DOCSLIB.ORG

Chromatographic Sterol Analysis As Applied to the Investigation of Milk Fat and Other Oils and Fats

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

CHROMATOGRAPHIC STEROL ANALYSIS AS APPLIED TO THE INVESTIGATION OF MILK FAT AND OTHER OILS AND FATS ACADEMISCH PROEFSCHRIFT TER VERKRIJGING VAN DE GRAAD VAN DOCTOR IN DE WISKUNDE EN NATUURWETENSCHAPPEN AAN DE UNIVERSITEIT VAN AMSTERDAM, OP GEZAG VAN DE RECTOR MAGNIFICUS DR. J. KOK, HOOGLERAAR IN DE FACULTEIT DER WISKUNDE EN NATUURWETENSCHAPPEN IN HET OPENBAAR TE VERDEDIGEN IN DE AULA DER UNIVERSITEIT (TIJDELIJK IN DE LUTHERSE KERK, INGANG SINGEL 411, HOEK SPUl) OP WOENSDAG 23 OKTOBER 1963, DES NAMIDDAGS TE 16 UUR DOOR JAN WILLEM COPIUS PEEREBOOM GEBOREN TE 'S-GRAVENHAGE qP CENTRUM VOOR LANDBOUWPUBLIKATIES EN LANDBOUWDOCUMENTATIE WAGENINGEN 1963 1"%-! .••: i PROMOTOR:PROF .DR .W .VA NTONGERE N Es ist nichtgenug zu wissen Manmuss auch anwenden Es ist nichtgenug zu wollen Manmuss auch tun. GOETHE Bij de voltooiing van dit proefschrift betuig ik in de eerste plaats gaarne mijn dank aan alle hoogleraren en lectoren, die tot mijn wetenschappelijke vorming hebben bijgedragen. Hooggeleerde WIBAUT, naar U gaat mijn dank uit voor het inzicht in de organische chemie, dat ik van U mocht ontvangen. Van mijn blijvende belangstelling voor klassieke onderwerpen uit de organische chemie als de sterolchemie, mogen vele gedeelten van dit proefschrift getuigen. Hooggeleerde VAN TONGEREN, Hooggeschatte Promotor, met gevoelens van grote erkentelijkheid richt ik mij tot U om dank te zeggen voor het onderricht in de ana­ lytische chemie en voor de grote steun, die ik bij de bewerking van dit proefschrift van U mocht ondervinden. Het geduld waarmede U steeds weer talloze onvolkomen­ heden in de Engelse tekst signaleerde, heeft mijn grote bewondering. Het onderzoek werd in zijn geheel uitgevoerd op het RIJKSZUIVELSTATION. Gaarne wil ik hierbij mijn dank betuigen aan mijn collegae en medewerkers van het RIJKSZUIVELSTATION, die op enigerlei wijze hebben bijgedragen aan het tot stand komen van dit proefschrift. Ir. B. M. KROL ben ik erkentelijk voor het vervaar­ digen der foto's. Zeer speciale dank ben ik verschuldigd aan Ir. J. B. Roos voor de waardevolle discussies en stimulerende kritiek betreffende „sterolanalyse". Het aantal malen dat in dit proefschrift wordt verwezen naar publikaties en rapporten van zijn hand, moge getuigen van mijn waardering voor het werk dat hij op dit gebied heeft verricht. Mej. H. W. BEEKESdan k ik voor de toegewijde assistentie en bekwame experimentele vaardigheid, die van zo grote waarde zijn geweest bij de uitvoering van het onderzoek. De directeur van het RIJKSZUIVELSTATION, Dr. J. G. VAN GINKEL, ben ik erkentelijk voor zijn toestemming dit onderzoek te mogen publiceren en voor de vele faciliteiten, die hij mij tijdens de bewerking van dit proefschrift heeft verleend. DRUK: N.V. NOORD-NEDERLANDSE DRUKKERIJ - MEPPEL Deze dissertatie verschijnt tevens als Nr. 69.8 in de reeks Verslagen van Landbouwkundige Onder­ zoekingen CONTENTS 1 CLASSICAL ANALYTICAL METHODS FOR NATURAL STEROLS, APPLIED TO FAT ANALYSIS 1 1.1 Fat analysis based upon characteristic values 1 1.1.1 Fatty acid values and special applications 2 1.1.2 Glyceride (fat) analysis 3 1.1.3 Guide (fat) analysis 4 1.2 The principal naturally occurring sterols 6 1.3 Sterol values in fat analysis 12 1.4 Application of the sterol content to fat analysis (sterol value a) ... 13 1.4.1 Gravimetric methods 13 1.4.2 Other procedures 16 1.4.3 Applications 19 1.5 Melting point of the sterol acetates as a characteristic value (sterol value m) 20 1.5.1 Procedures 20 1.5.2 Melting point diagrams 23 1.5.3 Reliability of BÖMER'S phytosterol acetate test 25 1.6 Cholesterol percentage as a characteristic of sterol mixtures (sterol value c) 31 1.6.1 Detection of vegetable fat in animal fat and vice versa 31 1.6.2 Detection of cholesterol from the melting point diagram 33 1.6.3 Other procedures 34 2 THE CHROMATOGRAPHIC SEPARATION OF STEROLS 38 2.1 Adsorption chromatography 38 2.2 Paperchromatography 39 2.3 Experimental procedures 45 2.3.1 Preparation of the sterol mixture 45 2.3.2 Procedure of paperchromatography 47 2.4 Quantitative evaluation of the paperchromatographic analysis .... 48 2.4.1 Quantitative evaluation by planimetry 49 2.4.2 Densitometrie evaluation 50 3 A STUDY OF THE SYSTEM: PARAFFIN/ACETIC ACID-WATER (84 : 16) 52 3.1 Principles of paperchromatography 52 3.1.1 Fundamental equations 52 IX 3.1.2 Applications of the RM concept 56 3.1.3 The occurrence of critical pairs 57 3.2 Experimental conditions in the system: paraffin/acetic acid-water (84:16) 58 3.2.1 Influence of external circumstances 58 3.2.2 Features of the partition process 60 3.3 Correlations between structure and RM values 62 3.3.1 RFan d RM values of a group of sterols 62 3.3.2 Critical pairs of sterols 66 3.3.3 Calculation of A RM values 68 3.4 Applications of the correlation between structure and RMvalues.. 72 3.4.1 Rules concerning the correlation and ARMvalue s 72 3.4.2 Identification of unknown sterols 73 3.4.3 Influence of different steric configurations 78 4 APPLICATIONS OF THE CHROMATOGRAPHIC STEROL SEPARATION TOTH E ANALYSIS OF FAT MIXTURES 81 4.1 Analysis of mixtures of animal and vegetable fats 81 4.1.1 Analysis of animal fats 81 4.1.2 Analysis of vegetable fats 82 4.2 Composition of the sterol mixture 83 4.3 Probable structure of the third-band phytosterols 86 4.4 Detection of cholesterol in mixtures with third-band phytosterols. 90 4.4.1 With the normal paperchromatographic procedure 90 4.4.2 Further examination of questionable samples 92 5 THIN-LAYER CHROMATOGRAPHY OF STEROLS 94 5.1 Introduction 94 5.2 Normal thin-layer chromatography of sterols 96 5.3 Reversed-phasethin-laye rchromatograph y ofsterol san d sterolacetate s 99 5.3.1 Separation of sterol acetates 100 5.3.2 Separation of sterols 102 5.4 Some applications 104 5.5 Separation of sterol acetate bromides 106 5.5.1 Bromine containing systems 106 5.5.2 Experimental procedure 108 5.5.3 Semi-quantitative evaluations 108 6 BEHAVIOUR OF SOME ABERRANT PHYTOSTEROL TYPES IN CONNECTION WITH THEIR POSSIBLE STRUCTURE 110 6.1 Failure of the original phytosterol acetate test of BOMER HO 6.1.1 Special behaviour of pumpkin phytosterols 110 6.1.2 Phytosterols of shea nut fat and Mowrah fat 112 6.1.3 Zl7-sterol mixtures 116 6.2 Structure of the pumpkin oil phytosterols 119 6.2.1 Characteristics of pumpkin oil 119 6.2.2 Paperchromatography 119 6.2.3 U.V. spectrophotometry 120 6.2.4 T.L.C. bromine system 120 6.2.5 Colour reactions 120 6.2.6 Melting point and optical rotation 122 6.2.7 Infrared and N.M.R. spectra 123 6.2.8 Thin-layer chromatography 126 7 CALCULATIONS ON THE BASIS OF STEROL VALUES 129 7.1 Identification of the type of admixed animal fat 129 7.2 Analysis of a cottonseed oil sample 131 7.3 Analysis of a palm oil sample 132 7.4 Analysis of a second palm oil sample 133 7.5 Detection of cocoa extraction fat in pure cocoa butter 134 SUMMARY 139 SAMENVATTING 141 REFERENCES 143 Chapter 1 143 Chapter 2-7 151 XI 6.1.1 Special behaviour of pumpkin phytosterols 110 6.1.2 Phytosterols of shea nut fat and Mowrah fat 112 6.1.3 zl7-sterol mixtures 116 6.2 Structure of the pumpkin oil phytosterols 119 6.2.1 Characteristics of pumpkin oil 119 6.2.2 Paperchromatography 119 6.2.3 U.V. spectrophotometry 120 6.2.4 T.L.C. bromine system 120 6.2.5 Colour reactions 120 6.2.6 Melting point and optical rotation 122 6.2.7 Infrared and N.M.R. spectra 123 6.2.8 Thin-layer chromatography 126 7 CALCULATIONS ON THE BASIS OF STEROL VALUES 129 7.1 Identification of the type of admixed animal fat 129 7.2 Analysis of a cottonseed oil sample 131 7.3 Analysis of a palm oil sample 132 7.4 Analysis of a second palm oil sample 133 7.5 Detection of cocoa extraction fat in pure cocoa butter 134 SUMMARY 139 SAMENVATTING 141 REFERENCES 143 Chapter 1 143 Chapter 2-7 151 XI The author wasawarde d the degree of Doctor of Science, Universityo fAmsterdam , The Netherlands,o na thesi s with the same title and contents, on 23st October 1963. 1 CLASSICAL ANALYTICAL METHODS FOR NATURAL STEROLS, APPLIED TO FAT ANALYSIS 1.1 FAT ANALYSIS BASED UPON CHARACTERISTIC VALUES As a consequence of the very complex composition of natural fats the analytical chemistry of lipoids forms a distinct field with special problems. Besides multifarious types of triglycerides as quantitatively most important fraction, a minor part consists of an enormous variety of other lipoid substances: monoglycerides, triglycerides, phosphatides,tocopherols ,sterols ,stero lesters ,hydrocarbons ,carotenoid san dtrace s of several other compounds. The triglycerides forming the main fraction of the fat consist ofa glycerolmolecul eesterifie d withthre efatt y acids.Th etriglycerid e fraction largely varies in composition, numerous combinations of the fatty acid constituents in their molecules being conceivable. Evidently, the great number of possible tri­ glycerides still further enhances the complexity of this type of analysis. One of the purposes of fat chemistry is the determination of all these individual types oflipoid si na fat , but inth epas tappropiat e analytical techniques werelacking . At the end of the nineteenth century a complete analysis of a natural fat thus was by no means possible. Nevertheless, fat analysis had to differentiate between the various types of oils and fats and to determine the proportion of the constituents of commercially available fat mixtures.
Recommended publications
  • Sterols As Dietary Markers for Drosophila Melanogaster

    Sterols As Dietary Markers for Drosophila Melanogaster

    bioRxiv preprint doi: https://doi.org/10.1101/857664; this version posted November 29, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 Sterols as dietary markers for Drosophila melanogaster 2 3 Oskar Knittelfelder1, Elodie Prince2, Susanne Sales1,3, Eric Fritzsche4, Thomas Wöhner4, 4 Marko Brankatschk2, and Andrej Shevchenko1,5 5 6 1MPI of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, 7 Germany 8 2Biotechnologisches Zentrum, Technische Universität Dresden, Tatzberg 47/49, 01309 9 Dresden, Germany 10 3Present address: Thermo Fischer Scientific GmbH, 63303 Dreieich, Germany 11 4Julius Kühn Institut, Pillnitzer Platz 3a, 01326 Dresden, Germany 12 5corresponding author: [email protected] 13 14 ORCID 15 Oskar Knittelfelder: 0000-0002-1565-7238 16 Marko Brankatschk: 0000-0001-5274-4552 17 Andrej Shevchenko: 0000-0002-5079-1109 18 19 Author contributions 20 Experiments design: OK, EP, MB, AS; methods development: OK, SS; experimental work: 21 OK, EP; materials and reagents: EF, TW; data analysis: OK; data interpretation: OK, EP, MB, 22 AS; manuscript preparation: OK, EP, MB, AS; funding: MB, AS 23 24 25 1 bioRxiv preprint doi: https://doi.org/10.1101/857664; this version posted November 29, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license.
  • • Our Bodies Make All the Cholesterol We Need. • 85 % of Our Blood

    • Our Bodies Make All the Cholesterol We Need. • 85 % of Our Blood

    • Our bodies make all the cholesterol we need. • 85 % of our blood cholesterol level is endogenous • 15 % = dietary from meat, poultry, fish, seafood and dairy products. • It's possible for some people to eat foods high in cholesterol and still have low blood cholesterol levels. • Likewise, it's possible to eat foods low in cholesterol and have a high blood cholesterol level SYNTHESIS OF CHOLESTEROL • LOCATION • All tissues • Liver • Cortex of adrenal gland • Gonads • Smooth endoplasmic reticulum Cholesterol biosynthesis and degradation • Diet: only found in animal fat • Biosynthesis: primarily synthesized in the liver from acetyl-coA; biosynthesis is inhibited by LDL uptake • Degradation: only occurs in the liver • Cholesterol is only synthesized by animals • Although de novo synthesis of cholesterol occurs in/ by almost all tissues in humans, the capacity is greatest in liver, intestine, adrenal cortex, and reproductive tissues, including ovaries, testes, and placenta. • Most de novo synthesis occurs in the liver, where cholesterol is synthesized from acetyl-CoA in the cytoplasm. • Biosynthesis in the liver accounts for approximately 10%, and in the intestines approximately 15%, of the amount produced each day. • Since cholesterol is not synthesized in plants; vegetables & fruits play a major role in low cholesterol diets. • As previously mentioned, cholesterol biosynthesis is necessary for membrane synthesis, and as a precursor for steroid synthesis including steroid hormone and vitamin D production, and bile acid synthesis, in the liver. • Slightly less than half of the cholesterol in the body derives from biosynthesis de novo. • Most cells derive their cholesterol from LDL or HDL, but some cholesterol may be synthesize: de novo.
  • Ligands of Therapeutic Utility for the Liver X Receptors

    Ligands of Therapeutic Utility for the Liver X Receptors

    molecules Review Ligands of Therapeutic Utility for the Liver X Receptors Rajesh Komati, Dominick Spadoni, Shilong Zheng, Jayalakshmi Sridhar, Kevin E. Riley and Guangdi Wang * Department of Chemistry and RCMI Cancer Research Center, Xavier University of Louisiana, New Orleans, LA 70125, USA; [email protected] (R.K.); [email protected] (D.S.); [email protected] (S.Z.); [email protected] (J.S.); [email protected] (K.E.R.) * Correspondence: [email protected] Academic Editor: Derek J. McPhee Received: 31 October 2016; Accepted: 30 December 2016; Published: 5 January 2017 Abstract: Liver X receptors (LXRs) have been increasingly recognized as a potential therapeutic target to treat pathological conditions ranging from vascular and metabolic diseases, neurological degeneration, to cancers that are driven by lipid metabolism. Amidst intensifying efforts to discover ligands that act through LXRs to achieve the sought-after pharmacological outcomes, several lead compounds are already being tested in clinical trials for a variety of disease interventions. While more potent and selective LXR ligands continue to emerge from screening of small molecule libraries, rational design, and empirical medicinal chemistry approaches, challenges remain in minimizing undesirable effects of LXR activation on lipid metabolism. This review provides a summary of known endogenous, naturally occurring, and synthetic ligands. The review also offers considerations from a molecular modeling perspective with which to design more specific LXRβ ligands based on the interaction energies of ligands and the important amino acid residues in the LXRβ ligand binding domain. Keywords: liver X receptors; LXRα; LXRβ specific ligands; atherosclerosis; diabetes; Alzheimer’s disease; cancer; lipid metabolism; molecular modeling; interaction energy 1.
  • Genetic Deletion of Abcc6 Disturbs Cholesterol Homeostasis in Mice Bettina Ibold1, Janina Tiemann1, Isabel Faust1, Uta Ceglarek2, Julia Dittrich2, Theo G

    Genetic Deletion of Abcc6 Disturbs Cholesterol Homeostasis in Mice Bettina Ibold1, Janina Tiemann1, Isabel Faust1, Uta Ceglarek2, Julia Dittrich2, Theo G

    www.nature.com/scientificreports OPEN Genetic deletion of Abcc6 disturbs cholesterol homeostasis in mice Bettina Ibold1, Janina Tiemann1, Isabel Faust1, Uta Ceglarek2, Julia Dittrich2, Theo G. M. F. Gorgels3,4, Arthur A. B. Bergen4,5, Olivier Vanakker6, Matthias Van Gils6, Cornelius Knabbe1 & Doris Hendig1* Genetic studies link adenosine triphosphate-binding cassette transporter C6 (ABCC6) mutations to pseudoxanthoma elasticum (PXE). ABCC6 sequence variations are correlated with altered HDL cholesterol levels and an elevated risk of coronary artery diseases. However, the role of ABCC6 in cholesterol homeostasis is not widely known. Here, we report reduced serum cholesterol and phytosterol levels in Abcc6-defcient mice, indicating an impaired sterol absorption. Ratios of cholesterol precursors to cholesterol were increased, confrmed by upregulation of hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase (Hmgcr) expression, suggesting activation of cholesterol biosynthesis in Abcc6−/− mice. We found that cholesterol depletion was accompanied by a substantial decrease in HDL cholesterol mediated by lowered ApoA-I and ApoA-II protein levels and not by inhibited lecithin-cholesterol transferase activity. Additionally, higher proprotein convertase subtilisin/kexin type 9 (Pcsk9) serum levels in Abcc6−/− mice and PXE patients and elevated ApoB level in knockout mice were observed, suggesting a potentially altered very low-density lipoprotein synthesis. Our results underline the role of Abcc6 in cholesterol homeostasis and indicate impaired cholesterol metabolism as an important pathomechanism involved in PXE manifestation. Mutations in the adenosine triphosphate-binding cassette transporter C6 (ABCC6) gene are responsible for pseudoxanthoma elasticum (PXE), a metabolic disease, hallmarked by a progressive elastic fber calcifcation of the skin, eyes and cardiovascular system.
  • TRP Channel Transient Receptor Potential Channels

    TRP Channel Transient Receptor Potential Channels

    TRP Channel Transient receptor potential channels TRP Channel (Transient receptor potential channel) is a group of ion channels located mostly on the plasma membrane of numerous human and animal cell types. There are about 28 TRP channels that share some structural similarity to each other. These are grouped into two broad groups: Group 1 includes TRPC ("C" for canonical), TRPV ("V" for vanilloid), TRPM ("M" for melastatin), TRPN, and TRPA. In group 2, there are TRPP ("P" for polycystic) and TRPML ("ML" for mucolipin). Many of these channels mediate a variety of sensations like the sensations of pain, hotness, warmth or coldness, different kinds of tastes, pressure, and vision. TRP channels are relatively non-selectively permeable to cations, including sodium, calcium and magnesium. TRP channels are initially discovered in trp-mutant strain of the fruit fly Drosophila. Later, TRP channels are found in vertebrates where they are ubiquitously expressed in many cell types and tissues. TRP channels are important for human health as mutations in at least four TRP channels underlie disease. www.MedChemExpress.com 1 TRP Channel Inhibitors, Antagonists, Agonists, Activators & Modulators (-)-Menthol (E)-Cardamonin Cat. No.: HY-75161 ((E)-Cardamomin; (E)-Alpinetin chalcone) Cat. No.: HY-N1378 (-)-Menthol is a key component of peppermint oil (E)-Cardamonin ((E)-Cardamomin) is a novel that binds and activates transient receptor antagonist of hTRPA1 cation channel with an IC50 potential melastatin 8 (TRPM8), a of 454 nM. Ca2+-permeable nonselective cation channel, to 2+ increase [Ca ]i. Antitumor activity. Purity: >98.0% Purity: 99.81% Clinical Data: Launched Clinical Data: No Development Reported Size: 10 mM × 1 mL, 500 mg, 1 g Size: 10 mM × 1 mL, 5 mg, 10 mg, 25 mg, 50 mg, 100 mg (Z)-Capsaicin 1,4-Cineole (Zucapsaicin; Civamide; cis-Capsaicin) Cat.
  • Regulation of TRP Channels by Steroids

    Regulation of TRP Channels by Steroids

    General and Comparative Endocrinology xxx (2014) xxx–xxx Contents lists available at ScienceDirect General and Comparative Endocrinology journal homepage: www.elsevier.com/locate/ygcen Review Regulation of TRP channels by steroids: Implications in physiology and diseases ⇑ Ashutosh Kumar, Shikha Kumari, Rakesh Kumar Majhi, Nirlipta Swain, Manoj Yadav, Chandan Goswami School of Biology, National Institute of Science Education and Research, Sachivalaya Marg, Bhubaneswar, Orissa 751005, India article info abstract Article history: While effects of different steroids on the gene expression and regulation are well established, it is proven Available online xxxx that steroids can also exert rapid non-genomic actions in several tissues and cells. In most cases, these non-genomic rapid effects of steroids are actually due to intracellular mobilization of Ca2+- and other ions Keywords: suggesting that Ca2+ channels are involved in such effects. Transient Receptor Potential (TRP) ion TRP channels channels or TRPs are the largest group of non-selective and polymodal ion channels which cause Ca2+- Steroids influx in response to different physical and chemical stimuli. While non-genomic actions of different Non-genomic action of steroids steroids on different ion channels have been established to some extent, involvement of TRPs in such Ca2+-influx functions is largely unexplored. In this review, we critically analyze the literature and summarize how Expression different steroids as well as their metabolic precursors and derivatives can exert non-genomic effects by acting on different TRPs qualitatively and/or quantitatively. Such effects have physiological repercus- sion on systems such as in sperm cells, immune cells, bone cells, neuronal cells and many others.
  • Isolation and Characterization of Two Sterols from the Green Alga, Selenastrum Capricornutum

    Isolation and Characterization of Two Sterols from the Green Alga, Selenastrum Capricornutum

    Portland State University PDXScholar Dissertations and Theses Dissertations and Theses 1-1-1976 Isolation and characterization of two sterols from the green alga, Selenastrum capricornutum Raymond Mark Owings Portland State University Follow this and additional works at: https://pdxscholar.library.pdx.edu/open_access_etds Let us know how access to this document benefits ou.y Recommended Citation Owings, Raymond Mark, "Isolation and characterization of two sterols from the green alga, Selenastrum capricornutum" (1976). Dissertations and Theses. Paper 861. https://doi.org/10.15760/etd.861 This Dissertation is brought to you for free and open access. It has been accepted for inclusion in Dissertations and Theses by an authorized administrator of PDXScholar. Please contact us if we can make this document more accessible: [email protected]. ISOLATIO[\ At\D CHAHACTERIZATIOi\ OF 1\'JO STEROLS FRON Tr-lE GREEi\ ALGA. SELENASTRL::I CAPRICORl\UTt.:~l by RA YNOND HARK O~\ Ii\GS A thesis submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY in Ef\VIRONHEl\TAL SCIEI\CE-CHEtv1[STRY Portland State University 1976 Ai': ABSTRA.CT OF THE THESIS OF Raymond tvlark O\vings for the Doctor of Philosophy in Environmental Science-Chemistry presented August 4, 1975. Title: Isolation and Characterization of Two Sterols From the Green Alga, Selanastrum capricornutum. APPROVED BY NEivlBERS OF THE THESIS COHNITTEE: Karl Dittmer, Chairman Norman C. Rose Edward N. Perdue Dennis \V. Barnum Richard R. Petersen 2 The green alga, Selenastrum capricornutum, was cul­ tured in artificial nutrient medium utilizing five-gallon carboys, each of which contained 16 1.
  • Evaluation of Certain Food Additives

    Evaluation of Certain Food Additives

    952 Food Additives WHO Technical Report Series WHO Technical Sixty-ninth report of the FOOD ADDITIVES Joint FAO/WHO Expert Committee on Food and Agriculture Organization of the United Nations S I N A P T A F I EVALUATION OF CERTAIN EVALUATION OF CERTAIN FOOD ADDITIVES WHO Technical Report Series 952 ISBN 978 92 4 120952 6 2,3-trimethylbutyramide (No. 1595) and N, , phytosterols, phytostanols and their esters, , calcium lignosulfonate (40–65), ethyl lauroyl arginate, paprika Pichia pastoris A. niger -unsaturated aldehydes, acids and related alcohols, acetals and esters; β , α expressed in niger Aspergillus L-monomenthyl glutarate (No. 1414). recommendations for intakes and Annexed to the report are tables summarizing the Committee’s toxicological evaluations of the food additives considered. aliphatic secondary alcohols, ketones and related esters; alkoxy-substituted allylbenzenes present in foods and essential oils and used as flavouring agents; esters of aliphatic acyclic primary alcohols with aliphatic linear saturated carboxylic acids; furan-substituted aliphatic hydrocarbons, alcohols, aldehydes, ketones, carboxylic acids and related esters, sulfides, disulfides and ethers; miscellaneous nitrogen-containing substances; monocyclic and bicyclic secondary alcohols, ketones and related esters; hydroxy- and alkoxy-substituted benzyl derivatives; and substances structurally related to menthol). Specifications for the following food additives were revised: canthaxanthin; carob bean gum and carob bean gum (clarified); chlorophyllin copper
  • Structural Basis for Human Sterol Isomerase in Cholesterol Biosynthesis and Multidrug Recognition

    Structural Basis for Human Sterol Isomerase in Cholesterol Biosynthesis and Multidrug Recognition

    ARTICLE https://doi.org/10.1038/s41467-019-10279-w OPEN Structural basis for human sterol isomerase in cholesterol biosynthesis and multidrug recognition Tao Long 1, Abdirahman Hassan 1, Bonne M Thompson2, Jeffrey G McDonald1,2, Jiawei Wang3 & Xiaochun Li 1,4 3-β-hydroxysteroid-Δ8, Δ7-isomerase, known as Emopamil-Binding Protein (EBP), is an endoplasmic reticulum membrane protein involved in cholesterol biosynthesis, autophagy, 1234567890():,; oligodendrocyte formation. The mutation on EBP can cause Conradi-Hunermann syndrome, an inborn error. Interestingly, EBP binds an abundance of structurally diverse pharmacolo- gically active compounds, causing drug resistance. Here, we report two crystal structures of human EBP, one in complex with the anti-breast cancer drug tamoxifen and the other in complex with the cholesterol biosynthesis inhibitor U18666A. EBP adopts an unreported fold involving five transmembrane-helices (TMs) that creates a membrane cavity presenting a pharmacological binding site that accommodates multiple different ligands. The compounds exploit their positively-charged amine group to mimic the carbocationic sterol intermediate. Mutagenesis studies on specific residues abolish the isomerase activity and decrease the multidrug binding capacity. This work reveals the catalytic mechanism of EBP-mediated isomerization in cholesterol biosynthesis and how this protein may act as a multi-drug binder. 1 Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. 2 Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. 3 State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China. 4 Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
  • (12) United States Patent (10) Patent No.: US 7,906,307 B2 S0e Et Al

    (12) United States Patent (10) Patent No.: US 7,906,307 B2 S0e Et Al

    US007906307B2 (12) United States Patent (10) Patent No.: US 7,906,307 B2 S0e et al. (45) Date of Patent: Mar. 15, 2011 (54) VARIANT LIPIDACYLTRANSFERASES AND 4,683.202 A 7, 1987 Mullis METHODS OF MAKING 4,689,297 A 8, 1987 Good 4,707,291 A 11, 1987 Thom 4,707,364 A 11/1987 Barach (75) Inventors: Jorn Borch Soe, Tilst (DK); Jorn 4,708,876 A 1 1/1987 Yokoyama Dalgaard Mikkelson, Hvidovre (DK); 4,798,793 A 1/1989 Eigtved 4,808,417 A 2f1989 Masuda Arno de Kreij. Geneve (CH) 4,810,414 A 3/1989 Huge-Jensen 4,814,331 A 3, 1989 Kerkenaar (73) Assignee: Danisco A/S, Copenhagen (DK) 4,818,695 A 4/1989 Eigtved 4,826,767 A 5/1989 Hansen 4,865,866 A 9, 1989 Moore (*) Notice: Subject to any disclaimer, the term of this 4,904.483. A 2f1990 Christensen patent is extended or adjusted under 35 4,916,064 A 4, 1990 Derez U.S.C. 154(b) by 0 days. 5,112,624 A 5/1992 Johna 5,213,968 A 5, 1993 Castle 5,219,733 A 6/1993 Myojo (21) Appl. No.: 11/852,274 5,219,744 A 6/1993 Kurashige 5,232,846 A 8, 1993 Takeda (22) Filed: Sep. 7, 2007 5,264,367 A 11/1993 Aalrust (Continued) (65) Prior Publication Data US 2008/OO70287 A1 Mar. 20, 2008 FOREIGN PATENT DOCUMENTS AR 331094 2, 1995 Related U.S. Application Data (Continued) (63) Continuation-in-part of application No.
  • Steroidal Triterpenes of Cholesterol Synthesis

    Steroidal Triterpenes of Cholesterol Synthesis

    Molecules 2013, 18, 4002-4017; doi:10.3390/molecules18044002 OPEN ACCESS molecules ISSN 1420-3049 www.mdpi.com/journal/molecules Review Steroidal Triterpenes of Cholesterol Synthesis Jure Ačimovič and Damjana Rozman * Centre for Functional Genomics and Bio-Chips, Faculty of Medicine, Institute of Biochemistry, University of Ljubljana, Zaloška 4, Ljubljana SI-1000, Slovenia; E-Mail: [email protected] * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +386-1-543-7591; Fax: +386-1-543-7588. Received: 18 February 2013; in revised form: 19 March 2013 / Accepted: 27 March 2013 / Published: 4 April 2013 Abstract: Cholesterol synthesis is a ubiquitous and housekeeping metabolic pathway that leads to cholesterol, an essential structural component of mammalian cell membranes, required for proper membrane permeability and fluidity. The last part of the pathway involves steroidal triterpenes with cholestane ring structures. It starts by conversion of acyclic squalene into lanosterol, the first sterol intermediate of the pathway, followed by production of 20 structurally very similar steroidal triterpene molecules in over 11 complex enzyme reactions. Due to the structural similarities of sterol intermediates and the broad substrate specificity of the enzymes involved (especially sterol-Δ24-reductase; DHCR24) the exact sequence of the reactions between lanosterol and cholesterol remains undefined. This article reviews all hitherto known structures of post-squalene steroidal triterpenes of cholesterol synthesis, their biological roles and the enzymes responsible for their synthesis. Furthermore, it summarises kinetic parameters of enzymes (Vmax and Km) and sterol intermediate concentrations from various tissues. Due to the complexity of the post-squalene cholesterol synthesis pathway, future studies will require a comprehensive meta-analysis of the pathway to elucidate the exact reaction sequence in different tissues, physiological or disease conditions.
  • Water Column Distribution and Carbon Isotopic Signal of Cholesterol

    Water Column Distribution and Carbon Isotopic Signal of Cholesterol

    Water column distribution and carbon isotopic signal of cholesterol, brassicasterol and particulate organic carbon in the Atlantic sector of the Southern Ocean Anne-Julie Cavagna, Frank Dehairs, Steven Bouillon, V. Woule-Ebongué, Frédéric Planchon, Bruno Delille, Ioanna Bouloubassi To cite this version: Anne-Julie Cavagna, Frank Dehairs, Steven Bouillon, V. Woule-Ebongué, Frédéric Planchon, et al.. Water column distribution and carbon isotopic signal of cholesterol, brassicasterol and particulate organic carbon in the Atlantic sector of the Southern Ocean. Biogeosciences, European Geosciences Union, 2013, 10 (4), pp.2787-2801. 10.5194/bg-10-2787-2013. hal-00914348v2 HAL Id: hal-00914348 https://hal.archives-ouvertes.fr/hal-00914348v2 Submitted on 25 Apr 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Distributed under a Creative Commons Attribution| 4.0 International License EGU Journal Logos (RGB) Open Access Open Access Open Access Advances in Annales Nonlinear Processes Geosciences Geophysicae in Geophysics Open Access Open Access Natural Hazards Natural Hazards and Earth System and Earth System Sciences Sciences Discussions Open Access Open Access Atmospheric Atmospheric Chemistry Chemistry and Physics and Physics Discussions Open Access Open Access Atmospheric Atmospheric Measurement Measurement Techniques Techniques Discussions Open Access Biogeosciences, 10, 2787–2801, 2013 Open Access www.biogeosciences.net/10/2787/2013/ Biogeosciences doi:10.5194/bg-10-2787-2013 Biogeosciences Discussions © Author(s) 2013.