OSG-1 化合物是由海洋生物- 蜈蚣櫛蛇尾( Ophiocoma scolopendrina ) 的肉體體壁部所分離得到,為雙醣之醣苷神經胺基酯 質(ganglioside)化合物。本篇論文旨在研究OSG-1的建構單元體的 合成, OSG-1 的主要成份為唾液酸( N-acetylneuramic acid, Neu5Ac)、葡萄糖(glucose, Glc)、植物神經鞘胺醇(phytosphingosine) 與α-羥基脂肪酸(α-hydroxyfatty acid)等四部份。 唾液酸建構單元體Neu-3是由唾液酸為起始物,經酯化反應、多 氧-乙醯化反應及苯硫醣苷化反應得到,總產率為86%。葡萄糖建構 單元體Glc-6是由葡萄糖作為起始物,經多氧-乙醯化反應、甲氧苯酚 基醣苷化反應、去乙醯基反應、一級醇保護反應、苷基化反應、一級 醇去保護基反應等六個反應步驟得到,總產率為37%。植物神經鞘胺 醇建構單元體Lxy-7是由來蘇糖( lyxlose)作為起始物,經氧-異亞丙基 化反應、一級醇保護反應、Wittig反應、疊氮等官能基轉換反應六個 反應步驟得到,總產率為21%。α-羥基脂肪酸的製備,為本研究自行 開拓的一條簡易且快速的合成途徑,α-羥基脂肪酸由D-(+)-蘋果酸 (D-(+)-malic acid)為起始物,經環亞己基保護反應、乙烷硫醣ㄓ柦r 應、Wittig 反應、氫化反應及水解反應等五個反應步驟得到,總產率 為34%。
The compound OSG-1, isolated from the sea cucumber Ophiocoma scolopendrina, is a ganglioside containing disaccharides. The synthesis of OSG-1 and its building blocks , such as N-acetylneuramic acid (Neu5Ac), glucose, phytosphingosine and α-hydroxyfatty acid will be discussed in this thesis. The building unit, Neu-3, was synthesized starting from sialic acid via a three-step procedure, involving esterification, per-O-acetylation, and thiophenol glycolsylation in 86% overall yield. The glucose building unit, Glc-6, was prepared using glucose as starting material through a six-step sequence, involving per-O-acetylation, 4-methoxyphenol glycolsylation, deacetylation, protection of primary alcohol, benzylation and deprotection primary alcohol, to give the product Glc-6 in a overall yield of 37%. The building unit of phytosphingosine, Lyx-7, was using lyxose as starting material through a seven-step sequence, involving O-isopropylidene reaction, protection of primary alcohol, Wittig reaction, azidization and functional group transformation to give the product Lyx-7 in a overall yield of 21%. The prepartion of α-hydroxyfatty acid was carved by a facile route in this thesis. The building unit of α-hydroxyfatty acid, Mal-6, is made from D-(+)-malic acid through cyclohexylidene protection reaction, thioethanol glycolsylation, Wittig reaction, hydrogenation and hydrolysis to give the product, Mal-6, in 34%.