Synthesis and Characterization of a Novel Liver-Targeted Prodrug of Cytosine-1-β-d-arabinofuranoside Monophosphate for the Treatment of Hepatocellular Carcinoma
摘要:
Cytotoxic nucleosides have proven to be ineffective for the treatment of hepatocellular carcinoma (HCC) due, in part, to their inadequate conversion to their active nucleoside triphosphates (NTP) in the liver tumor and high conversion in other tissues. These characteristics lead to poor efficacy, high toxicity, and a drug class associated with an unacceptable therapeutic index. Cyclic 1-aryl-1,3-propanyl phosphate prodrugs selectively release the monophosphate of a nucleoside (NMP) into CYP3A4-expressing cells, such as hepatocytes, while leaving the prodrug intact in plasma and extrahepatic tissues. This prodrug strategy was applied to the monophosphate of the well-known cytotoxic nucleoside cytosine-1-beta-D-arabinofuranoside (cytarabine, araC). Compound 19S (MB07133), in mice, achieves good liver targeting compared to araC, generating > 19-fold higher cytarabine triphosphate (araCTP) levels in the liver than levels of araC in the plasma and > 12-fold higher araCTP levels in the liver than in the bone marrow, representing a > 120-fold and > 28-fold improvement, respectively, over araC administration.
The Use of Chiral BINAM NHC-Rh(III) Complexes in Enantioselective Hydrosilylation of 3-Oxo-3-arylpropionic Acid Methyl or Ethyl Esters
作者:Qin Xu、Xingxing Gu、Sijia Liu、Qinyu Dou、Min Shi
DOI:10.1021/jo062453d
日期:2007.3.1
Axially chiral BINAM N-heterocyclic carbene (NHC)-Rh(III) complexes were applied in the enantioselective hydrosilylation of 3-oxo-3-arylpropionic acid methyl or ethyl esters. The reduction products 3-hydroxy-3-arylpropionic acid methyl or ethyl esters could be obtained in good yields with good to excellent enantioselectivities under mild conditions.
Cyclometalated iridium complexes are shown to be highly efficient and chemoselectivecatalysts for the transferhydrogenation of a wide range of carbonyl groups with formic acid in water. Examples include α‐substituted ketones (α‐ether, α‐halo, α‐hydroxy, α‐amino, α‐nitrile or α‐ester), α‐keto esters, β‐keto esters and α,β‐unsaturated aldehydes. The reduction was carried out at substrate/catalyst ratios of