Acetylcholine (ACh) neurotransmitter of the cholinergic system in the brain is involved in learning, memory, stress responses, and cognitive functioning. It is hydrolyzed into choline and acetic acid by two key cholinesterase enzymes, viz., acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). A loss or degeneration of cholinergic neurons that leads to a reduction in ACh levels is considered a significant contributing factor in the development of neurodegenerative diseases (NDs) such as Alzheimer’s disease (AD). Numerous studies have shown that cholinesterase inhibitors can raise the level of ACh and, therefore, enhance people’s quality of life, and, at the very least, it can temporarily lessen the symptoms of NDs. 1,2,3-triazole, a five-membered heterocyclic ring, is a privileged moiety, that is, a central scaffold, and is capable of interacting with a variety of receptors and enzymes to exhibit a broad range of important biological activities. Recently, it has been clubbed with other pharmacophoric fragments/molecules in hope of obtaining potent and selective AChE and/or BuChE inhibitors. The present updated review succinctly summarizes the different synthetic strategies used to synthesize the 1,2,3-triazole moiety. It also highlights the anticholinesterase potential of various 1,2,3-triazole di/trihybrids reported in the past seven years (2015–2022), including a rationale for hybridization and with an emphasis on their structural features for the development and optimization of cholinesterase inhibitors to treat NDs.

Background: Xanthones, natural or synthetic, due to their wide range of biological activities, have become an interesting subject of investigation for many researchers. Xanthonic scaffold has proven to have a vital role in anticancer drug development since many of its derivatives have shown anticancer activities on various cell lines. In addition, targeting epigenetic markers in cancer has yielded promising results. There have also been reports on the impact of xanthone and related polyphenolic compounds on epigenetics markers in cancer prevention and therapy. Objective: The objective of this review is to comprehensively highlight the main natural and nonnatural sources of xanthones having potential anti-cancer effects along with their key structural elements, structure-activity relationships (SARs), mechanisms of action, and epigenetic profile of xanthone- based anti-cancer compounds. The challenges and future directions of xanthone-based therapies are also discussed briefly. Method: The methods involved in the preparation of the present review included the collection of all recent information up to November 2021 from various scientific databases, indexed periodicals, and search engines such as Medline Scopus, Google Scholar, PubMed, PubMed Central, Web of Science, and Science Direct. Results: Exploration of the diversity of the xanthone scaffold led to the identification of several derivatives having prominent anti-cancer activity. Their unique structural diversity and synthetic modifications showed the ongoing endeavour of enriching the chemical diversity of the xanthone molecular framework to discover pharmacologically interesting compounds. However, studies regarding their modes of action, pharmacokinetic properties, clinical data, epigenetics, and safety are limited. Conclusion: Elucidation of the exact biological mechanisms and the associated targets of xanthones will yield better opportunities for these compounds to be developed as potential anticancer drugs. Further clinical studies with conclusive results are required to implement xanthones as treatment modalities in cancer.

Diabetes is a severe metabolic disorder characterized by hyperglycemia. Hyperglycemia is a hallmark of diabetes, a life-threatening metabolic condition. There are a variety of oral hypoglycemic drugs in the market for the treatment of diabetes mellitus, including biguanides, sulphonylurea, and alpha-glucosidase inhibitors. On the other hand, these conventional methods of treating diabetes are costly and associated with a variety of long-term issues, whereas medicinal herbs used to treat diabetes are inexpensive and have no harmful consequences or side effects. Because of the existence of different therapeutically relevant active phytochemicals such as tannins, flavonoids, alkaloids, and other compounds in medicinal plants, they can be used in treating diabetes. Various medicinal plants used to treat diabetes mellitus and their bioactive components are discussed in this review article. In this review, the prospects of these medicinal plants, as well as the challenges associated with their use, are discussed.

Background: Over the years, the xanthone nucleus has been serving as an interesting scaffold for the design of derivatives aiming at anti-inflammatory drug development. Objective: The objective of the current work was to design and synthesize two series of novel 3- (5'-substituted pentyloxy)-1-hydroxy xanthone & 6-(5'-substituted pentyloxy)-1-hydroxy xanthone derivatives. The designed compounds were examined in vivo for anti-inflammatory activity. The effect of the synthesized xanthone derivatives on the serum expression of IL-10 and TNF-α was evaluated to understand the underlying molecular mechanisms. Method: The title compounds were virtually designed and screened for ADME/T properties and docked onto the COX-2 protein. The synthesis of the xanthone derivatives was achieved by the condensation of salicylic acid derivatives and a suitable phenol in the presence of a mixture of phosphorus pentoxide–methanesulfonic acid as an acylation catalyst. The compounds were evaluated for in vivo anti-inflammatory activity by carrageenan induced paw edema method and serum expression of cytokines was evaluated using ELISA assays. Results: The selected compounds exhibited docking scores ranging between -10.7 to -6.8 (Kcal/mol), respectively, as compared with standard Celecoxib (-7.9 Kcal/mol) and the nonselective COX inhibitor Indomethacin (-6.4 Kcal/mol). Among the tested compounds, 9u has shown the highest activity with 65.6 % reduction in edema (69.8% for Celecoxib). Immunoassay results showed a significant drop in serum TNF-α and an elevation in serum IL-10. Conclusion: The findings highlight that some of the synthesized xanthone derivatives displayed marked anti-inflammatory activity, which can be further investigated to render efficient and novel non-ulcerogenic anti-inflammatory agents.

The DNA topoisomerase II (topo II) enzyme plays an important role in the replication, recombination, and repair of DNA. Despite their widespread applications in cancer therapy, new, selective, and potent topo II inhibitors with better pharmaceutical profiles are needed to handle drug resistance and severe adverse effects. In this respect, an array of 36 new anticancer compounds was designed based on a Xanthone core tethered to multifunctional Pyridine-amines and Imidazole scaffold via alkyl chain linkers. An integrated in silico approach was used to understand the structural basis and mechanism of inhibition of the hybrid xanthone derivatives. In this study, we established an initial virtual screening workflow based on pharmacophore mapping, docking, and cancer target association to validate the target selection process. Next, a simulation-based docking was conducted along with pharmacokinetic analysis to filter out the five best compounds (7, 10, 25, 27, and 30) having binding energies within the range of -60.45 to -40.97 kcal/mol. The screened compounds were further subjected to molecular dynamics simulation for 200 ns followed by MM-GBSA and ligand properties analysis to assess the stability and binding affinity to hTOP2 alpha. The top-ranking hits 3,7-bis(3-(2-aminopyridin-3-ylhydroxy)propoxy)-1-hydroxy-9H-xanthen-9-one (ligand 7) and 3,8-bis(3-(2-aminopyridin-3-ylhydroxy)propoxy)-1-hydroxy-9H-xanthen-9-one (ligand 25) were found to have no toxicity, optimum pharmacokinetic and, DFT properties and stable intermolecular interactions with the active site of hTopo II alpha protein. In conclusion, further in vitro and in vivo experimental validation of the identified lead molecules is warranted for the discovery of new human Topoisomerase 2 alpha inhibitors.