Kirschner D, Que Hee S S, Clark C S
Am Ind Hyg Assoc J. 1985 Dec;46(12):741-6. doi: 10.1080/15298668591395661.
An analytical chemical method for the 3- or beta-hydroxymyristic (BHM) acid component of endotoxins has been developed for the lipopolysaccharide (LPS) of E. coli, intact E. coli, and sewage sludge compost. Endotoxins are the pyrogens associated with the outer membranes of many gram-negative bacteria, for example, E. coli and Salmonella. The BHM acid content was used as a chemical marker for endotoxin presence, since BHM acid is present in the molecular subunit (Lipid-A) responsible for the toxicity and is the most abundant saturated fatty acid in that subunit. BHM acid quantification thus complements the Limulus bioassay to detect gram-negative bacteria presence in such samples as cotton and other dusts, blood, water, compost and air samples. BHM acid was isolated after digestion, ether extraction, alkaline hydrolysis, and ether extraction. The free acid was quantitated as the methyl ester using two GC columns as a screening method or by GC/MS for confirmatory purposes. Recoveries were unreliable below 15 ng of BHM acid. By the use of the 2-column screening technique, the amounts of BHM equivalent in E. coli LPS, intact E. coli and compost in micrograms BHM acid/g substrate were (arithmetic mean +/- standard deviation), respectively: 56 120 +/- 2200; 2650 +/- 339; and 14.7 +/- 5.7.
已开发出一种分析化学方法，用于检测大肠杆菌的脂多糖（LPS）、完整大肠杆菌及污水污泥堆肥中内毒素的3-羟基肉豆蔻酸或β-羟基肉豆蔻酸（BHM酸）成分。内毒素是与许多革兰氏阴性菌外膜相关的热原，如大肠杆菌和沙门氏菌。BHM酸含量被用作内毒素存在的化学标志物，因为BHM酸存在于负责毒性的分子亚基（脂质A）中，且是该亚基中含量最丰富的饱和脂肪酸。因此，BHM酸定量可补充鲎试剂生物测定法，以检测棉花及其他粉尘、血液、水、堆肥和空气样本等样品中革兰氏阴性菌的存在。经消化、乙醚萃取、碱性水解及乙醚萃取后分离出BHM酸。游离酸以甲酯形式定量，采用两根气相色谱柱作为筛选方法，或通过气相色谱/质谱联用进行确证。BHM酸含量低于15 ng时回收率不可靠。采用双柱筛选技术，大肠杆菌LPS、完整大肠杆菌及堆肥中BHM酸当量（以每克底物中BHM酸的微克数计）分别为（算术平均值±标准差）：56 120±2200；2650±339；以及14.7±5.7。
