New 1,3,4‒oxadiazole Quinazolines as Potential Anticancer Agents: Design, Synthesis, Biological Evaluation, and In silico Studies

BACKGROUND

A novel series of 1,3,4‒oxadiazole connected to derivatives of quinazolinone (7a-e and 8a-f) was synthesized in the current investigation, and its anticancer and Topoisomerase‒ II inhibitory activity was evaluated.

OBJECTIVE

These findings inspired the design, synthesis, and biological analysis of these 1,3,4‒oxadiazole-quinazolinone analogues as antiproliferative Topo‒II inhibitors.

METHODS

The novel compound structures were determined using mass spectrometry and spectral methods (IR, NMR: 1H & 13C). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colourimetric assay has been used to evaluate the anticancer efficacy of these drugs, and Autodock 4.2 provides a description of the docking results. For the more active members, additional biological tests, such as the Topo‒II inhibition experiment, were performed. These compounds' physicochemical and ADMET characteristics were examined in more detail.

RESULTS

In the experiment for antiproliferative activity, compounds 7d, 7e, 8c, 8e, and 8f demonstrated encouraging cytotoxicity findings against HCT‒116 and HepG2 cancer cell lines, with IC50 values ranging from 3.85 to 19.43 μM. Compounds 7d, 7e, and 8e were the most potent inhibitors of Topo II with IC50 values of 15.18, 17.55, and 12.59 μM, respectively. Additionally, the docked compound 8c showed the strongest conventional hydrogen bonds among the residues Leu507(B), Asn508(B), Asn520(B), and Glu522(B) in the Human topoisomerase‒IIβ active site in the DNA complex (4G0U) when compared to the findings of docking experiments.

CONCLUSIONS

New findings have discovered the fact that fused 1,3,4‒oxadiazole bearing quinazolinone contributed great significance in the field of medicinal chemistry due to their diverse biological properties. Finally, the in silico pharmacokinetic profile of all the synthesized derivatives was estimated using SwissADME, where some of the compounds followed Lipinski, Veber, Egan, and Muegge rules without deviation. The result of this activity advises that with a simple modification in structure, a potent anticancer agent can be generated with good efficacy.

Potential Serotonin 5-HT2A Receptor Agonist of Psychoactive Components of Silene undulata Aiton: LC-MS/MS, ADMET, and Molecular Docking Studies

BACKGROUND

Silene undulata is historically used for inducing vivid and prophetic lucid dreams, but limited information exists on its phytochemical composition and potential pharmacological properties.

OBJECTIVE

This study aimed to investigate the phytochemical composition of S. undulata through LC-MS/MS analysis and explore its potential serotonergic activity, which could support and confirm the traditional use of S. undulata as a dream-inducing plant.

METHODS

LC-MS/MS analysis was conducted on S. undulata extract, identifying 51 phytochemicals, including norharman, harmalol, harmaline, harmine, and ibogaine alkaloids. ADMET and Molecular docking investigations were employed to assess the serotonergic potential of these compounds.

RESULTS

The analysis revealed the presence of β-carboline alkaloids, such as norharman, harmalol, harmaline, harmine, and ibogaine, within S. undulata extract. ADMET analysis showed that these compounds have a favourable pharmacokinetic properties. In addition, molecular docking investigations showed that harmaline (-8.90 Kcal/mol), harmalol (-8.56 Kcal/mol), and ibogaine (-8.75 Kcal/mol) exhibited binding affinities comparable to the control molecule, LSD (-9.14 Kcal/mol), indicating potential agonistic activity at serotonin 5-HT2A receptor.

CONCLUSION

These findings provide insights into the potential therapeutic benefits of S. undulata, supporting its traditional use as a psychoactive plant. This study investigated the chemical constituents and potential serotonergic agonist activity of S. undulata for the first time. While promising, further research is necessary to uncover additional medicinal properties associated with the identified phytochemical components.

3D-QSAR Studies on High-affinity Phosphodiestera

BACKGROUND

Recent studies have found that Phosphodiesterase-4 (PDE4) is closely related to the pathogenesis of depression, cognitive impairment and neurological impairment.

OBJECTIVE

Our objective is to develop potent inhibitors of the high-affinity phosphodiesterase 4D isoform (PDE4D) that can serve as radioligands for Positron Emission Tomography (PET) imaging, thereby advancing research in the field of neurological diseases.

METHODS

We employed a multi-step approach combining three-dimensional quantitative structure-activity relationship (3D-QSAR) modeling, molecular docking, classification techniques, and CoMSIA analysis to investigate the conformational relationship of highaffinity PDE4D inhibitors as PET ligands. ADMET and Drug-likeness predictions were also conducted. By utilizing these methods, our aim was to identify more potent PDE4D inhibitors.

RESULTS

The results showed that the CoMSIA model with the best principal component scores (n=7) had a cross-validated Q2 value of 0.602 and a non-cross-validated R2 value of 0.976. These results affirmed the excellent predictive capability of the established CoMSIA model. Analysis of the generated 3D-QSAR contour plots highlighted specific regions in the molecular structure of the compounds that can be further optimized and modified. Guided by the contour plots, we designed 100 novel PDE4D inhibitors, and molecular docking was performed for the top 4 compounds with high activity. The molecular docking scores were promising, and ADMET and drug similarity predictions yielded satisfactory results. Taking into consideration these factors, compound 51c was determined to be the optimal compound, laying a solid foundation for further research.

CONCLUSION

For the continued development of PDE4D PET radioligand, these models and new compounds' developing methodology offer a theoretical foundation and crucial references.

In silico Evaluation of Ferulic Acid Based Multifunctional Conjugates as Potential Drug Candidates

BACKGROUND

Recent research has shown that ferulic acid (FA, trans-4-hydroxy-3- methoxycinnamic acid) has remarkable antioxidant properties and a wide range of biological activities. Conjugation of two or more biologically active compounds to produce a novel molecular scaffold is justified by the need to enhance biological activity against a single target or obtain a conjugate that behaves as a multi-target-directed ligand. In addition, the conjugation strategy decreases dose-dependent side effects by promoting the use of smaller doses of conjugated components to treat the disease. Moreover, the patient's compliance is positively affected when conjugating two active compounds into a single more active compound as this reduces the number of pills to be taken daily.

OBJECTIVE

This study aims to shed light on studies that design and synthesize FA-based hybrid compounds with enhanced biological activities and to in silico assess these compounds as potential drug candidates.

METHODS

The conjugate compounds were found by searching the literature using the keywords (ferulic acid-based hybrid or ferulic acid-based conjugate). To study conjugate pharmacokinetic parameters and toxicity (ADMET), software suites from Biovia Inc. (San Diego, California) were integrated into Discovery Studio 4.5. The structures were created using ChemDraw Ultra 7.0.

RESULTS

14 conjugates exhibiting variable biological activities were collected and three of them (compounds 3,5, and 6) in addition to the cis FA (compound 12) are the best-predicted compounds with low Daphnia toxicity and hepatotoxicity with acceptable pharmacokinetic properties.

CONCLUSION

Cis FA, FA conjugates 3,5, and 6 act as good drug candidates that can be used to modify new hits.

In Silico Screening of Some Active Phytochemicals to Identify Promising Inhibitors Against SARS-CoV-2 Targets

BACKGROUND

There are very few small-molecule drug candidates developed against SARS-CoV-2 that have been revealed since the epidemic began in November 2019. The typical medicinal chemistry discovery approach requires more than a decade of the year of painstaking research and development and a significant financial guarantee, which is not feasible in the challenge of the current epidemic.

OBJECTIVE

This current study proposes to find and identify the most effective and promising phytomolecules against SARS-CoV-2 in six essential proteins (3CL protease, Main protease, Papain- Like protease, N-protein RNA binding domain, RNA-dependent RNA polymerase, and Spike receptor binding domain target through in silico screening of 63 phytomolecules from six different Ayurveda medicinal plants.

METHODS

The phytomolecules and SARS-CoV-2 proteins were taken from public domain databases such as PubChem and RCSB Protein Data Bank. For in silico screening, the molecular interactions, binding energy, and ADMET properties were investigated.

RESULTS

The structure-based molecular docking reveals some molecules' greater affinity towards the target than the co-crystal ligand. Our results show that tannic acid, cyanidin-3-rutinoside, zeaxanthin, and carbolactone are phytomolecules capable of inhibiting SARS-CoV-2 target proteins in the least energy conformations. Tannic acid had the least binding energy of -8.8 kcal/mol, which is better than the binding energy of its corresponding co-crystal ligand (-7.5 kcal/mol) against 3 CL protease. Also, it has shown the least binding energy of -9.9 kcal/mol with a more significant number of conventional hydrogen bond interactions against the RdRp target. Cyanidin-3-rutinoside showed binding energy values of -8.8 and -7.6 kcal/mol against Main protease and Papain-like protease, respectively. Zeaxanthin was the top candidate in the N protein RBD with a binding score of - 8.4 kcal/mol, which is slightly better when compared to a co-crystal ligand (-8.2 kcal/mol). In the spike, carbolactone was the suitable candidate with the binding energy of -7.2 kcal/mol and formed a conventional hydrogen bond and two hydrophobic interactions. The best binding affinity-scored phytomolecules were selected for the MD simulations studies.

CONCLUSION

The present in silico screening study suggested that active phytomolecules from medicinal plants could inhibit SARS-CoV-2 targets. The elite docked compounds with drug-like properties have a harmless ADMET profile, which may help to develop promising COVID-19 inhibitors.

Novel Penicillin Derivatives Against Selected Multiple-Drug Resistant Bacterial Strains: Design, Synthesis, Structural Analysis, in silico and in Vitro Studies

INTRODUCTION

The rising numbers of multiple drug-resistant (MDR) pathogens and the consequent antibacterial therapy failure that resulted in severe medical conditions push to illustrate new molecules with extended activity against the resistant strains. In this manner, chemical derivatization of known antibiotics is proposed to save efforts in drug discovery, and penicillins serve as an ideal in this regard.

METHOD

Seven synthesized 6-aminopenicillanic acid-imine derivatives (2a-g) were structure elucidated using FT-IR, 1H NMR, 13C NMR, and MS spectroscopy. In silico molecular docking and ADMET studies were made. The analyzed compounds obeyed Lipinski's rule of five and showed promising in vitro bactericidal potential when assayed against E. coli, E. cloacae, P. aeruginosa, S. aureus, and A. baumannii. MDR strains using disc diffusion and microplate dilution techniques.

RESULT

The MIC values were 8 to 32 µg/mL with more potency than ampicillin, explained by better membrane penetration and more ligand-protein binding capacity. The 2g entity was active against E. coli. This study was designed to find new active penicillin derivatives against MDR pathogens.

CONCLUSION

The products showed antibacterial activity against selected MDR species and good PHK, PHD properties, and low predicted toxicity, offering them as future candidates that require further preclinical assays.

Anticancer Compounds from Cyanobacteria and their Implications in Apoptosis

Cyanobacteria have been recognized as a rich source of bioactive metabolites with potential biotechnological applications in the pharmacological industry. The chemically diverse natural compounds or their analogues cause cytotoxicity. They may kill various cancer cells by inducing apoptosis or changing the activation of cell signaling, particularly involving the protein kinase-C family of enzymes, mitochondrial dysfunctions, and oxidative damage. B cell lymphoma 2 (Bcl-2) is an essential component of apoptosis and is an antiapoptotic molecule. The key apoptotic regulators associated with cancer are members of the Bcl-2 protein family, the key member of which is Bcl-2. The Bcl-2 protein is a promising target for the emergence of new anti-tumor therapies because of its critical role in controlling apoptosis. This review explores the significance of Bcl-2 in the onset of cancer; it may be used as a target for developing high-quality drug therapies to treat various tumors. In addition, a number of computational techniques were used to identify novel hit compounds that may act as inhibitors of the apoptotic protein Bcl-2, including virtual screening, toxicity prediction, and drug-likeness analysis. Twenty-three compounds were assessed as potential hits against Bcl-2, and these compounds were subjected to ADMET property prediction. Dendroamide A and Welwitindolinone A appear to be the most stable and effective drugs against Bcl-2 out of all those evaluated. This article gives an overview of the bioactive compounds produced by cyanobacteria that have anticancer properties and may be exploited to create novel anticancer medications in the future.

Synthesis, In silico and In vitro Analysis of Hydrazones as Potential Antituberculosis Agents

Tuberculosis (TB) is a major cause of mortality and illness as reported by the W.H.O in 2019. The WHO report also mentioned the fact that about 10.0 million people fell ill with tuberculosis in the year 2018. Hydrazide-hydrazones having azomethine group (-NH-N=CH-) connected with carbonyl group is reported for the number of bioactivities like anti-inflammatory, anticonvulsant, anticancer, antiviral and antiprotozoal.

OBJECTIVE

The objective of our current study is to design and synthesise more potent hydrazide- hydrazones, containing anti-tubercular agents.

METHODS

In the current study, we synthesized 10 hydrazones (3a-3j) by stirring corresponding benzohydrazides (2) with substituted aldehydes (1a-j) in ethanol as a solvent and acetic acid as a catalyst at room temperature. All synthesized compounds were characterized by various spectroscopic techniques including elemental analysis, ultraviolet-visible spectroscopy, fluorescence, fourier- transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. Compounds (3a-3j) were tested for in vitro anti-TB activity using Microplate Alamar Blue Assay (MABA).

RESULTS

All our synthesized compounds (3a-3j) were found to be potent against Mycobacteria tuberculosis (H37RV strain) with MIC (minimum inhibitory concentrations) values of 3.125-50 μg/mL. The hydrazide CO-NH protons in (3a-j) compounds are highly deshielded and showed broad singlet at 9.520-9.168 ppm. All the compounds were found to have more intense emission in the 416 - 429 nm regions and strong absorption in the regions of 316 - 327 nm. Synthesized compounds were also tested for in silico analysis using different software for their Absorption, Distribution, Metabolism, Excretion and Toxicity (ADMET) analysis. All the compounds were found to be in silico non-carcinogenic.

CONCLUSION

It will be worth saying that our in silico and in vitro approaches used in the current study will become a guide for medicinal chemists to make structural modifications and synthesize more effective and potent hydrazone containing anti-tubercular agents.