Diverse Thiophenes as Scaffolds in Anti-cancer Drug Development: A Concise Review

Unveiling the Noncovalent Interactions between Formamide and Heteroaromatics: Microwave Spectroscopy of the Formamide Complexes with Furan and Thiophene

The noncovalent interactions between formamide (FM) and the heteroaromatic compounds (furan and thiophene) were investigated through microwave spectroscopy and theoretical calculations. Each of the investigated complexes exhibits a single rotational spectrum corresponding to the lowest energy structure predicted theoretically. In the detected structures, N-H···O and C-H···O hydrogen bonds dominate the complexation between FM and furan, resulting in a planar configuration. Conversely, a superposed configuration linked by a N-H···π hydrogen bond and C═O···π contact is observed for the FM-thiophene complex. In both cases, hydrogen bonding interactions with N-H as proton donor rank as the dominant forces, and the interaction energy of N-H···O is larger than that of N-H···π. It was found that the electrostatic component is the largest contributor to the attraction between FM and furan, while the dispersion component is the most significant attractive factor in the FM-thiophene complex. These findings highlight the distinct features of hydrogen bonding interactions of amides with heteroaromatics in the studied complexes.

GDU-952, a novel AhR agonist ameliorates skin barrier abnormalities and immune dysfunction in DNFB-induced atopic dermatitis in mice

The aryl hydrocarbon receptor (AhR) is widely expressed in the skin. It controls immune-mediated skin responses to various external environmental signals, promote terminal differentiation of epidermal keratinocytes and participates the maintenance of the skin barrier function. As a therapeutic target, AhR activation modulates many diseases progression driven by immune/inflammatory processes such as atopic dermatitis (AD) and psoriasis. In this study, we revealed that GDU-952 is a novel AhR agonist, which is able to decreases IgE serum levels, to inhibit pro-inflammatory cytokines such as IL-6 and TNF-α and to induce immunoregulatory effects through restoring Th1/Th2 immune balance and promoting CD4+FOXP3+regulatory T (Treg) populations in AD skin lesions. Furthermore, GDU-952 can strengthen the skin barrier function through upregulating epidermal differentiation-related and tight junction proteins. This may alleviate AD symptoms, such as dermatitis scores, epidermal hyperplasia and mast cell infiltration. These results offer a rationale for further preclinical/clinical studies to evaluate the possible use of GDU-952 in the management of AD.

Noncovalent Interactions between Aromatic Heterocycles and Carboxylic Acids: Rotational Spectroscopy of the Furan-Formic Acid and Thiophene-Formic Acid Complexes

The binary molecular complexes formed between the aromatic heterocycles furan and thiophene with formic acid were investigated using pulsed-jet Fourier transform microwave spectroscopy and quantum chemical computations. For both of the complexes, rotational spectra of the lowest energy isomer were detected and assigned. Rotational spectroscopic results and density functional theory calculations support that the preferred conformation of the furan-formic acid complex is characterized by a relatively strong O-H···O and a weak C-H···O hydrogen bonds while the O-H···π and C-H···O hydrogen bonds stabilize the thiophene-formic acid complex. Natural bond orbital analysis further proves the experimental observation, suggesting that the strength of the O-H···O(furan) interaction is about two times stronger than that of O-H···π(thiophene). The symmetry adapted perturbation theory analysis reveals that electrostatic interaction is dominant in stabilizing the two complexes and that dispersion becomes significant in the thiophene-formic acid complex compared to furan-formic acid.

Thiophenes-Naturally Occurring Plant Metabolites: Biological Activities and In Silico Evaluation of Their Potential as Cathepsin D Inhibitors

Naturally, thiophenes represent a small family of natural metabolites featured by one to five thiophene rings. Numerous plant species belonging to the family Asteraceae commonly produce thiophenes. These metabolites possessed remarkable bioactivities, including antimicrobial, antiviral, anti-inflammatory, larvicidal, antioxidant, insecticidal, cytotoxic, and nematicidal properties. The current review provides an update over the past seven years for the reported natural thiophene derivatives, including their sources, biosynthesis, spectral data, and bioactivities since the last review published in 2015. Additionally, with the help of the SuperPred webserver, an AI (artificial intelligence) tool, the potential drug target for the compounds was predicted. In silico studies were conducted for Cathepsin D with thiophene derivatives, including ADMET (drug absorption/distribution/metabolism/excretion/and toxicity) properties prediction, molecular docking for the binding interaction, and molecular dynamics to evaluate the ligand-target interaction stability under simulated physiological conditions.

Experimental and computational evidence for stabilising parallel, offset π[C(O)N(H)NC]⋯π(phenyl) interactions in acetohydrazide derivatives

Stabilising π[C(O)N(H)NC]⋯π(phenyl) interactions are described.

Mannich Bases: Centrality in Cytotoxic Drug Design

Mannich bases identified by Professor Carl Mannich have been the most extensively explored scaffolds for more than 100 years now. The versatile biological roles that they play have promoted their applications in many clinical conditions. The present review highlights the application of Mannich bases as cytotoxic agents, categorizing them into synthetic, semisynthetic and prodrugs classes and gives an exhaustive account of the work reported in the last two decades. The methods of synthesis of these cytotoxic agents, their anti-cancer potential in various cell lines and promising leads for future drug development have also been discussed. Structure-activity relationships along with the targets on which these cytotoxic Mannich bases act have been included as well.

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 photoredox/nickel dual-catalytic strategy for benzylic C–H alkoxylation

Reported herein is a photoredox/nickel dual-catalyzed benzylic C–H alkoxylation and the protocol features broad substrate scope and excellent functional group compatibility.