Low Molecular Weight Gelators for Organic Fluids: Gelation Using a Family of Cyclo(dipeptide)s

Hanabusa, Kenji; Matsumoto, Munehisa; Kimura, Mutsumi; Kakehi, Akikazu; Shirai, Hirofusa

doi:10.1006/jcis.1999.6672

Cited by 162 publications

(131 citation statements)

References 63 publications

Supporting

Mentioning

127

Contrasting

Order By: Relevance

“…Supramolecular gel is formed by entrapping solvents in a three-dimensional network structure created by entanglement of noncovalent interactions such as hydrogen bonds, van der Waals forces, p-p interaction, crystal/liquid bridges and electrostatic interaction. [15][16][17] Thus, the same mechanism could be operative in the case of CAM tablets. Specifically, in order to clarify the involvement of crystal/liquid bridges with a threedimensional network, we mixed bulk CAM with pH 1.0 hydrochloric acid because crystal/liquid bridges are generally formed with the surface of tablets prepared by high compaction conditions.…”

Section: Stabilization Mechanism Of Cam Tablets Under Low Ph Conditionmentioning

confidence: 94%

“…Supramolecular gelators have attracted special attention not only in academic fields but also in industrial fields such as cosmetics, health care, textile and foods. [15][16][17] In the pharmaceutical field particularly, novel gelators are expected to be applicable to the development of novel drug delivery system formulations such as ointments, transdermal therapeutic systems and sustained release formulations. 13,14,18) More detailed investigation into the mechanisms of gel formation to measure the Fourier transform infrared spectroscopy or Raman spectroscopy can be expected to facilitate the development of novel drug delivery system formulations containing CAM.…”

Section: Stabilization Mechanism Of Cam Tablets Under Low Ph Conditionmentioning

confidence: 99%

See 1 more Smart Citation

Stabilization Mechanism of Clarithromycin Tablets under Gastric pH Conditions

Fujiki

Iwao

Kobayashi

et al. 2011

CHEMICAL & PHARMACEUTICAL BULLETIN

View full text Add to dashboard Cite

Section: Stabilization Mechanism Of Cam Tablets Under Low Ph Conditionmentioning

confidence: 94%

Section: Stabilization Mechanism Of Cam Tablets Under Low Ph Conditionmentioning

confidence: 99%

Stabilization Mechanism of Clarithromycin Tablets under Gastric pH Conditions

Fujiki

Iwao

Kobayashi

et al. 2011

CHEMICAL & PHARMACEUTICAL BULLETIN

View full text Add to dashboard Cite

“…27, [35][36][37][38] For the thermodynamic nature of the gel state, two different scenarios have been proposed. In the first scenario, the gel state (GS) is a kinetically trapped metastable state, which avoids the transformation of the system to the crystals state (CS).…”

mentioning

confidence: 99%

“…It has been argued that "thermodynamically stable gels" represent deep local minima surrounded by high activation barriers which may make it impossible to access the global minimum, the CS. [36][37][39][40][41][42] Simple models have previously been used to describe gelation and crystallization behavior of proteins. Dixit et al developed a theoretical model to rationalize the gel-crystal equilibrium for proteins.…”

mentioning

confidence: 99%

Supramolecular Fibers in Gels Can Be at Thermodynamic Equilibrium: A Simple Packing Model Reveals Preferential Fibril Formation versus Crystallization

et al. 2016

View full text Add to dashboard Cite

Low Molecular Weight Gelators are able to form nanostructures, typically fibers, which entangle to form gel-phase materials. These materials have wide-ranging applications in biomedicine and nanotechnology. While it is known that supramolecular gels often represent metastable structures due to the restricted molecular dynamics in the gel state, the thermodynamic nature of the nanofibrous structure is not well understood. Clearly, 3D extended structures will be able to form more interactions than 1D structures. However, self-assembling molecules are typically amphiphilic, thus giving rise to a combination of solvophobic and solvophilic moieties where a level of solvent exposure at the nanostructure surface is favorable. In this study, we introduce a simple packing model, based on prisms with faces of different nature (solvophobic and solvophilic) and variable interaction parameters, to represent amphiphile self-assembly. This model demonstrates that by tuning shape and 'self' or 'solvent' interaction parameters either the 1D fiber or 3D crystal may represent the thermodynamic minimum. The model depends on parameters that relate to features of experimentally known systems: the number of faces exposed to the solvent or buried in the fiber; the overall shape of the prism; and the free energy penalties associated with the interactions can be adjusted to match their chemical nature. The model is applied to describe the pH dependent gelation/precipitation of well-known gelator Fmoc-FF. We conclude that, despite the fact that most experimentally produced gels probably represent metastable states, one-dimensional fibers can represent thermodynamic equilibrium. This conclusion has critical implications for the theoretical treatment of gels.A wide range of small molecules which are able to selfassemble into supramolecular gels have been investigated over the years as promising new materials with potential applications in nanotechnology and biomedicine.

show abstract

“…30 Cyclo(dipeptide)s comprising identical amino acid components exhibit good crystallinity but no gelation ability. In contrast, cyclo(dipeptide)s comprising a combination of two amino acids with different characteristics, such as a neutral amino acid (L-valine, L-leucine, and L-phenylalanine) and an acidic amino acid derivative (L-glutamic acid γ-ester or Laspartic acid β-ester), do act as gelators.…”

Section: Cyclo(dipeptide) Gelators and Thixotropymentioning

confidence: 99%

Physical Gelation by Low-Molecular-Weight Compounds and Development of Gelators

Hanabusa¹,

Suzuki²

2015

Bulletin of the Chemical Society of Japan

Self Cite

View full text Add to dashboard Cite

We discuss low-molecular-weight compounds, which undergo physical gelation, as gelators. There is a close relationship between crystallization and gelation with respect to the driving forces. Both crystallization and gelation are driven by noncovalent interactions such as hydrogen bonding, van der Waals forces, electrostatic interactions, and ππ interactions. Typical gelators, which include amino acid derivatives, trans-1,2-diaminocyclohexane derivatives, and cyclic(dipeptide)s, are discussed. A concept of "gelation-driving segment" has been proposed. Hydrogelators, functional gelators, and polymer-type gelators are developed by using gelation-driving segments.

show abstract

Low Molecular Weight Gelators for Organic Fluids: Gelation Using a Family of Cyclo(dipeptide)s

Cited by 162 publications

References 63 publications

Stabilization Mechanism of Clarithromycin Tablets under Gastric pH Conditions

Stabilization Mechanism of Clarithromycin Tablets under Gastric pH Conditions

Supramolecular Fibers in Gels Can Be at Thermodynamic Equilibrium: A Simple Packing Model Reveals Preferential Fibril Formation versus Crystallization

Physical Gelation by Low-Molecular-Weight Compounds and Development of Gelators

Contact Info

Product

Resources

About