Refinement of the structure of β-tricaprin

Jensen, L. H.; Mabis, A. J.

doi:10.1107/s0365110x66003839

Cited by 153 publications

(77 citation statements)

References 4 publications

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“…3. Tricaprin (4,20) is an obvious exception in that the chain folds nearly at right angles at the 2 carbon. In PP2, DMPC (15), and 1,2-dilauroyl-rac-glycero-3-phosphoethanolamine (19) (not shown in Fig.…”

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confidence: 99%

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Single crystal structure of a mixed-chain triacylglycerol: 1,2-dipalmitoyl-3-acetyl-sn-glycerol.

Goto¹,

Kodali²,

Small³

et al. 1992

Proc. Natl. Acad. Sci. U.S.A.

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The mixed chain triacylglycerol 1,2-dipalmitoyl-3-acetyl-sn-glycerol was synthesized and its crystal structure was determined to a rinal reliability factor (R) of 0.11. Two molecules are present in the monoclinic unit cell: space group P21; a = 5.375(1), b = 8.286(2), c = 42.96(1) i; 13 = 93.30(2)°, V = 1910 A3, p = 1.065 g/cm3, and jt = 5.7 cm-'. The structure is a trilayer: a bilayer of palmitate chains packed in the (3 mode (T//) and an interdigitated monolayer of acetates. The glycerol backbone and acetate extend roughly linearly from the sn-i chain. The sn-2 chain bends around the C-2 carbon to lie next to the sn-i chain. Analysis of the torsion angles indicate that the glycerol conformation of 1,2-dipalmitoyl-3-acetyl-sn-glycerol is markedly different from single acid triacylglycerols and from 1,2-diacyl-sn-glycerols but very similar to 1,2-dimyristoyl-sn-glycero-3-phosphocholine.Acylglycerols are ubiquitous and highly prevalent biological molecules. Triacylglycerols are the major form of lipids stored in tissues of both plants and animals. Although their physical properties such as polymorphic forms, melting and transition temperatures, volumes, and viscosity are generally known (1-3), specific detailed crystal structures are largely lacking. Only two structures on single-chain triacylglycerols, tricaprin by Jensen and Mabis in 1963 (4) and trilaurin by Larsson in 1964 (5), have been published. A single complex triacylglyceride structure, 2-(11-bromoundecanoyl)-1,1'-dicaprin, was published (6), but its structure, especially the conformation of the glycerol and the chain orientation, are quite similar to the structure of single-chain triacylglycerols (4, 5). Our understanding of the structure and polymorphism of acylglycerols would be greatly enhanced by knowing the crystal structures of some of the forms of mixed-chain triacylglycerols. Diacylglycerols are intermediates in the metabolism of triacylglycerols and phospholipids. Diacylglycerols are also membrane-oriented (7) second messengers participating in signal transduction across membranes (8, 9). The biologically active form of diacylglycerols are the membrane-bound 1,2-diacyl-sn-glycerols (10). The general structure of saturated 1,2-diacyl-sn-glycerols has been reported (11) and the crystal structure of 1,2-dilauroyl-sn-glycerol (12) and 1,2-dipalmitoyl-sn-glycerol (13) have been solved. We have synthesized the three acetyl derivative of 1,2-dipalmitoyl-sn-glycerol and defined its crystal structure.$ The structure of this triacylglycerol with an acetate in position 3 differs considerably around the glycerol backbone from 1,2-diacylglycerols (12-14) or simple acid triacylglycerols such as trilaurin (4, 5). The glycerol conformation is, however, quite similar to one of the two conformers of dimyristoyl phosphatidylcholine (15). 11 MATERIALS AND METHODS 1,2-Dipalmitoyl-3-acetyl-sn-glycerol (PP2) was synthesized as described by Kodali et al. (16). After several trials of crystallization, a fairly good crystal with dimensions of 0.02 x 0.06 x 0.5 ...

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confidence: 99%

“…The structure of the , form of the single-acid triacylglycerols tricaprin (4,20) and trilaurin (5) are isostructural and form a tuning-fork conformation with the glycerol bent so that two glycerol carbons lie in the bilayer plane and the third projects up from it (Fig. 3).…”

mentioning

confidence: 99%

Single crystal structure of a mixed-chain triacylglycerol: 1,2-dipalmitoyl-3-acetyl-sn-glycerol.

Goto¹,

Kodali²,

Small³

et al. 1992

Proc. Natl. Acad. Sci. U.S.A.

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“…The monoacid (n n n) class of TAGs has been studied in most detail, using single-crystal data (n = 10, Jensen & Mabis, 1966;n = 12, Larsson, 1965;Gibon et al, 1984; n = 16, van Langevelde et al, 1999) as well as high-resolution synchrotron powder diffraction (HR-SPD) data (n = 14, 18; van Langevelde et al, 2001a; n = 13, van Langevelde et al, 2001b;n = 15, 17, 19;Helmholdt et al, 2002) and confirmed earlier postulations of the packing of this type of polymorph (Lutton, 1971(Lutton, , 1972de Jong & van Soest, 1978). The singlecrystal packing of the (n n n) analogue EEE 1 (Culot et al, 2000) is also in accordance with this result.…”

Section: Introductionmentioning

confidence: 99%

Structures of mono-unsaturated triacylglycerols. III. The β-2 polymorphs of trans-mono-unsaturated triacylglycerols and related fully saturated triacylglycerols

Mechelen

Peschar

Schenk

2008

Acta Crystallogr Sect B

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Structures of mono-unsaturated triacylglycerols. III. The -2 polymorphs of trans-monounsaturated triacylglycerols and related fully saturated triacylglycerols van Mechelen, J.B.; Peschar, R.; Schenk, H. Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. The -2 crystal structures of a series of saturated and transmono-unsaturated triacylglycerols (TAGs) have been solved from high-resolution powder synchrotron diffraction data. The series comprises symmetric as well as asymmetric evennumbered TAGs and the trans-mono-unsaturated ones all have a single elaidoyl chain. The structures have been solved with the direct-space parallel-tempering program FOX and refined with the Rietveld program GSAS. The -2 structures all crystallized in the space group P " 1 1 with the same molecular conformation. Within the resolution of the data no significant difference in packing or conformation is observed between trans-mono-unsaturated TAGs and saturated (stearoyl or palmitoyl) chain-containing analogues, in spite of the lower melting points of the former. An analysis of the position of the stepped methyl end-plane in the various subgroups of TAGs confirms most but not all suppositions found in the literature.

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“…A closer examination of the isotropic displacement parameters show the majority of them are predominantly unspecific. This is quite interesting since diffraction studies on lipids or other cationic surfactants studied at room temperature consistently show strong anisotropy due to their vibrational motion about their chain axis 38 and excessive thermal motion can gave rise to disorder 39 or partial liquefaction of the structure. 40 Atomic displacement parameters for the chain ends of Bzth-Cl or Bzth-Br C (25); C(26), C(27) and C (22) were analyzed in terms of rigid body motion 40,41 and the physical significance of the obtained parameters were examined by a Hirshfeld rigid body test.…”

Section: A Structure Of the Hydrated Bzth Halide Saltsmentioning

confidence: 99%

Influence of the anions on the N-cationic benzethonium salts in the solid state and solution: Chloride, bromide, hydroxide and citrate hydrates

Paradies

Reichelt

2016

AIP Advances

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The crystal structures of the hydrated cationic surfactant benzethonium (Bzth) chloride, bromide, hydroxide, and citrate have been determined by X-ray diffraction analysis and compared with their structures in solution well above their critical micelle concentration. The differences in the nature of the various anions of the four Bzth-X materials lead to unique anion environments and 3-D molecular arrangements. The water molecule in the monoclinic Bzth-Cl or Bzth-Br forms is hydrogen bonded to the halides and particularly to the hydrogens of the methoxy groups of the Bzth moiety notwithstanding the weak Brønsted acidity of the methoxy hydrogens. The citrate strongly interacts with the hydrogens of the methoxy group forming an embedded anionic spherical cluster of a radius of 2.6 Å. The Bzth-OH crystallizes in a hexagonal lattice with two water molecules and reveals free water molecules forming hydrogen bonded channels through the Bzth-OH crystal along the c-axis. The distances between the cationic nitrogen and the halides are 4.04 Å and 4.20 Å, significantly longer than expected for typical van der Waals distances of 3.30 Å. The structures show weakly interacting, alternating apolar and polar layers, which run parallel to the crystallographic a-b planes or a-c planes. The Bzth-X salts were also examined in aqueous solution containing 20% (v/v) ethanol and 1.0 % (v/v) glycerol well above their critical micelle concentration by small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS). The [1,1,1] planes for the Bzth Cl or Br, the [0,0,2] and [1,1,0] planes for the Bzth-citrate, the [2,-1,0] planes and the [0,0,1] planes for the Bzth-OH found in the crystalline phase were also present in the solution phase, accordingly, the preservation of these phases are a strong indication of periodicity in the solution phase.

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Refinement of the structure of β-tricaprin

Cited by 153 publications

References 4 publications

Single crystal structure of a mixed-chain triacylglycerol: 1,2-dipalmitoyl-3-acetyl-sn-glycerol.

Single crystal structure of a mixed-chain triacylglycerol: 1,2-dipalmitoyl-3-acetyl-sn-glycerol.

Structures of mono-unsaturated triacylglycerols. III. The β-2 polymorphs of trans-mono-unsaturated triacylglycerols and related fully saturated triacylglycerols

Influence of the anions on the N-cationic benzethonium salts in the solid state and solution: Chloride, bromide, hydroxide and citrate hydrates

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