Synthesis of 1-sn-lysophosphatidylcholine and mixed acid 1-sn-phosphatidylcholine

1978 ◽  
Vol 56 (12) ◽  
pp. 1149-1153 ◽  
Author(s):  
Norman B. Smith ◽  
Arnis Kuksis

An investigation of the biochemical effects of L-lysophosphatidylcholine (1-acyl-sn-glycerol-3-phosphorylcholine) requires as a control for its detergent action the metabolically inert, unnatural enantiomer, D-lysophosphatidylcholine (3-acyl-sn-glycerol-1-phosphorylcholine). The latter can be easily prepared in milligram quantities from the commercially available DL-phosphatidylcholine. For this purpose rac-1,2-dipalmitoyl-sn-glycerol-3-phosphorylcholine is solubilized with the aid of one-half its weight of taurocholate and hydrolyzed with phospholipase A2 to completion and the intact residual 2,3-dipalmitoyl-sn-glycerol-1-phosphorylcholine recovered by chromatography. The pure D-phosphatidylcholine is then subjected to methanolysis in the presence of octylamine and the product isomerized with glacial acetic acid. The 3-palmitoyl-sn-glycerol-1-phosphorylcholine thus obtained is chromatographically pure, possesses correct optical rotation and NMR spectrum, and is resistant to hydrolysis by phospholipase A2 following reacylation to the diacylphosphatide. Acylation of the 1-sn-lysophosphatide provides a convenient method for preparation of mixed acid 1-sn-phosphatidylcholines which are not otherwise available.

1969 ◽  
Vol 47 (15) ◽  
pp. 2739-2746 ◽  
Author(s):  
J. C. MacDonald

The optical rotation of various concentrations of L-valine and L-leucine, dissolved in glacial acetic acid, or 5 or 6 M HCl, was measured with a photoelectric polarimeter at the nominal wavelengths 589, 578, 546, 436, and 365 nm and temperatures of 20, 25, and 30 °C. The specific rotation for any one wavelength, solute, and solvent could be defined by the equation [α]λT = A(1 + D(T − 25)) + BC, where T is temperature in °C, C is concentration in grams of solute per 100 ml of solution, and A, B, and D are constants. The best fit values of the constants were determined by computer calculation and are listed. Constants are also given for calculating a specific rotation based on grams of solute per 100 g of solution.


2008 ◽  
Vol 59 (1) ◽  
pp. 41-44
Author(s):  
Maria-Daniela Sofei ◽  
Maria Ilici ◽  
Valentin Badea ◽  
Carol Csunderlik ◽  
Vasile-Nicolae Bercean

The synthesis of 1H-3-aryl-7-ethoxycarbonyl-6-methyl-pyrazolo[5,1-c][1,2,4]triazoles (2) was carried out by cyclization of 1H-5-arylidenehydrazino-4-ethoxycarbonyl-3-methyl-pyrazoles (1) in the presence of bromine using glacial acetic acid as solvent and sodium acetate as base. The new nine obtained compounds were characterized by IR and NMR spectroscopy and mass spectrometry.


1979 ◽  
Vol 44 (8) ◽  
pp. 2330-2337 ◽  
Author(s):  
Jindřiška Maternová ◽  
Anastas A. Andreev ◽  
Dimitrii M. Shopov ◽  
Karel Setínek

It was found spectroscopically that cobalt(II) acetate dissolved in glacial acetic acid forms the octahedral complex [Co(OAc)2(HOAc)4] which in the presence of bromide ions gives the octahedral [Co(OAc)Br(HOAc)4] and tetrahedral bromo(acetate)cobalt(II) complexes with the higher number of Br- ions. When attached to an organic polymer cobalt(II) ions are bonded in the form of octahedral [Co(H2O)6]2+ cations which form with acetic acid similar complexes as in homogeneous phase and are able to coordinate one bromide ion. Drying the copolymer possessing octahedral hexaaquocobalt(II) cations leads to tetrahedral aquocomplexes which are solvated by gaseous acetic acid and converted into the acetate complexes with the liquid acid. The latter contain the acid in the inner coordination sphere and have tetrahedral symmetry.


Author(s):  
Prabal Boral ◽  
Atul K. Varma ◽  
Sudip Maity

AbstractFour coal samples from Jharia basin, India are treated with nitric acid in glacial acetic acid and aqueous media to find out the chemical, petrographic and spatial structure of the organic mass by X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) techniques. X-ray parameters of coal like interlayer spacing (d002), crystallite size (Lc), aroamticity (fa), average number of aromatic layers (Nc), and coal rank (I26/I20) have been determined using profile-fitting software. Considerable variation is observed in treated coals in comparison to the demineralized coals. The d002 values of treated coals have increased in both the media showing increase in disordering of organic moieties. A linear relationship has been observed between d002 values with the volatile matter of the coals. Similarly, the d002 values show linear relationship with Cdmf contents for demineralized as well as for the treated coals in both the media. The Lc and Nc values have decreased in treated coals corresponding to demineralized coals. The present study shows that nitration in both the media is capable of removing the aliphatic side chains from the coals and aromaticity (fa) increases with increase in rank and shows a linear relationship with the vitrinite reflectance. The corresponding I26/I20 values are least for treated coals in glacial acetic acid medium followed by raw and then to treated coals in aqueous medium. FTIR studies show that coal arenes of the raw coals are converted into nitro-arenes in structurally modified coals (SMCs) in both the media, the corresponding bands at 1550–1490 and 1355–1315 cm−1 respectively. FTIR study confirms that nitration is the predominant phenomenon, though, oxidation and nitration phenomena takes place simultaneously during treatment with nitric acid to form SMCs. In comparison to raw coals, the SMCs show higher aromaticity and may be easily converted to coal derived products like activated carbon and specialty carbon materials.


Author(s):  
Xue Yang ◽  
Yongling Liu ◽  
Tao Chen ◽  
Nana Wang ◽  
Hongmei Li ◽  
...  

Abstract Separation of natural compounds directly from the crude extract is a challenging work for traditional column chromatography. In the present study, an efficient method for separation of three main compounds from the crude extract of Dracocephalum tanguticum has been successfully established by high-speed counter-current chromatography (HSCCC). The crude extract was directly introduced into HSCCC by using dimethyl sulfoxide as cosolvent. Ethyl acetate/n-butyl alcohol/0.3% glacial acetic acid (4: 1: 5, v/v) system was used and three target compounds with purity higher than 80% were obtained. Preparative HPLC was used for further purification and three target compounds with purity higher than 98% were obtained. The compounds were identified as chlorogenic acid, pedaliin and pedaliin-6″-acetate.


1972 ◽  
Vol 94 (4) ◽  
pp. 1247-1249 ◽  
Author(s):  
R. S. Schwartz ◽  
H. Yokokawa ◽  
E. W. Graham

2014 ◽  
Vol 131 (22) ◽  
pp. n/a-n/a ◽  
Author(s):  
José Luís Ferreira ◽  
Susana Gomes ◽  
Célia Henriques ◽  
João Paulo Borges ◽  
Jorge Carvalho Silva

1972 ◽  
Vol 25 (10) ◽  
pp. 2107 ◽  
Author(s):  
GB Deacon ◽  
GD Fallon

Bismuth triarenesulphinates, Bi(02SR)3 [R = Ph, p-MeC6H4, p-ClC6H4, 2,4,6-(Me2CH)3C6H2, and p-MeCONHC6H4], have been prepared by reaction of bismuth triacetate with the appropriate arenesulphinio acids in glacial acetic acid, and the first two compounds have also been obtained by reaction of triphenyl-bismuth with the appropriate mercuric arenesulphinates. The sulphur-oxygen stretching frequencies of the bismuth sulphinates are indicative of O-sulphinate coordination, and the compounds are considered to be polymeric with bridging O-sulphinate groups and six-coordinate bismuth. Thermal decomposition of Bi(O2SR)3 (R = Ph, p-MeC6H4, or p-CIC6H4) under vacuum gave the corresponding triarylbismuth compounds and sulphur dioxide, the preparation of tri-p-chlorophenylbismuth being accompanied by formation of di-p-chlorophenyl sulphone and S-p-chlorophenyl p-chlorobenzenethiosulphonate. Pyrolysis of the other triarenesulphinates did not yield organobismuth compounds.


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