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某些多不饱和脂肪酸是营养必需脂肪酸(EFA),称为维生素 F。自从1964年发现 EFA 是生物合成前列腺素(PG)的前体以后,EFA 尤其是花生四烯酸(AA)的研究有了迅速的发展。一、EFA 是生物合成 PG 的前体PG 是具有广泛生理作用的活性物,按 PG 五员环结构的不同,可分为 A、B、C、D、E、F、G、H、I、TXA_2和 TXB_2等类。其中 PGG_2 PGH_2、PGI_2 TXA_2和 TXB_2是七十年代新发现的活性更强的不稳定的产物。释放 PG 的组织细胞膜结构中的磷脂,在磷脂酶 A_2的催化下,可使β位酯键水解,释放多不饱和脂肪酸如 A A。A A 在微粒体环加氧酶等的作用下生成环内过氧化产物 PGG_2和PGH_2。它们是 PG 生物合成的中间产物,可再转化为 PGE_2、PGF_2(?)、PGD_2、PGI_2和TXA_2等(详见下图)。
Some polyunsaturated fatty acids are the nutrient essential fatty acids (EFA), called vitamin F. Since EFA was discovered as a precursor of biosynthetic prostaglandins (PGs) in 1964, there has been a rapid development in the research of EFA, especially arachidonic acid (AA). EFA is a precursor of PG biosynthesis PG is a widely active physiological activity, according to the structure of PG five-member ring can be divided into A, B, C, D, E, F, G, H, TXA_2 and TXB_2 and so on. Of these, PGG_2 PGH_2, PGI_2 TXA_2 and TXB_2 were newly discovered more active and unstable products in the seventies. Phospholipids released from the membrane structure of PG tissue can catalyze the hydrolysis of β-ester bond under the catalysis of phospholipase A 2, releasing polyunsaturated fatty acids such as AA. A A generates intramolecular peroxidation products PGG_2 and PGH_2 under the action of microsomal cyclooxygenase and the like. They are intermediates of PG biosynthesis and can be further transformed into PGE_2, PGF_2 (?), PGD_2, PGI_2 and TXA_2 (see below).