Nakamura T, Aoyama Y, Fujita T, Katsui G
Lipids. 1975 Oct;10(10):627-33. doi: 10.1007/BF02532728.
Twelve d,1-3,4-3H2-alpha-tocopheryl esters were synthesized from d,1-3,4-3H2-alpha-tocopherol. They were acetate, propionate, butyrate, isobutyrate, caprylate, palmitate, acid succinate, benzoate, nicotinate, o-hydroxybenzoate, o-acetoxybenzoate, and pivalate. The hydrolysis of these esters with bile-pancreatic juice and with 9,000 x g supernatant of small intestine and liver homogenates of rats was examined. When these esters were incubated in small intestine or liver supernatants, hydrolysis occurred at a similar rate. In the incubation experiments, alpha-tocopheryl acetate, propionate, butyrate, isobutyrate, caprylate, palmitate, and acid succinate were classified as an easily hydrolyzable group. Alpha-tocopheryl benzoate and nicotinate were in a moderately hydrolyzable group. O-hydroxybenzoate and pivalate, which resisted hydrolysis, were in a scarcely hydrolyzable group. O-acetoxybenzoate was easily hydrolyzed to the o-hydroxybenzoate. Hydrolysis on straight chain fatty acid esters of alpha-tocopherol easily occurred in bile-pancreatic juice. In in vivo experiments, the lymphatic absorption rate of 6 esters, acetate, palmitate, acid succinate, nicotinate, o-hydroxybenzoate, and pivalate, was measured on thoracic duct fistula rats. Easily hydrolyzable esters were recovered mostly in lymph as alpha-tocopherol, whereas, an ester which strongly resisted hydrolysis, such as pivalate, appeared mainly unchanged. This fact suggested that hydrolysis of alpha-tocopheryl esters was not necessarily a prerequisite for intestinal absorption. The percentage of absorption of slowly hydrolyzed esters in lymph was relatively lower than that of moderately or easily hydrolyzable esters.
由d,1-3,4-3H₂-α-生育酚合成了12种d,1-3,4-3H₂-α-生育酚酯。它们分别是乙酸酯、丙酸酯、丁酸酯、异丁酸酯、辛酸酯、棕榈酸酯、琥珀酸酯、苯甲酸酯、烟酸酯、邻羟基苯甲酸酯、邻乙酰氧基苯甲酸酯和新戊酸酯。研究了这些酯在胆胰液以及大鼠小肠和肝脏匀浆9000×g上清液中的水解情况。当这些酯在小肠或肝脏上清液中孵育时，水解以相似的速率发生。在孵育实验中，α-生育酚乙酸酯、丙酸酯、丁酸酯、异丁酸酯、辛酸酯、棕榈酸酯和琥珀酸酯被归类为易水解组。α-生育酚苯甲酸酯和烟酸酯属于中等水解组。抗水解的邻羟基苯甲酸酯和新戊酸酯属于难水解组。邻乙酰氧基苯甲酸酯很容易水解为邻羟基苯甲酸酯。α-生育酚的直链脂肪酸酯在胆胰液中很容易发生水解。在体内实验中，对胸导管瘘大鼠测定了6种酯（乙酸酯、棕榈酸酯、琥珀酸酯、烟酸酯、邻羟基苯甲酸酯和新戊酸酯）的淋巴吸收速率。易水解的酯大多以α-生育酚的形式在淋巴中回收，而像新戊酸酯这样强烈抗水解的酯主要以未变化的形式出现。这一事实表明，α-生育酚酯的水解不一定是肠道吸收的先决条件。淋巴中水解缓慢的酯的吸收百分比相对低于中等或易水解的酯。
