Drawing with Iron on a Gel Containing a Supramolecular Siderophore. Issue 51 (4th November 2019)

• Record Type: Journal Article
• Authors: Xiao, Songjun; Paukstelis, Paul J.; Ash, Richard D.; Zavalij, Peter Y.; Davis, Jeffery T.
• Is Part Of: Angewandte Chemie international edition. Volume 58:Issue 51(2019)
• Page Start: 18434
• Page End: 18437
• Publication Date: 2019-11-04
• Subjects: G-quadruplexes -- hydrogels -- hydroxamic acid -- iron -- self-assembly; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201910872
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Guanosine‐5′‐hydroxamic acid (3 ) forms hydrogels when mixed with guanosine (1 ) and KCl. The 5′‐hydroxamic acid (HA) unit is pH‐responsive and also chelates Fe 3+ . When gels are prepared under basic conditions, the 5′‐HA groups are deprotonated and the anionic hydrogel binds cationic thiazole orange (TO), signaled by enhanced fluorescence. The HA nucleoside 3, when immobilized in the G‐quartet gel, acts as a supramolecular siderophore to form red complexes with Fe 3+ . We patterned the hydrogel's surface with FeCl3, by hand and by using a 3D printer. Patterns form instantly, are visible by eye, and can be erased using vitamin C. This hydrogel, combining self‐assembled G‐quartet and siderophore–Fe 3+ motifs, is strong, can be molded into different shapes, and is stable on the bench or under salt water. Abstract : Soft matter, hard shell : pH‐responsive hydrogels that can chelate Fe 3+ were prepared from guanosine‐5′‐hydroxamic acid (HA). At high pH, the hydrogel binds thiazole orange, signaled by enhanced fluorescence. The HA units can also act as a supramolecular siderophore to form red complexes with Fe 3+, which allowed the patterning of the hydrogel surface with FeCl3 .