Peters J H, Nolen H W, Gordon G R, Bradford W W, Bupp J E, Reist E J
Life Sciences Division, SRI International, Menlo Park, CA 94025.
J Chromatogr. 1989 Mar 24;488(2):301-13. doi: 10.1016/s0378-4347(00)82955-2.
Fecapentaene-12 (FP-12) and fecapentaene-14 (FP-14) are genotoxic unsaturated ether lipids produced by colonic bacteria in man. We have developed and applied to feces collections from normal volunteers direct isotopic dilution procedures using tritium-labeled (at C5) FP-12 and FP-14 for measuring these compounds. FPs were recovered from feces by solvent extraction, silica cartridge clean-up, and analytical liquid chromatography. Low levels of FP-12 and FP-14 (less than 0.1 to 2.4 micrograms/g of freeze-dried feces) were observed. Identity of chromatographic peaks was established by co-elution and by ultraviolet absorption spectra obtained via photodiode array scanning. Two unknown peaks were tentatively identified from absorption spectra as closely related compounds with increased (hexane?) or decreased (tetraene?) number of double bonds. Levels of FPs increased after incubation of feces at 37 degrees C for 96 h under anaerobic conditions and pre-FP-12 and pre-FP-14 peaks were observed, which showed identical spectra with authentic FPs. These were interpreted to be isomeric forms of the all-trans-[3H]FPs used for the isotopic dilution analysis. Total FPs (including pre-FP) yielded a range of 0.3-80 micrograms FP-12 and 2.8-44 micrograms FP-14 per g of freeze-dried feces from the study group.
粪五烯 -12（FP -12）和粪五烯 -14（FP -14）是人体结肠细菌产生的具有遗传毒性的不饱和醚脂。我们开发了使用氚标记（在C5位）的FP -12和FP -14的直接同位素稀释程序，并将其应用于正常志愿者的粪便样本，以测量这些化合物。通过溶剂萃取、硅胶柱净化和分析液相色谱从粪便中回收FPs。观察到FP -12和FP -14的含量较低（低于0.1至2.4微克/克冻干粪便）。通过共洗脱和经由光电二极管阵列扫描获得的紫外吸收光谱确定色谱峰的同一性。从吸收光谱中初步鉴定出两个未知峰，它们是双键数量增加（己烷？）或减少（四烯？）的密切相关化合物。在厌氧条件下将粪便于37℃孵育96小时后，FPs的含量增加，并观察到前FP -12和前FP -14峰，其光谱与 authentic FPs相同。这些被解释为用于同位素稀释分析的全反式 -[3H]FPs的异构体形式。研究组每克冻干粪便中总FPs（包括前FP）产生的范围为0.3 - 80微克FP -12和2.8 - 44微克FP -14。
