Francesca Montanari

Layered zirconium phosphate and phosphonate as heterogeneous catalyst in the preparation of pyrroles

Abstract Pyrroles may be prepared by condensation of alkyl and aryl amines and 1,4-diketones (Paal–Knorr reaction) under potassium exchanged layered Zirconium phosphate and zirconium sulfophenyl phosphonate catalyst in solvent free conditions.

Preparation and characterisation of hydrotalcite/carboxyadamantane intercalation compounds as fillers of polymeric nanocomposites

Mono- and di-carboxyadamantane derivatives were intercalated via ion-exchange procedure onto hydrotalcites with formula [Zn0.65Al0.35(OH)2](A)0.35·nH2O where A is Cl– or ClO4–. Furthermore, an intercalation compound of [Mg0.65Al0.35(OH)2](CO3)0.175·0.5H2O containing the mono-carboxyadamantane has been obtained by using the “memory effect” of the hydrotalcite. The obtained materials were characterised for their composition, thermal behaviour, X-ray diffraction patterns, FT-IR absorption spectra and BET specific surface areas. Structural and chemical considerations indicated that mono-carboxylic guests are accommodated in the interlayer region as an ordered bifilm of anions while the di-carboxylic guests give rise to a bifilm of partially interdigitated anions. The presence of hydrophobic anions makes the interlayer region of the hydrotalcites compatible with hydrophobic polymers, such as medium density polyethylene. As an example, the preparation and characterisation of a nanocomposite of polyethylene filled with MgAl hydrotalcite/carboxyadamantane are reported. The nanocomposite, containing 5% w/w of inorganic residue, was prepared by melt compounding and was characterised with X-ray powder diffraction and thermogravimetric techniques. The obtained results showed that the presence of the organically modified hydrotalcite lamellae shields in part the polymer from thermal oxidation, increasing the degradation temperature by about 160 °C and producing a char residue greater than pure polyethylene.

Anti-inflammatory, antioxidant and antifungal furanosesquiterpenoids isolated from Commiphora erythraea (Ehrenb.) Engl. resin

The topical anti-inflammatory, free radical scavenging and antifungal activities of essential oils and extracts of Commiphora erythraea (Ehrenb.) Engl. resin were investigated. The hexane extract significantly inhibited oedema when applied topically in Croton oil-induced ear oedema assay in mice. The same extract showed antioxidant activity in DPPH radical scavenging assay. A bioguided separation of the hexane extract led to the isolation of furanosesquiterpenoids 1 and 2 that showed a weak antifungal activity, while compounds 3-5 resulted to be antioxidant (EC(50) 4.28, 2.56 and 1.08 mg/mL, respectively) and anti-inflammatory (30, 26 and 32% oedema reduction, respectively).