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合成了N-巯基乙酰基-VGG(MAVGG)及经葡萄糖和半乳糖偶联的MAVGG(糖肽Glu-MAVGG和Gal-MAVGG),对其进行了99Tcm标记,测定了标记物在正辛醇与水中的分配系数Pow,并观察了3种标记物在荷S180小鼠体内的分布。结果显示,化学合成得到的糖肽经IR、NMR与MS验证与所设计的结构一致9。9Tcm的标记率和放化纯度均大于90%9。9Tcm-Glu-MAVGG,99Tcm-Gal-MAVGG和99Tcm-MAVGG的lgPow分别为-1.974、-2.128和-1.378,其T1/2α分别为24.3、37.1和46.3 min,T1/2β分别为221.5、158.4和198.4 min。注射后3 h99Tcm-Glu-MAVGG、99Tcm-Gal-MAVGG和99Tcm-MAVGG在肿瘤中的摄取率分别为1.46、1.55与0.67,肿瘤与肌肉的放射性摄取比(T/NT)分别为3.74、7.38与3.53。以上结果表明,经糖基修饰后,多肽的脂溶性降低,血液清除速率增大,肿瘤摄取率增高。三种标记物中,99Tcm-Gal-MA-VGG具有较大的血液清除率、较高的肿瘤摄取率与T/NT,提示其有可能作为肿瘤显像剂。
N-mercaptoacetyl -VGG (MAVGG) and MAVGG (glycopeptides Glu-MAVGG and Gal-MAVGG) conjugated with glucose and galactose were synthesized and labeled with 99Tcm. Water partition coefficient Pow, and observed the distribution of three kinds of markers in S180 mice. The results showed that the glycopeptides obtained by chemical synthesis were confirmed by IR, NMR and MS. Consistent with the designed structure, the labeling efficiency and radiochemical purity of 9.9Tcm were all greater than 90% 9.9Tcm-Glu-MAVGG, 99Tcm-Gal-MAVGG and The lgPow of 99Tcm-MAVGG was -1.974, -2.128 and -1.378, respectively, with T1 / 2α of 24.3, 37.1 and 46.3 min, and T1 / 2β of 221.5, 158.4 and 198.4 min, respectively. The uptake rates of 99Tcm-Glu-MAVGG, 99Tcm-Gal-MAVGG and 99Tcm-MAVGG at 3 h after injection were 1.46, 1.55 and 0.67, respectively. The tumor to muscle radioactivity uptake ratios (T / NT) were 3.74 and 7.38 3.53. The above results show that, after glycosylation, the polypeptide liposolubility decreased, the rate of blood clearance increased, increased tumor uptake. Among the three markers, 99Tcm-Gal-MA-VGG has a higher blood clearance rate and a higher tumor uptake rate and T / NT, suggesting that 99Tcm-Gal-MA-VGG may be used as a tumor imaging agent.