Syntheses and cytotoxicity evaluation of bis(indolyl)thiazole, bis(indolyl)pyrazinone and bis(indolyl)pyrazine: analogues of cytotoxic marine bis(indole) alkaloid

2,4-Bis(3'-indolyl)thiazoles, 3,5-bis(3'-indolyl)-2(1H)pyrazinone and 3,6-bis(3'-indolyl)pyrazine were synthesized and evaluated for cytotoxic activity against diverse human cancer cell lines by the National Cancer Institute. These compounds demonstrated significant inhibitory effects in the growth of a range of cancer cell lines. 2,4-Bis(3'-indolyl)thiazole displayed selective cytotoxicity against certain leukemia cell lines with GI50 values in the low micromolar range while the substituted derivatives showed a broad spectrum of cytotoxic activity. 3,5-Bis(3'-indolyl)-2(1H)pyrazinone and 3,6-bis[3'-(N-methyl-indolyl)]pyrazine possessed strong inhibitory activity against a wide range of human tumor cell lines. The mechanism of action remained unknown. The results suggested that 2,4-bis(3'-indolyl)thiazoles, 3,5-bis(3'-indolyl)-2(1H)pyrazinone and 3,6-bis[3'-(N-methyl-indolyl)] pyrazine offer potential as lead compounds for the discovery of anticancer agents.     

An efficient synthesis of bis(indolyl)methanes and evaluation of their antimicrobial activities

A versatile and efficient method has been developed for the synthesis of bis(indolyl)methanes by using aluminium triflate (0.5 mol%) as a novel catalyst. Further, some of the synthesized compounds were evaluated for their efficacy as antibacterial and antifungal activities. Most of the compounds have shown moderate to good inhibitory activity.     

An efficient synthesis of bis(indolyl)methanes and evaluation of their antimicrobial activities

A versatile and efficient method has been developed for the synthesis of bis(indolyl)methanes by using aluminium triflate (0.5 mol%) as a novel catalyst. Further, some of the synthesized compounds were evaluated for their efficacy as antibacterial and antifungal activities. Most of the compounds have shown moderate to good inhibitory activity.     

Isolation of two forms of carboxylester lipase (cholesterol esterase) from porcine pancreas

Carboxylester lipase (cholesterol esterase, EC 3.1.1.13) has been purified to homogeneity from porcine pancreas. The enzyme is isolated in two molecular mass forms, a monomer of 74 kDa and a dimer of 167 kDa. The dimer consists of two catalytically-active subunits which have molecular masses approximately 9 kDa greater than the monomers. The difference in size was not attributable to carbohydrate or lipid content. The catalytic properties of the two forms are comparable on a weight basis, the amino acid compositions are quite similar, and the N-terminal sequences are nearly identical for 24 residues. These similarities suggest a possible precursor-product relationship between the two carboxylester lipase forms.     

A mild and environmentally friendly scandium(III) trifluoromethanesulfonate-catalyzed synthesis of bis(3'-indolyl)alkanes and bis(3'-indolyl)-1-deoxyalditols

Bis(3'-indolyl)alkanes and bis(3'-indolyl) derivatives containing a 1-deoxyalditol moiety were synthesized in the presence of 5 mol% of scandium(III) trifluoromethanesulfonate [Sc(OTf)3] in CH3CN or EtOH-H2O mixture as a solvent from room temperature to 70 degrees C in good yields (78-97%).     

Biocatalysts for multicomponent Biginelli reaction: bovine serum albumin triggered waste-free synthesis of 3,4-dihydropyrimidin-2-(1H)-ones

Bovine serum albumin (BSA) promoted simple and efficient one-pot procedure was developed for the direct synthesis of 3,4-dihydropyrimidin-2(1H)-ones including potent mitotic kinesin Eg5 inhibitor monastrol under mild reaction conditions. The catalyst recyclability and gram scale synthesis have also been demonstrated to enhance the practical utility of process.     

Regioselective synthesis and biological evaluation of bis(indolyl)methane derivatized 1,4-disubstituted 1,2,3-bistriazoles as anti-infective agents

The regioselective synthesis of 1,4-disubstituted 1,2,3-bistriazoles from a variety of N-propargyl bis(indolyl)methanes with sodium azide using CuI as the catalyst in polyethyleneglycol-400 is reported. This process is of considerable synthetic advantages in terms of high atom economy, low environmental impact, mild reaction condition and good yields. The synthesized compounds have also been screened for their biological activity.     

Novel boronic acid derivatives of bis(indolyl) methane as anti-MRSA agents

Towards the search for a new generation of antibiotics to control methicillin-resistant Staphylococcus aureus (MRSA), the design and synthesis of various bis indolyl methane (BIM) derivatives based on their different electron donor and acceptor properties of the substituents have been made, in which boronic acid derivatives of BIM are found to be active against MRSA. The observed evidence with the lead compound reveals their strong anti-MRSA activity, which paves the way of design and further development of a new generation antibiotics.     

Borane and monoiodoborane derivatives of some bis(diphenylphosphino)alkanes

A series of borane and monoiodoborane derivatives of bis(diphenylphosphino)alkanes. (C₆H₅)₂P--- (CH₂)_n---P(C₆H₅)₂ in which n has values of 2 through 4 has been synthesized. Only compounds with the formulae [(C₆H₅)₂P]₂(CH₂)_n · (BH₃)₂ and (C₆H₅)₂P]₂CH₂)_n · BH₂I were isolable, the latter being boronium iodides. The compounds were characterized by their melting points, elemental analyses, molar conductivities, infrared spectroscopy, and ¹H and ¹¹B nuclear magnetic resonance spectroscopy. The relationship between the length of the carbon chain and the ¹¹B NMR chemical shift is discussed.     

Antileishmanial evaluation of clubbed bis(indolyl)-pyridine derivatives: One-pot synthesis,in vitro biological evaluations and in silico ADME prediction

A new series of bis(indolyl)-pyridine derivatives 6(a–m) were synthesized by Chichibabin reaction process and evaluated for antileishmanial and antibacterial activities to establish structure–activity relationship. The synthesis was carried out through one-pot multicomponent reaction of 3-acetylindole, aromatic aldehydes, and ammonium acetate in the presence of camphor-10-sulfonic acid as a catalyst. The compounds 6d (IC₅₀ = 102.47 μM) and 6f (IC₅₀ = 99.49 μM) had shown promising antileishmanial against L. donovani promastigotes when compared with standard sodium stibogluconate (IC₅₀ = 490.00 μM). All the synthesized compounds (MIC range = 41.35–228.69 μg/mL) had shown potent antibacterial activity than standard ampicillin (MIC range = 100.00–250.00 μg/mL) against all the tested bacterial strains. In silico ADME and metabolic site prediction studies were also held out to set an effective lead candidate for the future antileishmanial and antibacterial drug discovery initiatives.     

Synthesis, antimicrobial and antioxidant evaluation of quinolines and bis(indolyl)methanes

An improved and practical synthesis of substituted quinolines and bis(indolyl)methanes was achieved under microwave condition using Zn(OTf)(2) as catalyst. The synthesized compounds have been screened for antimicrobial and antioxidant activities.     

Synthesis of novel analogues of marine indole alkaloids: mono(indolyl)-4-trifluoromethylpyridines and bis(indolyl)-4-trifluoromethylpyridines as potential anticancer agents.

Mono(indolyl)-4-trifluoromethylpyridines and bis(indolyl)-4-trifluoromethylpyridines were synthesized using Suzuki cross-coupling reaction between 2-chloro-4-trifluoromethylpyridine 9, 2,6-dichloro-4-trifluoromethylpyridine 6 or 2,6-dichloro-3-cyano-4-trifluoromethylpyridine 23 and N-tosyl-3-indolylboronic acid 10. They were evaluated for cytotoxic activity against P388 and A-549 cells with IC(50) values. 4-Trifluoromethyl-2,6-bis[3'-(N-tosyl-6'-methoxylindolyl)]pyridine 18 was identified as the most potent in this series.     

Meglumine as a green,efficient and reusable catalyst for synthesis and molecular docking studies of bis(indolyl)methanes as antioxidant agents

An efficient and convenient Meglumine catalyzed procedure for the synthesis of bis(indolyl) methanes at ambient temperature under aqueous conditions in high yields. The catalytic reaction proceeds very smoothly. Clean reaction, ease of product isolation/purification, easily available reactants, metal free and environmentally friendly reaction conditions are the notable advantages of the present methodology. All the entitled compounds were characterized by IR, ¹H, ¹³C NMR, mass spectra and evaluated for their antioxidant (DPPH, H₂O₂ and NO scavenging methods). They exhibited potent in vitro antioxidant activity dose-dependently. The binding interactions and molecular docking studies for entitled compounds were studied against 3MNG protein. 4d exhibited marked binding affinity with excellent docking score of −7.6 K.cal/mol and emerged as a lead compound.     

Synthesis,antiproliferative and apoptosis induction potential activities of novel bis(indolyl)hydrazide-hydrazone derivatives

In recent years, indole-indazolyl hydrazide-hydrazone derivatives with strong cell growth inhibition and apoptosis induction characteristics are being strongly screened for their cancer chemo-preventive potential. In the present study, N-methyl and N,N-dimethyl bis(indolyl)hydrazide-hydrazone analog derivatives were designed, synthesized and allowed to evaluate for their anti-proliferative and apoptosis induction potential against cervical (HeLa), breast (MCF-7 and MDA-MB-231) and lung (A549) cancer cell lines relative to normal HEK293 cells. The MTT assay in conjunction with mitochondrial potential assays and the trypan blue dye exclusion were employed to ascertain the effects of the derivatives on the cancer cells. Further, mechanistic studies were conducted on compound 14a to understand the biochemical mechanisms and functional interactions with various signaling pathways triggered in HeLa and MCF-7 cells. Compound 14a induced apoptosis via caspase independent pathway through the participation of mitogen-activated protein kinases (MAPK) such as extracellular signal related kinase (ERK) and p38 as well as p53 pathways. It originates the activation of pro-apoptotic proteins such as Bak and Mcl-1s and also strongly induced the generation of reactive oxygen species. In downstream signaling pathway, activated p53 protein interacted with MAPK pathways, including SAPK/c-Jun N-terminal protein kinase (JNK), p38 and ERK kinases resulting in apoptotic cell death. The involvement of MAPK cascades such as p38, ERK and p38 on compound 14a induced apoptotic cell death was evidenced by the fact that the inclusion of specific inhibitors of p38, ERK1/2 and JNK MAPK (SB2035809, PD98059 and SP600125) prevented the compound 14a towards induced apoptosis. The results clearly showed that MAP kinase cascades were crucial for apoptotic response in compound 14a induced cellular killing and were dependent on p53 activity. Based on the results, compound 14a was identified as a promising candidate for cancer therapeutics and these findings furnish a basis for further in vivo experiments on anti-proliferative activity.     

Synthesis, antifungal and haemolytic activity of a series of bis(pyridinium)alkanes

A series of bis(pyridinium)alkanes have been prepared and their antifungal activity, haemolytic activity and ability to inhibit fungal phospholipase B1 have been investigated, together with those of the commercially available antiseptics octenidine and dequalinium. Removal of the amino substituents from the pyridinium rings resulted in a significant decrease in antifungal activity. However, shortening or removing the alkyl chains attached to the amino groups had little effect on antifungal activity and significantly reduced haemolytic activity. Only octenidine was a strong inhibitor of fungal phospholipase B1.     

Indium(III) chloride catalyzed three-component coupling reaction: a novel synthesis of 2-substituted aryl(indolyl)kojic acid derivatives as potent antifungal and antibacterial agents

Three-component coupling of aldehyde, indole and kojic acid has been achieved using a catalytic amount of InCl(3) under solvent free conditions to produce a novel series of 2-substituted aryl(indolyl)kojic acid derivatives in good yields and with high selectivity. These compounds are found to exhibit potent antifungal properties.     

A convenient synthesis of bis(phosphino)methanes: Formation of a nickel(II) bis(phosphino)methane monoxide complex

The reaction of (trimethylsilyl)methyl phosphines R₂PCH₂SiMe₃ with chlorophosphines ${\mathrm{ClPR}}_2^{\prime }$ provides ready access to a range of symmetrical or non-symmetrical diphosphinomethanes ${\mathrm{R}}_2{\mathrm{PCH}}_2{\mathrm{PR}}_2^{\prime }$. The products are obtained cleanly and can be used directly in the synthesis of transition metal complexes. This is illustrated by the preparation and structural characterization of the corresponding NiCl₂(P–P) derivatives.     

A theoretical analysis of the Ti(IV)-catalyzed glycoaminocyanation reaction

The chelation of the Lewis acid Ti(OiPr)(4) provides the necessary conformational control to induce pi-facial selectivity on the cyanation process. The steric hindrance imposed by the alpha-substituent restrains the addition for l-amino acid derivatives.     

A new synthesis of bis(diacylglycero)phosphate

The chemical synthesis of bis(diacylglycero)phosphate previously named bisphosphatidic acid, starting with a diacylglycerol and phosphatidic acid, is described. The phosphodiester bond formation is catalyzed by triisopropylbenzenesulfonylchloride. This simple approach allows the preparation of saturated as well as unsaturated bis(diacylglycero)phosphate species in one step without the use of any protecting group. The methods used until now yield only mono-acid species, or mixed-acid unsaturated species after many steps involving the introduction and the removal of protecting groups. The synthetic products have been characterized by component analysis and NMR-techniques.     

Novel bis(indolyl)maleimide pyridinophanes that are potent, selective inhibitors of glycogen synthase kinase-3

Novel bis(indolyl)maleimide pyridinophanes 3, 9a, 9b, 10a, 10b, and 11 were prepared by cobalt-mediated [2+2+2] cycloaddition of an appropriate alpha,omega-diyne with an N,N-dialkylcyanamide. These macrocyclic heterophanes were found to be potent, selective inhibitors of glycogen synthase kinase-3beta. An X-ray structure of a co-crystal of GSK-3beta and 3 (IC(50)=3nM) depicts the hydrogen bonding and hydrophobic interactions in the ATP-binding pocket of this serine/threonine protein kinase.