Picosecond structural relaxation of abietic acid based amine end capped para-phenylenevinylene trimers in solution.

The synthesis and photophysical properties of six new abietic acid based amine end-capped p-phenylenevinylene trimers (AECPV3) in their lowest excited singlet states are presented. The AECPV3 compounds show a large red-shift of both the absorption (25-30 nm) and emission (37-42 nm) maxima with respect to those of the corresponding trimers. Picosecond time-resolved fluorescence data reveal the presence of a fast conformational relaxation process (40-62 ps) of the initially excited compounds, leading to more planar conformers.

Activity of dehydroabietic acid derivatives against wood contaminant fungi.

The antifungal activity of 10 dehydroabietic acid derivatives with different configuration in A and B rings (cis/trans A/B junction) and different substituents and/or functionalities was evaluated in bioassays in vitro and in situ (pine wood blocks). The test compounds dissolved in acetone were assayed at several concentrations w/w (test compound/culture medium) against the fungi. The Relative Inhibition (RI) was determined by measuring the radial growth of colonies of the fungi treated with the test compounds by comparison with those of control cultures; the results are expressed as EC(50).

Antimicrobial activity of resin acid derivatives.

The wide potential of resin acids as bioactive agents gave rise to a growing effort in the search for new applications of the natural forms and their derivatives. In some of these compounds, the antimicrobial activity is associated to the presence in the molecules of functional groups such as the hydroxyl, aldehyde, and ketone or to their cis or trans configurations. The resin acid family covers a spectrum of antimicrobial activities against several microorganisms, from bacteria to fungi, in which the mode of action was studied by electron microscopy.

Resonance energy transfer in new fullerene-coumarin diads.

The fluorescence properties of new [60] and [70] fullerene-coumarin diads are studied. These diads were synthesized by covalently linking a coumarin dye to a fullerene (C60 or C70) by a cyclopropanation reaction. The absorption and fluorescence spectra, quantum yields and lifetimes of the diads are reported.

Antioxidant activity of a catechol derived from abietic acid.

The demand for novel effective antioxidant-based drugs has led to the synthesis and evaluation of the antioxidant potential in several molecules derived from natural compounds. In this work the in vitro antioxidant activity of an abietic acid-derived catechol (methyl 11,12-dihydroxyabietate-8,11,13-trien-18-oate, MDTO) was evaluated. This substance, possessing important biological properties, is similar to carnosic acid, a natural antioxidant from rosemary or sage leaves.

Synthesis and antiviral evaluation of benzimidazoles, quinoxalines and indoles from dehydroabietic acid.

Several heterocycles, such as benzimidazoles, quinoxalines and indoles incorporated into a hydrophenanthrene and naphthalene skeleton, were synthesised from two useful ortho-bromonitro precursors derived from dehydroabietic acid: methyl 12-bromo-13-nitro-deisopropyldehydroabietate and methyl 12-bromo-13,14-dinitro-deisopropyldehydroabietate. The new heterocycles were evaluated for their activity in vitro against several RNA and DNA viruses.

Synthesis and catalytic activity of a chiral periodic mesoporous organosilica (ChiMO).

A chiral vanadyl salen complex having two peripheral trimethoxysilyl groups has been used to obtain a chiral periodic mesoporous organosilica having MCM-41 periodicity and the two Si-CH2 groups anchored on the framework; this solid induces 30% enantioselectivity in the cyanosilylation of benzaldehyde.

Structural effects on the bioactivity of dehydroabietic acid derivatives.

The synthesis and the evaluation of the antimicrobial activity against a filamentous fungus, yeasts and bacteria of 15 hydrophenanthrene compounds derived from dehydroabietic acid, bearing different functional groups and different stereochemistry of the A/B ring junction are disclosed. The results obtained showed how their activity is dependent of the functionality at C-18, which can be increased by deisopropylation or introduction of other groups into the molecule. While the filamentous fungus tested is sensitive to almost all of the compounds under study, the aldehyde function showed to be of major importance to the inhibition of yeast.