conversion of singlet oxygen (1O2) to ozone (O3). The originally proposed mechanism for such biological ozone formation was that antibodies or amino acids catalyse the oxidation of water molecules by singlet oxygen to yield dihydrogen trioxide (HOOOH) as a precursor of ozone and hydrogen peroxide (H2O2). However, because HOOOH readily decomposes to form water and singlet oxygen rather than ozone and hydrogen peroxide, an alternative hypothesis has been proposed; ozone is formed due to the reaction of singlet oxygen with amino acids to form polyoxidic amino acid derivatives as ozone precursors. Evidence in support of the latter hypothesis is presented in this article, in that in the presence of singlet oxygen, methionine sulfoxide (RS(O)CH3), an oxidation product of methionine (RSCH3), was found to promote reactions that can best be attributed to the trioxidic anionic derivative RS+(OOO−)CH3 or ozone.
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14

Drzazga, Anna, Marta Okulus, Magdalena Rychlicka, Łukasz Biegała, Anna Gliszczyńska, and Edyta Gendaszewska-Darmach. "Lysophosphatidylcholine Containing Anisic Acid Is Able to Stimulate Insulin Secretion Targeting G Protein Coupled Receptors." Nutrients 12, no. 4 (April 22, 2020): 1173. http://dx.doi.org/10.3390/nu12041173.

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Diabetes mellitus is a worldwide health problem with high rates of mortality and morbidity. Management of diabetes mellitus by dietary components is achievable especially at the initial stage of the disease. Several studies confirmed the antidiabetic activities of simple phenolic acids and lysophosphatidylcholine (LPC). The main goal of this study was to identify new potential insulin secretion modulators obtained by combining the structures of two natural compounds, namely O-methyl derivatives of phenolic acids and phospholipids. LPC and phosphatidylcholine bearing methoxylated aromatic carboxylic acids were tested as potential agents able to improve glucose-stimulated insulin secretion (GSIS) and intracellular calcium mobilization in MIN6 β pancreatic cell line. Our results show that LPC with covalently bonded molecule of p-anisic acid at the sn-1 position was able to induce GSIS and intracellular calcium flux. Notably, 1-anisoyl-2-hydroxy-sn-glycero-3-phosphocholine did not affect the viability of MIN6 cells, suggesting its potential safe use. Furthermore, we have shown that three G protein coupled receptors, namely GPR40, GPR55, and GPR119, are targeted by this LPC derivative.
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15

Zhu, Min Peng, Su Hong Li, Xiu Hong Zhao, and Peng Guan. "Sample Preparation for HPLC Determination of Free and Oligosaccharides-Bound Sialic Acid in Bovine Colostrum." Advanced Materials Research 641-642 (January 2013): 882–85. http://dx.doi.org/10.4028/www.scientific.net/amr.641-642.882.

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An analytical method was developed for determining free and oligosaccharide-bound sialic acids in bovine colostrum by HPLC. The condition of acid hydrolysis for sample and sialic acids derivatization were investigated. The sialic acids were released from their parent oligosaccharides by acid hydrolysis using 40mL 0.1mol/L sulphuric acid for 100min. They were then derivatized using O-phenylenediamine (OPD) at 70°C for 40 min, the determination of the derivative could be carried out by UV detection. The total content of free and oligosaccharide bound sialic acids in bovine colostrum milk were 941.95μg/mL. The developed method is validated on various dairy products such as bovine milk and milk-based products.
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16

Skała, Ewa, Agnieszka Kicel, Monika A. Olszewska, Anna K. Kiss, and Halina Wysokińska. "Establishment of Hairy Root Cultures ofRhaponticum carthamoides(Willd.) Iljin for the Production of Biomass and Caffeic Acid Derivatives." BioMed Research International 2015 (2015): 1–11. http://dx.doi.org/10.1155/2015/181098.

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The aim of the study was to obtain transformed roots ofRhaponticum carthamoidesand evaluate their phytochemical profile. Hairy roots were induced from leaf explants by the transformation ofAgrobacterium rhizogenesstrains A4 and ATCC 15834. The best response (43%) was achieved by infection with A4 strain. The effects of different liquid media (WPM, B5, SH) with full and half-strength concentrations of macro- and micronutrients on biomass accumulation of the best grown hairy root line (RC3) at two different lighting conditions (light or dark) were investigated. The highest biomass (93 g L−1of the fresh weight after 35 days) was obtained in WPM medium under periodic light. UPLC-PDA-ESI-MS3and HPLC-PDA analyses of 80% aqueous methanol extracts from the obtained hairy roots revealed the presence of eleven caffeoylquinic acids and their derivatives and five flavonoid glycosides. The production of caffeoylquinic acids and their derivatives was elevated in hairy roots grown in the light. Only light-grown hairy roots demonstrated the capability for the biosynthesis of such flavonoid glycosides as quercetagetin, quercetin, luteolin, and patuletin hexosides. Chlorogenic acid, 3,5-di-O-caffeoylquinic acid and a tentatively identified tricaffeoylquinic acid derivative were detected as the major compounds present in the transformed roots.
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17

Kefurt, Karel, Zdeňka Kefurtová, and Jiří Jarý. "6-Amino-6-deoxyhexonolactams." Collection of Czechoslovak Chemical Communications 53, no. 8 (1988): 1795–805. http://dx.doi.org/10.1135/cccc19881795.

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6-Azido-6-deoxy-D-mannose (III), prepared from methyl 4,6-O-benzylidene-α-D-mannopyranoside, 6-azido-6-deoxy-D-talose (XI), prepared from methyl 6-azido-2,3-O-isopropylidene-α-D-mannopyranoside (VII) via 4-keto derivative VIII, and 6-azido-6-deoxy-L-idose (XVIII), obtained from 5,6-anhydro-1,2-O-isopropylidene-β-L-idofuranose, on oxidation with bromine and subsequent reduction of the azido group afforded the corresponding 6-amino-6-deoxyhexonolactams V, XV, and XXI. 6-Amino-6-deoxyhexonic acids IV and XIV were also prepared.
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18

Smith, Graham, and Urs D. Wermuth. "Hydrogen bonding in cyclic imides and amide carboxylic acid derivatives from the facile reaction ofcis-cyclohexane-1,2-carboxylic anhydride witho- andp-anisidine andm- andp-aminobenzoic acids." Acta Crystallographica Section C Crystal Structure Communications 68, no. 9 (August 1, 2012): o327—o331. http://dx.doi.org/10.1107/s0108270112030168.

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The structures of the open-chain amide carboxylic acidrac-cis-2-[(2-methoxyphenyl)carbamoyl]cyclohexane-1-carboxylic acid, C15H19NO4, (I), and the cyclic imidesrac-cis-2-(4-methoxyphenyl)-3a,4,5,6,7,7a-hexahydroisoindole-1,3-dione, C15H17NO3, (II), chiralcis-3-(1,3-dioxo-3a,4,5,6,7,7a-hexahydroisoindol-2-yl)benzoic acid, C15H15NO4, (III), andrac-cis-4-(1,3-dioxo-3a,4,5,6,7,7a-hexahydroisoindol-2-yl)benzoic acid monohydrate, C15H15NO4·H2O, (IV), are reported. In the amide acid (I), the phenylcarbamoyl group is essentially planar [maximum deviation from the least-squares plane = 0.060 (1) Å for the amide O atom] and the molecules form discrete centrosymmetric dimers through intermolecular cyclic carboxy–carboxy O—H...O hydrogen-bonding interactions [graph-set notationR22(8)]. The cyclic imides (II)–(IV) are conformationally similar, with comparable benzene ring rotations about the imide N—Carbond [dihedral angles between the benzene and isoindole rings = 51.55 (7)° in (II), 59.22 (12)° in (III) and 51.99 (14)° in (IV)]. Unlike (II), in which only weak intermolecular C—H...Oimidehydrogen bonding is present, the crystal packing of imides (III) and (IV) shows strong intermolecular carboxylic acid O—H...O hydrogen-bonding associations. With (III), these involve imide O-atom acceptors, giving one-dimensional zigzag chains [graph-setC(9)], while with the monohydrate (IV), the hydrogen bond involves the partially disordered water molecule which also bridges molecules through both imide and carboxy O-atom acceptors in a cyclicR44(12) association, giving a two-dimensional sheet structure. The structures reported here expand the structural database for compounds of this series formed from the facile reaction ofcis-cyclohexane-1,2-dicarboxylic anhydride with substituted anilines, in which there is a much larger incidence of cyclic imides compared to amide carboxylic acids.
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19

Kantlehner, Willi, Rüdiger Stieglitz, Hansjörg Lehmann, and Markus Vettel. "Orthoamide und Iminiumsalze, IIIC. Weitere Ergebnisse bei der Umsetzung von Orthoamiden der Alkincarbonsäuren mit CH2- und CH2/NH-aciden Verbindungen." Zeitschrift für Naturforschung B 74, no. 11-12 (December 18, 2019): 925–38. http://dx.doi.org/10.1515/znb-2019-0078.

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AbstractThe 1,1-bis(dimethylamino)-1,3-butadienes (keten aminals) 11a–l are prepared from orthoamide derivatives of alkyne carbonxylic acids 9b, d, e, i and CH2-acidic compounds 10a–c, f–h, k, o. The C-silylated orthoamide derivative 9c shows an ambivalent behaviour towards CH-acidic compounds. Reactions of 9c with strong CH2-acidic compounds like the nitro alkanes 10m, n and strongly enolized carbonyl compounds as methyl acetoacetate, cyanoacetamide, dibenzoylmethane, 1,3-dimethylbarbituric acid proceed under desilylation to give the ketene aminals 11u–z. In contrast to these reactions, the C-silylated ketene aminals 11o–t are obtained from 9c and weaker CH2-acidic compounds as dimethyl malonate, cyanoacetic acid derivatives and benzylcyanides. CH2/NH2-acidic compounds [cyanoacetamide (10d) and N-ethyl-cyanoacetamide (10f)] react with the orthoamide derivatives 9b, e–g at the acidic carbon-hydrogen bond to give the ketene aminals 11ac, ad, af, ag, ai, which cyclize to the pyridones 14a–d, d–g on heating. From the reaction of the orthoamide 9d with cyanoacetamide the pyridone 14c results directly. The persubstituted pyridone derivative 19 is formed by the reaction of cyanoacetamide with a mixture of the isomeric orthoamides 15 and 16. The 5,5-diamino-2,4-pentadienamide 11v attacks the orthoamide 9a at C3/C1. In the product 20 a cross conjugated multiple bond system is formed which contains an 1-aza-2,3-diamino function and a further ketene aminal function.
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20

Hellebø, Audny, Ulrike Vilas, Knut Falk, and Reinhard Vlasak. "Infectious Salmon Anemia Virus Specifically Binds to and Hydrolyzes 4-O-Acetylated Sialic Acids." Journal of Virology 78, no. 6 (March 15, 2004): 3055–62. http://dx.doi.org/10.1128/jvi.78.6.3055-3062.2004.

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ABSTRACT Infectious salmon anemia virus (ISAV) is the causative agent of infections in farmed Atlantic salmon. ISAV presumably represents a new genus within the Orthomyxoviridae. ISAV has been shown earlier to exhibit a receptor-destroying activity, which was defined as an acetylesterase with unknown specificity. We have analyzed the substrate specificity of the ISAV esterase in detail. Purified ISAV hydrolyzed free 5-N-acetyl-4-O-acetyl neuraminic acid. In addition, the purified 9-O-acetylated sialic acid derivative was also hydrolyzed, but at lower rates. When we used a glycosidically bound substrate, ISAV was unable to hydrolyze 9-O-acetylated sialic acid, which represents the major substrate for the influenza C virus esterase. ISAV completely de-O-acetylated glycoprotein-bound 5-N-acetyl-4-O-acetyl neuraminic acid. Thus, the enzymatic activity of the hemagglutinin-esterase of ISAV is comparable to that of the sialate-4-O-esterases of murine coronaviruses and related group 2 coronaviruses. In addition, we found that ISAV specifically binds to glycoproteins containing 4-O-acetylated sialic acids. Both the ISAV esterase and recombinant rat coronavirus esterase specific for 4-O-acetylated sialic acids hydrolyzed ISAV receptors on horse and rabbit erythrocytes, indicating that this sialic acid represents a receptor determinant for ISAV.
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21

Tandon, Manju, Piyush Kumar, Haiyan Xia, Lili Wang, and Leonard I. Wiebe. "Synthesis of Bromophenyl β-D-Glucuronides: Hydrophilic Precursors of Lipophilic Standards in the Analysis of Environmental Polychlorinated Biphenyls." Collection of Czechoslovak Chemical Communications 71, no. 7 (2006): 1042–50. http://dx.doi.org/10.1135/cccc20061042.

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A rapid PCB-screening protocol, based on a combination of extraction techniques and instrumental nuclear activation analysis (INAA), required water soluble brominated internal standard that undergoes facile hydrolysis to a lipophilic brominated counterpart. Bromophenyl glucuronic acids 2, 3, 7 were synthesized for this application. Glucuronic acids 2 and 3 were prepared by bromination of phenyl β-D-glucopyranosiduronic acid in 81 and 54%, respectively, whereas compound 7 was prepared by coupling methyl 2,3,4-tri-O-acetyl-α-D-glucopyranosyluronate bromide (5) with 2,4,6-tribromophenol. Incubation with β-glucuronidase indicated that tribromophenyl derivative 7 is an excellent substrate, with near quantitative conversion to tribromophenol within seconds of incubation with the enzyme.
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22

Gao, Rui Han, Ying Fan, Bo Xiao, Peng Chen, Jian Xin Zhang, Qing-di Zhou, Sai Feng Xue, Qian Jiang Zhu, and Zhu Tao. "Direct syntheses of cucurbit[7]uril-anchored polyacrylic acid microspheres and adsorption of basic dyes by the derivative." RSC Advances 5, no. 81 (2015): 65775–79. http://dx.doi.org/10.1039/c5ra09064d.

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A series of cucurbit[7]uril-anchored polyacrylic acids were synthesized using (NH4)2S2O8 as both an initiator and oxidant. The polymers were further esterified with 2-naphthol to yield derivatives, which could be used as a stationary phase for the absorption of basic dyes.
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23

Shaw, W., E. Kassen, and E. Chaves. "Increased urinary excretion of analogs of Krebs cycle metabolites and arabinose in two brothers with autistic features." Clinical Chemistry 41, no. 8 (August 1, 1995): 1094–104. http://dx.doi.org/10.1093/clinchem/41.8.1094.

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Abstract A marked increase in analogs of Krebs cycle metabolites was found in the urine of two brothers with autistic features. These metabolites included citramalic, tartaric (3-OH-malic), and 3-oxoglutaric acids and compounds tentatively identified as a citric acid analog and partially identified as a phenylcarboxylic acid by the fragmentation pattern of the trimethylsilyl (TMS) derivatives of the compounds and mass shifts of the same compounds derivatized with perdeuterated N,O-bis(trimethylsilyl)trifluoroacetamide. The molecular mass of the TMS derivative of the tentatively identified citric acid analog was 596 Da, based on a finding of a significant M - 15 ion at m/z 581. The citric acid analog was excreted in quantities as high as 137 mmol/mol creatinine, based on the response factor of citric acid as a surrogate calibrator. A carbohydrate with a retention time and mass spectrum identical to arabinose was also found in high concentrations in the urine of these brothers.
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24

Kliegel, Wolfgang, Ute Schumacher, Steven J. Rettig, and James Trotter. "Structural studies of organoboron compounds LXIV. Boron chelate formation with glycolohydroxamic acids, and the crystal and molecular structure of 5-(1-hydroxycyclohexyl)-2,2-diphenyl-1,3-dioxa-4-azonia-2-borata-4-cyclopentane." Canadian Journal of Chemistry 74, no. 3 (March 1, 1996): 445–52. http://dx.doi.org/10.1139/v96-048.

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The syntheses of representative diphenyl- and difluoroboron chelates of 2-hydroxycarbohydroxamic acids (glycolohydroxamic acids) are reported. Crystals of 5-(1-hydroxycyclohexyl)-2,2-diphenyl-1,3-dioxa-4-azonia-2-borata-4-cyclopentene, 2a, are triclinic, a = 11.5717(5), b = 11.7262(4), c = 14.3529(5) Å, α = 90.277(6)°, β = 110.497(5)°, γ = 96.814(5)°, Z = 4, space group [Formula: see text] The structure was solved by direct methods and refined by full-matrix least-squares procedures to R = 0.042 and Rw = 0.056 for 5318 reflections with I ≥ 3σ(F2). Compound 2a is the first N-unsubstituted hydroxamatoborate derivative to be structurally characterized by an X-ray crystallographic analysis. The solid state structure of 2a consists of centrosymmetric, hydrogen-bonded tetrameric units that also feature intermolecular [Formula: see text](aromatic) interactions. Bond lengths include: B—O(N) = 1.557(2) and 1.553(2) Å, B—O(N) = 1.558(2) and 1.566(2),Å B—C(phenyl) = 1.592(3)–1.601(3) Å. Key words: hydroxamatoborate, organoboron compound, crystal structure.
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25

Murata, Toshihiro, Tatsuo Katagiri, Masaaki Osaka, Shohei Yamauchi, Kenshi Yoshimura, Manami Kawada, Yu Fujii, Yuka Suzuki, and Kenroh Sasaki. "Hyaluronidase and degranulation inhibitors from the edible roots of Oenanthe javanica including seric acids F and G that were obtained by heating." Bioscience, Biotechnology, and Biochemistry 85, no. 2 (January 20, 2021): 369–77. http://dx.doi.org/10.1093/bbb/zbaa042.

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ABSTRACT Oenanthe javanica is a vegetable grown in East Asia and Australia in which the roots and aerial parts are boiled together to make certain traditional dishes. Nineteen compounds (1-19) were isolated from O. javanica roots and the chemical structures of 2 new norlignans were determined. The inhibitory effects of the compounds on hyaluronidase and degranulation in RBL-2H3 cells were evaluated to determine antiallergic and antiinflammation activities. Saponins (2-4) and the new norlignan seric acid G (12) were among the active compounds identified. Seric acid G (12), a methoxy derivative of seric acid F (11), was obtained as an interconverting mixture of 3:1 trans-cis isomers. Seric acids F and G (11, 12) were derived from seric acids C (10) and E, respectively, by decarboxylation and dehydration reactions that occurred during heating. It was confirmed by HPLC analysis that all eleven of the O. javanica cultivars contained seric acid C (10).
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26

Slobodianiuk, Oksana, Oleksandra Berezhnytska, Tetyana Kamens'ka, and Мария Русакова. "SYNTHESIS AND PROPERTIES OF NEW N-ACYL DERIVATIVES OF ANTHRANILIC ACID." Ukrainian Chemistry Journal 85, no. 4 (June 7, 2019): 59–70. http://dx.doi.org/10.33609/0041-6045.85.4.2019.59-70.

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A series of N-acyl derivatives of anthranil (or o -aminobenzoic acid) was first synthesized, namely 2-(4-octylbenzamido)benzoic acid, 2-(4-(heptyloxy)- benzamido)benzoic acid, 2-(4-(heptylsulfanyl)benz-amido)benzoic acid. 2-(4-octylbenzamido)benzoic acid was synthesized in five stages of octylbenzene, by acylating chloride acid using a Friedie-Crafts reaction. 2-(4-(heptyloxy)benzamido)benzoic acid was prepared from the methyl ester of p-hydroxybenzoic acid which, at the first stage, was activated with 1-bromoheptane in acetonitrile with potassium carbonate and catalytic amount of sodium iodide at heating. After that, hydrolysis of the ester group by hydroxide in the methanol–water system was performed. Synthesis of 2-(4-(heptylsulfanyl)benzamido)benzoic acid was carried out from p-sulfanylbenzoic acid, which was activated with 1-bromoheptane, in a system of ethanol–water with sodium hydroxide. Chlorinated hydrides of acids were obtained by reaction of acids with chlorinated thionyl in benzene. Acylation of the tret-butyl ester of anthranilic acid with formed chlorohydrides was carried out in pyridine upon heating and in dichloromethane with triethylamine (as the base), and dimethylaminopyridine (catalyst).At the last stage of the synthesis of all derivatives, the hydrolysis of tret-butyl esters with trifluoroacetic acid in dichloromethane to the formation of terminal compounds took place.The composition and structure of the synthesized compounds were determined using NMR 1H, infrared spectroscopy. The shape and position of the bands in the IR absorption spectra of the synthesized anthranilic acid derivatives are shifted and splited in comparison with the parent acid due to the presence of a secondary amino group, an additional aromatic moiety, and a different nature of the substitutes in the para-position to the amino group. For all synthesized derivatives, the sensitivity of various morphological forms Candida albicans was determined. The influence of the test substances on the cells of the yeast fungus was determined for 24–48 hours using Saburo and Spider nutrient media with the addition of mannitol. Compared with the already known influence of anthranilic acid on Candida albicans cells grown in Saburo nutrient medium for 24 hours, the compounds studied were more effective at all stages of cultivation. It has been shown that the synthetic derivatives studied are more active with respect to the cells in the biofilm composition, which consists of the yeast-like form of Candida albicans, than those cells that form a hyphal type biofilm. The yeast-like form of the Candida albicans cell is susceptible to synthetic derivatives. It is shown that the level of sensitivity of compounds 1-3 is higher in 4-6 times compared with anthranilic acid. Glyphs have been found to be more susceptible to the effects of the compounds studied than Е yeast cells of Candida albicans
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27

Gazotti, W. A., R. Faez, and Marco-A. De Paoli. "Electrochemical, electrochromic and photoelectrochemical behavior of a highly soluble polyaniline derivative: poly(o-methoxyaniline) doped with functionalized organic acids." Journal of Electroanalytical Chemistry 415, no. 1-2 (October 1996): 107–13. http://dx.doi.org/10.1016/s0022-0728(96)04712-2.

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28

Polívka, Zdeněk, Miloš Buděšínský, Jiří Holubek, Bohdan Schneider, Zdeněk Šedivý, Emil Svátek, Oluše Matoušová, et al. "4H-Benzo[4,5]cyclohepta[1,2-b]thiophenes and 9,10-dihydro derivatives - Sulfonium analogues of pizotifen and ketotifen; Chirality of ketotifen; Synthesis of the 2-bromo derivative of ketotifen." Collection of Czechoslovak Chemical Communications 54, no. 9 (1989): 2443–69. http://dx.doi.org/10.1135/cccc19892443.

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Reaction of ketone IX with 4-tetrahydrothiopyranylmagnesium bromide and the following dehydration with thionyl chloride afforded the sulfide III which was transformed to the methiodide II (sulfonium analogue of pizotifen). Similar sequence starting from the ketone XXIV and concluded by dehydration of the alcohol XX, cleavage of the enol ether, and by treatment with methyl iodide resulted in the formation of the sulfonium analogue of ketotifen (V). Three modified routes leading to ketotifen (IV) are being described. The chirality of ketotifen was proven by 1H NMR spectroscopy with the help of the optically active NMR shift reagent. The resolution of racemic ketotifen (IV) was achieved by crystallization of salts with optically active O,O'-diacyltartaric acids and homogeneous enantiomers were obtained. The X-ray crystallographic analysis of (+)-IV (-)-O,O'-di(p-toluoyl)-(R)-tartarate led to the three-dimensional structure of the molecule of (+)-ketotifen which enabled to determine its absolute configuration to be (R). One of the products of bromination of the ketone IX, the following methanolysis and dehydrobromination, identified as XXVII, was transformed by reaction with 1-methyl-4-piperidylmagnesium chloride, by the following acid-catalyzed dehydration, and cleavage of the enol ether to the 2-bromo derivative of ketotifen XXXIV. (R) (+)-Ketotifen (IV) was found to be the more active ketotifen enantiomer but the stereoselectivity of its action is only a partial one. The 2-bromo derivative of ketotifen (XXXIV) is much less active than ketotifen in the line of antihistamine activity.
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29

Satsuma, Koji, Minoru Masuda, and Kiyoshi Sato. "O-Demethylation and Successive Oxidative Dechlorination of Methoxychlor by Bradyrhizobium sp. Strain 17-4, Isolated from River Sediment." Applied and Environmental Microbiology 78, no. 15 (May 25, 2012): 5313–19. http://dx.doi.org/10.1128/aem.01180-12.

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ABSTRACTO-Demethylation of insecticide methoxychlor is well known as a phase I metabolic reaction in various eukaryotic organisms. Regarding prokaryotic organisms, however, no individual species involved in such reaction have been specified and characterized so far. Here we successfully isolated a bacterium that mediates oxidative transformation of methoxychlor, includingO-demethylation and dechlorination, from river sediment. The isolate was found to be closely related toBradyrhizobium elkaniiat the 16S rRNA gene sequence level (100% identical). However, based on some differences in the physiological properties of this bacterium, we determined that it was actually a different species,Bradyrhizobiumsp. strain 17-4. The isolate mediatedO-demethylation of methoxychlor to yield a monophenolic derivative [Mono-OH; 1,1,1-trichloro-2-(4-hydroxyphenyl)-2-(4-methoxyphenyl)ethane] as the primary degradation product. The chiral high-performance liquid chromatography (HPLC) analysis revealed that the isolate possesses high enantioselectivity favoring the formation of (S)-Mono-OH (nearly 100%). Accompanied by the sequentialO-demethylation to form the bis-phenolic derivative Bis-OH [1,1,1-trichloro-2,2-bis(4-hydroxyphenyl)ethane], oxidative dechlorination of the side chain proceeded, and monophenolic carboxylic acid accumulated, followed by the formation of multiple unidentified polar degradation products. The breakdown proceeded more rapidly when reductively dechlorinated (dichloro-form) methoxychlor was applied as the initial substrate. The resultant carboxylic acids and polar degradation products are likely further biodegraded by ubiquitous bacteria. The isolate possibly plays an important role for complete degradation (mineralization) of methoxychlor by providing the readily biodegradable substrates.
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30

Modro, Agnes M., and Tomasz A. Modro. "The prototropic equilibria in pentenylphosphonic systems." Canadian Journal of Chemistry 66, no. 7 (July 1, 1988): 1541–45. http://dx.doi.org/10.1139/v88-250.

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Dialkyl 2-chloropentylphosphonates, C3H7CHClCH2P(O)(OR)2, and monoalkyl 2-chloropentylphosphonic acids, C3H7CHClCH2PO2H(OR), have been dehydrohalogenated by strong bases to the corresponding pentenylphosphonic compounds. In all cases the kinetically controlled product was shown to be the E-1-pentenylphosphonic derivative. The α,β-unsaturated products underwent base-catalysed isomerization to the thermodynamically controlled E-2-pentenylphosphonic systems, thus indicating that the PO3R2 and PO3R− groups destabilize (relative to hydrogen) the adjacent olefinic bond. The hydrogen–deuterium isotope exchange was studied for the α,β- and β,γ-unsaturated products and the results obtained were in full agreement with the isomerization results.
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31

Himbert, Gerhard, and Dieter Fink. "Cycloadditionen, XXII [1]. Synthese und thermische Reaktion von S-(Alkyl/Aryl)- 2.3-butadienthiosäure-estern / Cycloadditions, XXII [1]. Synthesis and Thermal Reaction of S-(Alkyl/Aryl)-2,3-butadienethioates." Zeitschrift für Naturforschung B 49, no. 4 (April 1, 1994): 542–50. http://dx.doi.org/10.1515/znb-1994-0417.

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While the S-alkyl- or S-phenyl-2,3-butadienethioates 4 a-c are synthesized via the usual “Wittig ylide way”, the corresponding 2-methyl-2,3-butadienethioates 9 a-d and the 2-methyl-4.4-diphenyl-2,3-butadienethioates 9 e,f are obtained by condensation of the allenic acids 7 a,b with the thiols and thiophenols 8 in the presence of dicyclohexylcarbodiimide (DCC) and a catalytic am ount of 4-dimethylaminopyridine (DMAP). In contrast to N- or O-phenyl 2,3- butadienamides or -esters, resp., the phenyl derivatives of 4 and 9 do not undergo the intram olecular Diels-Alder reaction, but by heating, all representatives of 4 only decompose, while 9 a-d and 9 e,f rearrange to 3-alkyl(aryl)thio-2-cyclobuten-1-ones 12a-d and to 3-arylthio- 1-naphthols 14a, b, resp. Heating of the cyclobutenone 12d in the presence of N-methylaniline furnishes the 2-butenanilide 16. On reacting 1-phenylthio-1-propyne 17 with diphenylketene 18, the diphenylacetate 19 is isolated, where the naphthol derivative 14a represents the ester moiety.
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32

Janeba, Zlatko, Milena Masojídková, and Antonín Holý. "Alternative synthesis of 9-{3-[(diisopropoxyphosphoryl)methoxy]-2-hydroxypropyl}adenine and its free phosphonates substituted at the C-8 position of purine base." Collection of Czechoslovak Chemical Communications 75, no. 3 (2010): 371–81. http://dx.doi.org/10.1135/cccc2009569.

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For its high therapeutic effect, (S)-9-[3-hydroxy-2-(phosphonomethoxy)propyl]adenine (HPMPA) is an important member of a class of acyclic nucleoside phosphonates (ANPs). Although its constitutional isomer, 9-[2-hydroxy-3-(phosphonomethoxy)propyl]adenine (iso-HPMPA), exhibits no antiviral activity, our general interest in C-8 substituted adenine ANPs led us to prepare certain iso-HPMPA derivatives modified at the C-8 position of adenine. Novel alkylating agent, diisopropyl {[2-(tetrahydro-2-pyranyl)oxy-3-tosyloxypropoxy]methyl}phosphonate (9), was prepared by procedure starting from allyl alcohol (4). 9-{3-[(Diisopropoxyphosphoryl)methoxy]-2-hydroxypropyl}adenine (12) was prepared by alkylation of adenine with the alkylating agent 9 followed by acid hydrolysis, although elimination by-product 9-{3-[(diisopropoxyphosphoryl)methoxy]prop-1-enyl}adenine (11) predominated in the reaction mixture. Bromination of the compound 12 gave 8-bromoadenine derivative 13 quantitatively. Nucleophilic substitutions of the bromine atom of compound 13 with N- and O-nucleophiles, followed by phosphonate deprotection, afforded the free phoshonic acids 15–18.
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33

Gómez-López, Iván, Gloria Lobo-Rodrigo, María P. Portillo, and M. Pilar Cano. "Characterization, Stability, and Bioaccessibility of Betalain and Phenolic Compounds from Opuntia stricta var. Dillenii Fruits and Products of Their Industrialization." Foods 10, no. 7 (July 9, 2021): 1593. http://dx.doi.org/10.3390/foods10071593.

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The aim of the present study was the full characterization, quantification, and determination of the digestive stability and bioaccessibility of individual betalain and phenolic compounds of Opuntia stricta, var. Dillenii fresh fruits (peel, pulp, and whole fruit) and of the products of the industrialization to obtain jam (raw pressed juice (product used for jam formulation), by-product (bagasse), and frozen whole fruit (starting material for jam production)). Opuntia stricta var. Dillenii fruits and products profile showed 60 betalain and phenolic compounds that were identified and quantified by HPLC-DAD-ESI/MS and HPLC-DAD-MS/QTOF, being 25 phenolic acids (including isomers and derivatives), 12 flavonoids (including glycosides), 3 ellagic acids (including glycosides and derivative), and 20 betanins (including degradation compounds). In vitro gastrointestinal digestion was performed by INFOGEST® protocol. Fruit pulp showed the greater content of total betalains (444.77 mg/100 g f.w.), and jam only showed very low amounts of two betanin degradation compounds, Cyclo-dopa-5-O-β-glucoside (and its isomer) (0.63 mg/100 f.w.), and two Phyllocactin derivatives (1.04 mg/100 g f.w.). Meanwhile, fruit peel was the richer tissue in total phenolic acids (273.42 mg/100 g f.w.), mainly in piscidic acid content and total flavonoids (7.39 mg/100 g f.w.), isorhamnetin glucoxyl-rhamnosyl-pentoside (IG2) being the most abundant of these compounds. The stability of betalains and phenolic compounds during in vitro gastrointestinal digestion is reported in the present study. In Opuntia stricta var. Dillenii pulp (the edible fraction of the fresh fruit), the betanin bioaccessibility was only 22.9%, and the flavonoid bioaccessibility ranged from 53.7% to 30.6%, depending on the compound. In non-edible samples, such as peel sample (PE), the betanin bioaccessibility was 42.5% and the greater bioaccessibility in flavonoids was observed for quercetin glycoside (QG1) 53.7%, the fruit peel being the most interesting material to obtain antioxidant extracts, attending to its composition on antioxidant compounds and their bioaccessibilities.
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34

Barbero, Margherita, Silvano Cadamuro, Stefano Dughera, and Giovanni Ghigo. "o-Benzenedisulfonimide and its chiral derivative as Brønsted acids catalysts for one-pot three-component Strecker reaction. Synthetic and mechanistic aspects." Organic & Biomolecular Chemistry 10, no. 20 (2012): 4058. http://dx.doi.org/10.1039/c2ob25584g.

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35

Pacheco, Juan M., Tina M. Henry, Vivian K. O'Donnell, Jason B. Gregory, and Peter W. Mason. "Role of Nonstructural Proteins 3A and 3B in Host Rangeand Pathogenicity of Foot-and-Mouth DiseaseVirus." Journal of Virology 77, no. 24 (December 15, 2003): 13017–27. http://dx.doi.org/10.1128/jvi.77.24.13017-13027.2003.

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ABSTRACT The genome of foot-and-mouth disease virus (FMDV) differs from that of other picornaviruses in that it encodes a larger 3A protein (>50% longer than poliovirus 3A), as well as three copies of protein 3B (also known as VPg). Previous studies have shown that a deletion of amino acids 93 to 102 of the 153-codon 3A protein is associated with an inability of a Taiwanese strain of FMDV (O/TAW/97) to cause disease in bovines. Recently, an Asian virus with a second 3A deletion (amino acids 133 to 143) has also been detected (N. J. Knowles et al., J. Virol. 75:1551-1556, 2001). Genetically engineered viruses harboring the amino acids 93 to 102 or 133 to 143 grew well in porcine cells but replicated poorly in bovine cells, whereas a genetically engineered derivative of the O/TAW/97 virus expressing a full-length 3A (strain A12) grew well in both cell types. Interestingly, a virus with a deletion spanning amino acid 93 to 144 also grew well in porcine cells and caused disease in swine. Further, genetically engineered viruses containing only a single copy of VPg were readily recovered with the full-length 3A, the deleted 3A (amino acids 93 to 102), or the “super” deleted forms of 3A (missing amino acids 93 to 144). All of the single-VPg viruses were attenuated in porcine cells and replicated poorly in bovine cells. The single-VPg viruses produced a mild disease in swine, indicating that the VPg copy number is an important determinant of host range and virulence. The association of VPg copy number with increased virulence in vivo may help to explain why all naturally occurring FMDVs have retained three copies of VPg.
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36

Watt, Jacinta A., Carlie T. Gannon, Karen J. Loft, Zoran Dinev, and Spencer J. Williams. "'Click' Preparation of Carbohydrate 1-Benzotriazoles, 1,4-Disubstituted, and 1,4,5-Trisubstituted Triazoles and their Utility as Glycosyl Donors." Australian Journal of Chemistry 61, no. 11 (2008): 837. http://dx.doi.org/10.1071/ch08364.

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Glycosyl triazoles can be prepared from readily available anomeric azides through various ‘click’ methodologies: thermal Huisgen cycloaddition with alkynes, strain-promoted Huisgen cycloaddition of benzynes, and CuI-catalyzed azide-alkyne cycloaddition of terminal alkynes (CuAAC reaction). Here we investigate the formation of glycosyl 1-benzotriazoles from anomeric and non-anomeric carbohydrate azides using benzynes derived from substituted anthranilic acids. The reactivity of the resulting anomeric 1-benzotriazoles as glycosyl donors was investigated and compared with 1,4-disubstituted glycosyl triazoles (from the CuAAC reaction) and 1,4,5-trisubstituted glycosyl triazoles (prepared by Huisgen cycloaddition of glycosyl azides and dimethyl acetylene dicarboxylate). The 1,4,5-trisubstituted glycosyl triazoles were activated by Lewis acids and could be converted to O-glycosides, S-glycosides, glycosyl chlorides, and glycosyl azides. By contrast, under all conditions investigated, the 1,4-disubstituted glycosyl triazoles were unreactive as glycosyl donors. Glycosyl 1-benzotriazoles were generally inert as glycosyl donors; however, a tetrafluorobenzotriazole derivative, which bears electron-withdrawing substituents on the benzotriazole group, was a moderate glycosyl donor and could be converted to an S-glycoside by treatment with thiocresol and tin(iv) chloride.
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37

Tomori, Hiroshi, Hisayoshi Yoshihara, and Katsuyuki Ogura. "Facile Optical Resolution of a Dibenzopyrazinoazepine Derivative and the Nature of Molecular Recognition of Amines by Chiral 2,3-Di-O-(arylcarbonyl)tartaric Acids." Bulletin of the Chemical Society of Japan 69, no. 12 (December 1996): 3581–90. http://dx.doi.org/10.1246/bcsj.69.3581.

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38

Barbero, Margherita, Silvano Cadamuro, Stefano Dughera, and Giovanni Ghigo. "ChemInform Abstract: o-Benzenedisulfonimide and Its Chiral Derivative as Broensted Acids Catalysts for One-Pot Three-Component Strecker Reaction. Synthetic and Mechanistic Aspects." ChemInform 43, no. 43 (September 27, 2012): no. http://dx.doi.org/10.1002/chin.201243071.

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39

Lopez-Anaya, A., and M. Mayersohn. "Ascorbic and dehydroascorbic acids simultaneously quantified in biological fluids by liquid chromatography with fluorescence detection, and comparison with a colorimetric assay." Clinical Chemistry 33, no. 10 (October 1, 1987): 1874–78. http://dx.doi.org/10.1093/clinchem/33.10.1874.

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Abstract We describe a "high-performance" liquid-chromatographic method for separating and quantifying ascorbic acid (AA) and dehydroascorbic acid (DHA) in plasma and urine. We used a reversed-phase C18 column with an ion-pair reagent and detected the analytes by post-column reaction with 4,5-dimethyl-o-phenylenediamine to form a fluorescent derivative (measured at excitation and emission wavelengths of 365 and 440 nm, respectively). Isoascorbic acid (IA) is the internal standard. Retention times for DHA, AA, and IA are 5.6, 15.5, and 19.9 min, respectively. Between-day CVs for AA in plasma in concentrations of 8 and 20 mg/L were 9% and 7%, respectively. The limit of detection is 10 and 4 ng for AA and DHA, respectively. Results by the present method and the methoxyaniline colorimetric method for AA are comparably accurate.
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40

Birzoi, Roxana M., Delia Bugnariu, Christine Goers, Rafael Guerrero Gimeno, Thorsten Gust, Antje Riecke, Zoltán Benkõ, et al. "Di(phosphavinyl) Ethers (2,4-Diphospha-3-oxapentadienes)." Zeitschrift für Naturforschung B 64, no. 1 (January 1, 2009): 73–82. http://dx.doi.org/10.1515/znb-2009-0110.

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Hydrolytic cleavage of the P-chlorophosphaalkenes (RMe2Si)2C=PCl (R = Me: 1a; R = iPr: 1b) in the presence of triethylamine leads to di(phosphavinyl) ethers (2,4-diphospha-3-oxapentadienes) [(RMe2Si)2C=P]2O (2a, 2b) as main products, accompanied by alkylphosphinic acids (RMe2Si)2(H)CP(H)(O)OH (3a, 3b). The hydrolysis of (PhMe2Si)2C=PCl (1c) proceeds less selectively. Reactions with metal oxides under aprotic conditions provide 2a [impure, from 1a with (nBu3Sn)2O] and 2b [from iodophosphaalkene (iPrMe2Si)2C=PI with Ag2O] as oils. 1H, 13C, 29Si and 31P NMR spectra, however, allow unambiguous characterisation of 2a and 2b. Formation mechanisms, structure, and C=P-O π stabilisation of the oxabisphosphaalkene [(H3Si)2C=P]2O (2ʹ) were studied with DFT methods. The double [2+4] cycloaddition reaction of 2a with two equivalents of cyclopentadiene leads to the phosphinous anhydride 7 as a mixture of diastereomers whereas the addition of two equivalents of tetrachloro-o-benzoquinone proceeds in a diastereoselective fashion. An X-ray crystal structure determination of the resulting oxo-bridged bis(2-phospha-2,5-dioxa-3,4-benzophospholene) derivative 8 revealed the presence of a racemic mixture of (R,R)- and (S,S)-configurated molecules. The solid state structure of a by-product, bisylphosphonic tetrachlorocatechol monoester (Me3Si)2CH-P(=O)(OH)-o-OC6Cl4OH 9, was also determined crystallographically.
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41

Fási, Laura, Ahmed Dhahir Latif, István Zupkó, Sándor Lévai, Miklós Dékány, Zoltán Béni, Árpád Könczöl, György Tibor Balogh, and Attila Hunyadi. "AAPH or Peroxynitrite-Induced Biorelevant Oxidation of Methyl Caffeate Yields a Potent Antitumor Metabolite." Biomolecules 10, no. 11 (November 11, 2020): 1537. http://dx.doi.org/10.3390/biom10111537.

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Hydroxycinnamic acids represent a versatile group of dietary plant antioxidants. Oxidation of methyl-p-coumarate (pcm) and methyl caffeate (cm) was previously found to yield potent antitumor metabolites. Here, we report the formation of potentially bioactive products of pcm and cm oxidized with peroxynitrite (ONOO¯), a biologically relevant reactive nitrogen species (RNS), or with α,α′-azodiisobutyramidine dihydrochloride (AAPH) as a chemical model for reactive oxygen species (ROS). A continuous flow system was developed to achieve reproducible in situ ONOO¯ formation. Reaction mixtures were tested for their cytotoxic effect on HeLa, SiHa, MCF-7 and MDA-MB-231 cells. The reaction of pcm with ONOO¯ produced two fragments, an o-nitrophenol derivative, and a new chlorinated compound. Bioactivity-guided isolation from the reaction mixture of cm with AAPH produced two dimerization products, including a dihydrobenzofuran lignan that exerted strong antitumor activity in vitro, and has potent in vivo antimetastatic activity which was previously reported. This compound was also detected from the reaction between cm and ONOO¯. Our results demonstrate the ROS/RNS dependent formation of chemically stable metabolites, including a potent antitumor agent (5), from hydroxycinnamic acids. This suggests that diversity-oriented synthesis using ROS/RNS to obtain oxidized antioxidant metabolite mixtures may serve as a valid natural product-based drug discovery strategy.
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42

Traisaeng, Supitchaya, Deron Raymond Herr, Hsin-Jou Kao, Tsung-Hsien Chuang, and Chun-Ming Huang. "A Derivative of Butyric Acid, the Fermentation Metabolite of Staphylococcus epidermidis, Inhibits the Growth of a Staphylococcus aureus Strain Isolated from Atopic Dermatitis Patients." Toxins 11, no. 6 (May 31, 2019): 311. http://dx.doi.org/10.3390/toxins11060311.

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The microbiome is a rich source of metabolites for the development of novel drugs. Butyric acid, for example, is a short-chain fatty acid fermentation metabolite of the skin probiotic bacterium Staphylococcus epidermidis (S. epidermidis). Glycerol fermentation of S. epidermidis resulted in the production of butyric acid and effectively hindered the growth of a Staphylococcus aureus (S. aureus) strain isolated from skin lesions of patients with atopic dermatitis (AD) in vitro and in vivo. This approach, however, is unlikely to be therapeutically useful since butyric acid is malodorous and requires a high concentration in the mM range for growth suppression of AD S. aureus. A derivative of butyric acid, BA–NH–NH–BA, was synthesized by conjugation of two butyric acids to both ends of an –NH–O–NH– linker. BA–NH–NH–BA significantly lowered the concentration of butyric acid required to inhibit the growth of AD S. aureus. Like butyric acid, BA–NH–NH–BA functioned as a histone deacetylase (HDAC) inhibitor by inducing the acetylation of Histone H3 lysine 9 (AcH3K9) in human keratinocytes. Furthermore, BA–NH–NH–BA ameliorated AD S. aureus-induced production of pro-inflammatory interleukin (IL)-6 and remarkably reduced the colonization of AD S. aureus in mouse skin. These results describe a novel derivative of a skin microbiome fermentation metabolite that exhibits anti-inflammatory and S. aureus bactericidal activity.
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43

Chen, Buze, Sicong Liu, Haihong Wang, Guilin Li, Xiaoyuan Lu, and Hao Xu. "Differential Expression Profiles and Function Prediction of Transfer RNA-Derived Fragments in High-Grade Serous Ovarian Cancer." BioMed Research International 2021 (March 30, 2021): 1–17. http://dx.doi.org/10.1155/2021/5594081.

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Background. The present study is aimed at providing systematic insight into the composition and expression of transfer RNA (tRNA) derivative transcription in high-grade serous ovarian cancer (HGSOC). Methods. tRNA derivative expression profiles in three pairs of HGSOC and adjacent normal ovarian tissues were conducted by tRNA-derived small RNA fragment (tRF) and tRNA half (tiRNA) sequencing. The differentially expressed tRFs and tiRNAs between HGSOC and paired adjacent normal samples were screened. The targeted genes of differentially expressed tRFs and tiRNAs were screened. The Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) of target genes of tRFs and tiRNAs were analyzed. Results. There are a total of 20 significantly upregulated and 15 significantly downregulated tRFs and tiRNAs between the cancer group and the paracarcinoma group. The upregulated tRFs and tiRNAs are mucin-type O-glycan biosynthesis, glycosphingolipid biosynthesis, the glucagon signaling pathway, the AMPK signaling pathway, maturity-onset diabetes of the young, glycosphingolipid biosynthesis, the insulin signaling pathway, insulin resistance, leukocyte transendothelial migration, starch, and sucrose metabolism. The downregulated tRFs and tiRNAs are other glycan degradation, vitamin digestion and absorption, fatty acid elongation, and biosynthesis of unsaturated fatty acids. Conclusions. There are significantly expressed tRFs and tiRNAs in HGSOC tissues, and these may provide potential diagnostic biomarkers and therapeutic targets for HGSOC.
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44

Harmrolfs, Kirsten, Lena Mancuso, Binia Drung, Florenz Sasse, and Andreas Kirschning. "Preparation of new alkyne-modified ansamitocins by mutasynthesis." Beilstein Journal of Organic Chemistry 10 (March 3, 2014): 535–43. http://dx.doi.org/10.3762/bjoc.10.49.

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The preparation of alkyne-modified ansamitocins by mutasynthetic supplementation of Actinosynnema pretiosum mutants with alkyne-substituted aminobenzoic acids is described. This modification paved the way to introduce a thiol linker by Huisgen-type cycloaddition which can principally be utilized to create tumor targeting conjugates. In bioactivity tests, only those new ansamitocin derivatives showed strong antiproliferative activity that bear an ester side chain at C-3.
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45

Argentieri, Maria Pia, Moira Madeo, Pinarosa Avato, Marcello Iriti, and Sara Vitalini. "Polyphenol content and bioactivity of Achillea moschata from the Italian and Swiss Alps." Zeitschrift für Naturforschung C 75, no. 3-4 (March 26, 2020): 57–64. http://dx.doi.org/10.1515/znc-2019-0214.

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AbstractAchillea moschata Wulfen, which grows in the Alps, is extensively used by local people for its medicinal properties. Two studied samples were collected, at the flowering stage, in Val Mustair (Switzerland) and Valchiavenna (Italy), respectively. The aerial parts were defatted with petroleum ether (PET) and successively extracted with dichloromethane (DCM) and methanol (MeOH). High-performance liquid chromatography and electrospray ionization-tandem mass spectrometry analyses of the methanolic extracts evidenced that flavonoids were the predominant compounds compared to phenolic acids in both samples (89.5 vs. 33.0 μg/mg DW in A. moschata Valchiavenna and 82.5 vs. 40.0 μg/mg DW in A. moschata Val Mustair). Among flavonoid derivatives, luteolin and apigenin were the predominant aglycones, free and glycosilated. The A. moschata Valchiavenna extract was characterized by apigenin as the main compound (60.4 μg/mg DW), while A. moschata Val Mustair was characterized by its derivative apigenin 7-O-glucoside (44.7 μg/mg DW). The antioxidant activity of all the obtained extracts was tested by the DPPH (2,2-diphenyl-picryl hydrazyl) and ABTS (2,21-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) methods, which showed their increasing scavenger capacity in relation to extract polarity (PET extract < DCM extract < MeOH extract). The extracts were also investigated against three Gram-positive (Bacillus cereus, Enterococcus faecalis and Staphylococcus aureus) and three Gram-negative (Escherichia coli, Proteus mirabilis and Pseudomonas aeruginosa) bacterial species using the disc diffusion assay. DMC and PET were the most active extracts (inhibition diameter: ≥12 mm).
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46

Mseer, Marwa Abdulameer, Khudheyer Jawad, and Yahya Al-Khafaji. "Synthesis and Characterization of Heterocyclic Compounds Derived from Schiff base Glycerol Triester." NeuroQuantology 19, no. 9 (October 12, 2021): 88–96. http://dx.doi.org/10.14704/nq.2021.19.9.nq21141.

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Heterocyclic compounds were prepared from Schiff bases triester derivatives, the first step was included, p- aminobenzoic acids convert to p-amino benzoyl chloride in the presence of thionyl chloride then glycerol was added to form triesters compound A. second step reaction of triester product with the 4-nitrobenzaldehyde, and 3-amino benzaldehyde to produce M1, and M2. The third step. Involve reacted Schiff bases triester derivatives to give heterocyclic compounds M1S, M1A, M2P, and M2K. The structure of all compounds is monitored by (TLC), and identified by many techniques 1HNMR, FT-IR, and melting point.
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47

Dragović, Sanja, Verica Dragović-Uzelac, Sandra Pedisić, Zrinka Čošić, Maja Friščić, Ivona Elez Garofulić, and Zoran Zorić. "The Mastic Tree (Pistacia lentiscus L.) Leaves as Source of BACs: Effect of Growing Location, Phenological Stage and Extraction Solvent on Phenolic Content." Food Technology and Biotechnology 58, no. 3 (July 15, 2020): 303–13. http://dx.doi.org/10.17113/ftb.58.03.20.6662.

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Research background. Mastic tree (Pistacia lentiscus L.) of the Anacardiaceae family is an evergreen shrub from Mediterranean countries where it is used in traditional medicine. Analysis of P. lentiscus leaf, stem, fruit and root extracts showed high concentrations of principal groups of secondary metabolites (flavonoids, phenolic acids and tannins), suggesting the plant possesses great biological potential. Therefore, the aim of this research is to evaluate the impact of environmental parameters and the extraction solvent type on the concentration of phenols in mastic tree leaf extracts grown at four different locations along the Adriatic coast (Barbariga, Lun, Hvar and Vela Luka) during three phenological stages (early flowering, early fruiting and late fruiting). Experimental approach. Since mastic tree plant has phenolic compounds with different structures and chemical properties, ethanolic and methanolic leaf extracts were analysed using high-performance liquid chromatography (HPLC) coupled with UV/Vis PDA detector. Phenolic compounds were identified by comparing the retention times and spectral data with those of standards at 280 and 340 nm. Results and conclusions. In all samples, phenolic acids and flavonol glycosides were quantified, while catechin was quantified only in methanolic extracts. The 5-O-galloylquinic acid was determined as a predominant phenolic compound in all samples followed by monogalloyl glucose, 3,5-di-O-galloylquinic acid, 3,4,5-tri-O-galloylquinic acid and gallic acid, respectively. Myricetin-3-O-rhamnoside was found to be the predominant flavonol glycoside followed by myricetin-3-O-glucoside, myricetin-3-O-glucuronide, quercetin-3-O-rhamnoside and derivative of flavonol glycoside. The mass concentration of these compounds significantly varied during different phenological stages, at different growing locations and used extraction solvents. The highest phenolic mass concentration was determined in the samples harvested at Hvar growing location and extracted in 80 % methanol. The highest total phenolic acid mass concentration was obtained in the samples harvested during the flowering phenological stage and the highest total flavonoid mass concentration in the samples harvested during the early fruiting stage. Novelty and scientific contribution. The obtained data provide a better understanding of the P. lentiscus species phenolic concentration, which can lead to further investigations regarding the valorisation of mastic tree leaves as pharmaceutical products or as food products with added value.
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48

Udvardy, Antal, Csenge Tamara Szolnoki, Réka Gombos, Gábor Papp, Éva Kováts, Ferenc Joó, and Ágnes Kathó. "Mechanochemical P-derivatization of 1,3,5-Triaza-7-Phosphaadamantane (PTA) and Silver-Based Coordination Polymers Obtained from the Resulting Phosphabetaines." Molecules 25, no. 22 (November 16, 2020): 5352. http://dx.doi.org/10.3390/molecules25225352.

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We have described earlier that in aqueous solutions, the reaction of 1,3,5-triaza-7-phosphaadamantane (PTA) with maleic acid yielded a phosphonium-alkanoate zwitterion. The same reaction with 2-methylmaleic acid (citraconic acid) proceeded much slower. It is reported here, that in the case of glutaconic and itaconic acids (constitutional isomers of citraconic acid), formation of the corresponding phosphabetaines requires significantly shorter reaction times. The new phosphabetaines were isolated and characterized by elemental analysis, multinuclear NMR spectroscopy and ESI-MS spectrometry. Furthermore, their molecular structures in the solid state were determined by single crystal X-ray diffraction (SC-XRD). Synthesis of the phosphabetaines from PTA and unsaturated dicarboxylic acids was also carried out mechanochemically with the use of a planetary ball mill, and the characteristics of the syntheses in solvent and under solvent-free conditions were compared. In aqueous solutions, the reaction of the new phosphabetaines with Ag(CF3SO3) yielded Ag(I)-based coordination polymers. According to the SC-XRD results, in these polymers the Ag(I)-ion coordinates to the N and O donor atoms of the ligands; however, Ag(I)-Ag(I) interactions were also identified. The Ag(I)-based coordination polymer (CP1.2) formed with the glutaconyl derivative of PTA (1) showed considerable antimicrobial activity against both Gram-negative and Gram-positive bacteria and yeast strains
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49

Bvenura, Callistus, and Learnmore Kambizi. "Composition of Phenolic Compounds in South African Schinus molle L. Berries." Foods 11, no. 10 (May 10, 2022): 1376. http://dx.doi.org/10.3390/foods11101376.

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The Schinus molle tree is notoriously invasive in most parts of the world, and yet as a pseudospice, its berries potentially possess some significant health benefits which need to be explored. Therefore, polar metabolome of seed + husks (SH), husks (H), and de-hulled (DH) berries were profiled and quantified by untargeted metabolomics approach using UPLC-QTOF-MS. A total of 13 gallotannins, three phenolic acids, a phenolic acid glucoside, three phenolic acid esters, an organic acid, a gallotannin derivative, and nine flavonoids were detected and quantified. Phenolic acids ranged between 12.2–295.7; 4.9–77; and 89.7–1613.1 mg/kg in SH, DH seeds and H respectively. Flavonoids ranged between 1.8–267.5; 73.4–80.4; and 124–564.3 mg/kg in SH, DH seeds and H respectively. Gallotannins ranged between 1.1–146.6; 14.8–21.8; and 48.1–664.8 mg/kg in SH, DH seeds and H respectively. Feruloyltartaric A, quercetin 3-O-glucuronide, catechin digalloylshikimic acid B as well as digalloyl quinic acid were some of the dominant secondary metabolites revealed. These results indicate that S. molle berries are a rich source of secondary metabolites with elevated concentrations in the husks, while DH seeds possess lower concentrations to none. These findings open important insights into the potential of S. molle berries as a natural source of antioxidants for the food and pharmaceutical industries.
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50

Lehrer, Jason, Karen A. Vigeant, Laura D. Tatar, and Miguel A. Valvano. "Functional Characterization and Membrane Topology of Escherichia coli WecA, a Sugar-Phosphate Transferase Initiating the Biosynthesis of Enterobacterial Common Antigen and O-Antigen Lipopolysaccharide." Journal of Bacteriology 189, no. 7 (January 19, 2007): 2618–28. http://dx.doi.org/10.1128/jb.01905-06.

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ABSTRACT WecA is an integral membrane protein that initiates the biosynthesis of enterobacterial common antigen and O-antigen lipopolysaccharide (LPS) by catalyzing the transfer of N-acetylglucosamine (GlcNAc)-1-phosphate onto undecaprenyl phosphate (Und-P) to form Und-P-P-GlcNAc. WecA belongs to a large family of eukaryotic and prokaryotic prenyl sugar transferases. Conserved aspartic acids in putative cytoplasmic loops 2 (Asp90 and Asp91) and 3 (Asp156 and Asp159) were targeted for replacement mutagenesis with either glutamic acid or asparagine. We examined the ability of each mutant protein to complement O-antigen LPS synthesis in a wecA-deficient strain and also determined the steady-state kinetic parameters of the mutant proteins in an in vitro transfer assay. Apparent Km and V max values for UDP-GlcNAc, Mg2+, and Mn2+ suggest that Asp156 is required for catalysis, while Asp91 appears to interact preferentially with Mg2+, possibly playing a role in orienting the substrates. Topological analysis using the substituted cysteine accessibility method demonstrated the cytosolic location of Asp90, Asp91, and Asp156 and provided a more refined overall topological map of WecA. Also, we show that cells expressing a WecA derivative C terminally fused with the green fluorescent protein exhibited a punctate distribution of fluorescence on the bacterial surface, suggesting that WecA localizes to discrete regions in the bacterial plasma membrane.
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