Ultrasound-mediated synthesis, biological evaluation, docking and in vivo acute oral toxicity study of novel indolin-2-one coupled pyrimidine derivatives

Natural product-driven dual COX-LOX inhibitors: Overview of recent studies on the development of novel anti-inflammatory agents

Inflammation is a complicated physiological process that results in a variety of disorders. Several inflammatory mediators are produced during this process, which is responsible for long-term inflammatory conditions like osteoarthritis, rheumatoid arthritis, asthma, cancer, and neurological disorders. Inflammatory mediators are produced by an arachidonic acid pathway that gives us several anti-inflammatory targets. The most commonly used medications are NSAIDs to treat inflammation by inhibiting cyclooxygenase (COX) and lipoxygenase enzymes (5-LOX). However, this therapy is associated with adverse events like gastrointestinal disorders, renal failure, etc., limiting its use. Therefore, novel, efficacious, and safer anti-inflammatory agents are prerequisites for inhibiting both cyclooxygenase and lipoxygenase pathways. Though several synthetic analogs are under development, natural products may act as a potential source to identify novel molecules and herbal remedies. Valuable contributions have been made in this direction by the scientific communities. This review article briefly discusses the implications of phytochemicals and bioactive fractions in the development of dual COX-LOX inhibitors while highlighting different classes of phytoconstituents such as tannins, steroids, flavonoids, alkaloids, terpenoids, among others, that showed significant dual COX-LOX inhibition.

Explorations of novel pyridine-pyrimidine hybrid phosphonate derivatives as aurora kinase inhibitors

For developing novel therapeutic agents with good anticancer activities, a series of novel pyridine-pyrimidine hybrid phosphonate derivatives4(a-q) were synthesized by the Kabachnik-Fields method using CAN as catalyst. The compound 4o exhibited the most potent anticancer activity with an IC₅₀ value of 13.62 μM, 17.49 μM, 5.81 μM, 1.59 μM and 2.11 μM against selected cancer cell lines A549, Hep-G2, HeLa, MCF-7, and HL-60, respectively. Compound 4o displayed seven times more selectivity towards Hep-G2 cancer cell lines compared to the human normal hepatocyte cell line LO2 (IC₅₀ value 95.33 μM). Structure-Activity Relationship (SAR) studies were conducted on the variation in the aromatic ring (five-membered heterocyclic ring, six-membered heterocyclic ring) and the variation of substituents on the phenyl ring (electron donating groups, electron withdrawing groups). Furthermore, the mechanism of anticancer activity was clarified by further explorations in bioactivity by using in vitro aurora kinase inhibitory activity and molecular docking studies. The results showed that the compound 4o at IC₅₀concentrationdemonstrated distinctive morphological changes such as cell detachment, cell wall deformation, cell shrinkage and reduced number of viable cells in cancer cell lines. Compound 4o induced early apoptosis and late apoptosis of 27.7% and 6.1% respectively.

Ultrasound-assisted transition-metal-free catalysis: a sustainable route towards the synthesis of bioactive heterocycles

Heterocycles of synthetic and natural origin are a well-established class of compounds representing a broad range of organic molecules that constitute over 60% of drugs and agrochemicals in the market or research pipeline. Considering the vast abundance of these structural motifs, the development of chemical processes providing easy access to novel complex target molecules by introducing environmentally benign conditions with the main focus on improving the cost-effectiveness of the chemical transformation is highly demanding and challenging. Accordingly, sonochemistry appears to be an excellent alternative and a highly feasible environmentally benign energy input that has recently received considerable and steadily increasing interest in organic synthesis. However, the involvement of transition-metal-catalyst(s) in a chemical process often triggers an unintended impact on the greenness or sustainability of the transformation. Consequently, enormous efforts have been devoted to developing metal-free routes for assembling various heterocycles of medicinal interest, particularly under ultrasound irradiation. The present review article aims to demonstrate a brief overview of the current progress accomplished in the ultrasound-assisted synthesis of pharmaceutically relevant diverse heterocycles using transition-metal-free catalysis.

Ultrasound-assisted synthesis of pyrimidines and their fused derivatives: A review

The pyrimidine scaffold is present in many bioactive drugs; therefore, efficient synthetic routes that provide shorter reaction times, higher yields, and site-selective reactions are constantly being sought. Ultrasound (US) irradiation has emerged as an alternative energy source in the synthesis of these heterocyclic scaffolds, and over the last ten years there has been a significant increase in the number of publications mentioning US in either the construction or derivatization of the pyrimidine core. This review presents a detailed summary (with 140 references) of the effects of US (synergic or not) on the construction and derivatization of the pyrimidine core through classical reactions (e.g., multicomponent, cyclocondensation, cycloaddition, and alkylation reactions). The main points that were taken into consideration are as follows: chemo- and regioselectivity issues, and the results of conventional heating methods compared to US and mechanistic insights that are also presented and discussed for key reactions.

Recent Development in Indole Derivatives as Anticancer Agents for Breast Cancer

BACKGROUND

Breast Cancer (BC) is the second most common cause of cancer related deaths in women. Due to severe side effects and multidrug resistance, current therapies like hormonal therapy, surgery, radiotherapy and chemotherapy become ineffective. Also, the existing drugs for BC treatment are associated with several drawbacks such as poor oral bioavailability, non-selectivity and poor pharmacodynamics properties. Therefore, there is an urgent need for the development of more effective and safer anti BC agents.

OBJECTIVE

This article explored in detail the possibilities of indole-based heterocyclic compounds as anticancer agents with breast cancer as their major target.

METHODS

Recent literature related to indole derivatives endowed with encouraging anti BC potential is reviewed. With special focus on BC, this review offers a detailed account of multiple mechanisms of action of various indole derivatives: aromatase inhibitor, tubulin inhibitor, microtubule inhibitor, targeting estrogen receptor, DNA-binding mechanism, induction of apoptosis, inhibition of PI3K/AkT/NFkB/mTOR, and HDAC inhibitors, by which these derivatives have shown promising anticancer potential.

RESULTS

Exhaustive literature survey indicated that indole derivatives are associated with properties of inducing apoptosis and disturbing tubulin assembly. Indoles are also associated with the inhibition of NFkB/mTOR/PI3K/AkT and regulation of estrogen-mediated activity. Furthermore, indole derivatives have been found to modulate critical targets such as topoisomerase and HDAC. These derivatives have shown significant activity against breast cancer cells.

CONCLUSION

In BC, indole derivatives seem to be quite competent and act through various mechanisms that are well established in case of BC. This review has shown that indole derivatives can further be explored for the betterment of BC chemotherapy. A lot of potential is still hidden which demands to be discovered for upgrading BC chemotherapy.

New 2-Oxoindolin Phosphonates as Novel Agents to Treat Cancer: A Green Synthesis and Molecular Modeling

The work reports the facile synthesis of novel α-aminophosphonate derivatives coupled with indole-2,3-dione moieties, namely the diethyl(substituted phenyl/heteroaryl)(2-(2-oxoindolin-3-ylidene)hydrazinyl)methylphosphonates derivatives 4(a⁻n). One-pot three component Kabachnik-Fields reactions were used to synthesize these derivatives. The reaction was carried out at room temperature by stirring in presence of ceric ammonium nitrate (CAN) as a green catalyst. The structures of the synthesized compounds were established by spectral studies. The synthesized derivatives 4(a⁻n) were evaluated for their in vitro anticancer activity against six human cancer cell lines by the SRB assay method. The cancer cell lines used in this research work are SK-MEL-2 (melanoma), MCF-7 (breast cancer), IMR-32 (neuroblastoma) MG-63 (human osteosarcoma), HT-29 (human colon cancer) and Hep-G2 (human hepatoma). All the synthesized derivatives inhibited the cell proliferation. Importantly, all the target compounds showed no cytotoxicity towards normal tissue cells (GI₅₀ > 250 µM). A docking study was performed to predict the mode of action. Docking results indicate that the compounds have good binding with the enzyme tyrosine kinase as well as with microtubules, which makes them dual inhibitors. The result of in-silico bioavailability studies suggests that the compounds from the present series have good oral drug-like properties and are non-toxic in nature. In vivo acute oral toxicity study results indicate that the compounds can be considered safe, and therefore could be developed in the future as good anticancer agents or as leads for the design and synthesis of novel anticancer agents.