Spirocyclic compounds: potential drug leads in the fight against Mycobacterium tuberculosis

TB drug discovery needs scientists' attention since drug resistance in TB, including extensively drug-resistant TB (XDR-TB) and multidrug-resistant TB (MDR-TB), is a major healthcare concern. Since millions of fatalities from tuberculosis are recorded each year, there is an urgent need to discover new anti-tubercular medications that will either eradicate or control the disease. Spiro compounds have garnered a lot of attention in medicinal chemistry these days because of various biological activities mainly because of their adaptability and structural resemblance to significant pharmacophores. This article overviews the synthesis and activity of spirocyclic compounds as anti-tubercular agents. Both synthesized and naturally occurring spiro chemicals exhibit antitubercular properties. The promising antitubercular potential shown by some of the spirocyclic compounds has attracted scientists to explore them further to develop molecules with improved pharmacodynamic and pharmacokinetic properties and new mechanisms of action with enhanced safety and efficacy in tuberculosis. The current review covers the exploration of spiro compounds from the year 2004 to 2024 for the combat of Tuberculosis. This review gives the comprehensive advancements in this scaffold which would help the logical design of powerful, less toxic, and more effective spirocyclic anti-TB medicinal molecules.

Design, Synthesis and Biological Evaluation of Novel Spiro-[chroman-2,4'-piperidin]-4-one Analogues as Anti-Tubercular Agents

A series of novel spiro-[chromane-2,4'-piperidine]-4(3 H )-one derivatives were designed, synthesized and structures were confirmed by analytical methods viz., 1 H NMR, 13 C NMR and Mass spectrometry. Synthesized derivatives were evaluated for their anti-mycobacterial activity against Mycobacterium tuberculosis ( Mtb ) H37Ra strain. Among all the evaluated compounds, PS08 exhibited significant inhibition with MIC value of 3.72 μM while MIC values of the remaining compounds ranged from 7.68 to 230.42 μM in comparison to the standard drug INH (MIC 0.09 μM). The two most active compounds however showed acute cytotoxicity towards the human MRC-5 lung fibroblast cell line. The in-silico ADMET profiles of the titled compounds were predicted and found within the prescribed limits of the Lipinski and Jorgenson rules. Molecular docking study of the significantly active compound ( PS08 ) was also carried out after performing validation in order to understand the putative binding position of the test ligand at the active site of selected target protein Mtb tyrosine phosphatase (PtpB).

Dissecting Histone Deacetylase 3 in Multiple Disease Conditions: Selective Inhibition as a Promising Therapeutic Strategy

The acetylation of histone and non-histone proteins has been implicated in several disease states. Modulation of such epigenetic modifications has therefore made histone deacetylases (HDACs) important drug targets. HDAC3, among various class I HDACs, has been signified as a potentially validated target in multiple diseases, namely, cancer, neurodegenerative diseases, diabetes, obesity, cardiovascular disorders, autoimmune diseases, inflammatory diseases, parasitic infections, and HIV. However, only a handful of HDAC3-selective inhibitors have been reported in spite of continuous efforts in design and development of HDAC3-selective inhibitors. In this Perspective, the roles of HDAC3 in various diseases as well as numerous potent and HDAC3-selective inhibitors have been discussed in detail. It will surely open up a new vista in the discovery of newer, more effective, and more selective HDAC3 inhibitors.

Strategies for the synthesis of spiropiperidines - a review of the last 10 years

Spiropiperidines have gained in popularity in drug discovery programmes as medicinal chemists explore new areas of three-dimensional chemical space. This review focuses on the methodology used for the construction of 2-, 3- and 4-spiropiperidines, covering the literature from the last 10 years. It classifies the synthesis of each of the types of spiropiperidine by synthetic strategy: the formation of the spiro-ring on a preformed piperidine ring, and the formation of the piperidine ring on a preformed carbo- or heterocyclic ring. While 3- and 4-spiropiperidines are predominantly synthesised for drug discovery projects, 2-spiropiperidines are synthesised en route to natural products. The lack of 2-spiropiperidines in drug discovery is presumably due to limited general procedures for their synthesis.

Unpacking the Pathogen Box-An Open Source Tool for Fighting Neglected Tropical Disease

The Pathogen Box is a 400-strong collection of drug-like compounds, selected for their potential against several of the world's most important neglected tropical diseases, including trypanosomiasis, leishmaniasis, cryptosporidiosis, toxoplasmosis, filariasis, schistosomiasis, dengue virus and trichuriasis, in addition to malaria and tuberculosis. This library represents an ensemble of numerous successful drug discovery programmes from around the globe, aimed at providing a powerful resource to stimulate open source drug discovery for diseases threatening the most vulnerable communities in the world. This review seeks to provide an in-depth analysis of the literature pertaining to the compounds in the Pathogen Box, including structure-activity relationship highlights, mechanisms of action, related compounds with reported activity against different diseases, and, where appropriate, discussion on the known and putative targets of compounds, thereby providing context and increasing the accessibility of the Pathogen Box to the drug discovery community.

The Search for Potent, Small-Molecule HDACIs in Cancer Treatment: A Decade After Vorinostat

Histone deacetylases (HDACs) play a crucial role in the remodeling of chromatin, and are involved in the epigenetic regulation of gene expression. In the last decade, inhibition of HDACs came out as a target for specific epigenetic changes associated with cancer and other diseases. Until now, more than 20 HDAC inhibitors (HDACIs) have entered clinical studies, and some of them (e.g., vorinostat, romidepsin) have been approved for the treatment of cutaneous T-cell lymphoma. This review provides an overview of current knowledge, progress, and molecular mechanisms of HDACIs, covering a period from 2011 until 2015.

Synthesis, biological characterization and molecular modeling insights of spirochromanes as potent HDAC inhibitors

In the last decades, inhibitors of histone deacetylases (HDAC) have become an important class of anti-cancer agents. In a previous study we described the synthesis of spiro[chromane-2,4'-piperidine]hydroxamic acid derivatives able to inhibit histone deacetylase enzymes. Herein, we present our exploration for new derivatives by replacing the piperidine moiety with various cycloamines. The goal was to obtain highly potent compounds with a good in vitro ADME profile. In addition, molecular modeling studies unravelled the binding mode of these inhibitors.