Synthesis, binding and self-assembly properties of a well-defined pillar[5]arene end functionalised polydimethylacrylamide

International audienceThe synthesis, binding and self-assembly properties of a well-defined pillar[5]arene end-functionalised poly(dimethylacrylamide)(MePilla-PDMAC) are reported. In order to synthesise MePilla-PDMAC, a new trithiocarbonate type RAFT agent MePilla-CTA was developed incorporting a partially methylated pillar[5]-arene moiety. Kinetic studies clearly indicated the propensity of MePilla-CTA to control the polymeri-sation of DMAC. Interestingly, as PDMAC type chains display good solubilty both in organic and aqueous media, MePilla-PDMAC was able of specifically bind electron deficient guest molecules at the α-chain-end both in chloroform and water. Complex formation was found to be reversible upon addition of chloride anions or heating in organic and aqueous media, respectively. Furthermore, cryo-TEM, VT-NMR (1 H) and VT-DLS investigations also indicated the ability of MePilla-PDMAC to self-assemble into micelle-like aggregates in water showing reversible recognition properties

Secondary metabolites, evaluation of the DPPH Free-Radical Scavenging Effect by electron spin resonance and antibacterial activity of the endemic species Stachys circinata

The genus Stachys (Lamiaceae), widely known in folk medicine, contains about 200–300 species in the world [1]. In the Flora of Algeria, this genus is represented by 14 species of which four are endemic [2]. In continuation of our work on Stachys genus [3, 4, 5, 6], we report here the chemical constituents of the n-butanolic and dichloromethane extracts of the aerial parts of the Algerian species Stachys circinata L′Her. which has not been the subject of any previous study. Fifteen known compounds have been identified. We also report here the antibacterial and antioxidant activity of the n-butanolic extract by using disk diffusion and eletron spin resonance methods (ESR).The authors are grateful to the ATRSS and DGRSDT-MESRS (Algeria) for financial support.Peer Reviewe

Components and antioxidant, anti-inflammatory, anti-ulcer and antinociceptive activities of the endemic species Stachys mialhesi de Noé

One diterpenoid, horminone 1, two flavonoid glycosides, apigenin-7-O-(6″-E-p-coumaroyl)-β-d-glucopyranoside 2, isoscutellarein-7-O-(6″′-O-acetyl-β-d-allopyranosyl-(1 → 2)-β-d-glucopyranoside) 3, were isolated from n-butanolic extract of the aerial parts of Stachys mialhesi de Noé (BESM). Their structures were established on the basis of physical and spectroscopic analysis, and by comparison with the literature data. Antioxidant activity of this extract and the compound 3 was evaluated by the use of the Electron Spin Resonance method in order to visualize the inhibition of the DPPH radical. In this study, we also investigated the anti-inflammatory, anti-ulcer and antinociceptive activities of the BESM in experimental animal models at different doses. Our results showed that the BESM showed a strongest antioxidant activity. It decreased acetic acid induced writhing times; inhibited carrageenan-induced hind paw edema. All of these results suggested that the BESM possesses significant antioxidant, antinociceptive and anti-inflammatory activities

Components and antioxidant, anti-inflammatory, anti-ulcer and antinociceptive activities of the endemic species Stachys mialhesi de Noé

© 2011 Production and hosting by Elsevier B.V. on behalf of King Saud UniversityOne diterpenoid, horminone 1, two flavonoid glycosides, apigenin-7-O-(6″-E-p-coumaroyl)-β-d-glucopyranoside 2, isoscutellarein-7-O-(6″′-O-acetyl-β-d-allopyranosyl-(1 → 2)-β-d-glucopyranoside) 3, were isolated from n-butanolic extract of the aerial parts of Stachys mialhesi de Noé (BESM). Their structures were established on the basis of physical and spectroscopic analysis, and by comparison with the literature data. Antioxidant activity of this extract and the compound 3 was evaluated by the use of the Electron Spin Resonance method in order to visualize the inhibition of the DPPH radical. In this study, we also investigated the anti-inflammatory, anti-ulcer and antinociceptive activities of the BESM in experimental animal models at different doses. Our results showed that the BESM showed a strongest antioxidant activity. It decreased acetic acid induced writhing times; inhibited carrageenan-induced hind paw edema. All of these results suggested that the BESM possesses significant antioxidant, antinociceptive and anti-inflammatory activities.The authors are grateful to the ANDRS and DG-RSDT/MESRS for the financial support.Peer Reviewe