Design, synthesis, and correlation analysis of 7-substituted 4-hydroxyquinoline-3-carboxylic acids as inhibitors of cellular respiration

Novel Pyrazolo[4, 3-c]Quinolin-3-One Derivatives as PDE5A Inhibitors

BACKGROUND

PDE5A is a phosphodiesterase which specifically hydrolyzes the cGMP to GMP. It takes part in several physiological and pathological pathways and is considered an important drug target. Currently, PDE5 inhibitors (ex; Sildenafil, Tadalafil) available in the market are not only being used for the treatment of erectile dysfunction but at the same time, they are also in clinical trials being investigated as anticancer agents.

MATERIALS & METHODS

In this work, we have examined pyrazolo [4,3-c]quinolin-3-ones as PDE5A inhibitors. Pyrazolo [4,3-c]quinolin-3-ones are the class of tricyclic heterocyclic derivatives having a variety of therapeutically interesting drug candidates known for their anti-inflammatory, anti-viral, anti-anxiety and anti-cancer activity. Therefore, synthetic methods providing access to pyrazolo [4, 3-c] quinolin-3-ones are immensely valuable. Here, we are reporting a simple but efficient route for the synthesis of novel 8-morpholino-2-aryl - 2, 5-dihydro-3H-pyrazolo [4, 3-c] quinolin-3-one derivatives.

RESULTS

Further, molecular docking studies of synthesized compounds with human PDE5A protein showed that all the compounds exhibited good docking score in comparison with known inhibitors. In addition, all the synthesized molecules were evaluated against HCT116 cell lines for their antitumor activity.

CONCLUSION

Among all the synthesized compounds, compound 5a, 5d, and 6e showed better cytotoxicity. Thus, these derivatives can be studied as potential inhibitors of PDE5A.

Discovery of N-(2,4-di-tert-butyl-5-hydroxyphenyl)-4-oxo-1,4-dihydroquinoline-3-carboxamide (VX-770, ivacaftor), a potent and orally bioavailable CFTR potentiator

Quinolinone-3-carboxamide 1, a novel CFTR potentiator, was discovered using high-throughput screening in NIH-3T3 cells expressing the F508del-CFTR mutation. Extensive medicinal chemistry and iterative structure-activity relationship (SAR) studies to evaluate potency, selectivity, and pharmacokinetic properties resulted in the identification of N-(2,4-di-tert-butyl-5-hydroxyphenyl)-4-oxo-1,4-dihydroquinoline-3-carboxamide (VX-770, 48, ivacaftor), an investigational drug candidate approved by the FDA for the treatment of CF patients 6 years of age and older carrying the G551D mutation.

Synthesis, cytotoxicity and mechanistic evaluation of 4-oxoquinoline-3-carboxamide derivatives: finding new potential anticancer drugs

As part of a continuing search for new potential anticancer candidates, we describe the synthesis, cytotoxicity and mechanistic evaluation of a series of 4-oxoquinoline-3-carboxamide derivatives as novel anticancer agents. The inhibitory activity of compounds 10–18 was determined against three cancer cell lines using the MTT colorimetric assay. The screening revealed that derivatives 16b and 17b exhibited significant cytotoxic activity against the gastric cancer cell line but was not active against a normal cell line, in contrast to doxorubicin, a standard chemotherapeutic drug in clinical use. Interestingly, no hemolytical activity was observed when the toxicity of 16b and 17b was tested against blood cells. The in silico and in vitro mechanistic evaluation indicated the potential of 16b as a lead for the development of novel anticancer agents against gastric cancer cells.

Studies of anti-HIV transcription inhibitor quinolones: identification of potent N1-vinyl derivatives

The 6-desfluoroquinolones (6-DFQs) are anti-HIV agents that target Tat-mediated transcription. This particular mechanism of action makes this class of compounds very attractive for further structural investigations. Identification of the pharmacophore required for inhibition will ultimately result in the design of more selective analogues for use in combination therapy for the treatment of HIV infections. We have focused on the pyridone ring of the quinolone nucleus present in these compounds, designing new modifications to broaden the structure-activity relationship knowledge base. Herein, we present novel and very potent anti-HIV quinolones, most notably those bearing an amino or vinyl group at the N1 position. Attempts were made to determine the structural parameters necessary to impart potent anti-HIV activity to the vinyl derivatives.

Studies on anti-HIV quinolones: new insights on the C-6 position

The 6-desfluoroquinolones which have been developed by our group represent a promising class of compounds for the treatment of HIV infection since they act on transcriptional regulation, a crucial step in the replication cycle that has not been clinically exploited, yet. Focussing attention on the N-1 and C-6 positions, a novel series of quinolones has been synthesized. New SAR insights have been obtained, in particular, the hydroxyl group emerged as a suitable C-6 substituent when coupled with the appropriate arylpiperazine at the neighboring C-7 position.

The inhibition of factor inhibiting hypoxia-inducible factor (FIH) by beta-oxocarboxylic acids

Cyclic beta-oxocarboxylic acids inhibit factor inhibiting hypoxia-inducible factor via ligation to the active site iron.

Design, synthesis, and biological evaluation of novel 4-hydro-quinoline-3-carboxamide derivatives as an immunomodulator

A series of novel quinoline-3-carboxamide derivatives were synthesized and evaluated for their immunomodulatory activity. The compounds were tested in vitro for effects on spleen lymphocyte proliferation and TNF-alpha production by macrophage. Three compounds showed immunomodulatory profiles similar to and more potent than those of linomide and FR137316 and were selected for further pharmacological studies in vivo.

General definition of valence delta-values for molecular connectivity

The molecular connectivity valence delta-values have been defined in terms of the count of nonhydrogen valence electrons on a valence-state atom as screened from the nucleus by the core electrons. The core is defined as the nonvalence electrons minus 1. This general definition expresses the valence delta-values for second and third quantum level atoms and halogens. Valence delta-values have been derived for higher oxidation states of sulfur and phosphorus. The internal consistency of these delta-values is tested by their ability to closely correlate molar refraction values with 1 chi v. It is found that a second variable, the count of the number of alpha hydrogen atoms, greatly increases the quality of the correlation. Some biological SAR applications reveal the general utility of these findings.