The glutamine antagonist 6-diazo-5-oxo-l-norleucine (DON, 1) has shown robust anticancer efficacy in preclinical and clinical studies, but its development was halted due to marked systemic toxicities. Herein we demonstrate that DON inhibits glutamine metabolism and provides antitumor efficacy in a murine model of glioblastoma, although toxicity was observed. To enhance DON's therapeutic index, we utilized a prodrug strategy to increase its brain delivery and limit systemic exposure. Unexpectedly, simple alkyl ester-based prodrugs were ineffective due to chemical instability cyclizing to form a unique diazo-imine. However, masking both DON's amine and carboxylate functionalities imparted sufficient chemical stability for biological testing. While these dual moiety prodrugs exhibited rapid metabolism in mouse plasma, several provided excellent stability in monkey and human plasma. The most stable compound (5c, methyl-POM-DON-isopropyl-ester) was evaluated in monkeys, where it achieved 10-fold enhanced cerebrospinal fluid to plasma ratio versus DON. This strategy may provide a path to DON utilization in glioblastoma multiforme patients.
- MeSH
- antimetabolity antitumorózní mozkomíšní mok terapeutické užití MeSH
- diazooxonorleucin mozkomíšní mok terapeutické užití MeSH
- glioblastom farmakoterapie metabolismus MeSH
- glutamin metabolismus MeSH
- Haplorrhini MeSH
- lidé MeSH
- myši nahé MeSH
- myši MeSH
- nádory mozku farmakoterapie metabolismus MeSH
- prekurzory léčiv farmakokinetika terapeutické užití MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antimetabolity antitumorózní MeSH
- diazooxonorleucin MeSH
- glutamin MeSH
- prekurzory léčiv MeSH
2-Phosphonomethylpentanedioic acid (1, 2-PMPA) is a potent inhibitor of glutamate carboxypeptidase II which has demonstrated robust neuroprotective efficacy in many neurological disease models. However, 1 is highly polar containing a phosphonate and two carboxylates, severely limiting its oral bioavailability. We strategized to mask the polar groups via a prodrug approach, increasing the likelihood of passive oral absorption. Our initial strategy was to cover the phosphonate with hydrophobic moieties such as pivaloyloxymethyl (POM) and isopropyloxycarbonyloxymethyl (POC) while keeping the α- and γ-carboxylates unsubstituted. This attempt was unsuccessful due to the chemical instability of the bis-POC/POM derivatives. Addition of α,γ-diesters and α-monoesters enhanced chemical stability and provided excellent oral exposure in mice, but these mixed esters were too stable in vivo, resulting in minimal release of 1. By introducing POC groups on both the phosphonate and α-carboxylate, we synthesized Tris-POC-2-PMPA (21b), which afforded excellent release of 1 following oral administration in both mice and dog.
- MeSH
- antigeny povrchové MeSH
- aplikace orální MeSH
- biologická dostupnost MeSH
- glutamátkarboxypeptidasa II antagonisté a inhibitory MeSH
- inhibitory proteas chemie farmakologie MeSH
- jaterní mikrozomy MeSH
- lidé MeSH
- myši MeSH
- neuroprotektivní látky chemická syntéza farmakologie MeSH
- objevování léků MeSH
- prekurzory léčiv chemická syntéza farmakologie MeSH
- psi MeSH
- techniky in vitro MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- psi MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Názvy látek
- antigeny povrchové MeSH
- FOLH1 protein, human MeSH Prohlížeč
- glutamátkarboxypeptidasa II MeSH
- inhibitory proteas MeSH
- neuroprotektivní látky MeSH
- prekurzory léčiv MeSH