Isolation of (+)-1,4-diphenylbutane-2,3-diol from post-mortem liver.
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Adolescent↗
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Results for “Spectrophotometry, Infrared”
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High-performance liquid chromatography of carthamin, safflor yellow A and a precursor of carthamin. Application to the investigation of an unknown red pigment produced in cultured cells of safflower.
A reversed-phase high-performance liquid chromatographic (RP-HPLC) method was developed to analyse and purify carthamin, safflor yellow A (safflomin-A) and the yellow precursor of carthamin. A red pigment similar to carthamin was extracted from cell suspension cultures of safflower (Carthamus tinctorius L.) as an application of biotechnology. The RP-HPLC method was used to characterize the unknown red pigment. Various spectroscopic methods were used to characterize purified carthamin and the purified unknown pigment. Based on these spectral observations, it was concluded that the unknown red pigment produced in cultured cells of safflower differed from carthamin, although the unknown pigment might be a glycoside. From other observations, the possibility of anthocyanins and carotenoids were also discounted. It was assumed that the cultured cells lacked the biosynthetic pathway of the yellow precursor of carthamin, although they possessed the activity of the enzyme mediating the synthesis of carthamin from the yellow precursor.
Cells, Cultured↗
Oestrogen content of pomegranate seeds.
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Chromatography, High Pressure Liquid↗
Bioskin as an affinity matrix for the separation of glycoproteins.
Bioskin is a natural product produced by a mixed culture of Acetobacter xylinum, Saccharomyces cerevisiae and S. pombe cultured on media containing sucrose. It is of fibrillar nature able to retain some proteins, such as cytochrome c, by adsorption, and mainly composed of glucosamine and N-acetyl-D-glucosamine. This makes it possible that, at an adequate pH value, proteins charged as polyanionic molecules, such as catalase, can be retained by ionic adsorption using the positively charged amino groups of the matrix. In addition, bioskin can also be used as an affinity matrix to retain glycoproteins able to perform specific affinity reactions with the amino sugars of the matrix, such as invertase, fetuin or ovalbumin. Its possible use as a chromatographic support is discussed.
Adsorption↗
Post-column reaction detection system for the determination of organophosphorus compounds by liquid chromatography.
The development and application of a post-column reaction detection system for organophosphorus compounds based upon their photodegradation to ortho-phosphate followed by the formation of reduced heteropolymolybdate is reported. Photodegradation occurs in a fused-silica tube coiled about a 450-W xenon lamp in the presence of ammonium peroxydisulfate. Photodegradation yields were practically quantitative for the organophosphates, -phosphonates, and -phosphorodithioates tested. Factors affecting the rate of the chromogenic reaction were optimized so that its contribution to the total band-broadening was negligible. The effect of interfering organic modifiers in the mobile phase was studied using the acetate ion as a model. Separations were developed using no organic solvents in the mobile phases. The determination of dialkylphosphates in urine and organophosphorus pesticides in tomatoes illustrate the potential of the methodology.
Animals↗
High-performance liquid chromatography of steroidal drugs.
The high-performance liquid chromatographic (HPLC) analysis of progesterone, oxyprogesterone capronate and dehydroacetoxyprogesterone has been carried out successfully using so-called "test impurities". The quantitative and qualitative analysis of related compounds was studied by normal-phase HPLC with a UV detector (254 nm) using ethyl acetate-chloroform (98.5:1.5) and ethyl acetate-hexane (20:80) as solvent systems. Preparative separations of impurities by HPLC were investigated, subsequent structural identification being achieved by mass, UV and IR spectrometry. The method may be applied to the control of the quantitative purity of steroids in drugs and complex mixtures.
Chromatography, High Pressure Liquid↗
Gas-liquid and thin-layer chromatography of some 3- and 3,x-substituted pyrenes.
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Chromatography↗
Separation of rauwolfia alkaloids by thin-layer chromatography.
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Chromatography, Thin Layer↗
High-performance liquid chromatographic determination of ketoprofen degradation products.
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Chromatography, High Pressure Liquid↗
New ultraviolet labelling agents for high-performance liquid chromatographic determination of monocarboxylic acids.
New UV-labelling agents have been synthesized, which are designed to convert monocarboxylic acids into their highly UV-absorbing derivatives for enhancement of the sensitivities of UV detection in high-performance liquid chromatography. The reagents are p-nitrobenzyl, 3,5-dinitrobenzyl and 2-(phthalimino)ethyl p-toluenesulphonates. Each has been prepared by reaction of p-toluenesulphonyl chloride with p-nitrobenzyl alcohol, 3,5-dinitrobenzyl alcohol or N-(hydroxyethyl)phtalimide, respectively, in the presence of sodium hydroxide, and they are stable in the solid state for at least 6 months. Monocarboxylic acids were derivatized to their p-nitrobenzyl, 3,5-dinitrobenzyl or 2-(phthalimino)ethyl esters with each of the above reagents, respectively, then determined by high-performance liquid chromatography with UV detection. In the UV-labelling with each reagent, 18-crown-6 was used as the catalyst. The effects of the reaction solvent, reaction temperature and time and the concentrations of each reagent and the catalyst were also examined.
Carboxylic Acids↗
Chromatographic separation of aldehyde-containing compounds from bovine elastin.
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Aldehydes↗
The role of the diurnal variation of urinary pH in determining stone compositions.
The diurnal variation of urinary pH and urinary excretion of stone-forming constituents were investigated on 79 stone patients. Composition of the stones was analyzed by means of infrared spectrophotometry. In uric acid stone patients urinary pH was low during the 24-hour period. In mixed calcium oxalate-calcium phosphate stone patients urinary pH was low in the early morning but high in the daytime and at night. In magnesium ammonium phosphate stone patients urinary pH was high throughout the entire day. On the other hand, urinary excretion of calcium was high in the mixed calcium oxalate-calcium phosphate stone patients and low in uric acid or magnesium ammonium phosphate stone patients. These findings suggested that the diurnal variation of urinary pH and urinary excretion of calcium might have an important role in determining stone composition.
Adult↗
Urolithiasis in patients with end stage renal failure.
Renal stones from 30 chronic hemodialysis patients were subjected to morphological study by means of microscopic examination and to constitutional analysis with infrared spectrophotometry. In 29 patients calculi could be classified into 3 main types: 1) protein stones made of pure proteins or with a protein core and less than 30% calcium oxalate (9 cases, or 30%)--they were observed predominantly in patients with primary glomerular disease, 2) oxalo-protein stones with a core of calcium oxalate and a total stone content of more than 30% calcium oxalate (15 cases, or 50%)--they appeared to be related to metabolic factors, such as high urinary oxalate and low urinary citrate concentration, and to iatrogenic factors, namely vitamin D3 and calcium salt supplementation, and 3) aluminum-magnesium urate stones, probably induced by aluminum overload (6 cases, or 20%). Thus, our study indicates that a significant proportion (70%) of stones formed by hemodialysis patients may be due to metabolic and iatrogenic factors. Our data suggest that accurate analysis of such stones provides useful information on pathogenetic factors and consequently may give clues to their prophylaxis.
Adult↗
Glycosidic compounds of murolic, protoconstipatic and allo-murolic acids from lichens of Central Asia.
Eleven compounds isolated from the extract of the Central Asian lichens comprised eight new glycosides having murolic, protoconstipatic and allo-murolic acids, as the aglycones and a saccharide moiety linked at C-18 made up of one or two sugars (glucose and apiose or rhamnose or xylose or arabinose). The structures were elucidated by using extensive spectroscopic analysis (1D and 2D NMR, MS, IR, UV and CD) and chemical methods.
Asia, Central↗
Canthin-6-one alkaloids from Brucea mollis var. tonkinensis.
Three new alkaloids were isolated from the root-wood of Brucea mollis var. tonkinensis collected in China. Their structures were determined to be 11-O-beta-D-glucopyranosyl-(1-->6)-beta- D-glucopyranosylcanthin-6-one, 5-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosylcanthin-6-o ne and 11-hydroxycanthin-6-one-N-oxide, by chemical and spectral methods. In addition, two known alkaloids, canthin-6-one and canthin-6-one-N-oxide, were isolated.
Alkaloids↗
Phenolic compounds from Gastrodia rhizome and relaxant effects of related compounds on isolated smooth muscle preparation.
Gastrol (1), together with 10 known phenolic compounds, has been isolated from the MeOH extract of the rhizomes of Gastrodia elata Blume (Orchidaceae), and their structures were elucidated by detailed spectral analyses including by 2D NMR spectroscopic analyses. The relaxant effects of these constituents on smooth muscle preparations isolated from guinea-pig ileum were also studied in order to reveal their characteristic pharmacological activities.
Animals↗
A prenylated xanthone from Allanblackia floribunda.
A new prenylated xanthone, named allanxanthone A, was isolated from the stem bark of Allanblackia floribunda in addition to known compounds, 1,5-dihydoxyxanthone, 1,5,6-trihydroxy-3,7-dimethoxyxanthone, stigmasterol and stigmasteryl-3-O-beta-D-glucopyranoside. The structure of the new compound was assigned as 1,3,5-trihydroxy-2-(3-methylbut-2-enyl)-4-(1,1-dimethylprop-2-enyl) xanthone, by means of spectroscopic analysis. The 13C NMR spectral data of 1,5-dihydroxyxanthone is reported here for the first time as well as the in vitro cytotoxic activity of xanthone metabolites against the KB cell line.
Cameroon↗
Hericenols A-D and a chromanone from submerged cultures of a Stereum species.
Extracts of submerged cultures of a Stereum species afforded four new pentasubstituted phenolic compounds, named hericenols A, B, C, and D (1-4), 6-hydroxymethyl-2,2-dimethylchroman-4-one (5) and the known erinapyrone C. Hericenol A (1) showed weak antimicrobial activity while hericenol C (3) was weakly cytotoxic. The structures of the metabolites were determined by spectroscopic techniques.
Animals↗