Models for potential dendritic nitric oxide donors: crystal structures of two 2-nitroanilino precursors and nitric oxide-release behavior of the nitrosated derivatives.
Acta Crystallogr C Struct Chem 2018;
74:1038-1044. [PMID:
30191896 PMCID:
PMC6128391 DOI:
10.1107/s2053229618011737]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 08/20/2018] [Indexed: 11/10/2022] Open
Abstract
Two molecular precursors to dendrimeric materials that could serve as slow and sustained NO-releasing therapeutic agents have been synthesized and characterized. N1,N4-Bis(2-nitrophenyl)butane-1,4-diamine, C16H18N4O4, (I), crystallizes in a lattice with equal populations of two molecules of different conformations, both of which possess inversion symmetry through the central C-C bond. One molecule has exclusively anti conformations along the butyl chain, while the other has a gauche conformation of the substituents on the first C-C bond. N2,N2-Bis[2-(2-nitroanilino)ethyl]-N1-(2-nitrophenyl)ethane-1,2-diamine, C24H27N7O6, (II), crystallizes with one unique molecule in the asymmetric unit. Neighboring pairs of molecules are linked into dimers via N-H...O amine-nitro hydrogen bonds. The dimers are assembled into layers that stack in an A-B-A-B sequence such that the repeat distance in the stacking direction is over 46 Å. Molecular NO-release agents N1,N4-bis(2-nitrophenyl)-N1,N4-dinitrosobutane-1,4-diamine, C16H16N6O6, (III), and N1-(2-nitrophenyl)-N2,N2-bis{2-[(2-nitrophenyl)(nitroso)amino]ethyl}-N1-nitrosoethane-1,2-diamine, C24H24N10O9, (IV), were prepared via treatment of (I) and (II), respectively, with NaNO2 and acetic acid. The release of NO from solid-phase samples of (III) and (IV) suspended in phosphate buffer was monitored spectroscopically over a period of 21 days. Although (IV) released a greater amount of NO, as expected due to it having three NO moieties for every two in (III), the (IV):(III) ratio of the rate and extent of NO release was significantly less than 1.5:1, suggesting that some combination of electronic, chemical, and/or steric factors may be affecting the release process.
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