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1.
ChemSusChem ; 10(10): 2291-2300, 2017 05 22.
Artículo en Inglés | MEDLINE | ID: mdl-28376258

RESUMEN

The disposal of any waste by recovering it within the production plant represents the ultimate goal of every biorefinery. In this scenario, the selective preparation of monoalkyl glyceryl ethers (MAGEs) starting from glycidol, obtained as byproduct in the epichlorohydrin production plant, represents a very promising strategy. Here, we report the synthesis of MAGEs through the reaction of glycidol with alcohols catalyzed by a green homogeneous Lewis acids catalyst, such as BiIII triflate, under very mild reaction conditions. To evaluate the green potential of the proposed alternative, a simplified life cycle assessment (LCA) approach was followed by comparing the environmental performance of the proposed innovative route to prepare MAGEs with that of the most investigated pathway from glycerol. A considerable reduction of all impact categories considered was observed in our experimental conditions, suggesting that the glycidol-to-MAGEs route can be a valuable integration to the glycerol-to-MAGEs chain. Thanks to the use of primary data within the LCA model, the results achieved are a very good approximation of the real case.


Asunto(s)
Compuestos Epoxi/química , Éteres de Glicerilo/síntesis química , Propanoles/química , Catálisis
2.
ChemSusChem ; 9(23): 3272-3275, 2016 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-27880034

RESUMEN

The present work deals with the production of monoalkyl glyceryl ethers (MAGEs) through a new reaction pathway based on the reaction of glycidol and alcohols catalyzed by Lewis acid-based catalysts. Glycidol is quantitatively converted with high selectivity (99 %) into MAGEs under very mild reaction conditions (80 °C and 0.01 mol % catalyst loading) in only 1 h using Al(OTf)3 or Bi(OTf)3 as catalyst. The proposed method enhances the choice of possible green synthetic approaches for the production of value-added products such as MAGEs.


Asunto(s)
Alcoholes/química , Compuestos Epoxi/química , Éteres de Glicerilo/síntesis química , Propanoles/química , Catálisis , Tecnología Química Verde , Ácidos de Lewis/química
4.
J Oleo Sci ; 63(10): 1057-62, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25213442

RESUMEN

The selective preparation of monobenzyl glyceryl ethers, which are potential commodity chemicals with special functions, was explored to find new applications for glycerol. Among the acid catalysts investigated (sulfuric acid, heteropoly acid, Nafion(R), and zeolite), Zeolite Socony Mobil-5 (ZSM-5) afforded better results. The reaction of equimolar amounts of glycerol and benzyl alcohol at 150ºC for 7 h in the presence of 2 wt% ZSM-5 selectively afforded 3-(benzyloxy)propane-1,2-diol with a very small amount of the corresponding 2-benzyloxy isomer in 86% gas chromatography yield.


Asunto(s)
Alcoholes Bencílicos/química , Glicerol/química , Éteres de Glicerilo/síntesis química , Zeolitas , Catálisis , Esterificación , Temperatura , Factores de Tiempo
5.
J Med Chem ; 55(1): 503-14, 2012 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-22148427

RESUMEN

Extracts of the marine sponge Niphates digitalis collected in Dominica showed strong activity in a cell-based assay designed to detect antagonists of the androgen receptor (AR) that could act as lead compounds for the development of a new class of drugs to treat castration recurrent prostate cancer (CRPC). Assay-guided fractionation showed that niphatenones A (3) and B (4), two new glycerol ether lipids, were the active components of the extracts. The structures of 3 and 4 were elucidated by analysis of NMR and MS data and confimed via total synthesis. Biological evaluation of synthetic analogues of the niphatenones has shown that the enantiomers 7 and 8 are more potent than the natural products in the screening assay and defined preliminary SAR for the new AR antagonist pharmacophore, including the finding that the Michael acceptor enone functionality is not required for activity. Niphatenone B (4) and its enantiomer 8 blocked androgen-induced proliferation of LNCaP prostate cancer cells but had no effect on the proliferation of PC3 prostate cancer cells that do not express functional AR, consistent with activity as AR antagonists. Use of the propargyl ether 44 and Click chemistry showed that niphatenone B binds covalently to the activation function-1 (AF1) region of the AR N-terminus domain (NTD).


Asunto(s)
Antineoplásicos/química , Éteres de Glicerilo/química , Poríferos/química , Neoplasias de la Próstata/genética , Receptores Androgénicos/genética , Animales , Antineoplásicos/síntesis química , Antineoplásicos/aislamiento & purificación , Antineoplásicos/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Éteres de Glicerilo/síntesis química , Éteres de Glicerilo/aislamiento & purificación , Éteres de Glicerilo/farmacología , Humanos , Espectroscopía de Resonancia Magnética , Masculino , Conformación Molecular , Neoplasias de la Próstata/tratamiento farmacológico , Estereoisomerismo , Relación Estructura-Actividad , Transcripción Genética/efectos de los fármacos
6.
Bioresour Technol ; 102(19): 9304-7, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21840211

RESUMEN

A new fuel additive, namely solketal tert-butyl ether (STBE), was developed and optimized under continuous flow conditions using a Corning® Advanced-Flow™ glass reactor. STBE was obtained in two steps from glycerol, a renewable building-block produced in large amount in the processing of biodiesel. The advantages of the highly engineered Corning glass reactor included high mixing and heat-exchange efficiency, chemical resistance under corrosive flow conditions and a small hold-up. A robust, continuous, green and safe industrial-scale process is described.


Asunto(s)
Biocombustibles/análisis , Industria Química/instrumentación , Industria Química/métodos , Éteres de Glicerilo/química , Éteres de Glicerilo/síntesis química , Glicerol/química , Estructura Molecular
7.
Chem Phys Lipids ; 164(5): 315-40, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21635876

RESUMEN

The naturally occurring 1-O-alkyl-sn-glycerols and their methoxylated congeners, 1-O-(2'-methoxyalkyl)-sn-glycerols, are biologically active compounds, ubiquitously found in nature as diacyl glyceryl ether lipids and phosphoether lipids. The chief objective of this article is to provide a comprehensive and up to date review on such ether lipids. The occurrence and distribution of these compounds in nature are extensively reviewed, their chemical structure and molecular variety, their biosynthesis and chemical synthesis and, finally, their various biological effects are described and discussed. An unprecedented biosynthesis of the 2'-methoxylated alkylglycerols is proposed. The first synthesis of enantiopure (Z)-(2'R)-1-O-(2'-methoxyhexadec-4'-enyl)-sn-glycerol, the most prevalent 2'-methoxylated type alkylglycerol present in cartilaginous fish, is described. It was accomplished by a highly convergent five step process.


Asunto(s)
Lípidos/química , Glicerol/análogos & derivados , Glicerol/síntesis química , Éteres de Glicerilo/síntesis química , Éteres de Glicerilo/química , Lípidos/biosíntesis , Lípidos/síntesis química , Plasmalógenos/química , Plasmalógenos/metabolismo , Plasmalógenos/fisiología , Proteína Quinasa C/metabolismo , Estereoisomerismo
8.
J Am Chem Soc ; 131(34): 12193-200, 2009 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-19663381

RESUMEN

Secretory phospholipase A(2) (sPLA(2)) is an interesting enzyme for triggered liposomal drug delivery to tumor tissue due the overexpression of sPLA(2) in cancerous tissue. A drug delivery system based on the triggered release of therapeutics from sPLA(2)-sensitive liposomes constituted of pro anticancer ether lipids, which become cytotoxic upon sPLA(2)-catalyzed hydrolysis has previously been established. To optimize the hydrolysis rate of the lipids and thereby optimizing the release profile of the drugs from the liposomes, we have synthesized a thio-ester pro anticancer ether lipid. Liposomes constituted of this lipid showed an altered rate of hydrolysis by sPLA(2). We have tested the cytotoxicity of the thio-ester pro anticancer ether lipids toward cancer cells, and the results showed that the cytotoxicity is indeed maintained upon sPLA(2) exposure. To further understand the origin for the observed different hydrolysis rates for the esters, we have applied molecular dynamics simulations and density functional theory. The combination of these theoretical methods has given valuable insight into the molecular mechanism for sPLA(2) action on sulfur-containing phospholipids. It appears that the enzyme-catalyzed hydrolysis of thio-esters follow a different pathway compared to the hydrolysis pathway of the free thio-ester.


Asunto(s)
Antineoplásicos/administración & dosificación , Ésteres/química , Éteres de Glicerilo/química , Éteres de Glicerilo/metabolismo , Liposomas/química , Fosfolipasas A2 Secretoras/metabolismo , Azufre/química , Biocatálisis , Rastreo Diferencial de Calorimetría , Dominio Catalítico , Línea Celular Tumoral , Sistemas de Liberación de Medicamentos , Éteres de Glicerilo/síntesis química , Humanos , Hidrólisis , Liposomas/metabolismo , Modelos Moleculares , Teoría Cuántica
9.
Glycobiology ; 18(7): 559-65, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18450974

RESUMEN

Subunit vaccines capable of providing protective immunity against the intracellular pathogens and cancers that kill millions of people annually require an adjuvant capable of directing a sufficiently potent cytotoxic T lymphocyte response to purified antigens, without toxicity issues. Archaeosome lipid vesicles, prepared from isoprenoid lipids extracted from archaea, are one such adjuvant in development. Here, the stability of an archaeal core lipid 2,3-di-O-phytanyl-sn-glycerol (archaeol) is used to advantage to synthesize a series of disaccharide archaeols and show that subtle variations in the carbohydrate head group alters the type and potency of immune responses mounted in a mammal. Critically, a glycosylarchaeol was required to elicit high cytotoxic CD8(+) T cell activity, with highest responses to the antigen entrapped in archaeosomes containing disaccharides of glucose in beta- or alpha1-6 linkage (beta-gentiobiose, beta-isomaltose), or of beta-lactose. This first study on synthetic archaeal lipid adjuvants reveals potential for this class of regulatory friendly, easily scalable, inexpensive, and potent glyco-adjuvant.


Asunto(s)
Adyuvantes Inmunológicos/síntesis química , Disacáridos/inmunología , Éteres de Glicerilo/inmunología , Glucolípidos/química , Adyuvantes Inmunológicos/farmacología , Animales , Linfocitos T CD8-positivos/efectos de los fármacos , Linfocitos T CD8-positivos/inmunología , Disacáridos/síntesis química , Disacáridos/farmacología , Femenino , Éteres de Glicerilo/síntesis química , Éteres de Glicerilo/farmacología , Halobacterium salinarum/química , Ratones , Ratones Endogámicos C57BL , Imitación Molecular
10.
Chem Commun (Camb) ; (20): 2054-6, 2007 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-17713076

RESUMEN

Novel cationic liposomes, termed "archaeosomes", based on mixtures of neutral/cationic bilayer-forming lipids and archaeobacterial synthetic tetraether-type bipolar lipids show efficient in vitro gene transfection properties and represent a new approach for modulating the lipidic membrane fluidity of the complexes they form with DNA.


Asunto(s)
Éteres de Glicerilo/química , Transfección/métodos , Cationes/química , Línea Celular Tumoral , ADN/genética , Éteres de Glicerilo/síntesis química , Humanos , Liposomas , Estructura Molecular , Plásmidos/genética
11.
Chemistry ; 12(32): 8305-11, 2006 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-16847987

RESUMEN

The synthesis, characterization, and surface properties of soap-type amphiphiles comprising alkyl chains of 10-16 carbon atoms linked through an ether group to a glycerol-amino acid hydrophilic head group is described. The surface properties of members of this series derived from histidine and tyrosine were compared with those of phenylalanine and tryptophan derivatives described previously and with those of conventional soaps. In all cases, the amino acid derivatives showed superior surface properties, and an interesting differentiation was discovered regarding the orientation of tryptophan derivatives.


Asunto(s)
Éteres de Glicerilo/síntesis química , Histidina/química , Tensoactivos/síntesis química , Tirosina/química , Interacciones Hidrofóbicas e Hidrofílicas , Estructura Molecular , Fenilalanina/química , Propiedades de Superficie , Tensión Superficial , Triptófano/química
12.
Biotechnol Lett ; 27(2): 113-7, 2005 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-15703874

RESUMEN

Novel mutual pro-drugs in which 2',3'-dideoxyinosine anti-HIV (human immunodeficiency virus) drug and 3-octadecyloxy-propane-1,2-diol anti-inflammatory drug were attached to the same molecule via different biodegradable linkages, were synthesized through two-step enzymatic transesterification by a commercial lipase in acetone.


Asunto(s)
Bioquímica/métodos , Didanosina/síntesis química , Éteres de Glicerilo/síntesis química , Profármacos/síntesis química , Acetona , Fármacos Anti-VIH/síntesis química , Fármacos Anti-VIH/química , Antiinflamatorios/síntesis química , Antiinflamatorios/química , Didanosina/química , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Esterificación , Éteres de Glicerilo/química , Lipasa/química , Lipasa/metabolismo
13.
J Am Chem Soc ; 126(32): 10003-12, 2004 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-15303874

RESUMEN

Unsymmetrical archaeal tetraether glycolipid analogues 1-2 incorporating a 1,3-disubstituted cyclopentane ring into the bridging chain have been synthesized. The cyclopentane has been introduced with a totally controlled cis configuration, either into the middle of the aliphatic chain or at three methylene groups from the glycerol unit linked to the bulkier disaccharide residue. Freeze-fracture and cryotransmission electron microscopy experiments clearly demonstrated unprecedented glycolipid supramolecular organizations involving two-by-two monolayer associations coupled with interconnection and fusion phenomena. Furthermore, a significant difference in the hydration properties and in the lyotropic liquid crystalline behavior of bipolar lipids 1-2 was found depending on the position of the cyclopentane residue.


Asunto(s)
Archaea/química , Ciclopentanos/química , Glucolípidos/síntesis química , Ciclopentanos/síntesis química , Éteres de Glicerilo/síntesis química , Éteres de Glicerilo/química , Glucolípidos/química , Glicósidos/síntesis química , Glicósidos/química , Microscopía Electrónica
14.
Chemistry ; 8(3): 585-93, 2002 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-11855706

RESUMEN

The self-assembling properties of a new series of archaeal tetraether glycolipid analogues 1-6 that are characterized by a bipolar architecture with two similar or different glycosidic and/or phosphate polar heads and a lipid core possessing a cyclopentane unit and/or branched chains were studied by means of differential scanning calorimetry, optical microscopy, X-ray scattering, freeze-fracture electron microscopy and dynamic light scattering. Unsymmetrical phosphate derivatives 1 and 2 spontaneously formed thermostable multilamellar and unilamellar vesicles in which most of the bipolar lipids adopted a trans-membrane conformation, as revealed by freeze-fracture electron microscopy. Supramolecular aggregates of neutral glycolipids 3-6 were found to depend on both the saccharidic polar heads and the chain composition. The presence of one glycosidic residue with rather marked hydrophilic properties, such as the lactosyl moiety, was required to allow the formation of multilamellar vesicles. Surprisingly, the introduction of a cyclopentane unit in the bridging chain was able to induce an apparent two-by-two membrane association: this unusual behaviour might be the result of unsymmetrical interfacial properties of the lipid layer caused by the presence of the cyclopentane unit.


Asunto(s)
Archaea/química , Glucolípidos/química , Lípidos de la Membrana/química , Rastreo Diferencial de Calorimetría , Membrana Celular/química , Membrana Celular/ultraestructura , Técnica de Fractura por Congelación , Éteres de Glicerilo/síntesis química , Éteres de Glicerilo/química , Glucolípidos/síntesis química , Membranas Artificiales , Microscopía Electrónica , Éteres Fosfolípidos/síntesis química , Éteres Fosfolípidos/química , Relación Estructura-Actividad , Difracción de Rayos X
15.
Chemistry ; 6(4): 645-54, 2000 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-10807176

RESUMEN

Several biophysical properties of four synthetic archaeal phospholipids [one polyprenyl macrocyclic lipid A and three polyprenyl double-chain lipids (B, C, D) bearing zero, one or four double bonds in each chain] were studied using differential scanning calorimetry, electron and optical microscopies, stopped-flow/light scattering and solid-state 2H-NMR techniques. These phospholipids gave a variety of self-organized structures in water, in particular vesicles and tubules. These assemblies change in response to simple thermal convection. Some specific membrane properties of these archaeal phospholipids were observed: They are in a liquid-crystalline state over a wide temperature range; the dynamics of their polyprenyl chains is higher than that of n-acyl chains; the water permeability of the membranes is lower than that of n-acyl phospholipid membranes. It was also found that macrocyclization remarkably improves the barrier properties to water and the membrane stability. This may be related to the adaptation of Methanococcus jannaschii to the extreme conditions of the deep-sea hydrothermal vents.


Asunto(s)
Euryarchaeota/química , Membranas Artificiales , Fosfolípidos/química , Fosfolípidos/metabolismo , Microscopía por Crioelectrón , Deuterio , Éteres de Glicerilo/síntesis química , Membrana Dobles de Lípidos/química , Membrana Dobles de Lípidos/metabolismo , Liposomas/ultraestructura , Espectroscopía de Resonancia Magnética , Lípidos de la Membrana/síntesis química , Lípidos de la Membrana/química , Lípidos de la Membrana/metabolismo , Methanococcus/química , Permeabilidad , Fosfolípidos/síntesis química , Temperatura , Termodinámica , Agua
16.
Chem Phys Lipids ; 105(1): 105-13, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10727116

RESUMEN

Selenium and carotenoids show similar and complementary properties and protect against a variety of pathological processes. Mixtures of both compounds are found in nutritional supplements and are used to prevent several diseases. The synthetic connection of carotenoids with selenium in glycerols may increase the chemopreventive activity of the individual compounds. Beta-apo-8'-carotenoic acid and 7-selenacapryloic acid were esterified with glycerol to highly unsaturated stable di- and triglycerides. Intramolecular selenium:carotenoid ratios of 1:1, 2:1 and 1:2 were obtained for 1-(7-selenaoctanoyl)-3-(3beta-apo-8 -carotenoyl)-glycerol, 1,3-di-(beta-apo-8'-carotenoyl)-2-(7-selenaoctanoyl)-glycero l and 1,2-di-(7-selenaoctanoyl)-3-(beta-apo-8'-carotenoyl)-glycero l, respectively. The carotenoic acid was likewise connected to the pharmacologically interesting 11-selenalaurylglycerolether forming an alkyl-acylglyceride: 1-(11-selenadodecyl)-3-(beta-apo-8'-carotenoyl)-glycerol.


Asunto(s)
Antioxidantes/síntesis química , Glicéridos/síntesis química , Éteres de Glicerilo/síntesis química , Lípidos/síntesis química , Compuestos de Selenio/síntesis química , Carotenoides/síntesis química , Espectroscopía de Resonancia Magnética , Estructura Molecular
17.
Biochem Cell Biol ; 72(7-8): 297-303, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-7893469

RESUMEN

We have synthesized two ether lipids: 2'-(trimethylammonio)ethyl 4-(hexadecyloxy)-3(S)-methoxybutanephosphonate (compound 1) with antineoplastic activity and a maltosyl derivative (compound 2) without antineoplastic activity. We have compared the antineoplastic activity of these two compounds against WEHI-3B cells with their ability to disrupt the membranes of erythrocytes or neutrophils. Since ether lipids are highly hydrophobic molecules, it is possible that they may exert their cytotoxic action by inducing the nonspecific perturbation of cellular membranes, causing lysis and cell death. Membrane disruption was monitored by the lysis of cells or the change in erythrocyte membrane microviscocity and compared with the effect of detergents (known nonspecific lytic agents). Both compounds 1 and 2 caused the lysis of erythrocytes and neutrophils. The rate of lysis of erythrocytes was comparable to the rate of change of erythrocyte membrane microviscosity caused by both compounds 1 and 2. Both compounds caused the lysis of erythrocytes via a noncolloid osmotic mechanism that displayed features of the lysis caused by detergents at high concentrations.


Asunto(s)
Antineoplásicos/farmacología , Membrana Celular/efectos de los fármacos , Éteres de Glicerilo/farmacología , Hemólisis/efectos de los fármacos , Organofosfonatos , Fosfolípidos/farmacología , Antineoplásicos/química , Antineoplásicos/metabolismo , Muerte Celular/efectos de los fármacos , Membrana Celular/metabolismo , Permeabilidad de la Membrana Celular/efectos de los fármacos , Detergentes/farmacología , Membrana Eritrocítica/efectos de los fármacos , Membrana Eritrocítica/metabolismo , Éteres de Glicerilo/síntesis química , Humanos , Cinética , L-Lactato Deshidrogenasa/metabolismo , Leucemia Promielocítica Aguda , Muramidasa/metabolismo , Neutrófilos/efectos de los fármacos , Peroxidasa/metabolismo , Espectrometría de Fluorescencia , Temperatura , Células Tumorales Cultivadas , Ensayo de Tumor de Célula Madre
18.
Chem Phys Lipids ; 59(3): 263-5, 1991 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-1804570

RESUMEN

A new scheme for synthesis of saturated 1-O-alkyl-2-O-methyl-rac-glycerolipids is described. The reductive cleavage of 2-O-methyl-1,3-O,O-benzylideneglycerol with BH3.THF complex leads to 1-O-benzyl-2-O-methyl-rac-glycerol, which is a key in intermediate for the facile preparation of 1-O-alkyl-2-O-methyl-rac-glycerol and derivatives.


Asunto(s)
Antineoplásicos/síntesis química , Compuestos de Bencilideno/química , Diglicéridos/química , Éteres de Glicerilo/síntesis química , Borohidruros/química , Oxidación-Reducción
19.
Biochim Biophys Acta ; 1083(3): 271-6, 1991 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-2049391

RESUMEN

The preparation of liposomes from synthetic dialkyl amphiphiles is described. Two of these lipids were synthesised with mixed chains of 18:0,14:0 and 18:0,22:0 and one contained two identical alkyl chains of 18:0,18:0. Based on electron microscopic observations and encapsulation studies, liposomes formed from these lipids resemble those prepared from natural lipids. The polyhydroxyl head group of these lipids was designed to mimic the oligosaccharide rich surface of natural cells. SPLVs of all lipid compositions investigated, had higher encapsulation efficiency compared with that of MLVs. With SPLVs the encapsulation efficiency obtained with EPC liposomes were similar to those with novel lipids. However, the optimum was obtained with 4a:cholesterol. Encapsulation efficiency in both MLVs and SPLVs was higher with novel lipid containing different side chain length.


Asunto(s)
Éteres de Glicerilo/síntesis química , Liposomas/síntesis química , Meglumina/análogos & derivados , Inulina , Meglumina/síntesis química , Microscopía Electrónica
20.
Biol Mass Spectrom ; 20(2): 87-93, 1991 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-1883863

RESUMEN

Nicotinylidene and methylnicotinylidene derivatives of representative glycerol ethers and glycerol esters were prepared by their reaction with pyridine-3-carboxaldehyde and 3-acetyl pyridine respectively. Each compound gave two sets of diastereoisomers which could be separated by gas-liquid chromatography. The extent of formation of the derivatives was nearly quantitative and chromatographic peak shape was good. The compounds producing both peaks gave similar spectra but with differences that were characteristic of the isomer. The derivatives fragmented in an analogous manner to that reported earlier for nicotinate derivatives of alcohols and picolinyl derivatives of carboxylic acids, with the production of a series of diagnostic ions formed by radical-induced cleavage of the chain following random hydrogen abstraction. Branched chain compounds, exemplified by glycerol ethers, gave spectra in which one of the ions diagnostic of the branch-point was missing. Unsaturated compounds, exemplified by the glycerol esters, gave characteristic mass spectra in which separation between ions representing formal cleavage at each side of the double bond enabled the position of this bond to be determined. In addition the spectra of unsaturated compounds contained two abundant ions whose formation could be rationalized by abstraction of the allylic hydrogen atoms. The nicotinylidene derivatives gave more diagnostic spectra than the methylnicotinylidene derivatives, whose spectra were complicated by the appearance of ions produced by loss of the methyl and pyridyl groups from the derivative. Both derivatives were superior to the nicotinate derivatives of these dihydroxy compounds in that only one pyridine residue was introduced on derivatization; this gave a lower molecular weight increment and allowed compounds with longer chains to be examined.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Diglicéridos/síntesis química , Éteres de Glicerilo/análisis , Éteres de Glicerilo/síntesis química , Glándula de Harder/química , Lípidos/análisis , Niacina/análogos & derivados , Animales , Cromatografía de Gases y Espectrometría de Masas , Éteres de Glicerilo/química , Cobayas , Técnicas In Vitro , Masculino , Niacina/síntesis química
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