The Synthesis of a c(RGDyK) Targeted SN38 Prodrug with an Indolequinone Structure for Bioreductive Drug Release
摘要:
Preparation of a novel c(RGDyK) targeted SN38 prodrug Incorporating an indolequinone structure for bioreductively triggered drug release is described. This design yields a prodrug that targets surface molecules on tumor cells (alpha(v)beta(3) integrins) and releases drug under bioreductive conditions. There are three moieties in the prodrug design, namely a therapeutic drug SN38, an indolequinone structure serving as a drug releasing trigger, and an alpha(v)beta(3) integrin targeting peptide c(RGDyK). Preliminary studies showed that SN38 is released In the presence of a bioreductive enzyme (DT-diaphorase).
Human plasma-mediated hypoxic activation of indolequinone-based naloxone pro-drugs
作者:Baohua Huang、Shengzhuang Tang、Ankur Desai、Xue-min Cheng、Alina Kotlyar、Abraham Van Der Spek、Thommey P. Thomas、James R. Baker
DOI:10.1016/j.bmcl.2009.07.061
日期:2009.9
Hypoxia is known to occur in tissues in response to narcotic analgesic therapy using as a result of respiratory depression. The aim of this study was to synthesize a narcotic antagonist pro-drug that can be activated by tissue hypoxia to prevent the damage associated with respiratory depression. We synthesized three different pro-drugs of the narcotic antagonist naloxone utilizing indolequinone as the hypoxia-sensitive moiety. The indolequinone structure in the pro-drugs was designed to have an open reactive point at the N-1 position offering the possibility of further conjugation with macromolecules to modify the bio-availability of these pro-drugs in vivo. A pro-drug (labeled 1) where naloxone and the indolequinone moiety were linked through a carbonate bond was rapidly hydrolyzed in phosphate buffered saline. However, two additional pro-drugs (labeled 2 and 3) having carbamate linkers were stable in phosphate buffered saline for 24 h. The reductive release of naloxone from the pro-drugs was achieved in the presence of the bio-reductive enzyme DT-Diaphorase, with about 80% release occurring from the two pro-drugs in 24 h. More than 99% of naloxone was released from pro-drug 2 in 30% human plasma, however the release only occurred under hypoxic conditions. This system provides a potential means for feedback control to counter critical respiratory depression induced by narcotic analgesics. (C) 2009 Elsevier Ltd. All rights reserved.