Synthesis of first ever 4-quinolone-3-carboxylic acid-appended spirooxindole-pyrrolidine derivatives and their biological applications

Design, green synthesis, and anti-glutamate damage screening of chalcone derivatives with spiro-heterocyclic structures as potential anti-ischemic brain and eye damage agents

Antagonizing excessive glutamate-induced neuroexcitatory toxicity is one of the treatments for brain and retinal nerve damage in ischemic stroke patients. In this work, a series of 3-benzoyl-4-phenyl-spiropyrrolidone (spiroheterocyclic) compounds were designed and synthesized by modifying the Michael receptor of chalcone to reduce its toxicity. Several compounds with superior protective effects on PC12 cells were screened through an experimental model of glutamate-induced damage, and a quantitative evaluation of the structure-activity relationship (QSAR) model with a regression coefficient of R2 = 0.90723 was established through the random forest (RF) algorithm. Among these compounds, E38 significantly increased the survival rate of damaged cells, promoted colony formation, and inhibited LDH release and apoptosis, and the protective effect of E38 was possibly partly through the HO-1/SIRT1 pathway. More importantly, in mice model of middle cerebral artery occlusion (MCAO), E38 decreased cerebral infarct size, improved neurological scores, and mitigated retinal damage. In conclusion, this work presents a novel class of chalcone derivatives with neuroprotective activity and offers potential compounds for the treatment of ischemic stroke.

In-silico driven design and development of spirobenzimidazo-quinazolines as potential DNA gyrase inhibitors

DNA gyrase and Topoisomerase IV are promising antibacterial drug targets as they regulate bacterial DNA replication and topology. In a quest for novel DNA topoisomerase inhibitors, a multidisciplinary approach was adopted that involves computational prediction of binding sites and molecular modelling followed by green synthesis and biological evaluation of antibacterial activity of spirobenzimidazo quinazolines derivatives. Using basic quantum chemistry principles, we evaluated spirobenzimidazo quinazolines derivatives with their pharmacokinetic profiles. Based on the results of the aforesaid in-silico studies, we synthesized a series of titled compounds using green synthetic methodology that were validated as potential antimicrobial agents. Quantum chemoinformatics based predicted activity for the synthesized compounds 9b, 9c, and 9j was concomitant with biological evaluation of broadspectrum antibacterial activity. Biological evaluation revealed that inhibition of biofilm formation was due to their potential antibacterial activity. We believe that the novel spirobenzimidazo quinazolines have the potential to be alternatives to aminocoumarins and classical quinazolines upon detailed target specific biological studies.

An overview of spirooxindole as a promising scaffold for novel drug discovery

Introduction: Spirooxindole, a unique and versatile scaffold, has been widely studied in some fields such as pharmaceutical chemistry and synthetic chemistry. Especially in the application of medicine, quite a few compounds featuring spirooxindole motif have displayed excellent and broad pharmacological activities. Many identified candidate molecules have been used in clinical trials, showing promising prospects.Areas covered: This article offers an overview of different applications and developments of spirooxindoles (including the related natural products and their derivatives) in the process of drug innovation, including such as in anticancer, antimicrobial, anti-inflammatory, analgesic, antioxidant, antimalarial, and antiviral activities. Furthermore, the crucial structure-activity relationships, molecular mechanisms, pharmacokinetic properties, and main synthetic methods of spirooxindoles-based derivatives are also reviewed.Expert opinion: Recent progress in the biological activity profiles of spirooxindole derivatives have demonstrated their significant position in present-day drug discovery. Furthermore, we believe that the multidirectional development of novel drugs containing this core scaffold will continue to be the research hotspot in medicinal chemistry in the future.

Benefits and applications of microwave-assisted synthesis of nitrogen containing heterocycles in medicinal chemistry

Nitrogen containing heterocycles are of immense research interest because they are often found as naturally occurring bioactive compounds.

The crystal structure of 3-((phenylamino)methylene)-1,5-dioxaspiro[5.5]undecane-2,4-dione, C16H17N1O4

C16H17N1O4, triclinic, P1̅ (no. 2), a = 7.0971(3) Å, b = 7.6638(4) Å, c = 13.2375(6) Å, α = 92.116(10)°, β = 99.690(10)°, γ = 95.196(10)° V = 705.81(6) Å3, Z = 2, R gt(F) = 0.0529, wR ref(F 2) = 0.1489, T = 296(2) K.

Facile one-pot synthesis of spirooxindole-pyrrolidine derivatives and their antimicrobial and acetylcholinesterase inhibitory activities

A library of novel spirooxindole-pyrrolidine derivatives were facilely synthesized via 1,3-dipolar cycloaddition of azomethine ylide generated from sarcosine and paraformaldehyde with various 3-methyleneoxindolines.

4-Quinolone derivatives and their activities against Gram positive pathogens

Gram-positive bacteria are responsible for a broad range of infectious diseases, and the emergency and wide spread of drug-resistant Gram-positive pathogens including MRSA and MRSE has caused great concern throughout the world. 4-Quinolones which are exemplified by fluoroquinolones are mainstays of chemotherapy against various bacterial infections including Gram-positive pathogen infections, and their value and role in the treatment of bacterial infections continues to expand. However, the resistance of Gram-positive organisms to 4-quinolones develops rapidly and spreads widely, making them more and more ineffective. To overcome the resistance and reduce the toxicity, numerous of 4-quinolone derivatives were synthesized and screened for their in vitro and in vivo activities against Gram-positive pathogens, and some of them exhibited excellent potency. This review aims to outlines the recent advances made towards the discovery of 4-quinolone-based derivatives as anti-Gram-positive pathogens agents and the critical aspects of design as well as the structure-activity relationship of these derivatives. The enriched SAR paves the way to the further rational development of 4-quinolones with a unique mechanism of action different from that of the currently used drugs to overcome the resistance, well-tolerated and low toxic profiles.

Design and Synthesis of Sulfonamide-1,2,3-Triazole Derivatives Bearing a Dithiocarbamate Moiety as Antiproliferative Agents

A series of nine novel 1-(4′-sulfamoylphenyl)-1,2,3-triazole derivatives bearing a 4-dithiocarbamylmethyl moiety were designed using the molecular hybridisation approach and synthesised by alkyne/azide click chemistry. Most of the synthesised compounds exhibited moderate to good antiproliferative activity against oesophagus, gastric and prostate cancer cell lines, but a compound containing a 4-( t-butoxycarbonyl)piperazinylthiocarbonyl moiety showed the highest activity. Against a prostate cancer cell line, it had an IC50 value of 2.4 μM, about 10-fold more active than 5-flurouracil. This work shows that novel sulfonamide-1,2,3-triazole derivatives bearing a dithiocarbamate moiety linked to a 4-substituted piperazine are promising lead compounds for the development of antitumour agents.

Molecular diversity of phenothiazines: design and synthesis of phenothiazine-dithiocarbamate hybrids as potential cell cycle blockers

Novel phenothiazine-dithiocarbamate analogues were designed by molecular hybridization strategy and synthesized and evaluated for their anticancer activity in vitro against three selected cancer cell lines (EC-109, MGC-803, and PC-3). The preliminary structure-activity relationship (SAR) for this phenothiazine-dithiocarbamate hybrids is explored. Among all analogues, 2-oxo-2-(10H-phenothiazin-10-yl)ethyl 4-ethylpiperazine-1-carbodithioate (8a) showed the most potent inhibitory activity with an [Formula: see text] value of [Formula: see text] against PC-3 cells. In addition, compound 8a could arrest the cell cycle at the G1 phase and regulate the expression of G1 checkpoint-related proteins, suggesting that phenothiazine-dithiocarbamate hybrids might be useful as cell cycle blockers.

A synthesis of functionalized dihydro-1Η-pyrrolizines and spiropyrrolizines via [2 + 3] cycloaddition reactions

A one-pot synthesis of dihydro-1H-pyrrolizine derivatives via [Formula: see text] cycloaddition reaction of azomethine ylides, prepared in situ from proline and ninhydrin, with dialkyl acetylenedicarboxylates, in alcohols, is described. When sarcosine was used instead of proline, functionalized spiropyrrolizines were obtained. Under these conditions, alkyl propiolates produced stable spirans.