Inhibition of histone deacetylase inhibitors (HDACi) hold great promise in cancer therapy because of their demonstrated ability to arrest proliferation of nearly all transformed cell types. Of the several structurally distinct small molecule HDACi reported, macrocyclic depsipeptides have the most complex recognition cap-group moieties and present an excellent opportunity for the modulation of the biological activities of HDACi. Unfortunately, the structure-activity relationship (SAR) studies for this class of compounds have been impaired largely because most macrocyclic HDACi known to date comprise complex peptide macrocycles. In addition to retaining the pharmacologically disadvantaged peptidyl backbone, they offer only limited opportunity for side chain modifications. Here, we report the discovery of a new class of macrocyclic HDAG based on the macrolide antibiotics skeletons. SAR studies revealed that these compounds displayed both linker-length and macrolide-type dependent HDAC inhibition activities with IC50 in the low nanomolar range. In addition, these non-peptide macrocyclic HDACi are more selective against HDACs 1 and 2 relative to HDAC 8, another class I HDAC isoform, and hence have subclass HDAC isoform selectivity.
A Novel Potent Nicotinamide Phosphoribosyltransferase Inhibitor Synthesized via Click Chemistry
摘要:
The inhibition of NAD synthesis or salvage pathways has been proposed as a novel target for antitumoral drugs. Two molecules with this mechanism of action are at present undergoing clinical trials. In searching for similar novel molecules, we exploited copper-catalyzed [3 + 2] cycloaddition between azides and alkynes (click chemistry) to synthesize 185 novel analogues. The most promising compound displays an IC50 for cytotoxicity in vitro of 3.8 +/- 0.3 nM and an IC50 for NAD depletion of 3.0 +/- 0.4 nM. Herein, we strengthen previous data suggesting that this class of compounds induces autophagic cell death. In addition to characterizing this compound and providing a rationale via molecular docking, we reinforce the excellent potential of click chemistry for rapidly generating structure-activity relationships and for drug screening.