New Polyether Macrocycles as Promising Antitumor Agents-Targeted Synthesis and Induction of Mitochondrial Apoptosis.

A series of previously unknown aromatic polyether macrodiolides containing a cis,cis-1,5-diene moiety in the molecule were synthesized in 47-74% yields. Macrocycle compounds were first obtained by intermolecular esterification of aromatic polyether diols with α,ω-alka-nZ,(n+4)Z-dienedioic acids mediated by N-(3-(dimethylamino)propyl)-N'-ethylcarbodiimide hydrochloride (EDC·HCl) and 4-(dimethylamino)pyridine (DMAP). For the synthesized compounds, studies of cytotoxicity on tumor (Jurkat, K562, U937), conditionally normal (HEK293) cell lines, and normal fibroblasts were carried out. CC50 was determined, and the therapeutic selectivity index of cytotoxic action (SI) in comparison with normal fibroblasts was evaluated. With the involvement of modern methods of flow cytometry for the most promising macrocycles, their effect on mitochondria and the cell cycle was investigated. It was found that a new macrocycle exhibits pronounced apoptosis-inducing activity toward Jurkat cells and can retard cell division by blocking at the G1/S checkpoint. Also, it was shown that the synthesized macrodiolides influence mitochondria due to their high ability to penetrate the mitochondrial membrane.

Natural Acetogenins, Chatenaytrienins-1, -2, -3 and -4, Mitochondrial Potential Uncouplers and Autophagy Inducers-Promising Anticancer Agents.

The present paper details the complete stereoselective synthesis of four natural acetogenins, chatenaytrienins-1, -2, -3 and -4, previously isolated from the roots of fruit trees of the family Annonaceae (A. nutans and A. muricata), as an inseparable mixture. The novel organometallic reactions, developed by the authors, of Ti-catalyzed cross-cyclomagnesiation of O-containing and aliphatic allenes using available Grignard reagents were applied at the key stage of synthesis. We have studied the biological activity of the synthesized individual chatenaytrienins-1, -2, -3 and -4 in vitro, including their cytotoxicity in a panel of tumor lines and their ability to induce apoptosis, affect the cell cycle and mitochondria, and activate the main apoptotic signaling pathways in the cell, applying modern approaches of flow cytometry and multiplex analysis with Luminex xMAP technology. It has been shown that chatenaytrienins affect mitochondria by uncoupling the processes of mitochondrial respiration, causing the accumulation of ROS ions, followed by the initiation of apoptosis. The most likely mechanism for the death of cortical neurons from the consumption of tea from the seeds of Annona fruit is long-term chronic hypoxia, which leads to the development of an atypical form of Parkinson's disease that is characteristic of the indigenous inhabitants of Guam and New Caledonia.

Multicomponent Assembly of Bicyclic Aza-peroxides Catalyzed by Samarium Complexes and Their Cytotoxic Activity.

An original strategy toward bridged tetraoxazaspirobicycloalkanes was developed. The synthesis is based on a three-component condensation-cyclization reaction of primary arylamines with 1,1'-peroxybis (1-hydroperoxycycloalkanes) and pentane-1,5-dial catalyzed by Sm(NO3)3·6H2O. The structures and conformations of the products were determined by X-ray diffraction analysis and 1H and 13C NMR spectroscopy. High cytotoxic activity and biological potential toward ferroptosis induction were found for the synthesized bicyclic aza-peroxides.

Mono- and binuclear complexes of copper(II) with dimethylaminomethyl derivatives of 2-naphthol and 6-quinolinol: synthesis and in vitro study of antitumor properties.

1-(Dimethylamino)methyl-6-quinolinol scaffold, a structural moiety of the molecule of anticancer drug topotecan, was modified into copper-containing products to study cytotoxic properties. New mononuclear and binuclear Cu(II) complexes with 1-(N,N-dimethylamino)methyl-6-quinolinol were synthesized for the first time. The same way Cu(II) complexes with 1-(dimethylamino)methyl-2-naphtol ligand were synthesized. The structures of mono- and binuclear Cu(II) complexes with 1-aminomethyl-2-naphtol were confirmed by X-ray diffraction. The obtained compounds were examined for in vitro cytotoxic activity against Jurkat, K562, U937, MDA-MB-231, MCF7, T47D, and HEK293 cells. The induction of apoptosis and the effect of novel Cu complexes on the cell cycle were investigated. The cells showed a higher sensitivity to mononuclear Cu(II) complex with 1-(N,N-dimethylamino)methyl-6-quinolinolligand. All synthesized Cu(II) complexes had higher antitumor activity than the drugs topotecan, camptothecin, and platinum containing cisplatin.

Pentacyclic Triterpenoids-Based Ionic Compounds: Synthesis, Study of Structure-Antitumor Activity Relationship, Effects on Mitochondria and Activation of Signaling Pathways of Proliferation, Genome Reparation and Early Apoptosis.

The present research paper details the synthesis of novel ionic compounds based on triterpene acids (betulinic, oleanolic and ursolic), with these acids acting both as anions and connected through a spacer with various nitrogen-containing compounds (pyridine, piperidine, morpholine, pyrrolidine, triethylamine and dimethylethanolamine) and acting as a cation. Based on the latter, a large number of ionic compounds with various counterions (BF4-, SbF6-, PF6-, CH3COO-, C6H5SO3-, m-C6H4(OH)COO- and CH3CH(OH)COO-) have been synthesized. We studied the cytotoxicity of the synthesized compounds on the example of various tumor (Jurkat, K562, U937, HL60, A2780) and conditionally normal (HEK293) cell lines. IC50 was determined, and the influence of the structure and nature of the anion and cation on the antitumor activity was specified. Intracellular signaling, apoptosis induction and effects of the most active ionic compounds on the cell cycle and mitochondria have been discussed by applying modern methods of multiparametric enzyme immunoassay and flow cytometry.

Direct Synthesis of Polyaromatic Cyclophanes Containing Bis-Methylene-Interrupted Z-Double Bonds and Study of Their Antitumor Activity In Vitro.

An original synthetic route was developed for the preparation of previously unknown unsaturated polyaromatic macrolactones containing a 1Z,5Z-diene moiety in 48-71% yields and with >98% stereoselectivity. The method is based on intermolecular cyclocondensation of aromatic dicarboxylic acids with α,ω-alka-nZ,(n+4)Z-dienediols (1,12-dodeca-4Z,8Z-dienediol, 1,14-tetradeca-5Z,9Z-dienediol, 1,18-octadeca-7Z,11Z-dienediol) mediated by N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC)/4-dimethylaminopyridine (DMAP). The unsaturated diols were prepared by successive homo-cyclomagnesiation of tetrahydropyran ethers of O-containing 1,2-dienes with EtMgBr in the presence of Mg metal and the Cp2TiCl2 catalyst (10 mol.%) and subsequent treatment with 0.1 equiv. of para-toluenesulfonic acid of pyran ethers formed after the acid hydrolysis of magnesacyclopentanes. The resulting cyclophanes exhibited high cytotoxic activity in vitro against Jurkat, K562, U937, and HL60 cancer lines. Additionally, the synthesized products were studied for their effect on mitochondria, ability to induce apoptosis, and influence on the cell cycle using modern flow cytometry methods.

Natural Trienoic Acids as Anticancer Agents: First Stereoselective Synthesis, Cell Cycle Analysis, Induction of Apoptosis, Cell Signaling and Mitochondrial Targeting Studies.

The first Z-stereoselective method was developed for the synthesis of unsaturated acids containing a 1Z,5Z,9Z-triene moiety in 61-64% yields using the new Ti-catalyzed cross-coupling of oxygen-containing and aliphatic 1,2-dienes as the key synthetic step. It was shown for the first time that trienoic acids with non-methylene-interrupted Z-double bonds show moderate cytotoxic activities against tumor cell lines (Jurkat, K562, U937, HL60, HeLa), human embryonic kidney cells (Hek293), normal fibroblasts and human topoisomerase I (hTop1) inhibitory activity in vitro. The synthesized acids efficiently initiate apoptosis of Jurkat tumor cells, with the cell death mechanism being activated by the mitochondrial pathway. A probable mechanism of topoisomerase I inhibition was also hypothesized on the basis of in silico studies resorting to docking. The activation and inhibition of the most versatile intracellular signaling pathways (CREB, JNK, NFkB, p38, ERK1/2, Akt, p70S6K, STAT3 and STAT5 tyrosine kinases) responsible for cell proliferation and for initiation of apoptosis were studied by multiplex assay technology (Luminex xMAP).

Synthesis and cytotoxic activity of unsaturated macrolides and their hybrid molecules with a C60 fullerene.

Previously unreported macrodiolides containing a 1Z,5Z-diene fragment in the structure have been synthesized with high yields and stereoselectivity by our research group, using the intermolecular esterification of malonic acid with α,ω-diols containing bis-methylene-separated Z-double bonds, catalyzed by Hf(OTf)4 hafnium triflate. Under Bingel-Hirsch conditions, the synthesized macrodiolides were chemically bonded with a C60 fullerene to produce the corresponding methanofullerenes. The cytotoxic activity of macrodiolides and methanofullerenes in relation to Jurkat, K562, U937, HL60 tumor cell lines and normal fibroblasts was studied. Covalent binding of macrodiolides to the C60 fullerene molecule was found to significantly increase the cytotoxic effect (from 5 to 170 times) of the hybrid molecule as compared to the initial macrodiolide. Moreover, the synthesized hybrid molecules initiate apoptosis by uncoupling oxidation and phosphorylation of the mitochondrial membrane of tumor cells.

Synthesis and Anticancer Activity of Hybrid Molecules Based on Lithocholic and (5Z,9Z)-Tetradeca-5,9-dienedioic Acids Linked via Mono(di,tri,tetra)ethylene Glycol and α,ω-Diaminoalkane Units.

For the first time, hybrid molecules were synthesized on the basis of lithocholic and (5Z,9Z)-1,14-tetradeca-5,9-dienedicarboxylic acids, obtained in two stages using the homo-cyclomagnesiation reaction of 2-(hepta-5,6-diene-1-yloxy)tetrahydro-2H-pyran at the key stage. The resulting hybrid molecules containing 5Z,9Z-dienoic acids are of interest as novel synthetic biologically active precursors to create modern drugs for the treatment of human oncological diseases. The synthesized hybrid molecules were found to exhibit extremely high in vitro inhibitory activity against human topoisomerase I, which is 2-4 times higher than that of camptothecin, a known topoisomerase I inhibitor. Using flow cytometry and fluorescence microscopy, it was first shown that these new molecules are efficient apoptosis inducers in HeLa, U937, Jurkat, K562, and Hek293 cell cultures. In addition, the results of investigations into the effect of the synthesized acids on mitochondria and studies of possible DNA damage in Jurkat tumor cells are also presented.

Synthesis of Functionally Substituted Bicyclo[4.2.1]nona-2,4-dienes and Bicyclo[4.2.1]nona-2,4,7-trienes by Cobalt(I)-catalyzed [6π + 2π] Cycloaddition of 2-Tropylcyclohexanone.

The [6π + 2π] cycloaddition of 2-tropylcyclohexanone to allenes and alkynes was accomplished for the first time using the three-component catalytic system Co(acac)2(dppe)/Zn/ZnI2, thus giving previously unknown functionally substituted bicyclo[4.2.1]nona-2,4-dienes and bicyclo[4.2.1]nona-2,4,7-trienes in high yields (70-89%). The structures of the synthesized carbocycles were reliably proved using modern spectral methods and X-ray diffraction. The in vitro cytotoxic activity of the obtained bicyclo[4.2.1]nona-2,4-dienes and bicyclo[4.2.1]nona-2,4,7-trienes against the Jurkat, K562, and U937 tumor cell lines has been studied.

New synthetic analogues of natural 5Z,9Z-dienoic acids: Stereoselective synthesis and study of the anticancer activity.

A stereoselective method was developed for the synthesis of synthetic analogues of natural 5Z,9Z-dienoic acids by esterification of aliphatic and aromatic alcohols and carboxylic acids with (5Z,9Z)-1,14-tetradeca-5,9-dienedioic acid and (5Z,9Z)-1,14-tetradeca-5,9-dienediol, synthesized by Ti-catalyzed homo-cyclomagnesiation of the tetrahydropyran ether of hepta-5,6-dien-1-ol with Grignard reagents. In order to establish the effect of molecular structure on the antitumor activity, the obtained 5Z,9Z-dienoic acids were tested for the inhibitory activity against human topoisomerase I, the cytotoxic activity in vitro against several cancer and normal cell lines (Jurkat, HL-60, K562, U937, fibroblasts), the effect on the cell cycle, and apoptosis-inducing ability using flow cytofluorometry. In addition, the effect of the synthesized acids on the cancer cell production of some phosphorylated and unphosphorylated proteins responsible for proliferation and apoptosis was studied by a new multiplex assay technology, MAGPIX.

Total Synthesis of Natural Lembehyne C and Investigation of Its Cytotoxic Properties.

The first Z-stereoselective method for the synthesis of the natural marine alkynol lembehyne C, containing a 1Z,5Z,9Z-triene moiety, in 41% yield was developed using the new Ti-catalyzed cross-coupling of oxygenated and aliphatic 1,2-dienes as the key step. It was found for the first time that lembehyne C exhibits moderate cytotoxicity against Jurkat, K562, U937, and HL60 cancer cells and also efficiently induces apoptosis in Jurkat cells, with the cell death mechanism being activated by the mitochondrial pathway. The lembehyne C inhibition of the cell cycle follows the mitotic catastrophe mechanism.

Hybrid molecules based on fullerene C60 and 5Z,9Z-dienoic acids: Synthesis and cytotoxic activity.

The present research project details synthesis of new hybrid methanofullerenes based on acetylene and triazole esters of malonic acid containing 5Z,9Z-dienoic acids and fullerene C60 under Bingel-Hirsch conditions, including study of the cytotoxic activity with respect to Jurkat, K562, U937 and HL60 tumor cell lines. Hybrid methanofullerenes containing acetylenic fragments, unlike triazole substituents, were found to exhibit higher cytotoxicity, but are characterized by lower selectivity of action in relation to healthy cells.

New 1Z,5Z-diene macrodiolides: Catalytic synthesis, anticancer activity, induction of mitochondrial apoptosis, and effect on the cell cycle.

An original scheme was developed for the synthesis of previously undescribed unsaturated macrodiolides containing a 1Z,5Z-diene moiety in 44-80% yields and with high stereoselectivity (>95%) based on the intermolecular esterification of α,ω-diols with α,ω-alka-nZ,(n + 4)Z-dienedicarboxylic acids (1,12-dodeca-4Z,8Z-dienedicarboxylic acid, 1,14-tetradeca-5Z,9Z-dienedicarboxylic acid, 1,18-octadeca-7Z,11Z-dienedicarboxylic acid) catalyzed by hafnium triflate [Hf(OTf)4]. The unsaturated dicarboxylic acids were prepared via homo-cyclomagnesiation of tetrahydropyran ethers of O-containing 1,2-dienes with EtMgBr in the presence of Mg metal and the Cp2TiCl2 catalyst (10 mol.%) and the subsequent Jones oxidation of pyran ethers formed after the acid hydrolysis of magnesacyclopentanes. The thus prepared macrodiolides exhibit high cytotoxic activity in vitro against Jurkat, K562, U937, Hek293 and HeLa cancer cell lines. It was found that induction of the programmed cell death in Jurkat cells by macrodiolides corresponds to the mitochondrial apoptosis pathway. Also, it was shown that the prepared macrodiolides efficiently suppress phosphorylation of Akt and p38 kinases and CREB transcription factor in cancer cells.

Comparative in†vitro Studies of the Topoisomerase I Inhibition and Anticancer Activities of Metallated N-Confused Porphyrins and Metallated Porphyrins.

Using the original approach, a series of metallated N-confused porphyrins and metallated porphyrins have been synthesized and characterized. For all the synthesized porphyrins, in vitro studies of cytotoxic activity against K562, U937, HL-60, Jurkat, A549 and HeLa cancer cell lines, the ability to induce apoptosis and effects on the cell cycle as well as the kinetics of proliferative activity of porphyrins and their respective metallated complexes in real time have been developed. The inhibitory activity of metallated porphyrins against human topoisomerase I and the possible mechanism of inhibition have been carried out by modelling using molecular docking.

New 1,3-Diynoic Derivatives of Natural Lembehyne B: Stereoselective Synthesis, Anticancer, and Neuritogenic Activity.

An original method has been developed for the synthesis of 1,3-dyine derivatives of natural lembehyne B in high yields (50-67%) and with high selectivity (>98%). The key stage of the synthesis is new Ti-catalyzed cross-cyclomagnesiation of oxygenated and aliphatic 1,2-dienes induced by Grignard reagents. For studying the effect of the structure on the antitumor and neuritogenic activities, a series of lembehyne B analogues with different distances between the terminal hydroxy group and the 1,3-diyne moiety was prepared and tested for neuritogenic activity on mouse neuroblastoma Neuro 2A cells and for cytotoxicity, induction of apoptosis, and effects on the cell cycle using Jurkat, U937, K562, HeLa, and Hek293 tumor cell lines.

Synthesis, structure, and antitumor activity of 2,9-disubstituted perhydro 2,3a,7b,9,10a,14b-hexaazadibenzotetracenes.

Catalytic methods for the synthesis of previously unknown 2,9-disubstituted 3bR*,7aR*,10bR*,14aR*-cis-14c,14d-perhydro-2,3a,7b,9,10a,14b-hexaazadibenzotetracenes have been developed. The structures were established by 1D (1H, 13C) and 2D (COSY, HSQC, HMBC) NMR spectroscopy, MALDI TOF/TOF mass spectrometry, and X-ray diffraction analysis. Primary screening of the synthesized perhydro hexaazadibenzotetracenes for antitumor activity was carried out.

Synthesis of C60 Fullerene-Quadricyclane Hybrid Compound and Its Preliminary In Vitro Antitumor Activity in Combination with Cisplatin.

This paper describes the authors' preliminary studies directed toward the possibility of the practical implementation of the idea to design efficient antitumor drugs based on hybrid molecules composed of fullerene C60 and quadricyclanes. The essence of the proposed idea is that these hybrid molecules are able to cleave DNA owing to the fullerene moiety they contain and to simultaneously thermally affect tumor cells via cleavage of the carbon-carbon bond in quadricyclanes under the action of Pd and Pt ions. As a result, testing of the cytotoxic activity in vitro for a number of fullerene C60 hybrids with the norbornadiene or quadricyclane moieties against the human T-lymphoblastic leukemia cells (Jurkat cells) in combination of the known cisplatin drug, which was taken as the source of Pt ions, showed a statistically reliable dose-dependent increase in the number of dead cells in each group, which were formed according to the amount of cisplatin added, in comparison with the control, that is, cells treated with cisplatin or quadricyclane fullerene derivatives alone. Indeed, the difference between the percentages of viable cells after treatment with either cisplatin alone or cisplatin in combination with methanofullerene 5 ranged from ∼10% (for Pt (0.015 mkM), 5 (0.015 mkM)) to ∼55% (for Pt (0.03 mkM), 5 (0.045 mkM)).

Synthesis of New Cu Complex Based on Natural 5Z,9Z-Eicosadienoic Acid: Effective Topoisomerase I Inhibitor and Cytotoxin against the Cisplatin-Resistant Cell Line.

The complex (bipy)2Cu(5,9-eicd) was prepared by the reaction of Cu(OAc)2 with 5Z,9Z-eicosadienoic acid and 2,2'-bipyridine in methanol. The new copper complex showed high antitumor activity in vitro toward A2780cis, A2780, Hek293, K562, HL60, Jurkat, and U937 cell lines and efficiently inhibited human topoisomerase I. Using flow cytofluorometry, (bipy)2Cu(5,9-eicd) was studied for the effect on the cell cycle and apoptosis-inducing activity in tumor cells.

The Synthesis of Bicyclo[4.2.1]nona-2,4,7-trienes by [6π + 2π]-Cycloaddition of 1-Substituted 1,3,5-Cycloheptatrienes Catalyzed by Titanium and Cobalt Complexes.

The [6π + 2π]-cycloaddition of alkynes to 1-methyl-, propyl-, benzyl-, and hydroxymethyl-substituted 1,3,5-cycloheptatrienes in the presence of catalytic systems Ti(acac)2Cl2-Et2AlCl and Co(acac)2(dppe)/Zn/ZnI2 was performed for the first time to give practically valuable bicyclo[4.2.1]nona-2,4,7-trienes in high yields (72-88%). The structures of the obtained bicyclic compounds were reliably proved by NMR methods and X-ray diffraction analysis. The newly synthesized bicycles have been investigated for their in vitro cytotoxic activity against Jurkat, K562, U937, and HL60 tumor and normal cell lines and induction of apoptosis.