Synthesis of an estradiol glucuronide derivative and investigation of its radiopharmaceutical potential

Bioavailability of 99mTc-paclitaxel-glucuronide (99mTc-PAC-G)

An antitumor agent paclitaxel (PAC) has been proved to be efficient in the treatment of breast and ovarian cancer. Glucuronic acid-derived paclitaxel compound [paclitaxel-glucuronide (PAC-G)] was enzymatically synthesized using microsome preparate separated from rat livers. The biodistribution mechanism of PAC-G in healthy female Albino Wistar rats has been investigated. The expected structure is confirmed according to LC/MS results, and the possible attachment is to C2-hydroxyl group. PAC-G was labeled with 99mTc and the radiochemical yield of radiolabeled compound (99mTc-PAC-G) was 98.0±02.74 (n=9). The range of the breast/blood and breast/muscle ratios is approximately between 3 and 35 in 240ߙmin. All these experimental studies indicate that 99mTc-PAC-G may potentially be used in breast tissue as an imaging agent.

Enzymatic synthesis of uracil glucuronide, labeling with 125/131I, and in vitro evaluation on adenocarcinoma cells

Human UDP-glucuronosyltransferases (UGTs) are a family of membrane-bound enzymes of the endoplasmic reticulum. They catalyze the glucuronidation of various endogenous and exogenous compounds, converting them into more polar glucuronides. In this study, uracil glucuronide was enzymatically synthesized using a UGT-rich microsome preparate, which was separated from Hutu-80 cells. Two different glucuronide derivatives were obtained, with a total reaction yield of 22.95% +/- 2.4% (n = 4). The glucuronide ligands were defined as uracil-n-glucuronide (UNG) and uracil-o-glucuronide (UOG). These were then analyzed by high-performance liquid chromatography-mass spectrometry and labeled with I-125 and I-131, separately. The radiolabeled (125/131)I-UNG and (125/131)I-UOG presented good incorporation ratios for Hutu-80, Caco-2, Detroit 562, and ACBRI 519 cells. The incorporation ratios of (125/131)I-UOG were higher than those of (125/131)I-UNG and of other labeled components for all cell types, and were also statistically significant compared to the values of (125/131)I-UNG for primary human intestinal epithelial cells (ACBRI 519) and human intestinal adenocarcinoma cells. Cell incorporation rates of n-glucuronides and o-glucuronides were higher compared to uracil, with o-glucuronides being more selective. The results suggest that both I-125- and I-131-labeled glucuronides can be used in imaging and therapy, and further research should be done in preclinical stages.