Design, synthesis and stimuli responsive gelation of novel stigmasterol–amino acid conjugates

Svobodová, Hana; Nonappa, Nonappa; Wimmer, Zdeněk; Kolehmainen, Erkki

doi:10.1016/j.jcis.2011.05.084

Cited by 39 publications

(24 citation statements)

References 44 publications

(73 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The advantages of phytosteroids result from its biodegradability, the ability to affect numerous biological processes through membranes, to bind to specific hormone receptors and to be modified by synthetic methods [32-34]. …”

Section: Discussionmentioning

confidence: 99%

Estrogenic and mutagenic activities of Crotalaria pallida measured by recombinant yeast assay and Ames test

Boldrin

Resende

Höhne

et al. 2013

BMC Complement Altern Med

View full text Add to dashboard Cite

BackgroundCrotalaria pallida Ailton is a plant belonging to the Fabaceae family, popularly known as “rattle or rattlesnake” and used in traditional medicine to treat swelling of the joints and as a vermifuge. Previous pharmacological studies have also reported anti-inflammatory, antimicrobial and antifungal activities. Nevertheless, scientific information regarding this species is scarce, and there are no reports related to its possible estrogenic and mutagenic effects. Thus, the purpose of the present study was to investigate the estrogenic potential of C. pallida leaves by means of the Recombinant Yeast Assay (RYA), seeking an alternative for estrogen replacement therapy during menopause; and to reflect on the safe use of natural products to assess the mutagenic activity of the crude extract from C. pallida leaves, the dichloromethane fraction and stigmasterol by means of the Ames test.MethodsThe recombinant yeast assay with the strain BY4741 of Saccharomyces cerevisiae, was performed with the ethanolic extract, dichloromethane fraction and stigmasterol isolated from the leaves of C. pallida. Mutagenic activity was evaluated by the Salmonella/microsome assay (Ames test), using the Salmonella typhimurium tester strains TA100, TA98, TA97 and TA102, with (+S9) and without (-S9) metabolization, by the preincubation method.ResultsAll samples showed estrogenic activity, mainly stigmasterol. The ethanolic extract from C. pallida leaves showed mutagenic activity in the TA98 strain (-S9), whereas dichloromethane fraction and stigmasterol were found devoid of activity.ConclusionConsidering the excellent estrogenic activity performed by stigmasterol in the RYA associated with the absence of mutagenic activity when evaluated by the Ames test, stigmasterol becomes a strong candidate to be used in hormone replacement therapy during menopause.

show abstract

Section: Discussionmentioning

confidence: 99%

Estrogenic and mutagenic activities of Crotalaria pallida measured by recombinant yeast assay and Ames test

Boldrin

Resende

Höhne

et al. 2013

BMC Complement Altern Med

View full text Add to dashboard Cite

show abstract

“…In recent years, physical gelation of organic solvents by LMOGs has become one of the hot areas in the soft matter research due to their scientific values and many potential applications in the biomedical field, including tissue engineering, controlled drug release, medical implants, and so on [9-14]. The gels based on LMOGs are usually considered as supramolecular gels, in which the gelator molecules self-assemble into three-dimensional networks in which the solvent is trapped via various non-covalent interactions, such as hydrogen bonding, π-π stacking, van der Waals interaction, dipole-dipole interaction, coordination, solvophobic interaction, and host-guest interaction [15-20]. Such organogels have some advantages over polymer gels: the molecular structure of the gelator is defined, and the gel process is usually reversible.…”

Section: Introductionmentioning

confidence: 99%

Regulation of substituent groups on morphologies and self-assembly of organogels based on some azobenzene imide derivatives

et al. 2013

View full text Add to dashboard Cite

In this paper, new azobenzene imide derivatives with different substituent groups were designed and synthesized. Their gelation behaviors in 21 solvents were tested as novel low-molecular-mass organic gelators. It was shown that the alkyl substituent chains and headgroups of azobenzene residues in gelators played a crucial role in the gelation behavior of all compounds in various organic solvents. More alkyl chains in molecular skeletons in present gelators are favorable for the gelation of organic solvents. Scanning electron microscopy and atomic force microscopy observations revealed that the gelator molecules self-assemble into different aggregates, from wrinkle, lamella, and belt to fiber with the change of solvents. Spectral studies indicated that there existed different H-bond formations between amide groups and conformations of methyl chains. The present work may give some insight to the design and character of new organogelators and soft materials with special molecular structures.

show abstract

“…Thermal behavior of PMBiCm gel was investigated by using the "tubetesting method" to measure the transition temperature (T GS ) from gel to solution. [17][18][19][20] We chose PMBiC18 as a representative. The T GS values depend on the concentration of gelator.…”

Section: Thermal Property and Structure Of Polymer Organogelmentioning

confidence: 99%

“…Ultraviolet spectroscopy analysis was adopted to characterize the driving force for gelation. [21][22][23][24] The UV-Vis absorption spectra of PMBiCm (m = 14,16,18) in dilute solutions and in gel phase were shown in PMBiC16/n-heptane were the same as those in PMBiC18. The UVvisible absorption spectra indicated that the length of the alkoxy tail chain has no effect on the driving force of gel formed by PMBiCm in n-heptane.…”

Section: Mechanism Of Polymer Organogelmentioning

confidence: 99%

See 1 more Smart Citation

Organic gels prepared from side‐chain liquid crystalline polymers without the spacer

Chen

Yuan

et al. 2017

Polymers for Advanced Techs

View full text Add to dashboard Cite

A series of side-chain liquid crystal polymers (SCLCPs) without the spacer, named poly[ω-(4′-nalkyl oxybiphenyl-4-oxy)methacrylate (PMBiCm, m = 1,2,4,6,8,10,12,14,16,and 18), have been synthesized. The novel polymer organogels were prepared by introducing PMBiCm into common organic solvents. Solubility and gel properties of polymer organogelators differ widely according to the nature of the solvents. In aromatic solvents, PMBiCm completely dissolved in solvent due to good compatibility between biphenyl mesogen group and aromatic solvents.Poly[ω-(4′-n-alkyl oxybiphenyl-4-oxy)methacrylate were still insoluble in polar solvents such as acetone, ethanol, DMF, ethylene glycol, and n-butanol. This behavior resulted from mismatch of solubility parameter between PMBiCm and solvent. Considering the factors of solvent, we have systematically studied 3 organic solvents with different polarities (butyl acetate, n-butyl amine, and n-heptane). It is found that the length of the alkoxy tail chain of the SCLCPs has significant influence on gelability and gel thermal stability. In further studies discussed by UV-Vis spectroscopy, the results revealed that the π-π stacking interaction of the biphenyl mesogens might be the key factor for guiding the self-assembly processes and the polymer gel formation.This work is useful to comprehending physical mechanism of polymer organogels. Meanwhile, those expand SCLCPs to a wide range of applications. KEYWORDS alkoxy tail chain length, organogel, side-chain liquid crystalline polymer

show abstract

Design, synthesis and stimuli responsive gelation of novel stigmasterol–amino acid conjugates

Cited by 39 publications

References 44 publications

Estrogenic and mutagenic activities of Crotalaria pallida measured by recombinant yeast assay and Ames test

Estrogenic and mutagenic activities of Crotalaria pallida measured by recombinant yeast assay and Ames test

Regulation of substituent groups on morphologies and self-assembly of organogels based on some azobenzene imide derivatives

Organic gels prepared from side‐chain liquid crystalline polymers without the spacer

Contact Info

Product

Resources

About