The Dual-Stereocontrol Mechanism: Heteroselective Polymerization of rac-Lactide and Syndioselective Polymerization of meso-Lactide by Chiral Aluminum Salan Catalysts.

We describe alkoxo-aluminum catalysts of chiral bipyrrolidine-based salan ligands that follow the dual-stereocontrol mechanism wherein a given combination of stereogeneities at the metal site and the proximal center of the last inserted lactidyl ("match") is active towards lactide having a proximal stereogenic center of the opposite configuration, while the diastereomeric combination of stereogeneities ("mismatch") is inactive towards any lactide. Polymerization of rac-LA by the enantiomerically pure catalysts was sluggish and gave stereoirregular poly(lactic acid) (PLA) because selective insertion to a match diastereomer gives a mismatch diastereomer. The racemic catalysts showed higher activity and led to highly heterotactic PLA following polymeryl exchange between two mismatched catalyst enantiomers.

Identification of Lead Compounds as Inhibitors of STAT3: Design, Synthesis and Bioactivity.

STAT3 belongs to the signal transducers and activators of transcription (STAT) family. It has been demonstrated that STAT3 is constitutively activated in many tumors, playing a role in carcinogenesis and tumor progression. For this reason, it has being considered a potential target for cancer therapy.

Different 6-Aryl-Fulvenes Exert Anti-proliferative effects on Cancer Cells.

Fulvenes represent a class of molecules very interesting under a chemical point of view because are easily accessible starting materials and are still poorly characterized for their biological activities, with the exception of acylfulvene and irofulvenes which have been reported to exert cytotoxic properties. Here, we describe the synthesis and characterization of several aryl-fulvenes together with their effects on cancer cell growth by MTT method. The cytotoxic potential was investigated on a panel of tumor cell lines such as breast MCF7 and SkBr3, endometrial Ishikawa, prostate LnCaP and lung A549, in comparison with the cis-diamminedichloroplatinum(II) (cisplatin) which is largely used for the treatment of different types of cancer.

New titanocene derivatives with high antiproliferative activity against breast cancer cells.

The synthesis and characterization of some new titanocene-complexes, having a ethenyl-phenoxide or a benzyl group as substituents of the cyclopentadienyl rings, are reported. The synthesized compounds have been evaluated for their cytotoxic potential against two human breast cancer cell lines, that is: MCF7 and SkBr3. Most of these compounds have shown significant cytotoxic effects, compared to cisplatin, in MTT-based cell tests.

Synthesis, characterization and cytotoxic activity on breast cancer cells of new half-titanocene derivatives.

A series of novel titanocene-complexes has been prepared and evaluated for their growth regulatory effects in MCF7 and SkBr3 breast cancer cells. The capability of some of these compound to elicit relevant repressive effects on cancer cell growth could be taken into account towards novel pharmacological approaches in cancer therapy.

Synthesis and biological evaluation of new N-alkylcarbazole derivatives as STAT3 inhibitors: preliminary study.

The signalling pathway of Janus tyrosine Kinases-Signal Transducers and Activators of Transcription (JAK-STAT) is activated by a number of cytokines, hormones (GH, erythropoietin and prolactin), and growth factors. JAK-STAT signalling is involved in regulation of cell proliferation, differentiation and apoptosis. These activities are due to different members of JAK-STAT family consisting of: JAK1, JAK2, JAK3, Tyk2 and STAT1, STAT2, STAT3, STAT4, STAT5a, STAT5b, STAT6.