Gemcitabine, 2’-deoxy-2’,2’-difluorocytidine, is currently prescribed against a number of cancers. Here we report a linear synthesis of gemcitabine with a high-yielding direct conversion of 3,5-di-O-benzoyl-2-deoxy-2,2-difluororibose into the corresponding glycosyl urea as the key step, followed by conventional conversion to the cytosine base via the uracil derivative. The process proceeded with modest anomeric selectivity.
Hyaluronan (HA) is a ubiquitous, major component of the pericellular matrix and is necessary for various physiological processes. It plays a very important role in biological barriers. We previously reported that 4-methylumbelliferone (MU) inhibits HA synthesis and pericellular HA matrix formation in cultured human skin fibroblasts, Streptococcus equi FM100, and B16F10 melanoma cells. We hypothesized that MU-mediated inhibition of HA synthesis and pericellular HA matrix formation would increase the efficacy of anticancer drugs. We have already demonstrated in vitro, using a sandwich binding protein assay and a particle exclusion assay, that MU inhibits HA synthesis and formation of the pericellular HA matrix, respectively, in human KP1-NL pancreatic cancer cells. AlamarBlue assay revealed that the anticancer effect of gemcitabine in KP1-NL cells was increased by pretreatment with MU. In vivo simultaneous administration of MU and gemcitabine to tumor-bearing mice with severe combined immunodeficiency disease (SCID) decreased the size of the primary and metastatic tumors more than did gemcitabine alone. These data strongly suggest that a combination of MU and gemcitabine is effective against human pancreatic cancer cells. MU may have potential as a chemosensitizer and may provide us with a new anticancer strategy.
Answers from specialists on synthesis of gemcitabine
In pancreatic cancer, gemcitabine is administered as the sole agent, but in non-small cell lung cancer and bladder cancer, it is given in combination with cisplatin. In ovarian cancer it is given before carboplatin, and in breast cancer after paclitaxel. Gemcitabine is a prodrug; it undergoes intracellular phosphorylation to its active diphosphate and triphosphate form, which inhibits DNA synthesis leading to apoptosis. 3,4