|
1
|
Gao RD, Hin N, Prchalová E, Pal A, Lam J, Rais R, Slusher BS, Tsukamoto T. Model studies towards prodrugs of the glutamine antagonist 6-diazo-5-oxo-l-norleucine (DON) containing a diazo precursor. Bioorg Med Chem Lett 2021; 50:128321. [PMID: 34400301 DOI: 10.1016/j.bmcl.2021.128321] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 07/22/2021] [Accepted: 08/08/2021] [Indexed: 11/16/2022]
Abstract
Two distinct diazo precursors, imidazotetrazine and nitrous amide, were explored as promoieties in designing prodrugs of 6-diazo-5-oxo-l-norleucine (DON), a glutamine antagonist. As a model for an imidazotetrazine-based prodrug, we synthesized (S)-2-acetamido-6-(8-carbamoyl-4-oxoimidazo[5,1-d][1,2,3,5]tetrazin-3(4H)-yl)-5-oxohexanoic acid (4) containing the entire scaffold of temozolomide, a precursor of the DNA-methylating agent clinically approved for the treatment of glioblastoma multiforme. For a nitrous amide-based prodrug, we synthesized 2-acetamido-6-(((benzyloxy)carbonyl)(nitroso)amino)-5-oxohexanoic acid (5) containing a N-nitrosocarbamate group, which can be converted to a diazo moiety via a mechanism similar to that of streptozotocin, a clinically approved diazomethane-releasing drug containing an N-nitrosourea group. Preliminary characterization confirmed formation of N-acetyl DON (6), also known as duazomycin A, from compound 4 in a pH-dependent manner while compound 5 did not exhibit sufficient stability to allow further characterization. Taken together, our model studies suggest that further improvements are needed to translate this prodrug approach into glutamine antagonist-based therapy.
Collapse
Affiliation(s)
- Run-Duo Gao
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA; Johns Hopkins Drug Discovery, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Niyada Hin
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Eva Prchalová
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA; Johns Hopkins Drug Discovery, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Arindom Pal
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA; Johns Hopkins Drug Discovery, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Jenny Lam
- Johns Hopkins Drug Discovery, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Rana Rais
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA; Johns Hopkins Drug Discovery, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Barbara S Slusher
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA; Johns Hopkins Drug Discovery, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Takashi Tsukamoto
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA; Johns Hopkins Drug Discovery, Johns Hopkins University, Baltimore, MD 21205, USA.
| |
Collapse
|
|
2
|
Kaufman ER. Isolation and characterization of a mutant Chinese hamster cell line resistant to the glutamine analog 6-diazo-5-oxo-L-norleucine. SOMATIC CELL AND MOLECULAR GENETICS 1985; 11:1-10. [PMID: 3856328 DOI: 10.1007/bf01534729] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A mutant cell line, called don801, was isolated from a wild-type population of V79.5 Chinese hamster cells by its ability to grow in the presence of the glutamine analog 6-diazo-5-oxo-L-norleucine (DON), which is toxic for V79.5 cells. The don801 cells were found not to be cross-resistant to another glutamine analog, O-diazoacetyl-L-serine (azaserine, AS). It was shown that guanine but neither hypoxanthine nor adenine protected V79.5 cells from the toxic effects of DON, while hypoxanthine and adenine, but not guanine protected them against AS toxicity. Exposure of wild-type cells to DON was shown to result in a specific reduction of intracellular GTP pools, while in the mutant cells there was no effect on GTP levels. These results strongly suggested that DON was specifically inhibiting guanylate synthetase (GMP synthetase;xanthosine-5'-phosphate: L-glutamine amidoligase, EC 6.3.5.2) in V79.5 cells and that the enzyme in don801 cells was resistant to inhibition. In vitro assays of GMP synthetase activities from V79.5 and don801 cells confirmed this hypothesis. The mutant phenotype was also found to be dominant in intraspecific cell hybrids.
Collapse
|
|
15
|
Bennett L, Vail MH, Chumley S, Montgomery JA. Activity of adenos1ne analogs against a cell culture, line resistant to 2-fluoroadenine. Biochem Pharmacol 1966. [DOI: 10.1016/0006-2952(66)90079-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|