Synthesis and evaluation of in vitro antiviral activity of novel phenoxy acetic acid derivatives

Pyrazol(in)e derivatives of curcumin analogs as a new class of anti-Trypanosoma cruzi agents

Aim: We report the synthesis and biological evaluation of a small library of 15 functionalized 3-styryl-2-pyrazolines and pyrazoles, derived from curcuminoids, as trypanosomicidal agents. Methods & results: The compounds were prepared via a cyclization reaction between the corresponding curcuminoids and the appropriate hydrazines. All of the derivatives synthesized were investigated for their trypanosomicidal activities. Compounds 4a and 4e showed significant activity against epimastigotes of Trypanosoma cruzi, with IC₅₀ values of 5.0 and 4.2 μM, respectively, accompanied by no toxicity to noncancerous mammalian cells. Compound 6b was found to effectively inhibit T. cruzi triosephosphate isomerase. Conclusion: The up to 16-fold higher potency of these derivatives compared with their curcuminoid precursors makes them a promising new family of T. cruzi inhibitors.

Recent investigations into synthesis and pharmacological activities of phenoxy acetamide and its derivatives (chalcone, indole and quinoline) as possible therapeutic candidates

Medicinal chemistry can rightfully be regarded as a cornerstone in the public health of our modern society that combines chemistry and pharmacology with the aim of designing and developing new pharmaceutical compounds. For this purpose, many chemical techniques as well as new computational chemistry applications are used to study the utilization of drugs and their biological effects. In the biological interface, medicinal chemistry constitutes a group of interdisciplinary sciences, as well as controlling its organic, physical and computational pillars. Therefore, medicinal chemists working to design an integrated and developing system that portends an era of novel and safe tailored drugs either by synthesizing new pharmaceuticals or to improving the processes by which existing pharmaceuticals are made. It includes researching the effects of synthetic, semi-synthetic and natural biologically active substances based on molecular interactions in terms of molecular structure with triggered functional groups or the specific physicochemical properties. The present work focuses on the literature survey of chemical diversity of phenoxy acetamide and its derivatives (Chalcone, Indole and Quinoline) in the molecular framework in order to get complete information regarding pharmacologically interesting compounds of widely different composition. From a biological and industrial point of view, this literature review may provide an opportunity for the chemists to design new derivatives of phenoxy acetamide and its derivatives that proved to be the successful agent in view of safety and efficacy to enhance life quality.

Pyrazoline Hybrids as Promising Anticancer Agents: An Up-to-Date Overview

Pyrazolines are five-membered heterocycles possessing two adjacent nitrogens. They have attracted significant attention from organic and medicinal chemists due to their potent biological activities and the numerous possibilities for structural diversification. In the last decade, they have been intensively studied as targets for potential anticancer therapeutics, producing a steady yearly rise in the number of published research articles. Many pyrazoline derivatives have shown remarkable cytotoxic activities in the form of heterocyclic or non-heterocyclic based hybrids, such as with coumarins, triazoles, and steroids. The enormous amount of related literature in the last 5 years prompted us to collect all these published data from screening against cancer cell lines, or protein targets like EGFR and structure activity relationship studies. Therefore, in the present review, a comprehensive account of the compounds containing the pyrazoline nucleus will be provided. The chemical groups and the structural modifications responsible for the activity will be highlighted. Moreover, emphasis will be given on recent examples from the literature and on the work of research groups that have played a key role in the development of this field.

Highly efficient, catalyst-free, one-pot, pseudo-seven-component synthesis of novel poly-substituted pyrazolyl-1,2-diazepine derivatives

A novel, green and high yielding preparation of poly-substituted pyrazolyl-1,2-diazepine derivatives is describedviaa one-pot pseudo-seven-component condensation reaction under catalyst-free conditions in EtOH at room temperature.

2-pyrazoline derivatives in neuropharmacology: Synthesis, ADME prediction, molecular docking and in vivo biological evaluation

A novel series of 1,3,5-trisubstituted-2-pyrazoline derivatives (PFC-1 to PFC-16) were synthesized in a three step reaction using conventional and microwave assisted green chemistry approach. The synthesized derivatives were characterized and their chemical structures were established by various physicochemical methods such as IR, Mass, ¹H-NMR, ¹³C-NMR and elemental analysis. The synthesized compounds were tested for their neuropharmacological potential. The compounds exhibited significant antidepressant and anti-anxiety activities against various behavioral in vivo models. Compounds PFC-3 and PFC-12 were found to be the most active derivatives in the series. The 2-pyrazoline analogs, having 2-hydroxyphenyl and anthracen-9-yl substitution at 3^rd position while 4-benzyloxyphenyl and 4-methylphenyl substitution at 5^th position, were decisive in eliciting good antidepressant and anxiolytic properties, respectively. The docking experiments revealed that the synthesized derivatives were potential inhibitors of MAO-A protein, which plays a central role in managing depression and anxiety disorders. The most potent derivatives were found to be involved in some key interactions with Tyr407, Tyr444, Phe352 and Ala68 amino acid residues at the binding site of MAO-A protein. All the synthesized derivatives successfully passed the pharmacokinetic barriers of absorption, distribution, metabolism and elimination as predicted using in silico techniques without showing any substantial indication of acute and neurotoxicity. This was further confirmed in the laboratory by performing acute toxicity studies as per OECD guidelines.

Molecular structure, FT-IR, vibrational assignments, HOMO-LUMO analysis and molecular docking study of 1-[5-(4-Bromophenyl)-3-(4-fluorophenyl)-4,5-dihydro-1H-pyrazol-1-yl]ethanone

The optimized molecular structure, vibrational frequencies, corresponding vibrational assignments of 1-[5-(4-bromophenyl)-3-(4-fluorophenyl)-4,5-dihydro-1H-pyrazol-1-yl]ethanone have been investigated experimentally and theoretically using Gaussian09 software package. The title compound was optimized using the HF/6-31G(d) (6D, 7F), B3LYP/6-31G (6D, 7F) and B3LYP/6-311++G(d,p) (5D, 7F) calculations. The B3LYP/6-311++G(d,p) (5D, 7F) results and in agreement with experimental infrared bands. The geometrical parameters are in agreement with XRD data. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. The HOMO and LUMO analysis is used to determine the charge transfer within the molecule. Molecular electrostatic potential was also performed. From the MEP it is evident that the negative charge covers the C=O group and the positive region is over the rings. First hyperpolarizability is calculated in order to find its role in nonlinear optics. Molecular docking studies suggest that the compound might exhibit inhibitory activity against TPII and may act as anti-neoplastic agent.

Recent advances in the therapeutic applications of pyrazolines

INTRODUCTION

Pyrazolines are well-known and important nitrogen-containing five-membered ring heterocyclic compounds. Various methods have been worked out for their synthesis. Several pyrazoline derivatives have been found to possess diverse biological properties, which has stimulated research activity in this field.

AREAS COVERED

The present review sheds light on the recent therapeutic patent literature (2000 - 2011) describing the applications of pyrazolines and their derivatives on selected activities. Many of the therapeutic applications of pyrazoline derivatives have been discussed, either in the patent or in the general literature areas in this review. In addition to selected biological data, a wide range of pharmaceutical applications and pharmaceutical compositions are also summarized.

EXPERT OPINION

Pyrazoline derivatives have numerous prominent pharmacological effects, such as antimicrobial (antibacterial, antifungal, antiamoebic, antimycobacterial), anti-inflammatory, analgesic, antidepressant and anticancer. Further pharmacological effects include cannabinoid CB1 receptor antagonists, antiepileptic, antitrypanosomal, antiviral activity, MAO-inhibitory, antinociceptive activity, insecticidal, hypotensive, nitric oxide synthase inhibitor, antioxidant, steroidal and antidiabetic. Lastly, they also effect ACAT inhibition, urotensin II and somatostatin-5 receptors, TGF-β signal transduction inhibitors and neurocytotoxicity inhibitors activities. Many new pyrazoline derivatives have been synthesized and patented, but there are still new aspects to explore and work on.