Biomedical subjects
Publications and source records attributed to T Da Ros.
We report the synthesis of three novel, versatile fullerene intermediates whose main feature is the presence of an amino end group. Simple condensation reactions of these intermediates under standard conditions produce new derivatives that are useful for applications in materials science and medicinal chemistry.
[see structure]. A fullerene derivative containing a free amino group has been condensed with N-Fmoc-L-glutamic acid alpha-tert-butyl ester to give a C60-functionalized amino acid. The carboxylic end of this amino acid has been deprotected in acidic conditions, and the resulting acid has been used for solid-phase peptide synthesis. The final peptide, cleaved from the resin, was very soluble in water solutions and showed antimicrobial activity against two representative bacteria.
We report the isolation and characterization of bisadducts of fulleropyrrolidine derivatives. The compounds were characterized by means of a variety of spectroscopic techniques, including ES-MS, UV-vis, (1)H NMR, and (13)C NMR. The whole series of bisadducts was separated for the first time in the case of the bispyrrolidines, and the determination of their structure was obtained by NMR spectroscopy with the help of HMQC and HMBC techniques.
Photoprocesses associated with the complexation of a pyridine-functionalized C60 fullerene derivative to ruthenium- and zinc-tetraphenylporphyrins (tpp) have been studied by time-resolved optical and transient EPR spectroscopies. It has been found that upon irradiation in toluene, a highly efficient triplet-triplet energy transfer governs the deactivation of the photoexcited [Ru(tpp)], while electron transfer (ET) from the porphyrin to the fullerene prevails in polar solvents. Complexation of [Zn(tpp)] by the fullerene derivative is reversible and, following excitation of the [Zn(tpp)], gives rise to very efficient charge separation. In fluid polar solvents such as THF and benzonitrile, radical-ion pairs (RPs) are generated both by intramolecular ET inside the complex and by intermolecular ET in the uncomplexed form. Charge-separated states have lifetimes of about 10 micros in THF and several hundred of microseconds in benzonitrile at room temperature.
Recent advances in the chemistry of fullerene have allowed the synthesis of many classes of novel fullerene derivatives. Among these classes, fullerene-based amino acids and peptides are particularly interesting, both for structural studies and biological applications. In this review, we will discuss our own achievements in this rapidly growing field. In particular, the application of fulleroproline (Fpr) amino acids and peptides to medicinal chemistry and material science will be highlighted.
This review describes recent advances in the development of DNA-photocleavage agents. Major mechanisms of photosensitized DNA photocleavage are presented and the most popular categories of compounds are considered, which include metal complexes and many organic functional derivatives. DNA-targeted conjugates of photosensitizers are also described and discussed.
[structure] Two water-soluble fullerene derivatives have been computer-designed and synthesized. They may exhibit interesting anti-HIV activity owing to the presence of two ammonium groups strategically located on the spheroid surface.
Positively charged fullerene derivatives, moderately soluble in water:DMSO 9:1, have been tested using three strains of Mycobacterium spp. Some compounds inhibit the growth of Mycobacterium tuberculosis, a human clinical isolate, particularly virulent and resistant, at doses as low as 5 microg/mL.