Parodi P W
Lipids. 1982 Jun;17(6):437-42. doi: 10.1007/BF02535223.
Milk triglycerides from the echidna, koala, Tammar wallaby, guinea pig, dog, cat, Weddell seal, horse, pig and cow were subjected to fatty acid and stereospecific analysis to determine the positional distribution of the fatty acids in the triglycerides. The samples presented a wide range of fatty acids, most of which varied in content among species. The compositions of the acids at the 3 positions also varied among species, reflecting the content of these acids in the triglycerides. However, there was a general similarity in fatty acid positional distribution patterns for all the species with the exception of the echidna. The echidna exhibited a completely different fatty acid positional distribution pattern. The saturated acids were preferentialy esterified at the sn-1-position whereas the unsaturated acids were selectively esterified at the sn-2-position. The triglyceride carbon number distribution of milk from the above species (with the exception of the Weddell seal) was determined by gas liquid chromatography and compared to that predicted by the 1-random-2-random-3-random fatty acid distribution hypothesis. Agreement was excellent between observed and predicted composition for echidna, koala, Tammar wallaby, guinea pig and pig milk, and agreement was reasonable for dog, cat, horse and cow milk. Results are discussed in relation to biochemical mechanisms.
对针鼹、树袋熊、短尾矮袋鼠、豚鼠、狗、猫、威德尔海豹、马、猪和牛的乳甘油三酯进行了脂肪酸和立体专一性分析，以确定甘油三酯中脂肪酸的位置分布。这些样本呈现出广泛的脂肪酸种类，其中大多数脂肪酸的含量在不同物种间存在差异。甘油三酯3位上的酸组成在不同物种间也有所不同，这反映了这些酸在甘油三酯中的含量。然而，除针鼹外，所有物种的脂肪酸位置分布模式总体上具有相似性。针鼹呈现出完全不同的脂肪酸位置分布模式。饱和酸优先在sn-1位酯化，而不饱和酸则选择性地在sn-2位酯化。通过气相色谱法测定了上述物种（威德尔海豹除外）乳汁的甘油三酯碳数分布，并与1-随机-2-随机-3-随机脂肪酸分布假说预测的结果进行了比较。针鼹、树袋熊、短尾矮袋鼠、豚鼠和猪乳汁的观察组成与预测组成之间一致性极佳，狗、猫、马和牛乳汁的一致性则较为合理。结合生化机制对结果进行了讨论。
