Current Topics in Medicinal Chemistry - Volume 25, Issue 9, 2025

During and after the COVID-19 pandemic, Tuberculosis (TB) has reestablished with higher figures due to interruptions in the Directly Observed Treatment Short course (DOTS) despite underreporting. The rising consequences would have extended to extra-pulmonary forms of TB as well, including Tuberculous Meningitis (TBM). Considering the fact that TBM is the most dangerous and worst form of TB, we found the need to scan the literature to highlight various aspects of TBM. Epidemiology of TBM is proportionally less frightening, but the consequent mortalities and morbidities are more alarming than pulmonary TB. Here, we address critical research gaps in Tuberculous Meningitis that warrant further investigations. The highlighted aspects encompass a comprehensive understanding of TBM's clinical presentation and improved diagnostic tools for timely detection, the exploration of innovative chemotherapies and surgical interventions, the unraveling of the role of the blood-brain barrier in disease onset, investigating of the contributions of various brain cells to TBM development, deciphering the complex inflammatory response, exploring the involvement of Matrix Metalloproteinases in tissue damage, delving into host-pathogen genetics influencing susceptibility, utilizing robust in-vivo and in-vitro models for mechanistic insights, and more importantly between TBM and SARS-COVID-19 are discussed. Addressing these gaps will substantially advance our understanding of TBM's complex pathogenesis, contributing to more effective diagnostic, therapeutic, and preventive strategies against this debilitating disease.

The urgent need for novel antibiotics in the face of escalating global antimicrobial resistance necessitates innovative approaches to identify bioactive compounds. Actinomycetes, renowned for their prolific production of antimicrobial agents, stand as a cornerstone in this pursuit. Their diverse metabolites exhibit multifaceted bioactivities, including potent antituberculosis, anticancer, immunomodulatory, immuno-protective, antidiabetic, etc. Though terrestrial sources have been exploited significantly, contemporary developments in the field of antimicrobial drug discovery have put marine actinomycetes in a prominent light as a promising and relatively unexplored source of novel bioactive molecules. This is further boosted by post-genomic era advances like bioinformatics-based secretome analysis and reverse engineering that have totally revitalized actinomycetes antibiotic research. This review highlights actinomycetes-based chemically diverse scaffolds and clinically validated antibiotics along with the enduring significance of actinomycetes from untouched ecosystems, especially with recent advanced techniques in the quest for next-generation antimicrobials.

Non-fused pyrimidine scaffold is a significant component for designing new drugs. The review emphasizes the pharmacological importance of non-fused pyrimidine-containing moieties based on the broad spectrum of activities such as antiprotozoal, antibacterial, antimycobacterial, anticancer, anti-inflammatory activity, and CNS depressant. Pyrimidine derivatives are fascinating entities that display biological activities for the treatment of cancer. It also highlights the tendency of non-fused pyrimidine derivatives to suppress cell growth by obstructing the activity of VCP, CDK-2, EGFR, ATR, EphB4 & EphA2, PDGF as well as inhibitory action towards different cell lines such as MCF-7, HeLa, NCI/ADR-RES, NCI-H23, HOP-92, HCT-116, OV-3, MOLT-4, PC-3, MDA-MB-231, MALME-3M, K562 and Bcr-Abl. The review details the importance of morpholine, piperidine, and pyrrolidine ring substitutions on pyrimidine moiety as well as the role of H-bonding and amino linkage along with antibacterial activity due to the presence of pleuromutilin and tetrazole molecules. Researchers were motivated to develop and enhance the non-fused pyrimidine scaffold to uncover novel medicines by reading this review article.

Cancer is a multifaceted disease with high mortality rates, and current treatments face challenges such as chemoresistance and tumor adaptation. Since Virchow reported the first case of cancer-related chronic inflammation, numerous clinical and epidemiological studies have indicated that around 15-20% of malignant tumors are caused by inflammation. Cyclooxygenase-2 (COX-2), which is the key enzyme in inflammation, has been implicated in tumorigenesis through various mechanisms including promoting angiogenesis, inhibiting apoptosis, and enhancing the invasiveness of cancer cells. Moreover, COX inhibitors have demonstrated a substantial reduction in death rates associated with esophageal and colon cancer. In this context, targeting COX-2 is an effective strategy for cancer prevention and treatment.

This review focuses on the analysis of studies conducted between 2014 and 2024, which evaluate the structure-activity relationship of molecules intended to exhibit cytotoxic activity through COX inhibition. The studies followed both classical and non-classical COX-2 selective drug design strategies. While some focused on the classical approach, utilizing diaryl heterocyclic structures, others explored non-classical designs with a cyclic central scaffold and a linear core. Additionally, several manuscripts employed well-known COX inhibitors including licofelone, indomethacin, naproxen, tolfenamate, celecoxib, flumizole, and ketoprofen, as starting points for further derivatization and optimization. Cytotoxic activity was evaluated using various cell lines including MCF-7, HCT-116, and A549, through assays such as MTT, CellTiter, and MTS. Additionally, studies examined the relationship between COX-2 inhibition and key cancer pathways including apoptosis and the involvement of enzymes like HDAC, EGFR, and topoisomerase.

The majority of studies reported promising cytotoxic activity in COX-2 selective inhibitors. Compounds synthesized with diphenyl heterocyclic scaffolds exhibited enhanced COX-2 selectivity and anticancer efficacy. In particular, derivatives in studies 9, 16, and 24 demonstrated significant activity comparable to standard drugs like celecoxib and doxorubicin. However, only a few studies indicated a weak correlation between COX-2 inhibition and cytotoxicity suggesting the need for further investigation into other cancer-related mechanisms.

This review highlights the potential of COX-2 selective inhibitors in anticancer drug development. The findings support the development of selective COX-2 inhibitors with diverse chemical structures as a promising strategy for cancer therapy.