Chemical synthesis, molecular modeling and pharmacophore mapping of new pyrrole derivatives as inhibitors of InhA enzyme and Mycobacterium tuberculosis growth

In silico development of potential InhA inhibitors through 3D-QSAR analysis, virtual screening and molecular dynamics

Tuberculosis is one of the most ancient infectious diseases known to mankind predating upper Paleolithic era. In the current scenario, treatment of drug resistance tuberculosis is the major challenge as the treatment options are limited, less efficient and more toxic. In our study we have developed an atom based 3D QSAR model, statistically validated sound with R2 > 0.90 and Q2 > 0.72 using reported direct inhibitors of InhA (2018-2022), validated by enzyme inhibition assay. The model was used to screen a library of 3958 molecules taken from Binding DB and candidates molecules with promising predicted activity value (pIC50) > 5) were selected for further analyzed screening by using molecular docking, ADME profiling and molecular dynamic simulations. The lead molecule, ZINC11536150 exhibited good docking score (glideXP = -11.634 kcal/mol) compared to standard triclosan (glideXP =  -7.129 kcal/mol kcal/mol) and through molecular dynamics study it was observed that the 2nv6-complex of ZINC11536150 with Mycobacterium tuberculosis InhA (PDB entry: 2NV6) complex remained stable throughout the entire simulation time of 100 ns.Communicated by Ramaswamy H. Sarma.

Design and synthesis of Thieno[3, 2-b]pyridinone derivatives exhibiting potent activities against Mycobacterium tuberculosis in vivo by targeting Enoyl-ACP reductase

In this study, a series of novel thieno [3, 2-b]pyridinone derivatives were designed and synthesized using a scaffold hopping strategy. Six compounds showed potent anti-mycobacterial activity (minimum inhibitory concentration (MIC) ≤ 1 μg/mL) against Mycobacterium tuberculosis (Mtb) UAlRa. Compound 6c displayed good activity against Mtb UAlRv (MIC = 0.5-1 μg/mL). Compounds 6c and 6i also showed activity against Mtb UAlRa in macrophages and exhibited low cytotoxicity against LO-2 cells. The selected compounds displayed a narrow antibacterial spectrum, with no activity against representative Gram-positive, Gram-negative bacteria, as well as fungi. Furthermore, compound 6c demonstrated favorable oral pharmacokinetic properties with a T1/2 value of 47.99 h and exhibited good in vivo activity in an acute mouse model of tuberculosis (TB). The target of compound 6c was identified as a NADH-dependent enoyl-acyl carrier protein reductase (InhA) by genome sequencing of spontaneously compound 6c-resistant Mtb mutants, indicating that compound 6c may not require activation and can directly target InhA. In vitro antimicrobial assays against a recombinant M. smegmatis overexpressing the Mtb-InhA, along with InhA inhibition assays, confirmed that InhA is the target of thieno [3, 2-b]pyridinone derivatives. Overall, this study identified thieno [3, 2-b]pyridinone scaffold as a novel chemotype that is promising for the development of anti-TB agents.

Unlocking InhA: Novel approaches to inhibit Mycobacterium tuberculosis

Multidrug-resistant tuberculosis continues to pose a health security risk and remains a public health emergency. Antimicrobial resistance result from treatment regimens that are both insufficient and incomplete leading to the emergence of multidrug-resistant tuberculosis, extensively drug-resistant tuberculosis and totally drug-resistant tuberculosis. The impact of tuberculosis on the people suffering from HIV (Human immunodeficiency virus infection) have resulted in the increased research efforts in designing and discovery of novel antitubercular drugs that may result in decreasing treatment duration, minimising the need for multiple drug intake, minimising cytotoxicity and enhancing the mechanism of action of drug. While many drugs are available to treat tuberculosis, a precise and timely cure is still absent. Consequently, further investigation is needed to identify more recent molecular equivalents that have the potential to swiftly remove this disease. Isoniazid (INH), a treatment for tuberculosis (TB), targets the enzyme InhA (mycobacterium enoyl acyl carrier protein reductase), the Mycobacterium tuberculosis enoyl-acyl carrier protein (ACP) reductase, most common INH resistance is circumvented by InhA inhibitors that do not require KatG (catalase-peroxidase) activation, as a result, researchers are trying to work in the area of development of InhA inhibitors which could help in eradicating the era of tuberculosis from the world.

Pyrrole: A Decisive Scaffold for the Development of Therapeutic Agents and Structure-Activity Relationship

An overview of pyrroles as distinct scaffolds with therapeutic potential and the significance of pyrrole derivatives for drug development are provided in this article. It lists instances of naturally occurring pyrrole-containing compounds and describes the sources of pyrroles in nature, including plants and microbes. It also explains the many conventional and modern synthetic methods used to produce pyrroles. The key topics are the biological characteristics, pharmacological behavior, and functional alterations displayed by pyrrole derivatives. It also details how pyrroles are used to treat infectious diseases. It describes infectious disorders resistant to standard treatments and discusses the function of compounds containing pyrroles in combating infectious diseases. Furthermore, the review covers the uses of pyrrole derivatives in treating non-infectious diseases and resistance mechanisms in non-infectious illnesses like cancer, diabetes, and Alzheimer's and Parkinson's diseases. The important discoveries and probable avenues for pyrrole research are finally summarized, along with their significance for medicinal chemists and drug development. A reference from the last two decades is included in this review.

<em>In silico</em> study of phytochemicals contained in brucea javanica in inhibiting the InhA enzyme as antituberculosis

Background: Currently Mycobacterium tuberculosis is found to be resistant to the treatment of tuberculosis with rifampin and isoniazid (INH) and often stated as multi-drug resistance (MDR). Knowledge and determination of biological properties of plant extracts is a source of drug candidates in various health fields. Therefore, natural products are important in the discovery of new drugs, especially in disease therapy, particularly for tropical dis- eases, tuberculosis. Brucea javanica, known as Buah Makasar, is found in many Asian countries including Indonesia. This plant fruit has a very bitter taste so it cannot be directly consumed and is often used as a traditional medicine to prevent some diseases, especially malaria. There has been no research on the effectiveness of Buah Makasar in tuberculosis. Objective: This study aims to identify compounds contained in Brucea javanica, namely bruceines, bruceosides and yadanzio-sides in inhibiting the InhA enzyme found in the wall of Mycobacterium tuberculosis. Methods: This in-silico study is using Molegro Virtual Docker (MVD) Ver. 5.5. We compared it to the native ligand, namely N-(4- Methylbenzoyl)-4-Benzylpiperidine (code: 4PI) and the reference drug standard, INH. Results: In-silico results show that yadanziosides found in Brucea javanica have the potential to inhibit the InhA enzyme. Bruceoside F (-190.76 Kcal/mol) has the lowest MolDock score among the 27 other compounds. It is also having lower MolDock score than the native ligand 4PI (-120.61 Kcal/mol) and INH (- 54.44 Kcal/mol). Conclusions: Brucea javanica can be considered as source of drug development for againts tuberculosis.

An approach to pharmacological targets of pyrrole family from a medicinal chemistry viewpoint

Pyrrole is one of the most widely used heterocycles in the pharmaceutical industry. Due to the importance of pyrrole structure in drug design and development, herein, we tried to conduct an extensive review of the bioactive pyrrole based compounds reported recently. The bioactivity of pyrrole derivatives varies, so in the review, we categorized them based on their direct pharmacologic targets. Therefore, readers are able to find the variety of biologic targets for pyrrole containing compounds easily. This review explains around seventy different biologic targets for pyrrole based derivatives, so, it is helpful for medicinal chemists in design and development novel bioactive compounds for different diseases. This review presents an extensive meaningful structure activity relationship for each reported structure as much as possible. The review focuses on papers published between 2018 and 2020.