G. C. Stocco

Bio: G. C. Stocco is an academic researcher from University of Palermo. The author has contributed to research in topics: Carboxylate & Nuclear magnetic resonance spectroscopy. The author has an hindex of 13, co-authored 44 publications receiving 463 citations.

Organometallic complexes with biological molecules, IV. Di‐ and tri‐organotin(IV) amoxicillin derivatives: Solid‐state and solution‐phase spectroscopic investigations

Abstract: Novel di- and tri-organotin(IV) derivatives of amoxicillin (amoxicillin - =Amox - =6-[D(-)-β-amino-p-hydroxyphenylacetamido] penicillinate) have been prepared. The isolated compounds showed stoichiometries of the type R 2 SnClAmox.2H 2 O, R 3 SnClAmoxNa.2H 2 O and R 2 SnAmox 2 .2H 2 O (R=Me, Bu, Ph). The infrared spectra suggest that Amox − , in both R 2 SnClAmox.2H 2 O and R 2 SnAmox 2 .2H 2 O, behaves as a monoanionic bidentate ligand, coordinating the tin(IV) atom through the ester-type carboxylate, as well as through the lactamic carbonyl. In R 3 SnClAmoxNa.2H 2 O, Amox - coordinates the organotin(IV) moieties through the lactamic carbonyl. In all of the compounds, water molecules are not involved in coordinaton, as inferred by thermogravimetric (TG) investigation. In both R 2 SnClAmox.2H 2 O and R 3 SnClAmoxNa.2H 2 O, trigonal bipyramidal configrations are proposed in the solid state, on the basis of infrared (IR) and Mossbauer spectroscopy, while in R 2 SnAmox 2 .2H 2 O the coordination geometry at tin could be a skew-trapezoidal bipyramid, with two chelating amoxicillin residues which act as bidentate ligands in the trapezoidal plane, and with the organic groups in axial positions. The C-Sn-C angles calculated from the experimental Mossbauer quadrupole splitting predict a bent skeleton in all the R 2 SnAmox 2 2H 2 O derivatives. 1 H and 13 C NMR measurements showed that both R 2 SnClAmox.2H o and R 2 SnAmox.2H 2 O are stable in DMOS-d 6 solutions, maintaining their solid-state configuration, while R 3 SnClAmoxNa.2H 2 O dissociates. Coordination hypotheses have been checked through the correlation between the Mossbauer isomer shift (δ) and the partial atomic charge on tin atoms (Q Sn ) performed, for all the new organotin(IV) compounds, on the basis of an equalization procedure applied to idealized trigonal bipyramidal structures for R 2 SnClAmox.2H 2 O and R 3 SnClAmoxNa.2H 2 O and octahedral trans-R 2 for R 2 SnAmox 2 .2H 2 O

Gold derivatives for the treatment of cancer.

Abstract: The cytotoxicity and anti-tumour activity screening trials for both gold(I) and gold(III) are summarised. Gold(I) thiolates employed clinically in the treatment of rheumatoid arthritis display some potency against various tumours but a greater potential is found in their analogues. In particular, analogues featuring a linear P-Au-S arrangement in which the thiolate ligand is derived from a biologically active thiol display high potency. Further, targeting mitochondria with tetrahedrally coordinated gold(I) phosphine compounds with enhanced hydrophilicity is a research direction with exciting potential. Recent research has shown that gold(III) compounds featuring square-planar geometries, as found in cisplatin, may target DNA and may provide new anti-tumour agents.

Complexes of metals other than platinum as antitumour agents.

Abstract: The earliest reports on the therapeutic use of metals or metal-containing compounds in cancer and leukemia date from the sixteenth and nineteenth centuries. They were forgotten until the 1960s, when the anti-tumour activity of the inorganic complex cis-diammine-dichloroplatinum(II) (cisplatin) was discovered. This led to the development of other types of non-organic cytostatic drugs. Cisplatin has developed into one of the most frequently used and most effective cytostatic drugs for the treatment of solid carcinomas. Numerous other metal compounds containing platinum, other platinum metals, and even non-platinum metals were then shown to be effective against tumours in man and experimental tumours in animals. These compounds comprise main-group metallic compounds of gallium, germanium, tin, and bismuth, early-transition metal complexes of titanium, vanadium, niobium, molybdenum, and rhenium, and late-transition metal complexes of ruthenium, rhodium, iridium, platinum, copper, and gold. Several platnium complexes and four non-platnium-metal antitumour agents have so far entered early clinical trials. Gallium trinitrate and spirogermanium have already passed phase II clinical studies and have shown limited cytostatic activity against certain human carcinomas and lymphomas. The two early-transition metal complexes budotitane and titanocene dichloride have just reached the end of phase I clinical trials and have been found to have an unusual pattern of organ toxicity in man. Titanocene dichloride will soon enter phase II clinical studies.