RESUMO
Ten compounds, including a new anti-inflammatory acyl triterpene, 3ß-palmitoyloxy-1ß,11α-dihydroxy-olean-12-ene, were isolated from the bioactive organic extract prepared from the leaves of Sapium lateriflorum (syn: S. nitidum). The isolated compounds were screened for their cytotoxic activity against selected human cancer cell lines and did not display significant activity. They were also evaluated as anti-inflammatory agents in mouse models (TPA-induced edema in the ear and in a carrageenan-induced paw edema model). The results indicated that the new compound, 3ß-palmitoyloxy-1ß,11α-dihydroxy-olean-12-ene, was the compound with major anti-inflammatory activity similar to that of indomethacin, being the hydroxyl at C-11 important for the observed activity. The results of docking studies of the 3ß-palmitoyloxy esters of olean-12-ene with NF-κB and with COX-2 receptors were consistent with possible molecular mechanisms of the anti-inflammatory activity.
Assuntos
Anti-Inflamatórios/farmacologia , Edema/tratamento farmacológico , Ésteres/farmacologia , Sapium/química , Animais , Anti-Inflamatórios/isolamento & purificação , Linhagem Celular Tumoral , Edema/induzido quimicamente , Ésteres/isolamento & purificação , Humanos , México , Camundongos , Simulação de Acoplamento Molecular , Estrutura Molecular , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Folhas de Planta/químicaRESUMO
BACKGROUND: The sunflower oil industry produces a large amount of waste that is not currently commercially exploited, as in the case of oil-tank settlings. The recovery of a high value-added by-product, such as sunflower wax, would increase the commercial value of this waste. In this original research paper, a method that allows the recovery and purification of this by-product was developed. The wax was characterized and its potential use as an organogelator agent was investigated. RESULTS: The waste sample was composed of 45.1% oily material, 16.9% of this being impure waxes. Purification was performed through two different methods, obtaining three waxes with different degrees of purity. All the waxes were composed of wax esters with a range of 40-60 carbon atoms, exhibiting traces of carotenes, free fatty acids, and free fatty alcohols. The presence of phospholipids was observed in two of them. The third wax presented a higher total wax ester content and physicochemical characteristics (color and thermal behavior) similar to those of commercial sunflower waxes, and was the most efficient organogelator agent, requiring only a small amount of wax (1.5%) to structure high oleic sunflower oil. CONCLUSION: It was verified that sunflower wax could be recovered from oil-tank settlings. A purification method that allowed sunflower wax with similar physicochemical properties to those of commercial waxes to be obtained was also developed. The purified waxes were capable of structuring high oleic sunflower oil. © 2019 Society of Chemical Industry.
Assuntos
Helianthus/química , Extratos Vegetais/isolamento & purificação , Resíduos/análise , Ceras/isolamento & purificação , Fracionamento Químico , Ésteres/química , Ésteres/isolamento & purificação , Ácidos Graxos/química , Ácidos Graxos/isolamento & purificação , Extratos Vegetais/química , Óleo de Girassol/química , Ceras/químicaRESUMO
Carotenoids constitute a large group of lipophilic pigments whose health-promoting benefits have been widely recognized. Hydroxy-containing carotenoids can be found in both free form or esterified with fatty acids in several plant matrices, but the native carotenoid profile is overall poorly explored due to the difficulty of analyzing carotenoid esters. One of the main natural sources of carotenoids is the marigold flower, which has been extensively used by the industry for the production of food colorants or supplements, both often manufactured with no saponification process. Although lutein esters are well established as the major compounds naturally found in marigold petals and their products, carotenoid esters other than the lutein ones have not been extensively examined. We carried out a comprehensive identification of carotenoids and carotenoid esters from marigold petals by LC-DAD-(APCI+)MS/MS. Whereas 18 carotenoids were identified in the saponified extract, 56 were identified when no saponification procedure was carried out: 6 free carotenoids, 20 monoesters and 30 diesters. This is the first time that esters of zeaxanthin, violaxanthin, auroxanthin, zeinoxanthin and ß-cryptoxanthin are identified in marigold. The structural information obtained through characteristic fragmentation patterns and diagnostic fragments in MS and MS/MS spectra (APCI+) sustained the differentiation between carotenoid esters with similar characteristics. Therefore, the separation of carotenoids by reversed-phase liquid chromatography using C30 columns in combination with DAD and APCI-MS/MS detection allowed high sensitivity and selectivity for carotenoid ester analysis.
Assuntos
Calendula/química , Carotenoides/química , Carotenoides/isolamento & purificação , Luteína/química , Luteína/isolamento & purificação , beta-Criptoxantina/isolamento & purificação , Criptoxantinas/isolamento & purificação , Ésteres/análise , Ésteres/isolamento & purificação , Ácidos Graxos , Flores/química , Espectrometria de Massas em Tandem , Xantina/isolamento & purificação , Xantofilas/isolamento & purificação , Zeaxantinas/isolamento & purificaçãoRESUMO
The formation of toxic compounds, potentially carcinogenic, during food processing has been considered an important food safety issue. Among them, particular attention has been given to 3-monochloropropane-1,2-diol esters (3-MCPDE), 2-monochloropropane-1,3-diol esters (2-MCPDE) and glycidyl esters (GE), which can be formed during vegetable oil refining, especially palm oil. These substances may pose a health risk to humans due to their toxicity and carcinogenicity. The aim of this study was to investigate the effect of washing bleached palm oil (BPO) with different solvents, and evaluate the reduction of 3-MCPDE, 2-MCPDE and GE as well as assess the quality parameters of the final product. For this purpose, we used two types of washing with different solvents. A single washing was carried out in one step and a double washing in two steps using a solvent gradient. Single washing had a limited reduction in the levels of 3-MCPDE and 2-MCPDE and resulted in an increased level of GE, whereas double washing slightly reduced 3-MCPDE and 2-MCPDE and resulted in a significant reduction of GE levels. The reduction achieved in this study was up to 17.1% for 3-MCPDE, 56.4% for 2-MCPDE and 76.9% for GE levels. The reduction of 3-MCPDE and 2-MCPDE might be due to the removal of part of the ethanol-soluble chlorinated precursors from the oil which suggests that highly lipophilic forms of these substances are present in BPO. The substantial reduction on GE levels might be associated with the removal of the precursors present in the oil such as diacylglycerols. Thus, the washing treatment could be used as a supplementary strategy to reduce processing contaminants from palm oil, especially GEs.
Assuntos
Ésteres/isolamento & purificação , Contaminação de Alimentos/prevenção & controle , Óleo de Palmeira/química , alfa-Cloridrina/isolamento & purificação , Ésteres/análise , Contaminação de Alimentos/análise , alfa-Cloridrina/análiseRESUMO
INTRODUCTION: The larvicidal activity of oils, fatty acids, and methyl esters of Solanum lycocarpum fruit against Culex quinquefasciatus is unknown. METHODS: The larvicidal activity of samples of ripe and unripe fruit from S. lycocarpum was evaluated against third and fourth instar larvae of C. quinquefasciatus . RESULTS: The oils, fatty acids, and methyl esters of S. lycocarpum showed the greatest larvicidal effect (57.1-95.0%) at a concentration of 100mg/L (LC 50values between 0.70 and 27.54mg/L). CONCLUSIONS: Solanum lycocarpum fruit may be a good source of new natural products with larvicidal activity.
Assuntos
Culex/efeitos dos fármacos , Ésteres/farmacologia , Ácidos Graxos/farmacologia , Larva/efeitos dos fármacos , Óleos de Plantas/farmacologia , Solanum/química , Animais , Bioensaio , Relação Dose-Resposta a Droga , Ésteres/isolamento & purificação , Ácidos Graxos/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas , Dose Letal MedianaRESUMO
BACKGROUND: The aim of this study was to compare the performance of the following techniques on the isolation of volatiles of importance for the aroma/flavor of fresh cashew apple juice: dynamic headspace analysis using PorapakQ(®) as trap, solvent extraction with and without further concentration of the isolate, and solid-phase microextraction (fiber DVB/CAR/PDMS). RESULTS: A total of 181 compounds were identified, from which 44 were esters, 20 terpenes, 19 alcohols, 17 hydrocarbons, 15 ketones, 14 aldehydes, among others. Sensory evaluation of the gas chromatography effluents revealed esters (n = 24) and terpenes (n = 10) as the most important aroma compounds. CONCLUSION: The four techniques were efficient in isolating esters, a chemical class of high impact in the cashew aroma/flavor. However, the dynamic headspace methodology produced an isolate in which the analytes were in greater concentration, which facilitates their identification (gas chromatography-mass spectrometry) and sensory evaluation in the chromatographic effluents. Solvent extraction (dichloromethane) without further concentration of the isolate was the most efficient methodology for the isolation of terpenes. Because these two techniques also isolated in greater concentration the volatiles from other chemical classes important to the cashew aroma, such as aldehydes and alcohols, they were considered the most advantageous for the study of cashew aroma/flavor.
Assuntos
Anacardium/química , Fracionamento Químico/métodos , Frutas/química , Odorantes/análise , Óleos Voláteis/isolamento & purificação , Preparações de Plantas/química , Compostos Orgânicos Voláteis/isolamento & purificação , Bebidas , Ésteres/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Extração Líquido-Líquido , Óleos Voláteis/análise , Microextração em Fase Sólida , Paladar , Terpenos/isolamento & purificação , Compostos Orgânicos Voláteis/análiseRESUMO
A simple, fast, and efficient High-Performance Thin-Layer Chromatography (HPTLC) method was developed for the simultaneous quantitative determination of alcohols and acetates in Haitian vetiver essential oils (Chryzopogon zizanioides) and its acetylated form. Analytes were separated by using a mixture of n-hexane-chloroform-ethyl acetate (8:6:0.5, v/v/v) as mobile phase under 47% humidity. Quantification was achieved by densitometric evaluation of the analytes in absorbance mode under visible light (λ=530 nm) after staining with a vanillin-sulfuric acid reagent. Reference mixtures of alcohols and acetates were obtained by fractionation of Haitian vetiver oil or vetiver acetates, followed by purification of the fractions of interest by means of Over-Pressured Layer Chromatography (OPLC). The chemical composition of each reference fraction was determined by using GC-MS and GC×GC-MS, and their overall purity was determined by GC/FID and HPTLC. The TLC method provided compact spots for alcohols (R(f2)=0.18±0.01 and R(f1)=0.28±0.01) and acetates (R(f3)=0.65±0.01). Calibration plots showed good linear correlation with r²=0.9995±0.0001 and r²=0.9995±0.0001 for alcohols and r²=0.9996±0.0001 for acetates in a 40-200 ng spot⻹ concentration range with respect to peak areas. The method was validated for precision and accuracy. Limit of detection (LOD) and quantification (LOQ) were determined. Method specificity was confirmed using retention factor (R(f)) and GC-MS control of the standards reference mixtures.
Assuntos
Álcoois/análise , Cromatografia em Camada Fina/métodos , Ésteres/análise , Óleos Voláteis/química , Extratos Vegetais/química , Poaceae/química , Acetatos , Álcoois/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Ésteres/isolamento & purificação , Haiti , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos TestesRESUMO
Bioactivity-guided fractionation of n-hexane phase from MeOH extract of the seeds of Cassia fistula L. (Leguminosae) yielded two bioactive substances against Cladosporium cladosporioides and C. sphaerospermum. After spectroscopic analysis, these compounds were characterised as the known benzyl 2-hydroxy-3,6-dimethoxybenzoate and its dimer dibenzyl 2,2'-dihydroxy-3,6,3â³,6â³-tetramethoxy-biphenyl-1,1'-dicarboxylate, which showed a new structural arrangement.
Assuntos
Antifúngicos/análise , Cassia/química , Ésteres/análise , Conformação Molecular , Sementes/química , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Brasil , Fracionamento Químico , Cromatografia Líquida de Alta Pressão , Cladosporium/efeitos dos fármacos , Dimerização , Ésteres/isolamento & purificação , Ésteres/farmacologia , Hexanos , Hidroxibenzoatos/análise , Metanol , Estrutura Molecular , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
Six novel monoterpene chromane esters were isolated from the aerial parts of Peperomia obtusifolia (Piperaceae) using chiral chromatography. This is the first time that chiral chromane esters of this kind, ones with a tethered chiral terpene, have been isolated in nature. Due to their structural features, it is not currently possible to assess directly their absolute stereochemistry using any of the standard classical approaches, such as X-ray crystallography, NMR, optical rotation, or electronic circular dichroism (ECD). Herein we report the absolute configuration of these molecules, involving four chiral centers, using vibrational circular dichroism (VCD) and density functional theory (DFT) (B3LYP/6-31G*) calculations. This work further reinforces the capability of VCD to determine unambiguously the absolute configuration of structurally complex molecules in solution, without crystallization or derivatization, and demonstrates the sensitivity of VCD to specify the absolute configuration for just one among a number of chiral centers. We also demonstrate the sufficiency of using the so-called inexpensive basis set 6-31G* compared to the triple-ζ basis set TZVP for absolute configuration analysis of larger molecules using VCD. Overall, this work extends our knowledge of secondary metabolites in plants and provides a straightforward way to determine the absolute configuration of complex natural products involving a chiral parent moiety combined with a chiral terpene adduct.
Assuntos
Antiprotozoários/isolamento & purificação , Dicroísmo Circular/métodos , Ésteres/química , Monoterpenos/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Antiprotozoários/química , Cromatografia , Elétrons , Ésteres/isolamento & purificação , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Estrutura Molecular , Monoterpenos/química , Rotação Ocular , Peperomia/química , Componentes Aéreos da Planta/química , Extratos Vegetais/química , Soluções , Espectrometria de Massas por Ionização por Electrospray , Estereoisomerismo , Termodinâmica , VibraçãoRESUMO
The phytochemical investigation of Dimerostemma arnottii (Asteraceae) afforded, in addition to a known eudesmanolide, two unusual eudesmane methyl ester derivatives and a new eudesmanolide. Structural elucidation of the compounds was based on their 1D and 2D NMR spectroscopic as well as HR-ESI-MS data. There is a remarkable similarity between the structures of the eudesmanes from D. arnottii and those previously encountered in other Dimerostemma species, which is in agreement with the results of a previous phylogenetic study based on molecular data. The chemotaxonomic relevance of the isolated compounds is briefly discussed.
Assuntos
Asteraceae/química , Ésteres/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Sesquiterpenos/isolamento & purificação , Brasil , Ésteres/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Filogenia , Extratos Vegetais/química , Sesquiterpenos/química , Especificidade da Espécie , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
Chemical investigation of the methanolic extract of the ascidian Didemnum psammatodes has led to the identification of fourteen known compounds: three methyl esters (methyl myristate, methyl palmitate and methyl stearate), four steroids (cholesterol, campesterol, stigmasterol and beta-sitosterol), two fatty acids (palmitic acid and stearic acid), three glyceryl ethers {(1,2-propanediol, 3-(heptadecyloxy), batyl alcohol and 1,2-propanediol, 3-[(methyloctadecyl)oxy]} and two nucleosides (thymidine and 2'-deoxyguanosine). Their structures were proposed by NMR and comparison with literature data and GC analysis in comparison with authentic sample. The cytotoxic activity of these compounds was evaluated against human leukemia cell line panel using the MTT assay. The mixture of the three methyl esters was the most active group of compounds, showing antiproliferative and cytotoxic effects. Further studies on their mode of action suggest that these activities are connected with inhibition of DNA synthesis and induction of both necrosis and apoptosis.
Assuntos
Apoptose/efeitos dos fármacos , Citotoxinas/farmacologia , Leucemia/tratamento farmacológico , Urocordados/química , Animais , Divisão Celular/efeitos dos fármacos , Citotoxinas/química , Citotoxinas/isolamento & purificação , Ésteres/química , Ésteres/isolamento & purificação , Ésteres/farmacologia , Células HL-60 , Humanos , Células K562 , Leucemia/patologia , Leucemia de Células T , Peptídeos/química , Peptídeos/isolamento & purificação , Peptídeos/farmacologia , Leucemia-Linfoma Linfoblástico de Células PrecursorasRESUMO
The crude methanolic extract of Zuccagnia punctata was active toward the fungal pathogens of soybean Phomopsis longicolla and Colletotrichum truncatum. Assay guided fractionation led to the isolation of two chalcones, one flavanone and a new caffeoyl ester derivative as the compounds responsible for the antifungal activity. Another new caffeoyl ester derivative was isolated from the antifungal chloroform extract but proved to be inactive against the soybean infecting fungi up to 50 microg/mL
Assuntos
Ascomicetos/efeitos dos fármacos , Ácidos Cafeicos/isolamento & purificação , Chalcona/isolamento & purificação , Fabaceae/química , Fungicidas Industriais/isolamento & purificação , Glycine max/microbiologia , Ácidos Cafeicos/farmacologia , Chalcona/farmacologia , Ésteres/isolamento & purificação , Ésteres/farmacologia , Fungicidas Industriais/farmacologia , Doenças das Plantas/microbiologiaRESUMO
From the acetone and ethanol extracts of the tubercula of Aristolochia pubescens, two diterpene esters of aristolochic acids were isolated, together with 23 known compounds. The structures of the compounds were determined on the basis of spectroscopic analysis.
Assuntos
Aristolochia/química , Ácidos Aristolóquicos/química , Diterpenos/química , Ésteres/química , Ésteres/isolamento & purificação , Espectroscopia de Ressonância Magnética , Plantas Medicinais/químicaRESUMO
Six tropane alkaloid esters were isolated from the stems of Erythroxylum rotundifolium. The structures of three new tropane esters, 7beta-hydroxy-6beta-(3,4,5-trimethoxybenzoyloxy)-3alpha-(E)-(3,4,5-trimethoxycinnamoyloxy)tropane (1), 6beta-benzoyloxy-3alpha-(Z)-(3,4,5-trimethoxycinnamoyloxy)tropane (2), and (-)-6beta-benzoyloxy-3alpha-hydroxytropane (3), were established by spectroscopic techniques. When alkaloids 1-6 were evaluated against a panel of human cancer cell lines, the new compound 6beta-benzoyloxy-3alpha-(Z)-(3,4,5-trimethoxycinnamoyloxy)tropane (2) and three known compounds, 6beta-benzoyloxy-3alpha-(3,4,5-trimethoxycinnamoyloxy)tropane (4), 6beta-benzoyloxy-3alpha-(E)-(3,4,5-trimethoxycinnamoyloxy)tropane-7beta-ol (5), and 7beta-acetoxy-6beta-benzoyloxy-3alpha-(E)-(3,4,5-trimethoxycinnamoyloxy)tropane (6), demonstrated greatest activity with multidrug-resistant oral epidermoid carcinoma (KB-V1) cells incubated in the presence of vinblastine. Thus, tropane esters of this type can reverse the multidrug-resistance phenotype, presumably by interacting with P-glycoprotein.
Assuntos
Alcaloides/isolamento & purificação , Erythroxylaceae/química , Tropanos/isolamento & purificação , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Alcaloides/química , Alcaloides/farmacologia , Carcinoma de Células Escamosas , República Dominicana , Resistência a Múltiplos Medicamentos , Ensaios de Seleção de Medicamentos Antitumorais , Ésteres/química , Ésteres/isolamento & purificação , Ésteres/farmacologia , Humanos , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Caules de Planta/química , Estereoisomerismo , Tropanos/química , Tropanos/farmacologia , Células Tumorais Cultivadas/efeitos dos fármacosRESUMO
Melampodium divaricatum is a medicinal plant, which occurs in Central America. In a recent paper we reported the occurrence of acylated 2-hydroxy thymol glycosides as main constituents in this plant. This paper deals with the isolation of two new 2,5-dihydroxythymol ester derivatives. The formerly reported sesquiterpene lactone mikanokryptin was not found in our plant material.
Assuntos
Asteraceae/química , Ésteres/química , Plantas Medicinais/química , Timol/análogos & derivados , Timol/química , Acilação , América Central , Ésteres/isolamento & purificação , Conformação Molecular , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Timol/isolamento & purificaçãoRESUMO
The aerial parts of an Argentinian collection of Acanthospermum hispidum afforded 26 sesquiterpene lactones, including the two guaianolides (1 and 2) having a novel oxygen bridge between C-4 and C-14, three new cis,cis-germacranolides (4, 7, and 8), and two new melampolides (25 and 26). Guaianolides 1 and 2 seem to derive biosynthetically from the germacranolide 27 having the (1)D(14, 15)D(5) conformation. The structures were elucidated using extensive spectroscopic analysis.
Assuntos
Ésteres/isolamento & purificação , Furanos/isolamento & purificação , Lactonas/isolamento & purificação , Magnoliopsida/química , Argentina , Ésteres/química , Furanos/química , Lactonas/química , Espectroscopia de Ressonância MagnéticaRESUMO
Purified lutein diesters deposited on commercial nonporous glass beads were solubilized in supercritical CO(2) in a computerized batch extractor, and their solubilities were compared to their solubilities in hexane. Densities of 0.7, 0.8, and 0.9 g/mL were evaluated without modifiers. Both pressure and temperature increased solubility, although temperatures >50 degrees C promoted carotenoid loss as determined by mass balance. Solubility was enhanced by the use of modifiers and was related to their log P. Chloroform (log P = 2) increased 2.8 times the amount of solubilized lutein diesters compared to pure CO(2) at the same extraction conditions (0.9 g/mL and 40 degrees C) to yield 65% of the amount extracted with hexane. Supercritical CO(2) extraction of lutein diesters could represent a cleaner technology as compared to the current industrial use of hexane with important ecological and health-related implications.
Assuntos
Luteína/química , Magnoliopsida , Dióxido de Carbono , Ésteres/química , Ésteres/isolamento & purificação , Vidro , Luteína/isolamento & purificação , Solubilidade , SolventesRESUMO
Fifteen illudalane sesquiterpenoids, alcyopterosins A-O (1-15) have been isolated from the subAntarctic soft coral Alcyonium paessleri which was collected at a depth of 200 m near the South Georgia Islands, and their structures were elucidated by spectroscopic techniques. Eight of these compounds (2, 3, 5-8, 10, and 13) are the first natural nitrate esters, while the other four (1, 4, 11, and 12) are chlorinated. These compounds are as well the first illudalane sesquiterpenoids to be isolated from the marine environment. Compounds 1, 3, 5, and 8 showed mild cytotoxicity toward human tumor cell lines.
Assuntos
Cnidários/química , Ésteres/química , Nitratos/química , Nitratos/isolamento & purificação , Sesquiterpenos/química , Sesquiterpenos/isolamento & purificação , Animais , Regiões Antárticas , Linhagem Celular , Ésteres/isolamento & purificação , Ésteres/toxicidade , Humanos , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Nitratos/toxicidade , Sesquiterpenos/toxicidade , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
A benzoyl group was attached to the 3-hydroxyl group of the methyl ester derivative of corynomycolic acid fraction isolated from Corynebacterium pseudotuberculosis. The infrared spectrum of the 3-O-benzoylated compound displayed a series of characteristic absorptions found at 1110, 1267 and 1603 cm-1 that confirmed the presence of a monosubstituted phenyl grouping. The 1H-NMR spectrum showed peaks representing protons of the aromatic ring at 7.4 ppm and 8.0 ppm. The UV spectrum revealed two absorption maxima: at 190 and 228 nm. The mass spectrum of the 3-O-benzoylated material exhibited the following peaks: (1) a prominent peak at m/z 105 of the benzoyl group that constituted the base peak; (2) peaks of methyl esters representing the alpha-hydrocarbon side chain plus carbon atoms C1 and C2 of the mycolic acid molecule; and (3) peaks of molecular ion minus benzoic acid and/or molecular ion minus benzoxyl group. When subjected to liquid chromatography (LC) on an octadecylsilane-silica gel column the 3-O-benzoylated methyl ester derivatives of the corynomycolic acid fraction were separated into their constituent homologous fractions corresponding to underivatized corynomycolic acids with the chain length C30, C32 and C34. Reversed phase HPLC of saturated and monounsaturated species of 3-O-benzoylated derivatives of the mycolic acid fraction from C. diphtheriae and Rhodococcus rhodochrous led to the separation of the corresponding homologous fractions. Mass spectrometry by electron impact mode identified both series of the homologous materials differing in mass by 28 units.
Assuntos
Corynebacterium diphtheriae/química , Corynebacterium pseudotuberculosis/química , Ácidos Micólicos/análise , Rhodococcus/química , Cromatografia Líquida , Cromatografia em Camada Fina , Compostos Cromogênicos , Corynebacterium diphtheriae/metabolismo , Corynebacterium pseudotuberculosis/metabolismo , Ésteres/análise , Ésteres/química , Ésteres/isolamento & purificação , Espectrometria de Massas , Ácidos Micólicos/química , Ácidos Micólicos/isolamento & purificação , Rhodococcus/metabolismoRESUMO
[14C] palmitic acid or [3H] retinyl esters incorporated in microsomal membranes were removed by a cytosolic fraction enriched in fatty acid binding protein. When mouse liver cytosol was fractionated by 70% ammonium sulphate, a precipitate and a soluble fraction were obtained. The soluble fraction containing the fatty acid binding protein was able to remove from microsomal membranes, [14C] palmitic acid or [3H] retinyl esters, whereas the precipitate fraction had no removal capacity. Retinoid analysis indicated that 70% ammonium sulphate soluble fraction was enriched in endogenous retinyl esters with regard to cytosol or 70% ammonium sulphate precipitate fraction.