1,721,139 research outputs found
Medicinal Chemistry with Fullerenes and Fullerene Derivatives
No full textThe study of the biological applications of fullerenes has
attracted increasing attention despite the low solubility of the
carbon spheres in physiological media. The organic functionalisation
of fullerenes has helped solubilisation by covalent
attachment of hydrophilic appendages. Therefore, recently
synthesised fullerene derivatives reach satisfactory concentrations
in water. However, the tendency of the fullerenes to form
clusters is enhanced in polar media, where better solubilisation
can be achieved by means of multiple functionalisation or using
micellar systems. Once homogeneously dissolved, the fullerenes
and fullerene derivatives exhibit an interesting range of
biological activities, especially promising in the field of photodynamic
therapy, HIV, neuroprotection and apoptosis
Isolation and Characterization of Nine Tris-Adducts of N-Methyl-Fulleropyrrolidine Derivatives
No full textWe report the isolation and characterization of bis- and tris-adducts of fulleropyrrolidine derivatives.
First, all eight N-methyl regioisomers with two addends on the C60 sphere have been isolated;
second, C60 was used as starting material for the synthesis of tris-adducts, and the products formed
in detectable quantities have been isolated and characterized. Third, the same compounds were
obtained by introducing the third addend on each previously isolated bis-derivative: this approach
facilitated the assignment of the relative geometry through chromatographic comparison of the
diverse reaction mixtures. Finally, the obtained tris-adducts have been characterized by means of
ES-MS, UV-vis, 1H NMR, as well as comparison with UV spectra and elution order of Bingel and
Diels-Alder tris-adducts described in the literature
Biological Applications of Fullerenes
No full textThe appealing structure of fullerene, its electrochemical and photophysical properties have attracted the interest of the scientists to study the applications of C60 and its derivatives in different fields, including the biological and biomedical domains. Up to now, no clinical uses have been achieved but, despite this, there is still room for successfully applications of fullerenes in medicine and biology
Additions of Azomethine Ylides to Fullerene C60 Assisted by a Removable Anchor
No full textThe addition of nitrile oxides to [60]fullerene, leading to isoxazolinofullerenes, can be reversed
using reducing agents such as Mo(CO)6 or DIBALH. Thus, this reaction can be used, in principle,
for protection/deprotection of [60]fullerene or for solubilization purposes. The tether-controlled
tandem addition of nitrile oxides and azomethine ylides provides mainly cis-1 patterns. The
determination of the structure of bisadducts was obtained by NMR spectroscopy with the help of
HMQC, HMBC, and NOEDS techniques. The isoxazoline moiety could be removed using Mo(CO)6
leaving a fulleropyrrolidine derivativ
Twenty Years of Promises: Fullerene in Medicinal Chemistry
No full textMany biological activities have been envisioned for fullerenes and some
of them seem to be very promising. The lack of solubility in biologically friendly
environments is the major obstacle in the development of this field. The possibility
of multiple fuctionalization can be exploited to get more soluble compounds but,
up to now, only a few polyadducts, presenting perfectly defined geometry, can be
selectively prepared avoiding long purification processes.
The toxicity of this third allotropic form of carbon is an aspect related to application
in medicine and biology, while the concern about the environmental impact is due
to the industrial production of fullerenes. Many studies are dedicated to both
aspects and, so far, it is not possible to have a definitive answer although the current
findings allow some optimistic vision.
In this chapter the main biological applications of fullerene and fullerene derivatives
will be reviewed, with special attention to the most recent advances in this field.
Antiviral and antibacterial activity, enzymatic inhibition, and DNA photocleavage are
some aspects considered herein, together with the use of these nanostructures as
possible vectors for drug and gene delivery. The most promising applications include
the use of endohedral fullerenes, filled by gadolinium in magnetic resonance imaging
(MRI) and the antioxidant capacity exploitation of some tris-adducts and fullerols
A topologically new ruthenium porphyrin-fullerene donor acceptor ensemble
No full textA novel ruthenium porphyrin complex bearing an axially coordinated fullerene ligand (RuP-C60), that is, a fulleropyrrolidine that bears a pyridine moiety, was developed as an artificial reaction center mimic. Generally, the new donor acceptor dyad gives rise to rapid intramolecular deactivation of the ruthenium porphyrin triplet excited state, which evolves from instantaneous intersystem crossing. The product of the ruthenium porphyrin excited-state deactivation depends on the solvent polarity. While in non-polar solvents a transduction of triplet excited energy predominates, in medium and strongly polar media, charge-separation leads to the formation of RuP*+ C60*-
Fullerene-based Amino Acids and Peptides
No full textRecent 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
Fullerene derivatives: an actractive tool for biological application
No full textThe fullerene family, and especially C60, has very appealing photo-, electro-chemical and physical properties, which can be
exploited in many and different biological fields. Fullerene is able to fit inside the hydrophobic cavity of HIV proteases, inhibiting
the access of substrates to the catalytic site of the enzyme. It can be used as radical scavenger; in fact some water-soluble derivatives
are able to reduce ROS concentrations. At the same time, if exposed to light, fullerene can produce singlet oxygen in high quantum
yields. This action, together with the direct electron transfer from excited state of fullerene and DNA bases, can be used to cleave
DNA. In this review we report the most recent aspects of fullerene biological applications
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