Synthesis and biological evaluation of analogs of the marine alkaloids granulatimide and isogranulatimide

Iodine-dependent oxidative regioselective aminochalcogenation of indolines

A directing-group-free strategy for oxidative regioselective aminochalcogenation of indolines with amines and dichalconides is presented. This strategy combines tandem coupling sequences and oxidative dehydrogenation methods in a multi-component reaction, enabling the fast construction of a series of C2,3- or C2,5-aminochalcogenated indole derivatives. Moreover, the application of this synthetic approach is demonstrated through the late-stage modification of pharmaceuticals and the derivatization of the products, highlighting its potential and significance.

Recent Advancement in Drug Design and Discovery of Pyrazole Biomolecules as Cancer and Inflammation Therapeutics

Pyrazole, an important pharmacophore and a privileged scaffold of immense significance, is a five-membered heterocyclic moiety with an extensive therapeutic profile, viz., anti-inflammatory, anti-microbial, anti-anxiety, anticancer, analgesic, antipyretic, etc. Due to the expansion of pyrazolecent red pharmacological molecules at a quicker pace, there is an urgent need to put emphasis on recent literature with hitherto available information to recognize the status of this scaffold for pharmaceutical research. The reported potential pyrazole-containing compounds are highlighted in the manuscript for the treatment of cancer and inflammation, and the results are mentioned in % inhibition of inflammation, % growth inhibition, IC₅₀, etc. Pyrazole is an important heterocyclic moiety with a strong pharmacological profile, which may act as an important pharmacophore for the drug discovery process. In the struggle to cultivate suitable anti-inflammatory and anticancer agents, chemists have now focused on pyrazole biomolecules. This review conceals the recent expansion of pyrazole biomolecules as anti-inflammatory and anticancer agents with an aim to provide better correlation among different research going around the world.

Copper-iodine Co-catalyzed C−H Aminoalkenylation of Indoles via Temperature-controlled Selectivity Switch: Facile Synthesis of 2-Azolyl-3-alkenylindoles

An efficient copper-iodine co-catalyzed 2,3-difunctionalization of indoles with azoles and phenols via temperature-controlled selectivity switch has been developed for the green synthesis of 2-azolyl-3-alkenylindoles. The strategy involves the simultaneous establishment...

Aerobic Oxidative C-H Azolation of Indoles and One-Pot Synthesis of Azolyl Thioindoles by Flavin-Iodine-Coupled Organocatalysis

The aerobic oxidative cross-coupling of indoles with azoles driven by flavin-iodine-coupled organocatalysis has been developed for the green synthesis of 2-(azol-1-yl)indoles. The coupled organocatalytic system enabled the one-pot three-component synthesis of 2-azolyl-3-thioindoles from indoles, azoles, and thiols in an atom-economical manner by utilizing molecular oxygen as the only sacrificial reagent.

β-Carboline as a Privileged Scaffold for Multitarget Strategies in Alzheimer's Disease Therapy

The natural β-carboline alkaloids display similarities with neurotransmitters that can be favorably exploited to design bioactive and bioavailable drugs for Alzheimer's disease (AD) therapy. Several AD targets are currently and intensively being investigated, divided in different hypotheses: mainly the cholinergic, the amyloid β (Aβ), and the Tau hypotheses. To date, only symptomatic treatments are available involving acetylcholinesterase and NMDA inhibitors. On the basis of plethoric single-target structure-activity relationship studies, the β-carboline scaffold was identified as a powerful tool for fostering activity and molecular interactions with a wide range of AD-related targets. This knowledge can undoubtedly be used to design multitarget-directed ligands, a highly relevant strategy preferred in the context of multifactorial pathology with intricate etiology such as AD. In this review, we first individually discuss the AD targets of the β-carbolines, and then we focus on the multitarget strategies dedicated to the deliberate design of new efficient scaffolds.

Recent Progress of Benzimidazole Hybrids for Anticancer Potential

This review presents the detailed account of factors leading to cancer and design strategy for the synthesis of benzimidazole derivatives as anticancer agents. The recent survey for cancer treatment in Cancer facts and figures 2017 American Chemical Society has shown progressive development in fighting cancer. Researchers all over the world in both developed and developing countries are in a continuous effort to tackle this serious concern. Benzimidazole and its derivatives showed a broad range of biological activities due to their resemblance with naturally occurring nitrogenous base i.e. purine. The review discussed benzimidazole derivatives showing anticancer properties through a different mechanism viz. intercalation, alkylating agents, topoisomerases, DHFR enzymes, and tubulin inhibitors. Benzimidazole derivatives act through a different mechanism and the substituents reported from the earlier and recent research articles are prerequisites for the synthesis of targeted based benzimidazole derivatives as anticancer agents. The review focuses on an easy comparison of the substituent essential for potency and selectivity through SAR presented in figures. This will further provide a better outlook or fulfills the challenges faced in the development of novel benzimidazole derivatives as anticancer.

Retracted Article: The synthesis and biological activity of marine alkaloid derivatives and analogues

The ocean is the origin of life, with a unique ecological environment, which has given birth to a wealth of marine organisms. The ocean is an important source of biological resources and tens of thousands of monomeric compounds have been separated from marine organisms using modern separation technology. Most of these monomeric compounds have some kind of biological activity that has attracted extensive attention from researchers. Marine alkaloids are a kind of compound that can be separated from marine organisms. They have complex and special chemical structures, but at the same time, they can show diversity in biological activities. The biological activities of marine alkaloids mainly manifest in the form of anti-tumor, anti-fungus, anti-viral, anti-malaria, and anti-osteoporosis properties. Many marine alkaloids have good medicinal prospects and can possibly be used as anti-tumor, anti-viral, and anti-fungal clinical drugs or as lead compounds. The limited amounts of marine alkaloids that can be obtained by separation, coupled with the high cytotoxicity and low selectivity of these lead compounds, has restricted the clinical research and industrial development of marine alkaloids. Marine alkaloid derivatives and analogues have been obtained via rational drug design and chemical synthesis, to make up for the shortcomings of marine alkaloids; this has become an urgent subject for research and development. This work systematically reviews the recent developments relating to marine alkaloid derivatives and analogues in the field of medical chemistry over the last 10 years (2010–2019). We divide marine alkaloid derivatives and analogues into five types from the point-of-view of biological activity and elaborated on these activities. We also briefly discuss the optimization process, chemical synthesis, biological activity evaluation, and structure–activity relationship (SAR) of each of these compounds. The abundant SAR data provides reasonable approaches for the design and development of new biologically active marine alkaloid derivatives and analogues.

The ocean is the origin of life, with a unique ecological environment, which has given birth to a wealth of marine organisms.

DYRK1A inhibition as potential treatment for Alzheimer's disease

In total, 47,500,000 people worldwide are affected by dementia and this number is estimated to double by 2030 and triple within 2050 resulting in a huge burden on public health. Alzheimer's disease (AD), a progressive neurodegenerative disorder, is the most common cause of dementia, accounting for 60-70% of all the cases. The cause of AD is still poorly understood but several brain abnormalities (e.g., loss of neuronal connections and neuronal death) have been identified in affected patients. In addition to the accumulation of β-amyloid plaques in the brain tissue, aberrant phosphorylation of tau proteins has proved to increase neuronal death. DYRK1A phosphorylates tau on 11 different Ser/Thr residues, resulting in the formation of aggregates called 'neurofibrillary tangles' which, together with amyloid plaques, could be responsible for dementia, neuronal degeneration and cell death. Small molecule inhibition of DYRK1A could thus represent an interesting approach toward the treatment of Alzheimer's and other neurodegenerative diseases. Herein we review the current progress in the identification and development of DYRK1A inhibitors.

A Survey of Marine Natural Compounds and Their Derivatives with Anti-cancer Activity Reported in 2012

Although considerable effort and progress has been made in the search for new anticancer drugs and treatments in the last several decades, cancer remains a major public health problem and one of the major causes of death worldwide. Many sources, including plants, animals, and minerals, are of interest in cancer research because of the possibility of identifying novel molecular therapeutics. Moreover, structure-activity-relationship (SAR) investigations have become a common way to develop naturally derived or semi-synthetic molecular analogues with improved efficacy and decreased toxicity. In 2012, approximately 138 molecules from marine sources, including isolated compounds and their associated analogues, were shown to be promising anticancer drugs. Among these, 62% are novel compounds. In this report, we review the marine compounds identified in 2012 that may serve as novel anticancer drugs.

Synthesis and in vitro antiproliferative activity of amido and amino analogues of the marine alkaloid isogranulatimide

Marine organisms have proven to be a promising source of new compounds with activity against tumor cell lines. Granulatimide and isogranulatimide are marine alkaloids that have been shown to inhibit checkpoint kinase 1 (Chk1), a key protein in the DNA damage response and an emerging target for anticancer therapeutics. Here, we describe the synthesis and preliminary evaluation of amido and amino analogues of isogranulatimide. The new derivatives were prepared in three steps from 2-imidazol-1-yl-1H-indol-5-ylamine. Two of the compounds synthesized exhibited more potent in vitro antiproliferative activity (single-digit micromolar concentration range), by at least one log of magnitude, than the natural product isogranulatimide when evaluated in six human tumor cell lines: non-small-cell lung cancer (A549), colon cancer (LoVo), breast cancer (MCF7), oligodendroglioma (Hs683), glioblastoma (U373), and melanoma (SKMEL28). The mechanism of action of these derivatives remains to be elucidated, given that they did not significantly inhibit Chk1, however these compounds are easily synthesized and exhibit potent anticancer activity and are thus worthy of further study.

Tandem copper (Cu) catalysed N-arylation–vinylogous nitroaldol condensation of 3,5-disubstituted 4-nitropyrazoles

A tandem process involving copper catalysed N-arylation and vinylogous nitroaldol condensation is described.

Highly efficient and diastereoselective synthesis of new pyrazolylpyrrolizine and pyrazolylpyrrolidine derivates by a three-component domino process

Diastereoselective reactions between 4-formylpyrazoles, N-substituted maleimides and glycine derivates led to new series of pyrazolyldipyrrolo [3,4-a:3',4'-f]pyrrolizines and pyrazolylpyrrolo[3,4-c]pyrroles in good yields. The reactions proceeded by a domino process through azomethine ylides formed in situ via a 1,3-dipolar cycloaddition reaction.