Glyceroglycolipids are widely distributed among animals, plants, and microorganisms, but their physiological roles have been scarcely elucidated comparing to the compiling reports about the role of sphingoglycolipids in higher organisms. Recently, some biologically active glyceroglycolipids which have long fatty acids were reported. One kind of the glyceroglycolipids which were isolated from bacteria, Microbacterium sp. M874, prevent oxidative cell death induced by tert-butylhydroperoxide. In order to determine the active site and to elucidate the mechanism of the glyceroglycolipids as antioxidants in resistance to oxygen radical pure natural compounds and their analogues which are synthesized by chemical methods are required. We describe herein a synthesis of new found bioactive glyceroglycolipids. Suitably protected units, sugar part (2) and fatty acid (3), were prepared for synthesis of target glyceroglycolipid M874 (1) (Scheme 1). Compound 2 was prepared from tetraacetylgalactosyl bromide (4) via glycosylation of D-1,2-O-isopropylidene-sn-glycerol (5), removal of acetyl groups, benzylation and acidic hydrolysis of isopropylidene (Scheme 2). On the other hand, olefin 12 prepared from (S)-(-)-2-methyl- 1-butyl tosylate (11) and 11-bromoundecene (7) according to literature was converted into fatty acid (3) by oxidation using RuCl_3-NaIO_4 (Scheme 3). Glyceroglycolipid M874 (1) was synthesized by coupling of 2 with 3 and subsequent hydrogenolysis of benzyl groups (Scheme 4). ^1H- and ^<13>C-NMR spectra of synthesized glyceroglycolipid M874 (1) were in accordance with those of natural product which was previously reported, and antioxidant activity of synthesized product against Bacillus Subtilis was almost equal to that of natural product.
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