bluuebunny/crossref_metadata_2025_split huggingface dataset:
Liquid chromatography/tandem mass spectrometric study and analysis of xanthone and secoiridoid glycoside composition of Swertia chirata, a potent antidiabetic
Authors: Suryawanshi Satyendra , Mehrotra Nitin , Asthana R. K. , Gupta Ram C. 
Published: November 2006

AbstractSwertia chirata is a bitter plant, used in the Indian system of medicine (Ayurveda) for various human ailments. The bioactive constituents include the xanthone and secoiridoid glycosides consisting of mangiferin, amarogentin, amaroswerin, sweroside and swertiamarin. Methanolic extracts of S. chirata possess constituents with antidiabetic activities, which was investigated by high‐performance liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI‐MS/MS). Preliminary HPLC analyses were performed on a reversed‐phase C18 column using gradient elution. In the LC/ESI‐MS spectra, predominant [M+H]+ and [M+Na]+ ions were observed in positive ion mode and provided molecular mass information. The five components of S. chirata were structurally correlated and confirmed based on the fragmentation characteristics and information available in the literature. The fragmentation behavior of [M+H]+/[M+Na]+ ions of these components were deduced from the collision‐induced dissociation (CID) spectra obtained from the selective on‐column information‐dependant acquisition (IDA) approach. Xanthone‐C‐glycoside showed characteristic fragment ions due to fragmentation in the C‐glycosidic unit while iridoid‐O‐glycosides showed characteristic fragment ions due to cleavage in the glycoside linkage and retro‐Diels‐Alder (RDA) cleavage within an iridoid aglycone. Furthermore, on the basis of this information, an analytical assay was developed and validated to determine relative concentrations of mangiferin, amarogentin, amaroswerin, sweroside and swertiamarin. The detection was carried out using multiple reaction monitoring (MRM) in positive ionization mode with a total analysis time of 3.5 min. The method was successfully applied to standardize four different batches of herbal preparation on the basis of relative concentration of five bioactive components. Copyright © 2006 John Wiley & Sons, Ltd.
Developing multiple high‐throughput GLP methods for an investigational drug candidate in various matrices within a 96‐well plate
Authors: Zhang Jun , Kim Elaine J. , Ji Qin C. , El‐Shourbagy Tawakol A. 
Published: November 2006

AbstractIn early pharmaceutical product development, an investigational drug candidate is typically dosed to various species for toxicological and pharmacokinetic studies. Most of these studies require multiple analytical methods that have to be validated with good laboratory practice (GLP) prior to the application in regulated studies. Usually, these analytical methods are developed in either a serial or parallel approach. For either approach, the development of multiple analytical methods takes tremendous work from scientists and instruments, and thus is not cost‐effective. In this respect, a new strategy has been developed for simultaneous GLP method development using liquid chromatographic separation and tandem mass spectrometric detection. This high‐throughput approach allows system suitability, carryover, calibration curve, accuracy, precision, matrix effect and selectivity to be evaluated in one 96‐well plate. The strategy has been successfully implemented for multiple investigational drug candidates at Abbott Laboratories. The methods developed with this strategy are accurate, precise, selective, robust and matrix‐independent. As an example, ABT‐279 was used to demonstrate the feasibility of this strategy. Copyright © 2006 John Wiley & Sons, Ltd.
Intracellular distribution of lipolytic activity in the female gametophyte of germinating Douglas fir seeds
Authors: Ching Te May 
Published: November 2006

AbstractAcid (pH 5.2) and neutral (pH 7.1) lipase activity was studied in order to localize the sites of lipolysis in cellular fractions of catabolic organ of Douglas fir seed. Cellular particles were separated by differential centrifugation of the tissue homogenate and identified by electron microscopy. Emulsified native neutral lipids were provided as a substrate to protein body, mitochondrial, microsomal and soluble fractions, and endogenous lipids were used as a substrate for light and heavy fat body fractions. Little difference was observed in average specific activity of the two enzyme systems in dry seeds, but acid lipase activity increased sevenfold and neutral lipase activity fourfold during germination. Highest specific activity of both enzyme systems was found to be associated with the heavy fat bodies and the soluble fraction. Heavy fat bodies contained an ample quantity of endogenous substrate while the soluble fraction consisted of little substrate. Experimental data indicated that the soluble fraction was the source of lipases, and the heavy fat bodies were the site of in situ lipolysis.
Suitability ofGeotrichum candidum lipase for the stereospecific analysis of some triglycerides
Authors: Sampugna J. , Jensen R. G. 
Published: November 2006

AbstractA procedure is described for determining the stereospecific structure of triacid triglycerides containing oleic acid. The method utilizes the unique specificity of the lipase system fromGeotricum candidum for hydrolyzing fatty acids which containcis‐9‐unsaturation.The procedure involves a pancreatic lipase hydrolysis of 10–20 mg of substrate to determine the fatty acids in the β‐position and the incubation of another 50 mg of triglyceride withG. candidum lipase to obtain diglyceride for further treatment. The α,α‐ and α,β‐diglycerides are collected separately, converted to phenyl phosphatides and treated with phospholipase A. The analysis of the monoglycerides, produced with pancreatic lipase and the analysis of the β‐lysophosphatides allows the determination of the ratios of the original 2 position oleic acidsn‐triglycerides while the analysis of the α‐lysophosphatides aids in the determination of the originalsn‐triglycerides which contained oleic acid in the 3 position. The 1 position oleic acidsn‐triglycerides are calculated by difference.Racemic and enantiomeric triglycerides containing palmitic, stearic and oleic acids were synthesized and used to establish the limits of the new method. The good agreement between the actual and observed values for a mixture of isomers indicates that the procedure will be useful in the analysis of triacid triglycerides which contain oleic acid. The application of the procedure to triacid triglycerides which contain other unsaturated fatty acids is discussed.
Novel fatty acids from the royal jelly of honeybees (Apis mellifera, L.)
Authors: Weaver Nevin , Johnston Norah C. , Benjamin Ronna , Law John H. 
Published: November 2006

AbstractThree new compounds isolated from the royal jelly of honeybees (Apis mellifera, L.) have been identified as 8‐hydroxyoctanoic acid, 3‐hydroxydecanoic acid and a dextrorotatory isomer of 3,10‐dihydroxydecanoic acid.
Triglyceride sub‐classes of various dog adipose tissue sites
Authors: Gold Martin 
Published: November 2006

AbstractLipids were extracted from four dog adipose tissue sites, perirenal, pericardial, inguinal subcutaneous, and mesenteric. The triglycerides were purified by thin‐layer chromatography and the sub‐classes separated by silver nitrate‐silica gel plates. Gas chromatography was used to delineate the fatty acid composition of each subclass. The major sub‐class was 011, followed by 012, 001, 111 and 112 in that order (0=saturated fatty acid; 1=one double bond; 2=two double bonds). The other components were present in minor amounts. The pericardial triglyceride had more 012 while the perirenal adipose tissue contained less 011 and more 001 than other sites. The other sub‐classes were essentially similar.The distribution, based on 100%, of each saturated fatty acid was not the same in all sub‐classes, although the over‐all average was similar in each site.
Acetoacetate metabolism of rats fed high fat or restricted calorie diets
Authors: Chung Li Hsin , Dupont Jacqueline 
Published: November 2006

AbstractEthyl‐14C‐acetoacetate was used to trace oxidation and metabolism of acetoacetate when rats were fed a high fat diet (80% of total calories from beef tallow or corn oil, carbohydrate free), a high carbohydrate diet (2% corn oil) or a high carbohydrate diet with restriction of calories to one half of ad lib. consumption for two weeks. The rate of expiration of14CO2 in all groups of animals did not differ significantly and was not related to plasma concentration of acetoacetate. The high fat diets slightly enhanced the oxidation of acetoacetate to14CO2 over a 3 hr period compared to other diets. Incorporation of acetoacetate into fatty acids did not differ significantly among groups. Rats fed the high carbohydrate diet ad lib. incorporated into liver cholesterol more acetoacetate than did any other group, but dietary unsaturated fat resulted in greater incorporation of acetoacetate into cholesterol than saturated fat. High calorie and high beef tallow groups were ketonemic but the low concentration of plasma acetoacetate in rats fed a high corn oil diet indicates that unsaturated fatty acids are not ketogenic. The data show that utilization of acetoacetate is not significantly reduced in a ketonemic condition and support the premise that overproduction of ketone bodies is the cause of ketonemia. Rats appeared to be normal during the two‐week period when no carbohydrate was included in the diet.
Metabolic conversions and the positional distributions in liver lecithin of some unnatural dienoic acids in the rat
Authors: Sperecher Howard W. , Dutton H. J. , Gunstone F. D. , Holman Ralph T. 
Published: November 2006

AbstractThe metabolism of 9,15‐octadecadienoate, 12,15‐octadecadienoate and 7,13‐eicosadienoate was investigated in the fatdeficient rat. The liver lecithins of those animals receiving 9,15‐ and 12,15‐octadecadienoate, as well as the animal remaining on the fat‐deficient control, were isolated. The fatty acid distributional pattern was determined by the use of lecithinase A. All three of the experimental dienoic acids were incorporated into tissue lipids. None of the acids, however, was converted to longer chain polyunsaturated fatty acids. The 9,15‐octadecadienoate was esterified almost exclusively to the β‐position of lecithin, whereas 12,15‐octadecadienoate was about equally distributed between the α‐ and β‐positions.
Pentacylic triterpenes ofJurinea anatolic boiss. andJurinea consanguinea DC. Fruit
Authors: Mikolajczak K. L. , Smith C. R. 
Published: November 2006

AbstractPentacyclic triterpene alcohols, together with their acetate, myristate, and palmitate esters, comprise about 40% of the petroleum ether extract of the fruit (seed and pericarp) of twoJurinea species. All the triterpene esters and a porition of the free triterpene alcohols in theJ. anatolica extract are derived from the pericarp portion of the fruit. The triterpene alcohol moieties and their approximate percentage of the hydrolyzed extract ofJ. anatolica fruit are α‐amyrin, 5%; β‐amyrin, 6%; lupeol, 6%; and ψ‐taraxasterol plus taraxasterol, 16%.J. consanguinea fruit extract yields essentially the same amount of the same five triterpene alcohols on hydrolysis. These concentrations of triterpenoid materials are believed to be the largest found in plant tissues.
The isolation and tentative identification of diacylglyceryl ethers from the walker 256 carcinoma of the rat and a human lymphosarcoma
Authors: Bollinger James N. 
Published: November 2006

AbstractAn unusual lipid was observed and subsequently isolated by thin‐layer chromatography from the lipids of the Walker 256 carcinoma of the rat and a human lymphosarcoma. This lipid has been tentatively identified as a diacylgllyceryl ether by thinlayer chromatography, gas‐liquid chromatography and infrared analysis.
Ultracentrifugal isolation of serum chylomicron‐containing fractions with quantitation by infrared spectrometry and NCH elemental analysis
Authors: Hatch F. T. , Freeman N. K. , Jensen L. C. , Stevens G. R. , Lindgren F. T. 
Published: November 2006

AbstractAn ultracentrifugal method for isolating chylomicron‐containing fractions from serum by flotation, using either standard Spinco swinging‐bucket rotors or a specially fabricated swinging‐bucket rotor, is described. Lower limits of the Sf rates of the chylomicron fractions are evaluated using a computer technique to define lipoprotein flotation over a nonlinear NaCl density gradient. The latter is prepared by a special overlayering technique.Quantitation within a 9–50 μg region of mass assay is accomplished by both infrared spectrometry and elemental analysis for N, C and H. Results indicate that the chylomicron concentration in serum for a small population of nonfasting male adults ranges from approximately 0–50 mg %.
Sterol metabolism. IV. Microbial disposition of 5β‐cholestan‐3β‐ol
Authors: Smith Leland L. , Kohler Daniel P. , Hempel Judith E. , van Lier Johan E. 
Published: November 2006

AbstractCholesterol and 5β‐cholestan‐3β‐ol have been detected by thin‐layer and gas‐chromatographic means in hexane extracts of domestic sewage. Cholesterol was detected in the clear effluent after activated sludge treatment of domestic sewage, but 5β‐cholestan‐3β‐ol was undetectable in treated sewage. Attempts to detect either sterol in hexane extracts of marine bay water have not been successful because of the interference of other lipid‐like material.
The lipids of human pancreas with special reference to the presence of fatty acid methyl esters
Authors: Lough A. K. , Garton G. A. 
Published: November 2006

AbstractTotal lipids were extracted from human pancreas with chloroform‐methanol, chloroform‐methanol following acidification, and benzene. A similar proportional amount of total lipid was obtained by each procedure. Regardless of the method of extraction (i.e., whether or not methanol was present), a small proportion (about 1%) of the total lipid was found to consist of fatty acid methyl esters. Triglycerides constituted the major fraction (about 80%) of the pancreatic lipids; in addition to methyl esters, the remaining lipids comprised free fatty acids, phospholipids, cholesterol esters, and traces of free cholesterol. In general, each class of lipid had a similar over‐all fatty acid composition with palmitic and oleic acids as predominant components. The methyl esters had a relatively high content of linolenic acid, and the free fatty acids contained a notably high proportion of palmitic acid, in each case accompanied by a corresponding decrease in the proportion of oleic acid present.
The distribution of14C‐labeled cholesterol in the dog: Effect of long‐term epinephrine administration
Authors: Gans Joseph H. 
Published: November 2006

AbstractA time course study of14C‐cholesterol distribution in dogs was performed after the intravenous administration of 4‐14C‐cholesterol. Liver cholesterol attained isotopic equilibrium with plasma cholesterol within 24 hr after the administration of the labeled cholesterol. The tissue cholesterol pools of most organs attained isotopic equilibrium with plasma cholesterol between the second and ninth day after 4‐14C‐cholesterol had been given. Thoracic aorta cholesterol equilibrated most slowly with plasma cholesterol. Thirty‐seven to 75 days after the14C‐cholesterol had been given, the specific radioactivity of thoracic aorta cholesterol was 2 to 5 times greater than that of plasma cholesterol and 1.73 and 1.65 times greater than that of the abdominal and terminal aortic segments respectively. Adrenal gland cholesterol attained specific radioactivities greater than that of plasma cholesterol between the fourth and ninth day after 4‐14C‐cholesterol had been given, and this relationship was maintained over the 75‐day period of observation. The specific radioactivity of bile cholesterol was less than that of plasma cholesterol at all time periods.The daily administration of epinephrine in oil over a period of four to seven weeks was accompanied by a more equal distribution of14C‐cholesterol throughout the length of the aorta. An increase in the specific radioactivity of kidney cortex cholesterol, relative to that of plasma and kidney medullary cholesterol, also was observed in epinephrine‐treated dogs.
Isolation and characterization of cholesterol‐5B,6B‐oxide from an aerated aqueous dispersion of cholesterol
Authors: Chicoye E. , Powrie W. D. , Fennema O. 
Published: November 2006

AbstractAn unknown autoxidation product in an aerated cholesterol sol was isolated by preparative thin layer chromatography. This compound was identified as cholesterol‐5β,6β‐oxide by gas liquid chromatography along with infrared and mass spectrometry.
Fatty acid specificity of glyceride synthesis by homogenates of bovine mammary tissue
Authors: Askew E. W. , Emery R. S. , Thomas J. W. 
Published: November 2006

AbstractFatty acid esterification by cell free preparations of bovine mammary tissue was investigated to determine if the type of long chain fatty acid supplied might influence the rate of triglyceride synthesis by that tissue. Homogenates of lactating bovine mammary tissue esterified14C‐fatty acids into glycerides at rates dependent upon chain length and degree of unsaturation. Palmitic, stearic, oleic and linoleic acids were esterified at rates consistent with their concentration in milk fat. A comparison of free fatty acid concentrations of mammary tissue with levels saturating esterification suggested that supply of fatty acids does not limit glyceride synthesis. Certain combinations of fatty acids were facilitory, competitive or inhibitory to esterification. Stearic acid complimented esterification of palmitic and oleic acids. Unlabeledtrans‐11‐octadecenoic acid did not compete with14C‐palmitate as efficiently in the esterification process as did unlabeledcis‐9‐octadecenoic acid, indicating that the mammary gland may preferentially esterify thecis‐isomer of C‐18∶1. Linoleic acid inhibited esterification of palmitic, stearic and oleic acids.
Regulation of ovarian cholesterol esters: Evidence for the enzymatic sites of prostaglandin‐induced loss of corpus luteum function
Authors: Behrman H. R. , Macdonald G. J. , Greep R. O. 
Published: November 2006

AbstractThe regulation of cholesterol ester synthetase and cholesterol esterase by prostaglandins and gonadotrophins in luteinized ovaries of the rat was studied. Prostaglandin F2α (PGF2α) depressed ovarian cholesterol esters by 75% (p<.025) within 48 hr. Hypophysectomy (APX) produced a similar effect; prolactin administration to this group maintained cholesterol esters at a higher level than in the APX group but the trophic effect of prolactin was abolished by simultaneous PGF2α treatment. Progesterone output in incubated ovarian slices was reduced 50% by PGF2α treatment in vivo (p<.005), an effect similar to that produced by APX. Prolactin administration in vivo maintained the ability of the incubated tissue to synthesize progesterone at an elevated rate in APX rats but simultaneous PGF2α treatment abolished this action of prolactin. Cholesterol ester synthetase activity was severely depressed (p<.005) by PGF2α treatment to animals with intact pituitaries, a decrease similar to that produced by APX alone. The effect of APX on synthetase activity was reversed by prolactin treatment but not when PGF2α was administered with prolactin. Esterase activity, also maintained by prolactin in APX animals (p<.005), was not affected to the same extent by PGF2α although a decrease in activity was produced in both the intact and the APX+ prolactin group by PGF2α (p<.10). However simultaneous administration of luteinizing hormone (LH) reversed the effect of PGF2α in the APX+ prolactin +PGF2α group on esterase activity. These data indicate that the luteolytic action of PGF2α is directly on the corpus luteum and this action appears to be mediated by a neutralization of prolactin activity. The loss in synthetase activity and to some extent in esterase activity, induced by PGF2α depressed ovarian cholesterol ester turnover and the availability of cholesterol for conversion to progesterone.
Cholesterol esterification and cholesteryl ester hydrolysis by rabbit and human ovaries
Authors: Morin Robert J. 
Published: November 2006

AbstractEsterification of cholesterol occurred in vitro in rabbit and human ovaries via an acyl CoA‐cholesterolO‐acyltransferase reaction. The rate of esterification was increased in early pregnancy and may be one of the mechanisms whereby the content of stored ovarian cholesteryl esters is increased during this period. The increased cholesteryl esters were primarily in the form of cholesteryl oleate. The cholesteryl ester fatty acid patterns in both rabbit and human ovaries differed from those in sera, suggesting that a significant portion of these esters may have been derived from in situ synthesis. The rate of hydrolysis of cholesteryl esters during pregnancy was also increased, and occurred at a faster in vitro rate than esterification. Of the agents tested, only soy lecithin was found to significantly enhance the rate of hydrolysis of cholesteryl oleate by ovarian homogenates.
Fat metabolism in higher plants XLIX fatty acid biosynthesis by subcellular fractions of higher plants
Authors: Harwood J. L. , Stumpf P. K. 
Published: November 2006

AbstractA method is described for the rapid and comprehensive subcellular fraction‐ation of plant tissue using a combination of differential and discontinuous Ficoll gradient centrifugation. The procedure has been used to study the synthesis of fatty acids from acetate‐1‐14C or malonyl CoA‐1,3‐14C, by fractions of germinating pea and lupin seeds and developing avocado fruit, castor bean and safflower seeds. Particle free supernatants of seeds synthesize fatty acids from14C‐malonyl CoA in the presence of added cofactors. Since acetyl CoA carboxylase activity is absent the utilization of14C‐acetate by these fractions is minimal. Other particulate fractions show different activities depending on seed types. Active fractions include the low speed particulate of pea and lupin, the pea microsomes, the avocado mesocarp chloroplasts, and the fat fractions of castor bean and safflower. Individual fractions produce characteristic patterns of acids; especially noteworthy is oleic acid biosynthesis by soluble enzymes of castor bean and safflower from14C‐malonyl CoA. Some characteristics of the avocado supernatant, pea supernatant, and castor bean fat fraction synthesizing systems are compared. As a result of these studies, generalizations derived from work with mammalian or bacterial systems cannot be applied to higher plants.
Accumulation of cardiac fatty acids in rats fed synthesized oils containing C22 fatty acids
Authors: Beare‐Rogers J. L. , Nera E. A. , Craig B. M. 
Published: November 2006

AbstractSynthesized oils containing a high proportion of oleic, eicosenoic or docosenoic acid were fed to weanling rats as 20% w/w of the diet. After 1 week, a high intake of eicosenoate produced cardiac fat droplets detected histologically, whereas erucate (22∶1 Δ 13) or cetoleate (22∶1 Δ 11) caused an appreciably greater accumulation of cardiac lipid characterized by the dietary fatty acids.
trans‐6‐Hexadecenoic acid in the Atlantic leatherbackDermochelys coriacea coriaceaL. and other marine turtles
Authors: Hooper S. N. , Ackman R. G. 
Published: November 2006

AbstractDepot fat from the Atlantic leatherback turtle (Dermochelys coriacea coriaceaL.) was shown to contain ≈3% oftrans‐6‐hexadecenoic acid. Structural details were elucidated through comparative aspects of isolation techniques, NMR, IR, hydrogenation, oxidative fission, etc., and confirmed by similarity of properties with those of a sample of fatty acid of this structure isolated from the seed oil ofPicramnia sellowii. One additional leather‐back turtle oil sample, and depot fat from two other marine turtles, the loggerhead (Caretta caretta caretta) and ridley (Lepidochelys olivacea kempi) contained this acid, that from the ridley in a lower proportion. No corresponding C18acid was detected in the leatherback oil.