Synthesis of bisindolylmaleimides related to GF109203x and their efficient conversion to the bioactive indolocarbazoles

Synthesis, Molecular Docking and Biological Evaluation of N-Substituted Indole Derivatives as Potential Anti-Inflammatory and Antioxidant Agents

Novel N-substituted Indole derivatives with various hetero-cyclic moieties were synthesized via an ethyl linker in order to obtain highly potent anti-inflammatory and antioxidant agents. The structure of the obtained chemical compounds was determined using IR, ¹ H-NMR, and mass spectroscopy. Molecular docking was used to create selective and efficient COX-2 inhibitors from twelve novel indole derivatives (11a-c, 12a-c, 13a-c, and 14a-c). The compounds 13b and 14b had a high interaction energy, which inhibited the COX-2 enzyme. There is a relationship between anti-inflammatory activity and antioxidants, which is also defined by COX-2 inhibition, according to the mechanism of action. The Swiss ADME online programme was used to determine the drug-like properties of synthesized compounds. Two common and reliable methods were adopted to determine the antioxidant effect. In the DPPH assay, compounds 11a, 11b, and 14b, whereas compounds 11b, 13b, and 14b in the reducing power assay, were the most potent as compared with standard ascorbic acid. To evaluate the anti-inflammatory effect at an acute and chronic level, the carrageenan-induced paw edema method along with the formalin-induced inflammation method were used both at low dose and high dose. From the collected results, compounds 13b and 14b were the most potent against acute and chronic inflammation. The results showed that the synthesized compounds are unique as anti-inflammatory and antioxidant agents, and that they could be useful for drug discovery in the future.

Synthesis and Evaluation of Antimicrobial Activities of Novel N-Substituted Indole Derivatives

Indole motifs are one of the most significant scaffolds in the discovery of new drugs. We have described a synthesis of new N-substituted indole derivatives (1-3), and their in vitro antimicrobial activities were investigated. The synthesis of titled compounds has been demonstrated by utilizing commercially available starting materials. The antibacterial and antifungal activities were performed using new strains of bacteria Staphylococcus aureus, Escherichia coli, and Candida albicans using the disc diffusion method. Notably, the compound 4-(1-(2-(1H-indol-1-yl) ethoxy) pentyl)-N,N-dimethyl aniline (1) was found to be most potent than the other analogues (2 and 3), which has shown higher inhibition than the standard drug chloramphenicol.

Synthesis and Mechanochemical Activity of Peptide-Based Cu(I) Bis(N-heterocyclic carbene) Complexes

With the class of shock-absorbing proteins, nature created some of the most robust materials combining both mechanical strength and elasticity. Their excellent ability to dissipate energy to prevent surrounding cells from damage is an interesting property that regularly is exploited for applications in biomimetic materials. Similar to biomaterials, where mechanical stimuli are transmitted into a (bio)chemical response, mechanophoric catalysts transform mechanical energy into a chemical reaction. Force transmission is realized commonly by polymeric handles directing the applied force to the mechanophoric bond, which in turn leads to stress-induced activation of the catalyst. Therefore, shock-absorbing proteins able to take up and store mechanical energy elastically for subsequent force transduction to the labile bond seem to be perfect candidates to fulfill this task. Here, we report on the synthesis of two different latent mechanophoric copper(I) bis(N-heterocyclic carbene) complexes bearing either two carboxyl groups or two amino groups which allow conjugation reactions with either the N- or the C-terminus of amino acids or peptides. The chosen catalysts can be activated, for instance, by applying external mechanical force via ultrasound, removing one N-heterocyclic carbene (NHC) ligand. Post-modification of the mechanophoric catalysts via peptide coupling (Gly, Val) and first reactions showed that the mechanoresponsive behavior was still present after the coupling. Subsequent polycondensation of both catalysts lead to a polyamide including the Cu(I) moiety. Mechanochemical activation by ultrasound showed conversions in the copper(I)-catalyzed alkyne-azide “click” reaction (CuAAC) up to 9.9% proving the potential application for the time and spatial controlled CuAAC.

Design, Synthesis, and Evaluation of ω-(Isothiocyanato)alkylphosphinates and Phosphine Oxides as Antiproliferative Agents

A series of 21 novel, structurally diverse ω-(isothiocyanato)alkylphosphinates and phosphine oxides (ITCs) were designed and synthesized in moderate to good yields. The synthesized compounds were evaluated for in vitro antiproliferative activity using LoVo and LoVo/DX cancer cell lines. The biological activity of the synthesized compounds was higher than that of natural isothiocyanates such as benzyl isothiocyanate or sulforaphane. The antiproliferative activity of selected ITCs was also tested on selected cancer cell lines: A549, MESSA and MESSA/DX-5, HL60 and HL60MX2, BALB/3T3, and 4T1. These compounds were assessed for their mechanism of action as inducers of cell-cycle arrest and apoptosis. Ethyl (6-isothiocyanatohexyl)(phenyl)phosphinate (71) was tested in vivo on the 4T1 cell line and demonstrated moderate antitumor activity, similar to that benzyl isothiocyanate and cyclophosphamide.

Recent Developments and Biological Activities of N-Substituted Carbazole Derivatives: A Review

Carbazoles represent an important class of heterocycles. These have been reported to exhibit diverse biological activities such as antimicrobial, antitumor, antiepileptic, antihistaminic, antioxidative, anti-inflammatory, antidiarrhoeal, analgesic, neuroprotective and pancreatic lipase inhibition properties. A series of carbazole derivatives such as N-substituted carbazoles, benzocarbazoles, furocarbazoles, pyrrolocarbazoles, indolocarbazoles, imidazocarbazoles, etc. have been synthesized. The N-substituted derivatives have gained the attention of researchers due to their therapeutic potential against neurological disorders and cell proliferation. Herein an attempt is made to review the medicinal importance of recently synthesized N-substituted carbazoles.

Antitumour indolequinones: synthesis and activity against human pancreatic cancer cells

An important determinant of the growth inhibitory activity of indolequinones against pancreatic cancer cells is substitution on the 2-position with 2-unsubstituted derivatives being markedly more potent. A series of indolequinones bearing a range of substituents on nitrogen and at the indolylcarbinyl position was prepared by copper(II)-mediated reaction of bromoquinones and enamines, followed by functional group interconversions. The compounds were then assayed for their ability to inhibit the growth of pancreatic cancer cells. The pKa of the leaving group at the 3-position was shown to influence growth inhibitory activity that is consistent with the proposed mechanism of action of reduction, loss of leaving group and formation of a reactive iminium species. Substitutions on the indole nitrogen were well tolerated with little influence on growth inhibitory activity while substitutions at the 5- and 6-positions larger than methoxy led to decreased activity. The studies presented define the range of substitutions of 2-unsubstituted indolequinones required for optimal growth inhibitory activity.

The bisindolylmaleimides with anti-parallel conformation by N-dodecyl chains on indole rings: thermal property and intensive solid-state fluorescence in single crystal

N-Dodecyl chains were located in the indole rings of BIMs to adopt anti-parallel conformations, and intensive red emission was observed in single crystals.

Biomedical importance of indoles

The indole nucleus is an important element of many natural and synthetic molecules with significant biological activity. This review covers some of the relevant and recent achievements in the biological, chemical and pharmacological activity of important indole derivatives in the areas of drug discovery and analysis.

Directed modulation of protein kinase C isozyme selectivity with bisubstrate-based inhibitors

Kinases present an attractive target for drug development, since they are involved in vital cellular processes and are implicated in a variety of diseases, such as cancer and diabetes. However, obtaining selectivity for a specific kinase over others is difficult since many current kinase inhibitors exclusively target the highly conserved kinase ATP binding domain. Previously, a microarray-based strategy to discover so-called bisubstrate-based inhibitors that target the more specific peptide binding groove in addition to the ATP binding site was described. One attractive feature of this strategy is the opportunity to tune the selectivity of these inhibitors by systematically varying components. In an extension to this previous work, this study explores the potential of this guided selectivity modulation, leading to a series of inhibitors with different selectivity profiles against highly homologous protein kinase C (PKC) isozymes. Of the inhibitors studied, most exhibited improved potency and selectivity compared with their constituent parts. Furthermore, the selectivity was found to be tunable either through modification of the pseudosubstrate peptide (peptide binding groove) or the ATP-competitive part (ATP binding site). In a number of cases, the selectivity of the construct could be predicted from the initial peptide substrate profiling experiment. Since this strategy is applicable to all kinase sets, it could be used to rapidly develop uniquely selective inhibitors.

Marine pyrrolocarbazoles and analogues: synthesis and kinase inhibition

Granulatimide and isogranulatimide are alkaloids obtained from marine sources which have been shown to inhibit cell-cycle G2-checkpoint, targeting more particularly checkpoint 1 kinase (Chk1). At a structural level, they possess a characteristic pyrrolocarbazole framework also shared by the well-known rebeccamycin and staurosporine microbial metabolites which have been described to inhibit topoisomerase I and diverse kinases, respectively. This review reports precisely on the synthesis and kinase inhibitory activities of pyrrolocarbazole-based analogues of granulatimide.