Tetrahydroquinolinone derivatives exert antiproliferative effect on lung cancer cells through apoptosis induction

Synthesis, characterization and biological research of novel 2-(quinoline-4-carbonyl)hydrazide-acrylamide hybrids as potential anticancer agents on MCF-7 breast carcinoma cells by targeting EGFR-TK

Novel derivatives of the 2-(quinoline-4-carbonyl)hydrazide scaffold carrying the acrylamide moiety were synthesized and tested for their cytotoxic efficacy against the breast carcinoma MCF-7 cell line. The most active members 6a, 6b and 6h revealed significant antiproliferative action with an IC50 value of 3.39, 5.94 and 2.71 μM, respectively, which were more potent than the reference drug Dox (IC50 = 6.18 μM). Aiming to enlighten the antiproliferative activity, compounds 6a and 6h were examined for their inhibitory potential against EGFR kinase. The results demonstrated that compound 6h displayed potent inhibitory activity, as concluded from the IC50 value (IC50 = 0.22 μM) compared to the standard drug Lapatinib (IC50 value of 0.18 μM). Compound 6h was found to induce significant cellular cycle arrest at the G1 phase and provoke apoptosis. Besides, compound 6h triggered apoptosis via upregulating p53 and initiator caspase 9 by 7.4- and 8.7-fold, respectively, compared to DMSO controls.

Meldrum's acid assisted formation of tetrahydroquinolin-2-one derivatives a short synthetic pathway to the biologically useful scaffold

A new method for the preparation of tetrahydroquinolin-2-one derivatives is presented. This approach involves a two-step reaction between enaminones and acylating agents, immediately followed by electrophilic cyclization, all within a single synthesis procedure, eliminating the need to isolate intermediates. The entire process is facilitated by the use of acyl Meldrum's acids which not only shortens the preparation time of the substrates but also easily extends the range of substituents That can be used. The method's scope and limitations were evaluated with various reagent combinations thus demonstrating its general applicability to the synthesis of tetrahydroquinolin-2-one core. Interestingly, some exceptions to the regular reaction pathway were observed when a strong EDG (electron donating group) was introduced via acyl Meldrum's acids. The underlying mechanism of this phenomenon was elucidated during the investigation.

Developing our knowledge of the quinolone scaffold and its value to anticancer drug design

INTRODUCTION

The quinolone scaffold is a bicyclic benzene-pyridinic ring scaffold with nitrogen at the first position and a carbonyl group at the second or fourth position. It is endowed with a diverse spectrum of pharmacological activities, including antitumor activity, and has progressed into various development phases of clinical trials for their target-specific anticancer activity.

AREAS COVERED

The present review covers both classes of quinolones, i.e. quinolin-2(H)-one and quinolin-4(H)-one as anticancer agents, along with their possible mode of binding. Furthermore, their structure-activity relationships, molecular mechanisms, and pharmacokinetic properties are also covered to provide insight into their structural requirements for their rational design as anticancer agents.

EXPERT OPINION

Synthetic feasibility and ease of derivatization at multiple positions, has allowed medicinal chemists to explore quinolones and their chemical diversity to discover newer anticancer agents. The presence of both hydrogen bond donor (-NH) and acceptor (-C=O) functionality in the basic scaffold at two different positions, has broadened the research scope. In particular, substitution at the -NH functionality of the quinolone motif has provided ample space for suitable functionalization and appropriate substitution at the quinolone's third, sixth, and seventh carbons, resulting in selective anticancer agents binding specifically with various drug targets.