The subgroup of 2'-hydroxy-flavonoids: Molecular diversity, mechanism of action, and anticancer properties

Enhancing the physicochemical properties and bioactivities of 2'-hydroxyflavanone through fungal biotransformation

Flavonoids comprise a group of natural compounds with diverse bioactivities; however, their low water solubility and limited bioavailability often impede their potential health benefits for humans. In this study, five derivatives, namely 2',5'-dihydroxyflavanone (1), 2'-dihydroxyflavanone-5'-O-4″-O-methyl-β-d-glucoside (2), 2'-dihydroxyflavanone-6-O-4″-O-methyl-β-d-glucoside (3), 2'-dihydroxyflavanone-3'-O-4″-O-methyl-β-d-glucoside (4) and hydroxyflavanone-2'-O-4″-O-methyl-β-d-glucoside (5), were biosynthesized from 2'-hydroxyflavanone through microbial transformation using Beauveria bassiana ATCC 7159. Product 1 was identified as a known compound while 2-5 were structurally characterized as new structures through extensive 1D and 2D NMR analysis. The water solubility of biotransformed products 1-5 was enhanced by 30-280 times compared to the substrate 2'-hydroxyflavanone. Moreover, the antioxidant assay revealed that 1 and 2 exhibited improved 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity relative to the substrate, decreasing the logIC50 from 8.08 ± 0.11 μM to 6.19 ± 0.08 μM and 7.15 ± 0.08 μM, respectively. Compound 5 displayed significantly improved anticancer activity compared to the substrate 2'-hydroxyflavanone against Glioblastoma 33 cancer stem cells, decreasing the IC50 from 25.05 μM to 10.59 μM. Overall, fungal biotransformation represents an effective tool to modify flavonoids for enhanced water solubility and bioactivities.

Exploring Tumor-Promoting Qualities of Cancer-Associated Fibroblasts and Innovative Drug Discovery Strategies With Emphasis on Thymoquinone

Tumor epithelial development and chemoresistance are highly promoted by the tumor microenvironment (TME), which is mostly made up of the cancer stroma. This is due to several causes. Cancer-associated fibroblasts (CAFs) stand out among them as being essential for the promotion of tumors. Understanding the fibroblastic population within a single tumor is made more challenging by the undeniable heterogeneity within it, even though particular stromal alterations are still up for debate. Numerous chemical signals released by tumors improve the connections between heterotypic fibroblasts and CAFs, promoting the spread of cancer. It becomes essential to have a thorough understanding of this complex microenvironment to effectively prevent solid tumor growth. Important new insights into the role of CAFs in the TME have been revealed by recent studies. The objective of this review is to carefully investigate the relationship between CAFs in tumors and plant secondary metabolites, with a focus on thymoquinone (TQ). The literature published between 2010 and 2023 was searched in PubMed and Google Scholar with keywords such as TQ, TME, cancer-associated fibroblasts, mechanism of action, and flavonoids. The results showed a wealth of data substantiating the activity of plant secondary metabolites, particularly TQ's involvement in blocking CAF operations. Scrutinized research also clarified the wider effect of flavonoids on pathways related to cancer. The present study highlights the complex dynamics of the TME and emphasizes the critical role of CAFs. It also examines the possible interventions provided by secondary metabolites found in plants, with TQ playing a vital role in regulating CAF function based on recent literature.

Computational studies of potential antiviral compounds from some selected Nigerian medicinal plants against SARS-CoV-2 proteins

The challenges posed by COVID-19's emergence have led to a search for its therapies. There is no cure for COVID-19 infection yet, but there is significant progress in vaccine formulation for prophylaxis and drug development (such as paxlovid) for high-risk patients. As a contribution to the ongoing quest for solutions, this study shows potent phytocompounds identification as inhibitors of SARS-CoV-2 targets using in silico methods. We used virtual screening, molecular docking, and molecular dynamics (MD) simulations to investigate the interaction of some phytochemicals with 3CLpro, ACE2, and PLpro proteins crucial to the SARS-CoV-2 viral cycle. The predicted docking scores range from −5.5 to −9.4 kcal/mol, denoting appreciable binding of these compounds to the SARS-CoV-2 proteins and presenting a multitarget inhibition for COVID-19. Some phytocompounds interact favorably at non-active sites of the enzymes. For instance, MD simulation shows that an identified site on PLpro is stable and likely an allosteric region for inhibitor binding and modulation. These phytocompounds could be developed into effective therapy against COVID-19 and probed as potential multitarget-directed ligands and drug candidates against the SARS-CoV-2 virus. The study unveils drug repurposing, selectivity, allosteric site targeting, and multitarget-directed ligand in one piece. These concepts are three distinct approaches in the drug design and discovery pipeline.

Ligand fishing as a tool to screen natural products with anticancer potential

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.

Phosphine-Mediated Redox Cyclization of 1-(2-Nitroaryl)prop-2-ynones to 3-Hydroxyquinolin-4-ones: Formal Intramolecular Oxyamination of α,β-Ynones

3-Hydroxyquinoline-4(1H)-ones (3HQs) are privileged structural motifs. The current methods for their synthesis necessitate strongly acidic or basic conditions, which hamper the generality and practicality. Here, we describe phosphine-mediated redox transformation of easily accessible 1-(2-nitroaryl)prop-2-ynones to 3HQs. Besides establishing a new entry to the synthesis of 3HQs under neutral conditions, this method is the first formal intramolecular oxyamination of α,β-ynones. The synthetic utility of this method is demonstrated in the total synthesis of japonine, its analogs, and rare quinoline derivatives.

Zapotin, a Polymethoxyflavone, with Potential Therapeutic Attributes

The use of plants as traditional medicines is common and has prevailed in many different cultures over time. Polymethoxyflavones (PMFs) are natural polyphenols from the group of flavonoids. Zapotin, a member of the PMFs, is found mainly in citrus plants and is almost exclusively limited to their peels. The chemical structure of zapotin has been questioned from the very beginning, since the structure of flavonoids with a single oxygen atom in the C2′ position is extremely rare in the plant kingdom. To clarify this, the structural determination and bio-inspired synthesis of zapotin are discussed in detail in this review. Due to the broad biological potential of PMFs, the complication in the isolation process and characterization of PMFs, as well as their purification, have been estimated by adapting various chromatographic methods. According to available data from the literature, zapotin may be a promising curative agent with extensive biological activities, especially as a chemopreventive factor. Apart from that, zapotin acts as an antidepressant-like, anticancer, antifungal, and antioxidant agent. Finally, accessible studies about zapotin metabolism (absorption, distribution, metabolism, excretion, and toxicity) underline its potential in use as a therapeutic substance.