- Rapidly Recoverable Thixotropic Hydrogels from the Racemate of Chiral OFm Monosubstituted Cyclo(Glu-Glu) Derivatives
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Both chiral OFm monosubstituted cyclo(l-Glu-l-Glu) and cyclo(d-Glu-d-Glu) display a robust gelation ability in a variety of organic solvents and water. In contrast to an individual enantiomer, their racemate can form rapidly recoverable thixotropic hydrogels with a remarkably shorter thixotropic recovery time. This unexpected thixotropic behavior is induced by the random arrangement of d- and l-enantiomers in the cell units, leading to the formation of pseudoracemate , noncrystalline self-assemblies in the resulting 3D fibrous network.
- Wang, Lu,Jin, Xin,Ye, Lin,Zhang, Ai-Ying,Bezuidenhout, Deon,Feng, Zeng-Guo
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- Template-assisted photodimerization of: N -unprotected uracil derivatives: Selective formation of the cis - Syn photodimer
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A UV light-induced photodimerization of 5-[(imidazol-1-yl)methyl]uracil using glutamate- and aspartate-derived cyclic dipeptides (2,5-diketopiperazines-DKPs) as templates was investigated. Dual salt bridge formation between imidazole side chains and carboxylic acids resulted in the preorganization of the uracil monomers and the preferential formation of the cis-syn photodimer.
- Weckenmann,Maichle-M?ssmer,Nachtsheim
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- Bio-based epoxy resin precursor containing cyclic amide structure, and preparation method and application thereof
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The invention discloses a bio-based epoxy resin precursor containing a cyclic amide structure, and also discloses a preparation method and application of the bio-based epoxy resin precursor containingthe cyclic amide structure. The preparation method comp
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Paragraph 0042-0043
(2019/03/10)
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- Five- and six-membered ring opening of pyroglutamic diketopiperazine
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A variety of ring-opening reactions of pyroglutamic diketopiperazine at both the five-membered and six-membered rings is described. Mild, basic conditions facilitate nucleophilic attack by amines at the diketopiperazine carbonyls giving pyroglutamides in excellent yield. Reaction with nucleophiles under acidic conditions give bis-glutamate derivatives of 2,5-diketopiperazine (DKP). These reactions provide simple, two-step sequences to pyroglutamides and symmetrical diketopiperazines from commercial pyroglutamic acid with control of product dictated by reaction conditions, catalyst, and nucleophile.
- Parrish, Dennis A.,Mathias, Lon J.
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p. 1820 - 1826
(2007/10/03)
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- Macromolecular self-assembly of diketopiperazine tetrapeptides
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Basic solutions of tetrapeptides derived from L-aspartic acid diketopiperazines are shown to form microcapsules when acidified to pH 2.4. An initial structure-activity study clearly demonstrates that a very delicate balance exists between the tetrapeptide
- Bergeron, Raymond J.,Phanstiel IV, Otto,Yao, Guo Wei,Milstein, Sam,Weimar, William R.
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p. 8479 - 8484
(2007/10/02)
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