Claudia Averbuj

In vivo damage to chorioallantoic membrane blood vessels by porphycene-induced photodynamic therapy☆

Photodynamic therapy (PDT) was performed in the chick embryo chorioallantoic membrane (CAM) for the purpose of quantitative evaluation of several porphycenes as potential photosensitizers. Porphycenes are structural isomers of porphine possessing lower symmetry of the macrocycle and are characterized by 10-fold higher absorption at the therapeutic wavelengths for PDT (lambda > 630 nm). PDT-induced damage to CAM blood vessels included vasoconstriction and blanching as was monitored during irradiation and videotaped. Image analysis techniques enabled us to follow PDT-induced constriction of vessel diameter (to 50%), reduction of blood perfusion (to 40% lower optical density) and shrinkage of implanted tumours (to 10% of their original area). The observed PDT efficacy of functionalized porphycenes is positively correlated with the number of polar substituents.

Addition–β-elimination: a new method for the preparation of organometallic compounds

Abstract The addition–β-elimination mechanism is a powerful method for the production of organometallic derivatives. Using this new method, we report the first transformation of enol ethers into the corresponding vinyl zirconium derivatives. Moreover, the in situ formation of Ti(II) and subsequent reaction with halogeno alkynes offers a new route for the preparation of functionalized alkynyl titanium and trismetalated olefin derivatives.

Synthesis and reactivity of polymetallated olefins and functionalized metalloalkynes

Abstract The first straightforward synthesis of tris-metallated olefins and functionalized metallated alkynes is reported via the use of low-valent titanium derivatives.