7-Acylamino-3H-1,2-benzoxathiepine 2,2-dioxides as new isoform-selective carbonic anhydrase IX and XII inhibitors.

A series of 3H-1,2-benzoxathiepine 2,2-dioxides incorporating 7-acylamino moieties were obtained by an original procedure starting from 5-nitrosalicylaldehyde, which was treated with propenylsulfonyl chloride followed by Wittig reaction of the bis-olefin intermediate. The new derivatives, belonging to the homosulfocoumarin chemotype, were assayed as inhibitors of the zinc metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1). Four pharmacologically relevant human (h) isoforms were investigated, the cytosolic hCA I and II and the transmembrane, tumour-associated hCA IX and XII. No relevant inhibition of hCA I and II was observed, whereas some of the new derivatives were effective, low nanomolar hCA IX/XII inhibitors, making them of interest for investigations in situations in which the activity of these isoforms is overexpressed, such as hypoxic tumours, arthritis or cerebral ischaemia.

Indium(III) chloride catalyzed highly diastereoselective domino synthesis of indenodithiepines and indenodithiocines.

An atom-economical diastereoselective synthesis of indenodithiepines and indenodithiocines has been developed via a domino reaction of propargylic alcohols and dithioacetals in the presence of InCl3 as a catalyst. A range of functionalized dithiepines and dithiocines, fused to the indene ring, were obtained in good to excellent yields under mild conditions.

Discovery of a novel class of AKT pleckstrin homology domain inhibitors.

AKT, a phospholipid-binding serine/threonine kinase, is a key component of the phosphoinositide 3-kinase cell survival signaling pathway that is aberrantly activated in many human cancers. Many attempts have been made to inhibit AKT; however, selectivity remains to be achieved. We have developed a novel strategy to inhibit AKT by targeting the pleckstrin homology (PH) domain. Using in silico library screening and interactive molecular docking, we have identified a novel class of non-lipid-based compounds that bind selectively to the PH domain of AKT, with "in silico" calculated K(D) values ranging from 0.8 to 3.0 micromol/L. In order to determine the selectivity of these compounds for AKT, we used surface plasmon resonance to measure the binding characteristics of the compounds to the PH domains of AKT1, insulin receptor substrate-1, and 3-phosphoinositide-dependent protein kinase 1. There was excellent correlation between predicted in silico and measured in vitro K(D)s for binding to the PH domain of AKT, which were in the range 0.4 to 3.6 micromol/L. Some of the compounds exhibited PH domain-binding selectivity for AKT compared with insulin receptor substrate-1 and 3-phosphoinositide-dependent protein kinase 1. The compounds also inhibited AKT in cells, induced apoptosis, and inhibited cancer cell proliferation. In vivo, the lead compound failed to achieve the blood concentrations required to inhibit AKT in cells, most likely due to rapid metabolism and elimination, and did not show antitumor activity. These results show that these compounds are the first small molecules selectively targeting the PH domain of AKT.

Push-pull bithienyl chromophore with an unusual transverse path of conjugation.

The synthesis, structure, and electronic properties of a novel cross-conjugated 10H-bisthienodithiocin-10-dicyanoethylene are reported. The X-ray single-crystal structure of the compound reveals a nonplanar conformation. The FT-IR and FT-Raman spectra of the compound show a great resemblance, which is a spectroscopic observation common to many push-pull systems. The UV-vis spectrum in CHCl3 displays a strong absorption at 370 nm accompanied by a shoulder at 430 nm so that the optical gap is 2.88 eV. On the other hand, the electrochemical gap amounts to 2.38 V. DFT and TDDFT quantum chemical calculations, at the B3LYP/6-31G** level, have been also performed to (i) determine the minimum-energy molecular structure, (ii) gain knowledge about the equilibrium atomic charges distribution, the topologies, and absolute energies of the frontier molecular orbitals around the gap and about the molecular vibrations which give rise to the most outstanding Raman bands experimentally evidenced, and (iii) to analyze the nature of the vertical one-electron excitations associated to the strongest UV-vis absorptions.

Platinum (II) complexes with stereochemically-defined thiepane dioxide diamine ligands as anticancer drugs.

Platinum (II) complexes are accredited with biological activities. New complexes with thiepane dioxide diamine as ligands, characterized by defined stereochemical features, a flexible 7-membered thiepane moiety and by C2 symmetry, were prepared. The complexes, related to the diamino cyclohexane family of platinum complexes, were soluble in dimethyl sulfoxide with the solvent substituting one chloride ion. These positively-charged complexes were tested against a human carcinoma cell line A431 and its cisplatin-resistant counterpart A431/Pt and were found to show: i) capability in bypassing cisplatin-resistance; ii) cytotoxicity comparable to that of oxaliplatin; iii) lower activity than cisplatin. In both cells lines, [PtCl(DACH)(DMSO)]+ was more cytotoxic than oxaliplatin. The best activity was shown by the platinum complexes with ligands which presented C2 symmetry.

Direct synthesis of fused 1,2,3,4,5-pentathiepins.

Treatment of nucleophilic heterocycles like pyrroles and thiophenes, and their tetrahydro derivatives, with S2Cl2 and DABCO in chloroform at room temperature provides a simple one-pot synthesis of fused mono and bispentathiepins. N-Methylpyrrole and its 2-chloro and 2,5-dichloro derivatives and N-methylpyrrolidine all give the same dichloropentathiepin 1a. N-Ethyl, isopropyl and tert-butylpyrrolidine behave similarly; the isopropylpyrrolidine also gives the bispentathiepin 6which undergoes an intriguing rearrangement to the symmetrical monopentathiepin 1c. N-Methyl and ethyl indole give either 2,3-dichloro derivatives 8 or the pentathiepinoindoles 9, depending upon the reaction conditions. Thiophene and tetrahydrothiophene give the pentathiepin 10. X-Ray crystal structures are provided for the pentathiepins 1a and 1d, and possible reaction pathways are suggested for the extensive cascade reactions reported.

Synthesis and antiinflammatory activity of cis- and trans-6,6a,7,8,9,10,10a,11-octahydro-11-oxodibenzo[b,e]thiepinacetic and -oxepinacetic acids.

A series of cis- and trans-6,6a,7,8,9,10,10a,11-octahydro-11- oxodibenzo[b,e]thiepinacetic acids (6-9) and -oxepinacetic acids (10-13) were prepared and their antiinflammatory activity was examined in the rat carrageenan hind paw edema test. The antiinflammatory activity of these compounds depended on their stereochemical features (C6a, C10a, and C2'). The 6a,10a-trans compounds exhibited considerable antiinflammatory activity, whereas the 6a,10a-cis compounds were inactive. Among the trans compounds, 6,6a,7,8,9,10,10a,11-octahydro-11-oxodibenzo[b,e]thiepin-3-p ropionic acid (9a) and its oxepin analogue (13a) showed an antiinflammatory activity superior to that of indomethacin. The phenethyl ester (25) of 9a showed potent antiinflammatory activity, and its safety index (UD50/ED50) was over 14 times higher than that of indomethacin. The phenethyl ester (25) is the most favorable compound with high antiinflammatory activity and little ulcerogenicity.