Amano K, Ribi E, Cantrell J L
J Biochem. 1983 May;93(5):1391-9. doi: 10.1093/oxfordjournals.jbchem.a134274.
Endotoxic glycolipids extracted from the polysaccharide heptose-less Re mutant of Salmonella typhimurium were hydrolyzed with alkaline and acid reagents. Treatment with hydroxylamine caused the liberation of all O-ester linked fatty acids and resulted in abrogation of the toxicity (lethality to chick embryos) and ability to regress tumors (line-10 tumors in strain 2 guinea pigs). Treatment with dilute sodium hydroxide caused partial removal of O-ester linked fatty acids without loss of these activities. Toxicity and tumor-regressive potency were retained after removal of 2-keto-3-deoxyoctonate (KDO) by exposing the glycolipids to sodium acetate solution at pH 4.5. The majority of the glycolipids of the endotoxic extracts were rendered non-toxic but retained antitumor activity when hydrolyzed with boiling 0.1 N hydrochloric acid, which split KDO and glycosidic phosphate from the glycolipid molecules. Non-toxic glycolipid fractions possessing antitumor activity were separated from the acid hydrolysate by means of preparative thin layer chromatography. It was concluded that glycosidic bound phosphate and at least a portion of the fatty acids of the lipid A moiety are essential for toxicity, but that this phosphate is not an essential structural feature for tumor-regression activity.
从鼠伤寒沙门氏菌多糖庚糖缺失型Re突变体中提取的内毒素糖脂，用碱性和酸性试剂进行水解。用羟胺处理会使所有O-酯键连接的脂肪酸释放出来，并导致毒性（对鸡胚的致死性）和使肿瘤消退的能力（2型豚鼠的10号线肿瘤）丧失。用稀氢氧化钠处理会使O-酯键连接的脂肪酸部分去除，但这些活性不会丧失。通过将糖脂暴露于pH 4.5的醋酸钠溶液中去除2-酮-3-脱氧辛酸（KDO）后，内毒素提取物的毒性和肿瘤消退效力得以保留。当用沸腾的0.1 N盐酸水解时，内毒素提取物中的大部分糖脂变得无毒，但保留了抗肿瘤活性，盐酸从糖脂分子中裂解出KDO和糖苷磷酸。通过制备性薄层色谱法从酸水解物中分离出具有抗肿瘤活性的无毒糖脂组分。得出的结论是，糖苷结合的磷酸和脂质A部分的至少一部分脂肪酸对毒性至关重要，但这种磷酸对于肿瘤消退活性不是必需的结构特征。
