380441-58-7Relevant academic research and scientific papers
Complexation-induced unfolding of heterocyclic ureas. Simple foldamers equilibrate with multiply hydrogen-bonded sheetlike structures
Corbin,Zimmerman,Thiessen,Hawryluk,Murray
, p. 10475 - 10488 (2001)
The synthesis and conformational studies of heterocyclic ureas (amides) 1-7 and their concentration-dependent unfolding to form multiply hydrogen-bonded complexes are described. Ureas 1 and 7 were prepared by reacting 2-aminopyridine and aminonaphthyridine 25, respectively, with triphosgene and 4-(dimethylamino)-pyridine (DMAP). Amine 25, in turn, was synthesized by a Knorr condensation of 2,6-diaminopyridine and 4,6-nonanedione. Heterocyclic ureas 3, 4, and 16 were prepared by treating their corresponding amino precursors with butylisocyanate, whereas bisureido naphthyridines 6 and 17 were prepared by heating 2,7-diamino-1,8-naphthyridine (13) with butylisocyanate and 3,4,5-tridodecyloxyphenyl isocyanate, respectively. The hydrogen-bonding modules 2 and 5 were synthesized by reacting 13 and 2-amino-1,8-naphthyridine with valeric anhydride. X-ray crystallographic analyses were performed on ureas 1, 3, 16, and 17, indicating that these ureas are intramolecularly hydrogen-bonded in the solid state. Moreover, detailed 1H NMR solution studies of 1, 3, 4, 6, and 7 indicate that similar folded structures form in chloroform. In addition, naphthyridinylureas 3 and 7 unfold and dimerize by forming four hydrogen bonds at high concentrations, and ureas 1 and 4 unfold in the presence of their hydrogen-bonding complements, amides 2 and 5, to form Complexes with three and four hydrogen bonds, respectively. Likewise, the mixing of 6 and 7 results in a mutual unfolding and formation of a robust, sheetlike, sextuply hydrogen-bonded complex. The hydrogen-bonding modules described are useful building blocks for self-assembly, and the unfolding process represents a very primitive mimicry of the helix-to-sheet transition shown by peptides and potentially shown by the hypothetical naphthyridinylurea 8.
Interfacial bioconjugation on emulsion droplet for biosensors
Zhang, Qifan,Scigliano, Anita,Biver, Tarita,Pucci, Andrea,Swager, Timothy M.
, p. 5307 - 5313 (2018/05/05)
Interfacial bioconjugation methods are developed for intact liquid emulsion droplets. Complex emulsion droplets having internal hydrocarbon and fluorocarbon immiscible structured phases maintain a dynamic interface for controlled interfacial reactivity. The internal morphological change after binding to biomolecules is readily visualized and detected by light transmission, which provides a platform for the formation of inexpensive and portable bio-sensing assays for enzymes, antibodies, nucleic acids and carbohydrates.
