110-42-9Relevant articles and documents
Development of mesoscopically assembled sulfated zirconia nanoparticles as promising heterogeneous and recyclable biodiesel catalysts
Das, Swapan K.,El-Safty, Sherif A.
, p. 3050 - 3059 (2013)
The nanoassembly of nearly monodisperse nanoparticles (NPs) as uniform building blocks to engineer zirconia (ZrO2) nanostructures with mesoscopic ordering by using a template as a fastening agent was explored. The mesophase of the materials was investigated through powder X-ray diffraction and TEM analysis (TEM) and N2 sorption studies. The TEM results revealed that the mesopores were created by the arrangement of ZrO2 NPs with sizes of 7.0-9.0nm and with broad interparticle pores. Moreover, the N2 sorption study confirmed the results. The surface chemical analysis was performed to estimate the distribution of Zr, O, and S in the sulfated ZrO2 matrices. The materials in this study displayed excellent catalytic activity in the biodiesel reaction for effective conversion of long-chain fatty acids to their methyl esters, and the maximum biodiesel yield was approximately 100%. The excellent heterogeneous catalytic activity could be attributed to the open framework, large surface area, presence of ample acidic sites located at the surface of the matrix, and high structural stability of the materials. The catalysts revealed a negligible loss of activity in the catalytic recycles.
Stoloniferins VIII-XII, resin glycosides, from Ipomoea stolonifera
Noda, Naoki,Takahashi, Naotsugu,Miyahara, Kazumoto,Yang, Chong-Ren
, p. 837 - 841 (1998)
Five new ether-soluble resin glycosides were isolated from whole plants of Ipomoea stolonifera. Their structures have been determined on the basis of chemical and spectral data. Similar to the resin glycosides previously isolated, all of them are monomers of a jalapinolic acid tetra- or penta- glycoside in which the sugar moiety is partially acylated by organic acids and also combined with the carboxy group of the aglycone to form a macrocyclic ester structure.
Lupeol-3-O-decanoate, a new triterpene ester from Cadaba farinosa Forssk. growing in Saudi Arabia
Al-Musayeib, Nawal M.,Mohamed, Gamal A.,Ibrahim, Sabrin R. M.,Ross, Samir A.
, p. 5297 - 5302 (2013)
A new triterpene ester (1) together with eight known compounds (2-9) were isolated from the leaves of Cadaba farinosa Forssk. Their chemical structures were established on the basis of physical, chemical, and spectroscopic methods (IR, 1D and 2D NMR, and mass spectral analyses) to be: lupeol-3-O-decanoate (1), lupeol (2), β-sitosterol (3), ursolic acid (4), 12-aminododecanoic (5), dillenetin-3-O-β-d-glucopyranoside (6), stachydrine (7), 3-hydroxy-stachydrine (8), and quercetin-3-O-β-d-glucopyranoside (9). That is the first report for the isolation of compound 5 from a plant source. Compounds 5, 6, and 9 were evaluated for their antioxidant activity.
AN 8-HYDROXYOCTADECA-CIS-11,14-DIENOIC ACID FROM MIRABILIS JALAPA SEED OIL
Ahmad, Mohammad Shamim,Rauf, Abdul,Mustafa, Jamal,Osman, Sheikh Mohammad
, p. 2247 - 2250 (1984)
A fatty acid, found as a minor component in the seed oil of Mirabilis jalapa, is shown to be the hitherto unknown 8-hydroxyoctadeca-cis-11,14-dienoic acid. - Key Word Index: Mirabilis jalapa; Nyctaginaceae; seed oil; 8-hydroxyoctadeca-cis-11,14-dienoic acid.
NEW BUTENOLIDES FROM THE GORGONIAN EUPLEXAURA FLAVA(NUTTING)
Kikuchi, Hiroyuki,Tsukitani, Yasumasa,Nakanishi, Hajime,Shimizu, Iwao
, p. 233 - 236 (1982)
Four new butanolides (1a-d) were isolated from the Japanese gorgonian Euplexaura flava(Nutting).The structures of these compounds were elucidated from spectral data and chemical reactions.
Carbon-carbon bond fission on oxidation of primary alcohols to carboxylic acids
Bekish, Andrei V.
, p. 3082 - 3085 (2012)
α-Carbon-carbon bond cleavage is shown to be a general side reaction accompanying the oxidation of unbranched primary alcohols to the corresponding carboxylic acids using HNO3, CrO3/H2SO 4/H2O/acetone, CrO3/CH3COOH, PDC/DMF, H5IO6/CrO3, KMnO4/H +, KMnO4/HO-, NiCl2/NaClO, TEMPO/PhI(OAc)2. Therefore, the product formed is always contaminated with a carboxylic acid containing one carbon atom less. Systems such as PhI(OAc)2/TEMPO or H5IO6/CrO 3/CH3CN reduce to a minimum the content of this impurity. Temperature, the order of reagent addition, and additives such as oxalic acid or cerium salts produce a profound effect on the formation of the undesirable impurity during the Jones oxidation of primary alcohols.
Ando,Tsukamoto
, p. 1031 (1974)
Isolation and characterization of the chemical constituents from Plumeria rubra
Akhtar, Nasim,Saleem, Muhammad,Riaz, Naheed,Ali, M. Shaiq,Yaqoob, Asma,Nasim, Faiz-Ul-Hassan,Jabbar, Abdul
, p. 291 - 298 (2013)
Rubranonoside (=7-O-α-l-rhamnopyranosyl-4′-O-β-d- glucopyranosylnaringenin; (1), a new flavanone glycoside, rubranin (=(2S,3S,4R)-2-{[(2R,16E)-2-hydroxyhexaeico-16-en]amino}octadecane-1,3, 4-triol-1-O-β-d-glucopyranoside; (2), a new sphingolipid, rubradoid (plumieridine-1-O-β-d-galactopyranoside; (3), a new iridoid galactoside, rubrajaleelol (4) and rubrajaleelic acid (5), two new nor-terpenoids together with known iridoids: 1-α-plumieride (6), plumieride p-Z-coumarate (7) and plumieride-p-E-coumarate (8) have been isolated from the EtOAc-soluble fraction of the MeOH extract of Plumeria rubra. Their structures were assigned from 1H, 13C NMR spectra and 2D NMR analyses (COSY, NOESY, HMQC and HMBC experiments) in combination with HRMS experiments and comparison with literature data of related compounds. All the isolates (1-8) were tested for their antioxidant, antiurease, cytotoxic and phytotoxic activities and were found almost inactive.
Convenient method for the synthesis of N-(ethyloxycarbonyl) ester derivatives from amino acids
Kanth,Periasamy
, p. 1523 - 1530 (1995)
Amino acids upon treatment with ethyl chloroformate in methanol in the presence of potassium carbonate give the corresponding N-(ethyloxycarbonyl) amino acid ester derivatives in good yields. These derivatives can be also synthesized by performing the reaction in THF in the presence of alcohols.
DITERPENES FROM THE LATEX OF EUPHORBIA BROTERI
a Jose Sexmero,Marcos, Isidro Sanchez
, p. 207 - 212 (1988)
Six polycyclic diterpenes have been isolated from the latex of Euphorbia broteri Daveau.Two had a tigliane skeleton: 12-O-(2Z,4E-octadienoyl)-4-deoxyphorbol-13,20-diacetate and 12-O-(2Z,4E-octadienoyl)-phorbol-13,20-diacetate and four an ingenane skeleton: 20-acetyl-ingenol-3-decadienoate, 3-O-tetradecanoyl-ingenol, 20-O-tetradecanoyl-ingenol and 5-O-tetradecanoyl-ingenol.The second and last two compounds are described as natural compounds for the first time.Their structures were established by spectroscopic methods, by chemical correlations and by H/H and C/H correlations in their 1H NMR and 13C NMR spectra.Key Word Index - Euphorbia broteri; Euphorbiaceae; latex; proinflammatory fractions; ingenol and phorbol mono-,di- and triesters; tetracyclic diterpenes.
Carboxylic Acid Reductase Can Catalyze Ester Synthesis in Aqueous Environments
Pongpamorn, Pornkanok,Kiattisewee, Cholpisit,Kittipanukul, Narongyot,Jaroensuk, Juthamas,Trisrivirat, Duangthip,Maenpuen, Somchart,Chaiyen, Pimchai
supporting information, p. 5749 - 5753 (2021/02/01)
Most of the well-known enzymes catalyzing esterification require the minimization of water or activated substrates for activity. This work reports a new reaction catalyzed by carboxylic acid reductase (CAR), an enzyme known to transform a broad spectrum of carboxylic acids into aldehydes, with the use of ATP, Mg2+, and NADPH as co-substrates. When NADPH was replaced by a nucleophilic alcohol, CAR from Mycobacterium marinum can catalyze esterification under aqueous conditions at room temperature. Addition of imidazole, especially at pH 10.0, significantly enhanced ester production. In comparison to other esterification enzymes such as acyltransferase and lipase, CAR gave higher esterification yields in direct esterification under aqueous conditions. The scalability of CAR catalyzed esterification was demonstrated for the synthesis of cinoxate, an active ingredient in sunscreen. The CAR esterification offers a new method for green esterification under high water content conditions.
Visible-Light-Induced Nickel-Catalyzed Cross-Coupling with Alkylzirconocenes from Unactivated Alkenes
Bai, Songlin,Gao, Yadong,Jiang, Chao,Liu, Xiaolei,Qi, Xiangbing,Wang, Jing,Wu, Qingcui,Yang, Chao
, p. 675 - 688 (2020/03/11)
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Structural and theoretical studies of the methoxycarbonylation of higher olefins catalysed by (Pyrazolyl-ethyl)pyridine palladium (II) complexes
Zulu, Siyabonga,Alam, Mohd.G.,Alam, Mohd. G.,Ojwach, Stephen O.,Akerman, Matthew P.
, (2019/08/21)
Reactions of 2-[1-(3,5-dimethylpyrazol-1-yl)ethyl]pyridine (L1) and 2-[1-(3,5-diphenylpyrazol-1-yl)ethyl]pyridine (L2) with the [Pd (COD)Cl2] or [Pd (COD)MeCl] produced palladium (II) complexes [Pd(L1)ClMe] (1), [Pd(L1)Cl2] (C2), [Pd(L2)ClMe] (3), and [Pd(L2)Cl2] (4) in quantitative yields. Solid state structures of complexes 1, 3 and 4 established the formation of mononuclear compounds, containing one bidentate ligand unit per metal atom, to give square planar complexes. All the other spectroscopic characterization data and elemental analyses were consistent with the observed structures. All the palladium (II) complexes 1–4 gave active catalysts in the methoxycarbonylation of 1-octenes. The catalysts demonstrated 100% chemoselectivities towards esters and favored the formation of linear isomers. Reaction conditions such as the type of phosphine derivative, acid promoter, solvent system, time, pressure and temperature have been investigated and shown to affect both the catalytic activity and regio-selectivity of the catalysts. Solid-angle modelling established the comparable steric contributions from the ligands, consistent with the similar regioselectivities of the resultant catalysts.