Design, synthesis, biological evaluation and structure-activity relationship of sophoridine derivatives bearing pyrrole or indole scaffold as potential antitumor agents

Taking sophoridine as a lead compound, 58 sophoridine derivatives were designed, synthesized and evaluated for their antiproliferative activity in the HepG2 cancer cell line. Among the 58 compounds, 33 compounds showed potent antiproliferative activity with IC₅₀ less than 10 μM. Compound 5w showed the most potent anti-proliferative activity in the HepG2 cancer cell line. Thus, we further extended our characterization of the antiproliferative activity of 5w in six cancer cell lines (HepG2, SMMC-7721, Hela, CNE1, CNE2 and MCF7). The representative compound 5w displayed robust anti-proliferative activities in all the tested cell lines with IC₅₀ values in range of 0.93-1.89 μM which were much lower than that of sophoridine. Here, we report the structure-activity relationships (SAR) in a sophoridine series of compounds, which indicated that introduction of N-benzyl indole group on the 14-carbon atom of sophoridine can significantly enhance the antiproliferative activity. By molecular docking and enzymatic assay, compound 5w was found to be able to inhibit the activity of DNA Topo I. Furthermore, apoptosis assay displayed that compound 5w could significantly induce the apoptosis of HepG2 cells in a dose-dependent manner by activating caspase-3, increasing expression of cleaved caspase-3 and reducing the ratio of Bcl-2/Bax. The in vivo antitumor assay demonstrated that 5w suppressed the growth of HepG2 xenografts in nude mice without any obvious side effects.

PKC in Regenerative Therapy: New Insights for Old Targets

Effective therapies for chronic or non-healing wounds are still lacking. These tissue insults often result in severe clinical complications (i.e., infections and/or amputation) and sometimes lead to patient death. Accordingly, several research groups have focused their efforts in finding innovative and powerful therapeutic strategies to overcome these issues. On the basis of these considerations, the comprehension of the molecular cascades behind these pathological conditions could allow the identification of molecules against chronic wounds. In this context, the regulation of the Protein Kinase C (PKC) cascade has gained relevance in the prevention and/or reparation of tissue damages. This class of phosphorylating enzymes has already been considered for different physiological and pathological pathways and modulation of such enzymes may be useful in reparative processes. Herein, the recent developments in this field will be disclosed, highlighting the pivotal role of PKC α and δ in regenerative medicine. Moreover, an overview of well-established PKC ligands, acting via the modulation of these isoenzymes, will be deeply investigated. This study is aimed at re-evaluating widely known PKC modulators, currently utilized for treating other diseases, as fruitful molecules in wound-healing.

The role of chirality in a set of key intermediates of pharmaceutical interest, 3-aryl-substituted-γ-butyrolactones, evidenced by chiral HPLC separation and by chiroptical spectroscopies

The enantiomers of four chiral 3-aryl-substituted-γ-butyrolactones, key intermediates for the preparation of compounds of pharmaceutical interest, were successfully isolated by enantioselective chromatography, employing the Chiralpak AD-H chiral stationary phase. For all compounds the same elution order was observed, as monitored by a full set of chiroptical methods that we employed, namely ORD (optical rotatory dispersion), ECD (electronic circular dichroism, or CD in the UV range), and VCD (vibrational circular dichroism, or CD in the IR range). By density functional theory (DFT) calculations we were able to determine that the first eluted enantiomer has (S) absolute configuration in all four cases. We were able to justify the elution order by molecular docking calculations for all four enantiomeric pairs and suitable modeling of the stationary and mobile phases of the employed columns. The optimal performance of the chiroptical spectroscopies and of the DFT calculations allows us to formulate a lactone chirality rule out of the CO stretching region of the VCD spectra.

Synthesis and biological evaluation of new aryl-alkyl(alkenyl)-4-benzylpiperidines, novel Sigma Receptor (SR) modulators, as potential anticancer-agents

In the early 2000s, the Sigma Receptor (SR) family was identified as potential "druggable" target in cancer treatment. Indeed, high density of SRs was found in breast, lung, and prostate cancer cells, supporting the idea that SRs could play a role in tumor growth and progression. Moreover, a link between the degree of SR expression and tumor aggressiveness has been postulated, justified by the presence of SRs in high metastatic-potential cancer cells. As a consequence, considerable efforts have been devoted to the development of small molecules endowed with good affinity towards the two SR subtypes (S1R and S2R) with potential anticancer activity. Herein, we report the synthesis and biological profile of aryl-alkyl(alkenyl)-4-benzylpiperidine derivatives - as novel potential anticancer drugs targeting SR. Among them, 3 (RC-106) exhibited a preclinical profile of antitumor efficacy on a panel of cell lines representative of different cancer types (i.e. Paca3, MDA-MB 231) expressing both SRs, and emerged as a hit compound of a new class of SR modulators potentially useful for the treatment of cancer disease.