20: dihydrosphingosine

DL-erytAro-Dihydrosphingosine (dl-erytAro-2-aniinooctadecan>l,3-diol) [3102-56-5] M 301.5, m 85-86 , 85-87 , pK ,t -- 8.8. Purified by recrystn from pet ether-EtOAc or CHCI3. The ( )-N-dichloroacetyl derivative has m 142-144° (from MeOH). [Shapiro et al. J Am Chem Soc 80 2170 1958 Shapiro and Sheradsky J Org Chem 28 2157 796i.] The D-isomer crystallises from pet ether-Et20 and has m... 

A syn-selective asymmetiic nih o-aldol reaction has been reported for structurally simple aldehydes using a new catalyst generated from 6,6-bis[(tiiethylsilyl)ethynyl]BINOL (g in Scheme 3.18). The syn selectivity in the nitro-aldol reaction can be explained by steric hindrance in the bicyclic transition state as can be seen in Newman projection. In the favored h ansition state, the catalyst acts as a Lewis acid and as a Lewis base at different sites. In conbast, the nonchelation-controlled transition state affords anti product with lower ee. This stereoselective nitro-aldol reaction has been applied to simple synthesis of t/ireo-dihydrosphingosine by the reduction of the nitro-aldol product with H2 and Pd-C (Eq. 3.79). 

Scheme 3. Catalytic asymmetric synthesis of threo-dihydrosphingosine.

Ayar, A., Thatcher, N.M., Zehavi, U., Trentham, D.R. and Scott, R.H., 1998, MobUization of intraceUular calcium by intraceUular flash photolysis of caged dihydrosphingosine in cultured neonatal rat sensory neurones, Acto Bioc/rim. Polon. 45 311-326. 

Siemann DW, Jiang JB, Balias L, Janzen W (1993) Threo-dihydrosphingosine potentiates the in vivo antitumor efficacy of dsplatin and adriamycin. Proc Am Assoc Cancer Res 34 410,2452... 

Demethoxydaunomycinone, 71 1-Deoxynojirimycin, 175 Dihydroactinidiolide, 77 Dihydrosphingosine, 31 25,28-Dihydroxy-7,8-dihydroergosterol, 151 Dodecahedrane, 251 (Z)-8-Dodecenyl-l-acetate, 281... 

Precoated silica gel plates (silica gel 60) were purchased from Scientific Products. Bio-Sil A (200 - 400 Mesh) was obtained from Bio-Rad Laboratories. Fatty acid methyl esters, sphingosine and dihydrosphingosine were products of Supelco, Inc. as were 10% DEGS-PS, 3% SP-2340 and 3% OV-17 (all on Supelcoport support). N-acetyl and N-glycolyl neuraminic acid, DEAE-Sephadex A50 and neuraminidase type IX were obtained from Sigma Company. Ganglio-side standards from human brain and neutral glycosphingolipid standards from bovine erythrocytes were prepared in this laboratory. 

Fatty acids and sphingosines. The lipid composition of the four monosialogangliosides is shown in Table II. The major fatty acids are palmitic, stearic and oleic acids. The long chain base is composed mainly of C-18 sphingosine with less than 20% of dihydrosphingosine. 

Serum Diabetic nephropathy (DN) Healthy subjects 25 DN patients 8 type 2 diabetes mellitus patients 33 UPLC Q-TOF MS Leucine, dihydrosphingosine, and phytosphingosine (54)... 

The jyn-selective asymmetric nitroaldol reaction was successfully applied to the catalytic, asymmetric synthesis of ftireo-dihydrosphingosine (94), which elicits a variety of cellular responses by inhibiting protein kinase C (Figure 22).44 The nitroaldol reaction of hexadecanal 92 with 3 equiv. of nitroethanol (86) in the... 

Figure 22. Catalytic, asymmetric synthesis of t/ireo-dihydrosphingosine.

Stewart, M.E., and Downing, D.T., Free sphingosines of human skin include 6-hydroxysphingosine and unusually long-chain dihydrosphingosines, J. Invest. Dermatol., 105, 613, 1995. 

Fig. 4.5. Sphingomyelin synthesis in Hymenolepis diminuta distribution of label in various intermediates, separated by thin-layer chromatography, after incubation with cytidine-5 -diphospho [methyl-13C]choline. The position of the lipid standards is indicated by the arrows, (a) sphingomyelin (b) dihydrosphingosine (c) sphingosine (d) ketosphingosine (e) ceramide. The origin is at band O. d.p.m., disintegrations/min. (After Bankov Barrett, 1985.)...

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