Dysregulation of the AXL receptor tyrosine kinase has been associated with many types of cancer. It has not been until recently, however, that targeting AXL has come under the spotlight because of ever accumulating evidence of its strong correlation with poor prognosis and drug resistance. The entry of the first AXL-branded inhibitor in clinical trials in 2013 marked an important milestone for the clinical validation of AXL as an anticancer target. Nevertheless, to weigh the current contribution and potential future impact of AXL inhibition in the clinic, it is fundamental to recognize that several kinase inhibitors approved or in clinical development have AXL as either a prominent secondary or even the primary target. Through this review, the chemical and biological properties of the main inhibitors targeting AXL (either intentionally or unintentionally) will be discussed, along with the prospects and challenges to translate AXL inhibitors into a bona fide therapeutic option.

Palladium-activated prodrug therapy is an experimental therapeutic approach that relies on the unique chemical properties and biocompatibility of heterogeneous palladium catalysis to enable the spatially-controlled in vivo conversion of a biochemically-stable prodrug into its active form. This strategy, which would allow inducing local activation of systemically administered drug precursors by mediation of an implantable activating device made of Pd(0), has been proposed by our group as a way to reduce drug’s systemic toxicity while reaching therapeutic levels of the active drug in the affected tissue / organ. In the seminal study of such an approach, we reported that propargylation of the N1 position of 5-fluorouracil suppressed the drug’s cytotoxic properties, showed high stability in cell culture and facilitated the bioorthogonal restoration of the drug’s pharmacological activity in the presence of extracellular Pd(0)-functionalized resins. To provide additional insight on the properties of this system, we have investigated different N1-alkynyl derivatives of 5-fluorouracil and shown that the presence of substituents near the triple bond influence negatively on its sensitivity to palladium catalysis under biocompatible conditions. Comparative studies of the N1- versus the N3-propargyl derivatives of 5-fluorouracil revealed that masking each or both positions equally led to inactive derivatives (>200-fold reduction of cytotoxicity relative to the unmodified drug), whereas the depropargylation process occurred faster at the N1 position than at the N3, thus resulting in greater toxigenic properties in cancer cell culture.

Pyrazolopyrimidines with potent antiproliferative properties were developed by an adaptive strategy that applies ligand-based design and phenotypic screening iteratively and is informed by biochemical assays. To drive development toward specific oncopathways, compounds were tested against cancer cells that overexpress, or not, AXL kinase. Identified phenotypic hits were found to inhibit oncotargets AXL, RET, and FLT3. Subsequent optimization generated antiproliferative lead compounds with unique selectivity profiles, including selective AXL inhibitors and a highly potent inhibitor of FLT3.

The search for novel targeted inhibitors active on glioblastoma multiforme is crucial to develop new treatments for this unmet clinical need. Herein, we report the results from a screening campaign against glioma cell lines using a proprietary library of 100 structurally-related pyrazolopyrimidines. Data analysis identified a family of compounds featuring a 2-amino-1,3-benzoxazole moiety (eCF309 to eCF334) for their antiproliferative properties in the nM range. These results were validated in patient-derived glioma cells. Available kinase inhibition profile pointed to blockade of the PI3K/mTOR pathway as being responsible for the potent activity of the hits. Combination studies demonstrated synergistic activity by inhibiting both PI3Ks and mTOR with selective inhibitors. Based on the structure activity relationships identified in this study, five new derivatives were synthesized and tested, which exhibited potent activity against glioma cells but not superior to the dual PI3K/mTOR inhibitor and lead compound of the screening eCF324.

Access to clean and safe water sadly remains an issue in the 21 ^st century. Water reservoirs, whether groundwater or surface water, are routinely contaminated by various harmful Emerging Contaminants (ECs). One of most prevalent pollutants among these pollutants is Bisphenol A, which is classified as an Endocrine Disrupting Compound (EDC). This substance adversely interferes with the endocrine system, primarily by mimicking estrogen, and has been considered a potential contributor to Polycystic Ovary Syndrome (PCOS) with 82.70 % of 1,391 women studied showing a positive correlation between BPA exposure and PCOS. PCOS is currently the most prevalent endocrine disorder affecting women of reproductive age; however, its pathogenesis remains unclear, complicating diagnosis and subsequently patient care. In this review, these topics are thoroughly examined, with particular emphasis on biochar, a new promising method for large‐scale water purification. Biochar, derived from various organic waste materials, has emerged as a cost‐effective substance with remarkable adsorption properties achieving up to 88 % efficiency over four cycles of reuse, similar to that of activated carbon. This review interrogates the suitability of biochar for counteracting the issue of EDC pollutants.