Mourier P, Brun A
Rhône Poulenc Rorer, Centre de Recherche de Vitry Alfortville, Vitry sur Seine, France.
J Chromatogr B Biomed Sci Appl. 1997 Dec 19;704(1-2):197-205. doi: 10.1016/s0378-4347(97)00477-5.
A major metabolic pathway of spiramycins in pig liver is described. This biochemical reaction involves L-cysteine--a common amino acid present in most animal tissues--which reacts with the aldehyde function of the antibiotic forming a thiazolidine ring. This transformation of spiramycin derivatives drastically increased their polarity. A preliminary HPLC method enabling the quantitation of each metabolite in the range 0.5 microg/g of liver tissue is proposed. Spiramycin S is used as an internal standard while extraction procedures take into account the physico-chemical properties of the thiazolidine moieties. By comparison, previous HPLC methods underestimated the exact amount of antibiotic residues because these metabolites were not extracted from the studied tissues.
描述了螺旋霉素在猪肝中的主要代谢途径。这种生化反应涉及L-半胱氨酸（一种存在于大多数动物组织中的常见氨基酸），它与抗生素的醛基反应形成噻唑烷环。螺旋霉素衍生物的这种转化极大地增加了它们的极性。提出了一种初步的高效液相色谱法，能够定量肝组织中0.5微克/克范围内的每种代谢物。以螺旋霉素S作为内标，同时提取程序考虑了噻唑烷部分的物理化学性质。相比之下，以前的高效液相色谱法低估了抗生素残留的确切量，因为这些代谢物未从研究组织中提取出来。
