Urinary metabolites of 1-(3-Mercapto-2-D-methyl-1-oxopropyl)-L-proline(SQ-14225),a new antihypertensive agent, in rats and dogs.
作者:TOSHIHIKO IKEDA、TORU KOMAI、KENJI KAWAI、HIDEYO SHINDO
DOI:10.1248/cpb.29.1416
日期:——
The in vivo metabolism of 1-(3-mercapto-2-D-methyl-1-oxopropyl)-L-proline (SQ-14225) was investigated in rats and dogs. SQ-14225 labeled with 14C at the mercaptoacyl moiety was administered orally and the metabolites in the 24 hr urine were identified by comparing their Rf values with those of authentic samples. Unchanged SQ-14225 was trapped via its sulfhydryl group by the previous addition of N-ethylmaleimide to prevent air oxidation. In both animal species, most of the radioactivity was excreted as unchanged SQ-14225 and its disulfide (SQ-14551). A significant amount of the urinary radioactivity was accounted for by mixed disulfides, among which the disulfide with L-cysteine (Cys-SQ-14225) was predominant. N-Acetyl-Cys-SQ-14225 was also detected as a minor component, but the amount of the mixed disulfide with glutathione (GS-SQ-14225) was negligible. S-Methyl-SQ-14225 and its sulfoxide were also recognized. As judged from the negligible incorporation of radioactivity into collagen after administration of SQ-14225-3H labeled at the proline moiety, the metabolic cleavage of the amide bond in SQ-14225 was not significant.
在老鼠和狗身上研究了1-(3-巯基-2-D-甲基-1-氧代丙基)-L-脯氨酸(SQ-14225)的体内代谢。SQ-14225在巯基酰基部分标记了14C,经口服给药,通过比较其Rf值与真实样品的Rf值来确定24小时尿液中的代谢物。通过预先添加N-乙基马来酰亚胺来防止空气氧化,SQ-14225的巯基部分被捕获,未发生改变。在这两种动物中,大部分放射性物质以未改变的SQ-14225及其二硫键(SQ-14551)的形式排出体外。尿液中的放射性物质大部分来自混合二硫键,其中以L-半胱氨酸二硫键(Cys-SQ-14225)为主。N-乙酰基-Cys-SQ-14225也被检测为次要成分,但与谷胱甘肽(GS-SQ-14225)的混合二硫键的含量可以忽略不计。S-甲基-SQ-14225及其亚砜也被识别。从给药SQ-14225-3H标记的脯氨酸部分后放射性物质在胶原蛋白中的