scholarly journals New synthesis of S-alkyl-DL-homocysteines

1969 ◽  
Vol 47 (17) ◽  
pp. 3271-3273 ◽  
Author(s):  
Harold M. Kolenbrander

A simple method for the synthesis of S-alkyl-DL-homocysteines is described. The method involves the reaction of homocysteine thiolactone with a primary alkyl halide in sodium methoxide solution.

2017 ◽  
Vol 11 (1) ◽  
pp. 17-26
Author(s):  
Olufunmilola Akinyemi ◽  
Geza Bruckner ◽  
John Johnson ◽  
Terry A. Lennie ◽  
David Hildebrand

Fatty acid profiling has become a very useful and effective tool in the diagnosis, prevention and treatment of several diseases with cardiovascular disease being particularly important. In order to arrive at accurate conclusions that would help promote the health of individuals plagued by such diseases, not only excellent laboratory methods are required, but also very important monitoring responses to treatment. Improvements in methods of fatty acid profiling in biological systems regarding safety of extraction, precision and time for analysis are valuable. The ω-3 index (a measure of the amount of eicosapentaenoic acid, EPA, and docosahexaenoic acid, DHA, in Red Blood Cell membranes expressed as the percent of total fatty acids) is of growing interest because it has been reported to provide prognostic information regarding the risk for heart diseases. Sodium methoxide has been widely used for the determination of ω -3 fatty acids in food samples. This study demonstrates that sodium methoxide can be used effectively in RBC fatty acid profiling and determination of the ω-3 index. Briefly, the fatty acid profiles and ω-3 index of red blood cell samples were analyzed and results compared using three different methods: a two- step extraction and methylation method described by Hara and Radin, a single step extraction and methylation method described by Harris et al. and the sodium methoxide method. Our results revealed that there were no statistically significant differences (p<0.05) between the three methods for the representative fatty acids, [16:0 (p = 0.10), 18:0 (p=0.40), 18:1(ω9) (p = 0.29), 18:2(ω6) (p = 0.95), 18:3(ω3) (p = 0.50), 20:5(ω3) (p=0.56), 22:6(ω3) (p = 0.06)] and ω-3 index (p = 0.11) except for 20:4(ω6), (P = 0.02). In conclusion, we show that sodium methoxide can be used effectively in a one-step extraction and methylation procedure for high throughput analysis of fatty acids in red blood cell membranes. It is rapid (10 minute extraction and methylation), simple, safer than and as accurate as other commonly reported methods.


1976 ◽  
Vol 54 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Stewart John Campbell ◽  
David Darwish

The Sommelet rearrangement of (+)-ethylmethyl-p-nitrobenzylsulfonium perchlorate, (+)-1, and (+)-ethylmethyl-p-chlorobenzylsulfonium perchlorate, (+)-2, are described. Elution of (+)-1 through an hydroxide exchange resin generated ethylmethylsulfonium p-nitro-benzylide (+)-3 which decomposed in methanol at room temperature to ethyl 2-methyl-5-nitro-benzyl sulfide, 6, and (+)-methyl α-(2-methyl-5-nitrophenyl)ethyl sulfide, (+)-7, with 18 to 20.3% asymmetric induction. Decomposition of (+)-2 in sodium methoxide solution at 70 °C for 2 h produced ethyl 2-methyl-5-chlorobenzyl sulfide, 8, and (+)-methyl α-(2-methyl-5-nitro-phenyl)ethyl sulfide, (+)-9, with 21 to 25.5% asymmetric induction. The lower estimates of asymmetric induction for each sulfide were made by comparison with specific rotations of authentic samples obtained by synthesis and resolution. The higher estimates were obtained by the use of a chiral lanthanide shift reagent Eu(hfbc)3 with the sulfone derivatives of these chiral sulfides. The ylide (+)-3 reacted with aldehydes in high yield to produce oxiranes with no induction of asymmetry.


2017 ◽  
Vol 12 (4) ◽  
pp. 198-203
Author(s):  
Anca Daniela RAICIU ◽  
◽  
Daniel CORD ◽  
Alin FOCŞA ◽  
◽  
...  

Introduction. Hops (Humulus lupulus L.) is used as a raw material for the production of beer but has also biological properties. Phytoestrogens present in the hops have an antioxidant, anti-inflammatory and probiotic role, while having an effect on the diseases of osteoporosis, diabetes and vasomotor effects (calf) during menopause. Material and method. 8-prenilnaringenine was prepared according to a modification of the initial method. To a cooled solution of naringenin was added a methanolic sodium methoxide solution and prenyl bromide. Results and discussions. The estrogenic effect has been attributed to substances such as β-acids, β-sitosterol, xanthohumol and desmethylxanthohumol. Further investigations have shown that 8-prenylnaringenine is a major hops estrogen. 8-prenilnaringenin acts on estrogen receptors that mediate bone osteoblastic formation and inhibit osteoclastic bone resorption.


1988 ◽  
Vol 66 (12) ◽  
pp. 2975-2980 ◽  
Author(s):  
Juan A. López Sastre ◽  
José Molina Molina ◽  
Dolores Portal Olea ◽  
Cristina Romero-Avila

Penta-O-acetyl-D-glucose diethyl dithioacetal monoxide 3 was obtained by oxidation of penta-O-acetyl-D-glucose diethyl dithioacetal 2 with 3-chloroperbenzoic acid. By reaction of 3 with sodium methoxide in methanol and further acetylation, 3,4,6-tri-O-acetyl-2,5-anhydro-D-mannose-diethyl dithioacetal monoxide 8 and the reduction product 3,4,6-tri-O-acetyl-2,5-anhydro-1,1-bis(ethylthio)-1-deoxy-D-arabino-hex-1-enitol 4 were obtained. Reduction of 8 yielded the corresponding dithioacetal derivative 9, which was converted to 3,4,6-tri-O-acetyl-2,5-anhydro-D-mannose diethyl acetal 11.


ChemInform ◽  
2008 ◽  
Vol 39 (38) ◽  
Author(s):  
Danzhen Li ◽  
Hanjie Huang ◽  
Xu Chen ◽  
Zhixin Chen ◽  
Wenjuan Li ◽  
...  

2007 ◽  
Vol 180 (9) ◽  
pp. 2630-2634 ◽  
Author(s):  
Danzhen Li ◽  
Hanjie Huang ◽  
Xu Chen ◽  
Zhixin Chen ◽  
Wenjuan Li ◽  
...  

2010 ◽  
Vol 7 (3) ◽  
pp. 1066-1070 ◽  
Author(s):  
A. K. Ramasamy ◽  
V. Balasubramaniam ◽  
K. Mohan

An efficient method for the synthesis of various substituted 4-methoxy-1H-quinolin-2-ones from various substituted aniline with malonic acid, phosphorous oxychloride, sodium methoxide and glacial acetic acid under different conditions is described. The title compounds were synthesized from three steps; the first step involved the synthesis of substituted 2, 4-dichloro quinoline from aniline (substituted), with malonic acid and phosphorous-oxychloride. In the second step, the substituted 2, 4 dichloro compounds was heated with freshly prepared methanolic sodium methoxide solution to give 2, 4-dimethoxy quinoline compounds, it was then refluxed with glacial acetic acid and hydrochloric acid to give the titled compounds in the final step. The purity of the synthesized compounds was confirmed by their C, H and N analysis and the structure was analyzed on the basics of Mass, FT-IR and1H NMR.


Author(s):  
K.-H. Herrmann ◽  
E. Reuber ◽  
P. Schiske

Aposteriori deblurring of high resolution electron micrographs of weak phase objects can be performed by holographic filters [1,2] which are arranged in the Fourier domain of a light-optical reconstruction set-up. According to the diffraction efficiency and the lateral position of the grating structure, the filters permit adjustment of the amplitudes and phases of the spatial frequencies in the image which is obtained in the first diffraction order.In the case of bright field imaging with axial illumination, the Contrast Transfer Functions (CTF) are oscillating, but real. For different imageforming conditions and several signal-to-noise ratios an extensive set of Wiener-filters should be available. A simple method of producing such filters by only photographic and mechanical means will be described here.A transparent master grating with 6.25 lines/mm and 160 mm diameter was produced by a high precision computer plotter. It is photographed through a rotating mask, plotted by a standard plotter.


Author(s):  
Dean A. Handley ◽  
Jack T. Alexander ◽  
Shu Chien

In situ preparation of cell cultures for ultrastructural investigations is a convenient method by which fixation, dehydration and embedment are carried out in the culture petri dish. The in situ method offers the advantage of preserving the native orientation of cell-cell interactions, junctional regions and overlapping configurations. In order to section after embedment, the petri dish is usually separated from the polymerized resin by either differential cryo-contraction or solvation in organic fluids. The remaining resin block must be re-embedded before sectioning. Although removal of the petri dish may not disrupt the native cellular geometry, it does sacrifice what is now recognized as an important characteristic of cell growth: cell-substratum molecular interactions. To preserve the topographic cell-substratum relationship, we developed a simple method of tapered rotary beveling to reduce the petri dish thickness to a dimension suitable for direct thin sectioning.


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