Fluorescent octahydrophenazines as novel inhibitors against herpes simplex viruses

A new series of racemic fluorescent octahydrophenazines (rac-PZ1-11) have been designed and synthesized via the efficient nucleophilic aromatic substitution (SNAr) of tetrafluorobenzenedinitriles (1a-c) and racemic cyclohexane-1,2-diamines (rac-2a and b). The bioactivities of these racemic rac-PZs (20 μM) against herpes simplex virus type-1 (HSV-1) were evaluated by the relative cell viability of Vero cells infected with HSV-1. It was found that rac-PZ3 shows much higher anti-HSV-1 activity than others, with EC50 = 9.2 ± 1.4 μM. Further investigation into the anti-HSV activities of rac-PZ3 and its enantiomers RR- and SS-PZ3 indicates that rac-PZ3 can also efficiently inhibit HSV-2 and even ACV-resistant HSV-2 (EC50 = 11.0 ± 2.3 and 14.9 ± 2.8 μM, respectively), SS-PZ3 has better activities against HSV-1, HSV-2 and ACV-resistant HSV-2 (EC50 = 4.1 ± 1.1, 5.8 ± 1.0 and 7.9 ± 1.2 μM, respectively), but RR-PZ3 has almost no antiviral activities. The primary mechanism study indicates that rac-PZ3 efficiently reverses the HSV-1/2-induced cytopathic effect and suppresses the expression of viral mRNA and proteins. In addition, rac-, RR- and SS-PZ3 possess excellent fluorescence properties with almost the same emission wavelength and high fluorescence quantum yields (ΦF = 90.3-92.3 % in cyclohexane solutions and 54.4-57.3 % in solids) and can target endoplasmic reticulum and cell membrane. The efficient anti-HSV bioactivities and excellent fluorescence of PZ3 prove its potential applications in antiviral therapy and biological imaging.

Recent advancement in the synthesis of quinoline derivatives via multicomponent reactions

The synthesis of quinoline derivatives through multicomponent reactions (MCRs) has emerged as an efficient and versatile strategy in organic synthesis. MCRs offer the advantage of constructing complex molecular architectures in a single step, utilising multiple starting materials in a convergent manner. This review provides an overview of recent advancements in the field of quinoline synthesis via MCRs. Various MCRs, such as the Povarov reaction, the Gewald reaction, and the Ugi reaction have been successfully employed for the synthesis of diverse quinoline scaffolds. These methodologies not only showcase high atom economy but also allow the incorporation of structural diversity into the final products. The versatility of MCRs enables the introduction of functional groups and substitution patterns tailored to specific applications. This review highlights the significance of quinoline derivatives in medicinal chemistry, materials science, and other interdisciplinary areas. The continuous innovation and development of novel MCR-based approaches for quinoline synthesis hold great promise for the rapid and efficient generation of valuable compounds with a wide range of biological and physicochemical properties.

A simple iodine-DMSO-promoted multicomponent reaction for the synthesis of 2,4-disubstituted dihydrotriazole-3-ones

A series of 2,4-disubstituted 1,2,4-triazole-3-ones 4 were prepared via an iodine-DMSO-promoted three-component reaction of formaldehyde, amines and hydrazines in moderate yields.

Chemoselective synthesis of fully substituted pyrroles via a one-pot four-component isocyanide-based reaction

Small-ring heterocycles comprising pyrrole and pyrazole are well known for their rich biological properties. In this article, an efficient green sonochemical approach was designed for the synthesis of novel, fully substituted pyrroles connected to pyrazole scaffolds via a one-pot, four-component isocyanide-based sequential reaction. This reaction was carried out using various 5-amino-pyrazoles, aldehydes, dialkyl acetylenedicarboxylates and isocyanides for the synthesis of fully functionalized pyrroles with high chemoselectivity in the presence of a catalytic amount of PTSA·H2O, in good to excellent yields under ultrasound irradiation. This waste-free (-H2O) reaction exhibited a high atom economy and step economy via creating four new bonds, including two C-N and two C-C bonds, and the formation of two five-member heterocycles which are connected in a single operation. The mechanism of this four-component domino process involved sequential imination-dipolar cyclization-[1,5]-H shift reactions. The synthesized compounds possess interesting fluorescence features, and the bioactive scaffolds might attract great interest in the fields of clinical diagnostics and biomedical research in the future.