Molecular hybrids of substituted phenylcarbamoylpiperidine and 1,2,4-triazole methylacetamide as potent 15-LOX inhibitors: Design, synthesis, DFT calculations and molecular docking studies.

Inflammation is a multifaceted phenomenon triggered by potentially active mediators acutely released arachidonic acid metabolites partially in lipoxygenase (LOX) pathway which are primarily accountable for causing several diseases in humans. It is widely believed that an inhibitor of the LOX pathway represents a rational approach for designing more potent antiinflammatory leads with druggable super safety profiles. In our continual efforts in search for anti-LOX molecules, the present work was to design a new series of N-alkyl/aralkyl/aryl derivatives (7a-o) of 4-phenyl-5-(1-phenylcarbamoylpiperidine)-4H-1,2,4-triazole-3-thiol which was commenced in seriate formation of phenylcarbamoyl derivative (1), hydrazide (2), semicarbazide (3) and 4-phenyl-5-(1-phenylcarbamoylpiperidine)-4H-1,2,4-triazole-3-thiol (4). The aimed compounds were obtained by reacting 4-phenyl-5-(1-phenylcarbamoylpiperidine)-4H-1,2,4-triazole-3-thiol with assorted N-alkyl/aralkyl/aryl electrophiles. All compounds were characterized by FTIR, 1H-, 13C-NMR spectroscopy, EI-MS and HR-EI-MS spectrometry and screened against soybean 15-LOX for their inhibitory potential using chemiluminescence method. All the compounds except 7m and 7h inhibited the said enzyme remarkably. Compounds 7c,7l, 7j and 7a displayed potent inhibitions ranging from IC50 1.92 ± 0.13 µM to 7.65 ± 0.12 µM. Other analogues 7g, 7o, 7e, 7b, 7d, 7k and 7n revealed excellent inhibitory values ranging from IC50 12.45 ± 0.38 µM to 24.81 ± 0.47 µM. All these compounds did not reveal DPPH radical scavenging activity. Compounds 7i-o maintained > 90 % human blood mononuclear cells (MNCs) viability at 0.125 mM as assayed by MTT whilst others were found toxic. Pharmacokinetic profiles predicted good oral bioavailability and drug-likeness properties of the active scaffolds. SAR investigations showed that phenyl substituted analogue on amide side decreased inhibitory activity due to inductive and mesomeric effects while the mono-alkyl substituted analogues were more active than disubstituted ones and ortho substituted analogues were more potent than meta substituted ones. MD simulation predicted the stability of the 7c ligand and receptor complex as shown by their relative RMSD (root mean square deviation) values. Molecular docking studies displayed hydrogen bonding between the compounds and the enzyme with Arg378 which was common in 7n, 7g, 7h and baicalein. In 7a and quercetin, hydrogen bonding was established through Asn375. RMSD values exhibited good inhibitory profiles in the order quercetin (0.73 Å) < 7 g < baicalein < 7a < 7n < 7 h (1.81 Å) and the binding free energies followed similar pattern. Density functional theory (DFT) data established good correlation between the active compounds and significant activity was associated with more stabilized LUMO (lowest unoccupied molecular orbitals) orbitals. Nevertheless, the present studies declare active analogues like 7c, 7 l, 7a, 7j as leads. Work is ongoing in derivatizing active molecules to explore more effective leads as 15-LOX inhibitors as antiinflammatory agents.

Investigations of Limeum Indicum Plant for Diabetes Mellitus and Alzheimer's Disease Dual Therapy: Phytochemical, GC-MS Chemical Profiling, Enzyme Inhibition, Molecular Docking and In-Vivo Studies.

Limeum indicum has been widely utilized in traditional medicine but no experimental work has been done on this herb. The primary objective of this study was to conduct a phytochemical analysis and assess the multifunctional capabilities of aforementioned plant in dual therapy for Alzheimer's disease (AD) and Type 2 diabetes (T2D). The phytochemical screening of ethanol, methanol extract, and their derived fractions of Limeum indicum was conducted using GC-MS, HPLC, UV-analysis and FTIR. The antioxidant capacity was evaluated by DPPH method. The inhibitory potential of the extracts/fractions against α-, ß-glucosidase acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and monoaminine oxidases (MAO-A & B) was evaluated. Results revealed that acetonitrile fraction has highest inhibitory potential against α-glucosidase (IC50=68.47±0.05 µg/mL), methanol extract against ß-glucosidase (IC50=91.12±0.07 µg/mL), ethyl acetate fraction against AChE (IC50=59.0±0.02 µg/mL), ethanol extract against BChE (28.41±0.01 µg/mL), n-hexane fraction against MAO-A (IC50=150.5±0.31 µg/mL) and methanol extract for MAO-B (IC50=75.95±0.13 µg/mL). The docking analysis of extracts\fractions suggested the best binding scores within the active pocket of the respective enzymes. During the in-vivo investigation, ethanol extract produced hypoglycemic effect (134.52±2.79 and 119.38±1.40 mg/dl) after 21 days treatment at dose level of 250 and 500 mg/Kg. Histopathological findings further supported the in-vivo studies.

Computational Exploration of Fluorocyclopentenyl-purines and-pyrimidines Derivatives as Potential Inhibitors of Epidermal Growth Factor Receptor (EGFR) for the Treatment of Breast Cancer.

The Epidermal Growth Factor Receptor (EGFR) is an important therapeutic target for the treatment of a variety of epithelial malignancies, including breast cancer, in which EGFR is aberrantly expressed.The fluorocyclopentenyl-purine-pyrimidines derivatives, which have previously been described as powerful compounds against breast cancer, were selected to investigate their potential against EGFR using computational tools in an effort to obtain potent inhibitors with fewer adverse effects. The molecule's chemical reactivity and stability were assessed by determining the HOMO-LUMO energy gap using density functional theory (DFT) calculations. Among all the selected compounds, PU4 displayed a HOMO-LUMO gap of 0.191 eV. Additionally, molecular docking analysis was performed to assess the binding affinities of PU4 within the active pocket of EGFR-TK. The compound PU4 showed potent interactions with EGFR exhibiting -32.3 kJ/mol binding energy which was found best as compared to gefitinib i. e., -27.4 kJ/mol which was further validated by molecular dynamics simulations and ADMET analysis. The results of these analyses indicate that the top hits obtained from the virtual screening possess the ability to act as effective EGFR inhibitor. Therefore, it is recommended to further investigate the inhibitory potential of these identified compounds using in vitro and in vivo approaches.

Assessing p-tolyloxy-1,3,4-oxadiazole acetamides as lipoxygenase inhibitors assisted by in vitro and in silico studies.

The underlying correlation between the inflammation, innate immunity and cancer is extensively familiar and linked through a process mediated by three enzymes; cyclooxygenase (COX), lipoxygenase (LOX) and cytochrome P450 (CYP450). The ever increase in the reported side effects of the antiinflammatory drugs against the targeted enzymes and the resistance developed afterwards compels the researchers to synthesize new effective molecules with safer profile. On the basis of these facts, our ongoing research on 1,3,4-oxadiazole derivatives deals with the synthesis of a new series of N-alkyl/aralky/aryl derivatives of 5-((p-tolyloxymethyl)-4H-1,3,4-oxadiazole-2-ylthio)acetamide (6a-o) which were developed by the sequential conversion of p-tolyloxyacetic acid (a) into ester (1) hydrazide (2) and 5-(p-tolyloxymethyl)-4H-1,3,4-oxadiazole-2-thiol (3). The designed compounds (6a-o) were acquired by the reaction of 1,3,4-oxadiazole (3) with numerous electrophiles (5a-o) in KOH. The synthesized analogues (6a-o) were characterized by FTIR, 1H-, 13C NMR spectroscopy, EI-MS and HR-EI-MS spectrometry, and were further assessed for their inhibitory potential against the soybean 15-LOX enzyme. The results showed excellent inhibitory potential of the compounds against the said enzyme, specifically 6o, 6b, 6n and 6e with inhibitory values (IC50 ± SEM) of 21.5 ± 0.76, 24.3 ± 0.45, 29.1 ± 0.65 and 31.3 ± 0.78 µM, respectively. These compounds displayed < 55 % blood mononuclear cells (MNCs) cellular viability as measured by MTT assay at 0.25 mM concentration. Other compounds demonstrated moderate inhibitory activities with IC50 values in the range of 33.2 ± 0.78 to 96.3 ± 0.73 µM and exhibited little cellular viability against MNCs except 6i, 6j, 6 m and 6 k that showed 61-79 % cellular viability. It was observed that most of the compounds (6o, 6b, 6n, 6e) were found more toxic towards MNCs at studied concentration of 0.25 mM. SAR studies revealed that the positions and nature of substituents accompanying phenyl ring have great influence on 15-LOX inhibitory activity. In the most active compound 6o, the amino acids Asp768 and Val126 were involved in hydrogen bonding, Thr529 was linked with π-anion interaction and π-sulphur interaction was displayed with Tyr525 and two π-alkyl interactions were formed with the benzene ring and amino acid residues Pro530 and Arg533. The in silico pharmacokinetics profiles and density functional theory calculations of the compounds further supported the in vitro findings. Further work on the synthesis of more oxadiazole derivatives is in progress in search for potential 'leads' for the drug discovery as LOX inhibitors.

Synthesis and computational studies of highly selective inhibitors of human recombinant tissue non-specific alkaline phosphatase (h-TNAP): A therapeutic target against vascular calcification.

In this study, we have discovered small druglike molecules as selective inhibitors of human tissue-nonspecific alkaline phosphatase (h-TNAP), an enzyme critical for the regulation of extracellular matrix calcification. The upregulation of h-TNAP is associated with various pathologies particularly the vascular calcification (VC). Selective inhibition of h-TNAP over h-NPP1 may serve as a useful therapeutic strategy against vascular calcification. A series of novel triazolyl pyrazole derivatives (10a-y) in which thiol bearing triazole moiety as the zinc binding functional group was introduced to a pyrazole based pharmacophore was synthesized and evaluated as potent and selective inhibitors of h-TNAP over h-NPP1. The biological screening against h-TNAP, h-IAP, h-NPP1 and h-NPP3 showed that many of the synthesized compounds are selective inhibitors of TNAP. Particularly, the compounds 10a-h, 10j, 10m-q, 10u, 10w and 10x displayed high potency and complete selectivity towards h-TNAP over h-NPP1. Compound 10q emerged as a highly potent inhibitor (IC50 = 0.16 µM or 160 nM) against h-TNAP with 127-fold increased inhibition compared to levamisole. On the other hand, compound 10e was found to be most selective inhibitor against the tested APs and NPPs (IC50 = 1.59 ± 0.36 µM). Binding sites architecture analysis, molecular-docking and molecular dynamics simulations (MDS), revealed the basis for h-TNAP and h-IAP ligand selectivity as well as selectivity towards h-TNAP over h-NPP1. These newly discovered inhibitors are believed to represent valuable lead structures to further streamline the generation of candidate compounds to target VC.