1731-92-6Relevant articles and documents
Synthesis of mesoporous ZSM-5 zeolites and catalytic cracking of ethanol and oleic acid into light olefins
Zhao, Tingting,Li, Fuwei,Yu, Hongchang,Ding, Shilei,Li, Zhixia,Huang, Xinyuan,Li, Xiang,Wei, Xiaohan,Wang, Zhenlin,Lin, Hongfei
, p. 101 - 110 (2019/02/24)
Conversion of biomass-derived chemicals into light olefins is a promising method to maintain sustainable development of light olefin industry. In this study, three mesoporous ZSM-5 zeolites (MZSM-5-A, MZSM-5-B and MZSM-5-C) with major pore diameter about 4.8 nm, 16 nm and 22 nm were synthesized using a hydrothermal method by utilizing different templates. The catalytic activity of catalysts was studied by catalytic cracking of ethanol and oleic acid. The influence of reaction temperature on conversion and product selectivity was investigated. The characterization of ZSM-5 samples showed that the orders of the external surface area and mesopore volume were MZSM-5-C > MZSM-5-B > MZSM-5-A > conventional HZSM-5. In ethanol to light olefin reaction, MZSM-5-C achieved the highest light olefin yield (318.3 mL g?1) and ethylene selectivity (42.3%) at 400 °C. In oleic acid to light olefin reaction, MZSM-5-B achieved a complete conversion of oleic acid at 500 °C, and obtained the highest light olefin selectivity (38.1%) at 550 °C. The difference may be relevant to the size and chemical structure of feedstock molecular as well as the acidity of catalysts. Regardless of ethanol or oleic acid as feedstock, introduction of mesopore in zeolites significantly enhanced the light olefin yield and selectivity.
Metathesis of renewable polyene feedstocks – Indirect evidences of the formation of catalytically active ruthenium allylidene species
Kovács, Ervin,Sághy, Péter,Turczel, Gábor,Tóth, Imre,Lendvay, Gy?rgy,Domján, Attila,Anastas, Paul T.,Tuba, Róbert
supporting information, p. 213 - 217 (2017/09/12)
Cross-metathesis (CM) of conjugated polyenes, such as 1,6-diphenyl-1,3,5-hexatriene (1) and α-eleostearic acid methyl ester (2) with several olefins, including 1-hexene, dimethyl maleate and cis-stilbene as model compounds has been carried out using (1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene)-dichloro(o-isopropoxyphenylmethylene)ruthenium (Hoveyda-Grubbs 2nd generation, HG2) catalyst. The feasibility of these reactions is demonstrated by the observed high conversions and reasonable yields. Thus, regardless of the relatively low electron density, =CH–CH= conjugated units of molecules, including compound 2 as a sustainable, non-foodstuff source, can be utilized as building blocks for the synthesis of various value-added chemicals via olefin metathesis. DFT-studies and the product spectrum of the self-metathesis of 1,6-diphenyl-1,3,5-hexatriene suggest that a Ru η1-allylidene complex is the active species in the reaction.
Dammarane triterpenoids from Carnauba, Copernicia prunifera (Miller) H. E. Moore (Arecaceae), wax
De Almeida, Buana C.,Araújo, Bruno Q.,Barros, Elcio D. S.,Freitas, Samya D. L.,Maciel, Dayany S. A.,Ferreira, Ari J. S.,Guadagnin, Rafael C.,Vieira, Gerardo M.,Lago, Jo?o H. G.,Chaves, Mariana H.
, p. 1371 - 1376 (2017/07/13)
Phytochemical investigation from carnauba (Copernicia prunifera) wax led to the identification of sixteen dammarane–type triterpenes, including thirteen new characterized as: (24R*)-methyldammara-20,25-dien-3α-ol and a mixture of alkyl (24R*)-methyldammar-25-en-20-ol-3β-carboxylates, together with three previously described triterpenes: carnaubadiol, (24R*)-methyldammara-20,25-dien-3β-ol and (24R*)-24-methyldammara-20,25-dien-3-one. Moreover, four fatty alcohols (eicosanol, docosanol, tetracosanol and hexacosanol) as well as four sterols (cholesterol, campesterol, stigmasterol, and sitosterol) were also obtained. These compounds were isolated using classical chromatographic methods and their structures were determined by spectroscopic and chemical methods.
Development and Applications of Transesterification Reactions Catalyzed by N-Heterocyclic Olefins
Blümel, Marcus,Noy, Janina-Miriam,Enders, Dieter,Stenzel, Martina H.,Nguyen, Thanh V.
supporting information, p. 2208 - 2211 (2016/06/01)
A novel method to utilize N-heterocyclic olefins (NHOs), the alkylidene derivatives of N-heterocycic carbenes, as organocatalysts to promote transesterification reactions has been developed. Because of their strong Br?nsted/Lewis basicity, NHOs can enhance the nucleophilicity of alcohols for their acylation reactions with carboxylic esters. This transformation can be employed in industrially relevant processes such as the production of biodiesel, the depolymerization of polyethylene terephthalate (PET) from plastic bottles for recycling purposes, and the ring-opening polymerization of cyclic esters to form biodegradable polymers such as polylactide (PLA) and polycaprolactone (PCL).
Cytotoxic ceramides from the Red Sea sponge Spheciospongia vagabunda
Eltamany, Enas Elsayed,Ibrahim, Amany K.,Radwan, Mohamed M.,Elsohly, Mahmoud A.,Hassanean, Hashim A.,Ahmed, Safwat A.
, p. 3467 - 3473 (2015/08/03)
Extracts of Egyptian marine organisms from the Red Sea were screened for their anticancer activity using sulforhodamine B assay. The extract of the Red Sea sponge Spheciospongia vagabunda possessed promising anticancer activity against HepG2 (liver cancer cell line) and MCF-7 (breast cancer cell line). Isolation of three new ceramides: N-[(2S,3S,4R)-1,3,4-trihydroxytetradecan-2-yl] tridecanamide (1), (R)-2′-hydroxy-N-[(2S,3S,4R)-1,3,4-trihydroxypentacosan-2-yl] octadecanamide (2) and (R,Z)-2′-hydroxy-N-[(2S,3S,4R)-1,3,4-trihydroxytricosan-2-yl) nonadec-10-enamide (3) was accomplished via bioassay-guided fractionation. Structure elucidation was achieved using spectroscopic techniques, including 1D and 2D NMR and HRMS. Compounds 2 and 3 displayed high potential cytotoxicity against HepG2 (IC50 24.7 and 21.3 μM, respectively) and MCF-7 (IC50 26.8 and 29.8 μM, respectively), compared with doxorubicin as control drug.
GC-FID analysis of fatty acids and biological activity of Zanthoxylum rhetsa (Roxb.) DC seed oil
Naik, Rajashri R.
, p. 1929 - 1935 (2016/02/27)
The Fatty acid content and composition of fixed oil from Zanthoxylum rhetsa seeds was determined. The seeds were found to contain about ～19.5% of crude fixed oil on a dry weight basis. Fatty acids were converted into methyl esters and analyzed by GC-FID. Ten fatty acids were identified using GC-FID. The major monounsaturated and saturated fatty acids were oleic acid (41.6 - 43.5%) and palmitic acid (26.8-30.2%) respectively, whereas the α-linolenic acid (12.1 - 12.5%) and linoleic acid (10.0%) were polyunsaturated fatty acid. Stearic acid (5.2 - 6.0%), myristic acid (0.1%), traces of pentadecanoic, heptadecanoic and arachidic acid were also identified. These fatty acids have not been reported earlier from the oil of Z. rhetsa. Fixed oil exhibited significant free radical scavenging activity which was measured using DPPH, and is also known to inhibit the gastrointestinal motility significantly.
Improved protocol toward 1,3,4-oxadiazole-2(3H)-thiones and scale-up synthesis in the presence of SDS as a micelle promoted catalyst
Yildirim, Ayhan
, p. 473 - 478 (2015/06/30)
Convenient procedure for in situ cyclization of hydrazinecarbodithioate potassium salts to 1,3,4-oxadiazole-2(3H)-thiones under normal phase micellar media catalysis promoted by sodium dodecyl sulfate (SDS) as an anionic surfactant is reported. The main advantage of this procedure is to provide shorter reaction time for the completion of cyclization; scale-up synthesis is possible and the oxadiazoles were obtained in high to excellent yields (87-100%), making the protocol an attractive alternative to the available methods.
Further secondary metabolites from Seriphidium stenocephalum
Shafiq, Nusrat,Ali, Liaqat,Riaz, Naheed,Khatoon, Tasneem,Touseef, Muhammad Imran,Jabbar, Abdul,Tareen, Rasool Bakhsh,Saleem, Muhammad
, p. 704 - 712 (2016/01/12)
In continuation of our search for bioactive secondary metabolites from Seriphidium stenocephalum, chromatographic analysis of some ignored fractions from previous work on ethyl acetate part of the methanolic extract yielded five new sphingolipids; seriphidalin A [(2S,3S,4R,12E)-2-{[heptdecanoyl]amino}unieicos-12-ene-1,3,4-triol; 1], seriphidalin B [(2S,3S,4R,12E)-2-{[(2R)-2-hydroxydodidecanoyl]amino}trididec-12-ene-1,3,4-triol; 2], seriphidalin C [(2S,3S,4R,9E)-2-{[(2R)-2-hydroxydodidecanoyl]amino}didec-9-ene-1,3,4-triol; 3], seriphidalin D [(2S,3S,4R)-2-{[(2R,5E)-2-hydroxyheptadec-5-enoyl]amino}pentadecane-1,3,4-triol-1-O-β-D-galactopyranoside; 4] and seriphidalin E [(2S,3S,4R,7E,12E)-2-{[(2R)-2-hydroxyheptanoyl]amino}heptadeca-7,12-diene-1,3,4-triol-1-O-β-D-glucopyranoside; 5] together with five known compounds (6-10). The structures of the isolated compounds were determined by 1D and 2D NMR and high resolution mass spectrometry.
Lycopersicon esculentum Seeds: An industrial byproduct as an antimicrobial agent
Taveira, Marcos,Silva, Luis R.,Vale-Silva, Luis A.,Pinto, Eugenia,Valentao, Patricia,Ferreres, Federico,Guedes De Pinho, Paula,Andrade, Paula B.
experimental part, p. 9529 - 9536 (2011/05/30)
Lycopersicon esculentum (tomato) fruit is a widely studied matrix. However, only few works focus their attention on its seeds, which constitute a major byproduct of the tomato processing industry. In this study the antimicrobial potential of ten different tomato seed extracts from "Bull s heart" and "Cherry" varieties were analyzed against Gram-positive (Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus luteus, Enterococcus faecalis and Bacillus cereus) and Gram-negative (Proteus mirabilis, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhimurium) bacteria and fungi (Candida albicans, Aspergillus fumigatus and Trichophyton rubrum). Regarding antibacterial capacity, the different extracts were revealed to be active only against Gram-positive bacteria, E. faecalis being the most susceptible one (MIC: 2.5-10 mg/mL). Concerning antifungal activity, "Bull s heart" extracts were the most active. In a general way C. albicans was the most susceptible species (MIC: 5-10 mg/mL). The chemical composition of the extracts was also pursued, concerning organic acids, phenolics and fatty acids, in order to establish a possible relationship with the observed antimicrobial effect.
DIRECT METHOD AND REAGENT KITS FOR FATTY ACID ESTER SYNTHESIS
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Page/Page column 18; 21-22; 29, (2008/12/07)
Provided are efficient, cost-effective and water tolerant methods (e.g., single-vial methods) for preparing fatty acid esters from organic matter, comprising: obtaining organic matter comprising at least one fat substituent, contacting the organic matter in a reaction mixture with a basic solution under conditions suitable to provide for hydrolytic release of monomeric fatty acids from the at least one fat substituent to provide a base-treated reaction mixture, and esterifying the monomeric fatty acids of the base-treated reaction mixture by acidification of the reaction mixture and treating in the presence of an organic alcohol to provide fatty acid esters. The methods optionally further comprise, prior to esterifying, neutralizing the base-treated reaction mixture to provide for neutralized fatty acids, separating the neutralized fatty acids from the neutralized reaction mixture, and dissolving the separated fatty acids in the esterification reaction mixture. Also provided are related methods and kits for fat analysis.
