Design, synthesis, biological evaluation and molecular modeling of novel 1,3,4-oxadiazole derivatives based on Vanillic acid as potential immunosuppressive agents

Developing a vanillin-derived imidazo-pyridin-containing fluorescent probe for imaging cysteine in living pulmonary cells under oxygen supply variation

In this work, derived from vanillin and imidazo-pyridin backbone, a fluorescent probe IPV-Cys was developed for imaging the cysteine (Cys) level in living pulmonary cells under oxygen supply variation. By mimicking the oxygen supply variation in both the solution test and cellular imaging, the optical performance and imaging effect of IPV-Cys was investigated. In the solution system, the oxygen supply variation caused no impact on the reporting signals. The fluorescence reporting signal intensity at 490 nm suggested the enhancement along with the increase of the Cys concentration. The advantages of IPV-Cys included relatively high sensitivity, high stability, and high selectivity. On the basis of the low cyto-toxicity, IPV-Cys achieved the monitoring the endogenous Cys level in in living pulmonary cells and the impact of the oxygen supply variation by reporting fluorescence signals. The information here was meaningful for both the pre-clinical diagnosis and surgical techniques.

Computational identification of mitochondrial dysfunction biomarkers in severe SARS-CoV-2 infection: Facilitating therapeutic applications of phytomedicine

BACKGROUND

Currently, SARS-CoV-2 has not disappeared and continues to prevail worldwide, with the ongoing risk of mutations and the potential for severe COVID-19. The impairment of monocyte mitochondrial function caused by SARS-CoV-2, leading to a metabolic and immune dysregulation, is a crucial factor in the development of severe COVID-19.

PURPOSE

Discover effective phytomedicines based on mitochondrial-related biomarkers in severe SARS-CoV-2 infection.

METHODS

Firstly, differential gene analysis and gene set enrichment analysis (GSEA) were conducted on monocytes datasets to identify genes and pathways distinguishing severe patients from uninfected individuals. Then, GO and KEGG enrichment analysis on the differentially expressed genes (DEGs) obtained. Take the DEGs and intersect them with the MitoCarta 3.0 gene set to obtain the differentially expressed mitochondrial-related genes (DE-MRGs). Subsequently, machine learning algorithms were employed to screen potential mitochondrial dysfunction biomarkers for severe COVID-19 based on score values. ROC curves were then plotted to assess the distinguish capability of the biomarkers, followed by validation using two additional independent datasets. Next, the effects of the identified biomarkers on metabolic pathways and immune cells were explored through Gene Set Variation Analysis (GSVA) and CIBERSORT. Finally, potential nature products for severe COVID-19 were screened from the expression profile dataset based on dysregulated mitochondrial-related genes, followed by in vitro experimental validation.

RESULTS

There are 1812 DEGs and 17 dysregulated mitochondrial processes between severe COVID-19 patients and uninfected individuals. A total of 77 DE-MRGs were identified, and the potential biomarkers were identified as RECQL4, PYCR1, PIF1, POLQ, and GLDC. In both the training and validation sets, the area under the ROC curve (AUC) for these five biomarkers was greater than 0.9. And they did not show significant changes in mild to moderate patients (p > 0.05), indicating their ability to effectively distinguish severe COVID-19. These biomarkers exhibit a highly significant correlation with the dysregulated metabolic processes (p < 0.05) and immune cell imbalance (p < 0.05) in severe patients, as demonstrated by GSVA and CIBERSORT algorithms. Curcumin has the highest score in the predictive model based on transcriptomic data from 496 natural compounds (p = 0.02; ES = 0.90). Pre-treatment with curcumin for 8 h has been shown to alleviate mitochondrial membrane potential damage caused by the SARS-CoV-2 S1 protein (p < 0.05) and reduce elevated levels of reactive oxygen species (ROS) (p < 0.01).

CONCLUSION

The results of this study indicate a significant correlation between severe SARS-CoV-2 infection and mitochondrial dysfunction. The proposed mitochondrial dysfunction biomarkers identified in this study are associated with the disease progression, metabolic and immune changes in severe SARS-CoV-2 infected patients. Curcumin has a potential role in preventing severe COVID-19 by protecting mitochondrial function. Our findings provide new strategies for predicting the prognosis and enabling early intervention in SARS-CoV-2 infection.

Assessment of the therapeutic potential of a novel phosphoramidate acyclic nucleoside on induced hepatocellular carcinoma in rat model

AIMS

Hepatocellular Carcinoma (HCC) is renowned as a deadly primary cancer of hepatic origin. Sorafenib is the drug-of-choice for targeted treatment of unresectable end-stage HCC. Unfortunately, great proportion of HCC patients showed intolerance or unresponsiveness to treatment. This study assesses potency of novel ProTide; SH-PAN-19 against N-Nitrosodiethylamine (DEN)-induced HCC in male Wistar rats, compared to Sorafenib.

MAIN METHODS

Structural entity of the synthesized compound was substantiated via FT-IR, UV-Vis, 1H NMR and 13C NMR spectroscopic analysis. In vitro, SH-PAN-19 cytotoxicity was tested against 3 human cell lines; hepatocellular carcinoma; HepG-2, colorectal carcinoma; HCT-116 and normal fibroblasts; MRC-5. In vivo, therapeutic efficacy of SH-PAN-19 (300 mg/kg b.w./day) against HCC could be revealed and compared to that of Sorafenib (15 mg/kg b.w./day) by evaluating the morphometric, biochemical, histopathological, immunohistochemical and molecular key markers.

KEY FINDINGS

SH-PAN-19 was relatively safe toward MRC-5 cells (IC50 = 307.6 μg/mL), highly cytotoxic to HepG-2 cells (IC50 = 24.9 μg/mL) and prominently hepato-selective (TSI = 12.35). Oral LD50 of SH-PAN-19 was >3000 mg/kg b.w. DEN-injected rats suffered hepatomegaly, oxidative stress, elevated liver enzymes, hypoalbuminemia, bilirubinemia and skyrocketed AFP plasma titre. SH-PAN-19 alleviated the DEN-induced alterations in apoptotic, angiogenic and inflammatory markers. SH-PAN-19 produced a 2.5-folds increase in Caspase-9 and downregulated VEGFR-2, IL-6, TNF-α, TGFβ-1, MMP-9 and CcnD-1 to levels comparable to that elicited by Sorafenib. SH-PAN-19 resulted in near-complete pathological response versus partial response achieved by Sorafenib.

SIGNIFICANCE

This research illustrated that SH-PAN-19 is a promising chemotherapeutic agent capable of restoring cellular plasticity and could stop HCC progression.

Discovery of pyrazole-carbohydrazide with indole moiety as tubulin polymerization inhibitors and anti-tumor candidates

In this work, a series of indole-containing pyrazole-carbohydrazide derivatives A1-A25 were synthesized, and their biological activity on tubulin polymerization inhibition and mitotic catastrophe was evaluated. For introducing indole group to CA-4 pattern, the carbohydrazide linker was used for the first time. As the top hit, A18 suggested notable antiproliferation efficacy and tubulin polymerization inhibitory activity. Inferring comparable antitubulin effect with the positive control Colchicine, A18 indicated obviously lower cyto-toxicity. The cell scratch test showed that A18 could block the cell migration, while the confocal imaging depicted that A18 could induce the mitotic catastrophe via a Colchicine-like approach. The docking simulation visualized the probable binding pattern of A18. With the information in this work, some new hints on modification might be involved in further tubulin-related investigations.

Design, synthesis, and insecticidal activity evaluation of piperine derivatives

Structural optimization of natural products has become one of the most effective ways to develop novel pesticides. In this study, 30 novel pesticide derivatives containing a linear bisamide were synthesized. Then, their insecticidal activities against P. xylostella were evaluated. Results indicate that different bisamide substitutes show different larvicidal structure–activity relationships. At the same time, 2-trifluoroethyl is the most efficient substituent. The bioactivity results showed that most of the desired compounds exhibited better insecticidal activity against P. xylostella than piperine. Among them, compound D28 resulted in 90% mortality at 1 mg/ml concentration. This study provides a novel protocol for the discovery of new insecticides. The molecular docking results indicated that compound D28 could act on γ-aminobutyric acid receptors.

Development of New Thiophene-Containing Triaryl Pyrazoline Derivatives as PI3Kγ Inhibitors

A series of new thiophene-containing triaryl pyrazoline derivatives, 3a–3t, were synthesized and evaluated regarding PI3K inhibition activity and anti-tumor potency based on a trial of introducing significant moieties, including pyrazoline and thiophene, and simplifying the parallel ring structures. Most of the tested compounds indicated potent PI3K inhibitory potency, with this series of compounds showing more potency for PI3Kγ than PI3Kα. The top hit 3s seemed more potent than the positive control LY294002 on inhibiting PI3Kγ (IC₅₀ values: 0.066 μM versus 0.777 μM) and more selective from PI3Kα (Index values: 645 versus 1.74). It could be inferred that the combination of para- and meta-, as well as the modification of the electron-donating moieties, led to the improvement in potency. The anti-proliferation inhibitory activity and the enzymatic inhibition potency indicated consistent tendencies. The top hit 3s could inhibit the phosphorylation of Akt by inhibiting PI3K through the PI3K-Akt-mTOR pathway. The molecular docking simulation indicated that the binding pattern of 3s into PI3Kγ was preferable than that of PI3Kα, with more hydrogen bond, more π-involved interactions, and fewer π-sulfur interactions. The information in this work is referable for the further development of selective inhibitors for specific isoforms of PI3K.

Pyrazoline derivatives as tubulin polymerization inhibitors with one hit for Vascular Endothelial Growth Factor Receptor 2 inhibition

In this work, to check the effect of the transposition of the rings in typical patterns, a series of pyrazoline derivatives 3a-3t bearing the characteristic 3,4,5-trimethoxy phenyl and thiophene moieties were synthesized and evaluated as tubulin polymerization inhibitors. Basically, as the concise output of our design, a majority of the synthesized compounds showed potency in inhibiting the tubulin polymerization. The top hit, 3q, exhibited potent anti-proliferation activity on cancer cell lines. It was comparable on tubulin-polymerization inhibition with the positive control Colchicine but lower toxic. The VEGFR2 inhibitory potency was introduced occasionally. The flow cytometry assay confirmed the apoptotic procedure and the confocal imaging revealed the tubulin-microtubule dynamics pattern. The anti-cancer mechanism of 3q was similar to Colchicine but not exactly the same on forming multi-polar spindles. The docking simulation visualized the possible binding patterns of 3q into tubulin and VEGFR2, respectively. The results inferred that further investigations on the transposition of the rings might lead to the improvement of tubulin polymerization inhibitory activity and the steadily introduction of the VEGFR2 inhibition.

A novel series of benzothiazepine derivatives as tubulin polymerization inhibitors with anti-tumor potency

In this work, a series of diaryl benzo[b][1,4]thiazepine derivatives D1-D36 were synthesized and screened as tubulin polymerization inhibitors with anti-tumor potency. They were designed by introducing the seven-member ring benzothiazepine as the linker for CA-4 modification for the first time. Among them, the hit compound D8 showed potential on inhibiting the growth of several cancer cell lines (IC₅₀ values: 1.48 μM for HeLa, 1.47 μM for MCF-7, 1.52 μM for HT29 and 1.94 μM for A549), being comparable with the positive controls Colchicine and CA-4P. The calculated IC₅₀ value of D8 as an tubulin polymerization inhibitor was 1.20 μM. The results of the flow cytometry assay revealed that D8 could induce the mitotic catastrophe and the death of living cancer cells. D8 also indicated the anti-vascular activity. The possible binding pattern was implied by docking simulation, inferring the possibility of introducing interactions with the nearby tubulin chain. Since the novel structural trial has been conducted with preliminary discussion, this work might stimulate new ideas in further modification of tubulin-related anti-cancer agents and therapeutic approaches.

A Review Exploring Therapeutic Worth of 1,3,4-Oxadiazole Tailored Compounds

1,3,4-Oxadiazole, a five-membered aromatic ring can be seen in a number of synthetic molecules. The peculiar structural feature of 1,3,4-oxadiazole ring with pyridine type of nitrogen atom is beneficial for 1,3,4-oxadiazole derivatives to have effective binding with different enzymes and receptors in biological systems through numerous weak interactions, thereby eliciting an array of bioactivities. Research in the area of development of 1,3,4-oxadiazole-based derivatives has become an interesting topic for the scientists. A number of 1,3,4-oxadiazole based compounds with high therapeutic potency are being extensively used for the treatment of different ailments, contributing to enormous development value. This work provides a systematic and comprehensive review highlighting current developments of 1,3,4-oxadiazole based compounds in the entire range of medicinal chemistry such as anticancer, antifungal, antibacterial, antitubercular, anti-inflammatory, antineuropathic, antihypertensive, antihistaminic, antiparasitic, antiobesity, antiviral, and other medicinal agents. It is believed that this review will be of great help for new thoughts in the pursuit for rational designs for the development of more active and less toxic 1,3,4-oxadiazole based medicinal agents.

1,3,4-oxadiazole/chalcone hybrids: Design, synthesis, and inhibition of leukemia cell growth and EGFR, Src, IL-6 and STAT3 activities

A new series of 1,3,4-oxadiazole/chalcone hybrids was designed, synthesized, identified with different spectroscopic techniques and biologically evaluated as inhibitors of EGFR, Src, and IL-6. The synthesized compounds showed promising anticancer activity, particularly against leukemia, with 8v being the most potent. The synthesized compounds exhibited strong to moderate cytotoxic activities against K-562, KG-1a, and Jurkat leukemia cell lines in MTT assays. Compound 8v showed the strongest cytotoxic activity with IC₅₀ of 1.95 µM, 2.36 µM and 3.45 µM against K-562, Jurkat and KG-1a leukemia cell lines, respectively. Moreover; the synthesized compounds inhibited EGFR, Src, and IL-6. Compound 8v was most effective at inhibiting EGFR (IC₅₀ = 0.24 μM), Src (IC₅₀ = 0.96 μM), and IL-6 (% of control = 20%). Additionally, most of the compounds decreased STAT3 activation.

(E)-1,3-diphenyl-1H-pyrazole derivatives containing O-benzyl oxime moiety as potential immunosuppressive agents: Design, synthesis, molecular docking and biological evaluation

A series of novel (E)-1,3-diphenyl-1H-pyrazole derivatives containing O-benzyl oxime moiety were firstly synthesized and their immunosuppressive activities were evaluated. Among all the compounds, 4n exhibited the most potent inhibitory activity (IC50 = 1.18 μM for lymph node cells and IC50 = 0.28 μM for PI3Kγ), which was comparable to that of positive control. Moreover, selected compounds were tested for their inhibitory activities against IL-6 released in ConA-simulated mouse lymph node cells, 4n exhibited the most potent inhibitory ability. Furthermore, in order to study the preliminary mechanism of the compounds with potent inhibitory activity, the RT-PCR experiment was performed to assay the effect of selected compounds on mRNA expression of IL-6. Among them, compound 4n strongly inhibited the expression of IL-6 mRNA.

Recent syntheses of PI3K/Akt/mTOR signaling pathway inhibitors

This review focuses on the syntheses of PI3K/Akt/mTOR inhibitors that have been reported outside of the patent literature in the last 5years but is largely centered on synthetic work reported in 2011 and 2012. While focused on syntheses of inhibitors, some information on in vitro and in vivo testing of compounds is also included. Many of these reported compounds are reversible, competitive adenosine triphosphate (ATP) binding inhibitors, so given the structural similarities of many of these compounds to the adenine core, this review presents recent work on inhibitors based on where the synthetic chemistry was started, that is, inhibitor syntheses which started with purines/pyrimidines are followed by inhibitor syntheses which began with pyridines, pyrazines, azoles, and triazines then moves to inhibitors which bear no structural resemblance to adenine: liphagal, wortmannin and quercetin analogs. The review then finishes with a short section on recent syntheses of phosphotidyl inositol (PI) analogs since competitive PI binding inhibitors represent an alternative to the competitive ATP binding inhibitors which have received the most attention.

Substituted oxadiazoles: a patent review (2010 - 2012)

INTRODUCTION

The oxadiazoles represent a class of five-membered heterocyclic compounds which are of considerable interest in different areas of medicinal chemistry and drug discovery. Oxadiazoles can exist in different regioisomeric forms and employ in various agents with a broad range of biological activities. This review covers the work reported on various biological activities of oxadiazole derivatives from 2010 to 2012.

AREAS COVERED

Oxadiazole derivatives attract great attention due to their different kinds of pharmaceutical activities including antiviral, antimicrobial, anticancer, anticonvulsant, antidiabetic and anti-inflammatory activity. This paper provides a general review of oxadiazole derivatives published in international journals and patented between 2010 and 2012.

EXPERT OPINION

Oxadiazoles have been used frequently in drug-like molecules as bioisosteres for ester and amide functionalities and displayed numerous prominent pharmacological effects. The broad pharmacological profile of oxadiazole derivatives has attracted the attention of many researchers to explore this scaffold to its multiple potential against several activities. Therefore, oxadiazole motif is likely to be present in other therapeutic molecules in the future.