| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1988: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1987: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Research Abstract |
The physiological role of sulfatides is not clear at present. They are the compounds grouped to sphingo-glycolipids, and are characterised in having very polar sulfonic acid moiety in the molecule. Usually sulfatide is obtained as a mixture of seversal compounds. This structural complexity of sulfatide is due to the complexity of its lipid part, ceramide, which is constitued of a base, called sphingosine, and an acid. Both of the latters are the mixtures of the compounds of various carbon chain length. Therefore, the complexity of sulfatide is mainly attributable to that of sphinogosine and the acid part. In order to synthesize chemically pure sulfatide, it is therefore necessary to sythesize chemically pure sphingosine. This is one problem in sulfatide synthesis.
Another problem in sulfatide synthesis is the regio-selective introduction of a sulfonic acid group in the sugar (i.e.,galactose)portion.
The present study was done for solving these two problems, and clarified the followings:
(1) A new method of regio- and stereo-selective synthesis of amino-sugars via regioselective mono-oxidation of glycosides was exploited. Thus, the method of practical synthesis of aminosugars from easily available xylose or glucose was established. By application of this new method, an antibiotic, nojirimycin, a famous glucosidase inhibitor, was synthesised economically.
(2) 4-Amino-4-deoxy-arabinose obtained by the above method was converted to a "chiral common intermediate" to various sphingosines. Synthesis of C-18 sphingosine from this intermediate was described.
(3) Regioselective introduction of sulfonic acid group into the galactose portion: Sulfatation of beta-galactoside derivatives by dibutyltin oxide and chlorsulfonic acid gave 3-sulfonic acid derivatives regioselectively.
(4) Sugar sulfonic acid esters were well analysed by using photometric ion chromatography (PIC). This is an example of application of HPLC to such highly polar and not UV absorbale compounds.
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