Cancer is the second leading cause of death in the world and its incidence is expected to increase with the aging of the world's population and globalization of risk factors. Natural products and their derivatives have provided a significant number of approved anticancer drugs and the development of robust and selective screening assays for the identification of lead anticancer natural products are essential in the challenge of developing personalized targeted therapies tailored to the genetic and molecular characteristics of tumors. To this end, a ligand fishing assay is a remarkable tool to rapidly and rigorously screen complex matrices, such as plant extracts, for the isolation and identification of specific ligands that bind to relevant pharmacological targets. In this paper, we review the application of ligand fishing with cancer‐related targets to screen natural product extracts for the isolation and identification of selective ligands. We provide critical analysis of the system configurations, targets, and key phytochemical classes related to the field of anticancer research. Based on the data collected, ligand fishing emerges as a robust and powerful screening system for the rapid discovery of new anticancer drugs from natural resources. It is currently an underexplored strategy according to its considerable potential.

Oligosaccharides derived from λ-carrageenan (λ-COs) are gaining interest in the cancer field. They have been recently reported to regulate heparanase (HPSE) activity, a protumor enzyme involved in cancer cell migration and invasion, making them very promising molecules for new therapeutic applications. However, one of the specific features of commercial λ-carrageenan (λ-CAR) is that they are heterogeneous mixtures of different CAR families, and are named according to the thickening-purpose final-product viscosity which does not reflect the real composition. Consequently, this can limit their use in a clinical applications. To address this issue, six commercial λ-CARs were compared and differences in their physiochemical properties were analyzed and shown. Then, a H2O2-assisted depolymerization was applied to each commercial source, and number- and weight-averaged molar masses (Mn and Mw) and sulfation degree (DS) of the λ-COs produced over time were determined. By adjusting the depolymerization time for each product, almost comparable λ-CO formulations could be obtained in terms of molar masses and DS, which ranged within previously reported values suitable for antitumor properties. However, when the anti-HPSE activity of these new λ-COs was screened, small changes that could not be attributed only to their small length or DS changes between them were found, suggesting a role of other features, such as differences in the initial mixture composition. Further structural MS and NMR analysis revealed qualitative and semi-quantitative differences between the molecular species, especially in the proportion of the anti-HPSE λ-type, other CARs types and adjuvants, and it also showed that H2O2-based hydrolysis induced sugar degradation. Finally, when the effects of λ-COs were assessed in an in vitro migration cell-based model, they seemed more related to the proportion of other CAR types in the formulation than to their λ-type-dependent anti-HPSE activity.

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Background: Fargesin is a natural product that was identified by our group in previous work as a potent ligand of the sterol-binding protein-2 (SCP-2) of Aedes aegypti, the mosquito that which causes the propagation of diseases such as zika, dengue, Chikungunya, and yellow fever. Objectives: propose structural analogs synthetically accessible to be evaluated by molecular docking, preserving the fargesin privileged group's benzodioxol and methoxybenzene, with different spacer groups. Materials and Methods: Structures were obtained in PubChem® and SciFinder® databases, in .sdf format. Chemical structures were converted to pdbqt format by the OpenBabel GUI® program. Macromolecular target SCP-2 (PDB ID: 1PZ4) was extracted from the RSCB-PDB® platform, and molecular docking was performed using the Autodock vina program. The target binding site was defined based on the crystallographic ligand (palmitic acid), with grid box dimensions 16x12x18 Å. Results: The database built had 1231 molecules, with molecules that had binding energy lower than -6.9 Kcal/mol considered valid results. Thus, of the 447 molecules that were most favorable, the best results were for the compounds: 188 (-12.6 Kcal/mol), 350 (-12.6 Kcal/mol), 351 (-12.3 Kcal/mol), 773 (-12.3 Kcal/mol) and 831 (-12.1 Kcal/mol). Conclusion: The results of this paper showed that isoflavonoids synthetically acessible are promising candidates for larvicidal agents, which corroborates with other published data from our research group and encourages experimental investigations.