College of Life Sciences, Hebei Normal University, Shijiazhuang, 050016 Hebei, China.
Exp Appl Acarol. 2012 Dec;58(4):453-70. doi: 10.1007/s10493-012-9586-1. Epub 2012 Jun 13.
Untreated eggs of the tick Amblyomma hebraeum Koch (Acari: Ixodidae) exhibited antimicrobial activity (AMA) against Gram-negative but not Gram-positive bacteria; eggs denuded of wax by solvent extraction showed no AMA. The unfractionated egg wax extract, however, showed AMA against Gram-positive but not Gram-negative bacteria, as also shown by Arrieta et al. (Exp Appl Acarol 39: 297-313, 2006). In this study we partitioned the egg wax into various fractions, using a variety of techniques, analyzed their compositions, and tested them for AMA. The crude aqueous extract exhibited AMA. However, although more than 30 metabolites were identified in this extract by nuclear magnetic resonance analysis, none of them seemed likely to be responsible for the observed AMA. In the crude organic extract, cholesterol esters were the most abundant lipids, but were devoid of AMA. Fatty acids (FAs), with chain lengths between C13 and C26 were the next most abundant lipids. After lipid fractionation and gas chromatography/mass spectroscopy, free FAs, especially C16:1 and C18:2, accounted for most of the AMA in the organic extract. The material responsible for AMA in the crude aqueous extract remains unidentified. No AMA was detected in the intracellular contents of untreated eggs.
未处理的恙螨 Amblyomma hebraeum Koch 卵（蜱螨目：硬蜱科）对革兰氏阴性菌具有抗菌活性（AMA），但对革兰氏阳性菌没有活性；通过溶剂提取去除蜡质的卵则没有 AMA。然而，未分级的卵蜡提取物对革兰氏阳性菌和革兰氏阴性菌均具有 AMA，正如 Arrieta 等人所证明的那样（Exp Appl Acarol 39: 297-313, 2006）。在这项研究中，我们使用多种技术将卵蜡分成不同的馏分，分析它们的成分，并测试它们的 AMA。粗提的水提取物表现出 AMA。然而，尽管通过核磁共振分析在该提取物中鉴定出了 30 多种代谢物，但似乎没有一种代谢物能够解释观察到的 AMA。在粗提的有机提取物中，胆固醇酯是最丰富的脂质，但没有 AMA。脂肪酸（FAs），链长在 C13 和 C26 之间，是下一个最丰富的脂质。经过脂质分级和气相色谱/质谱分析，游离 FAs，尤其是 C16:1 和 C18:2，占有机提取物中大部分 AMA。负责粗提水提取物 AMA 的物质仍未确定。未经处理的卵的细胞内内容物中未检测到 AMA。
