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Hassan AMIA, Zhao Y, Chen X, He C. Blockage of Autophagy for Cancer Therapy: A Comprehensive Review. Int J Mol Sci 2024; 25:7459. [PMID: 39000565 PMCID: PMC11242824 DOI: 10.3390/ijms25137459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2024] [Revised: 06/25/2024] [Accepted: 07/03/2024] [Indexed: 07/16/2024] Open
Abstract
The incidence and mortality of cancer are increasing, making it a leading cause of death worldwide. Conventional treatments such as surgery, radiotherapy, and chemotherapy face significant limitations due to therapeutic resistance. Autophagy, a cellular self-degradation mechanism, plays a crucial role in cancer development, drug resistance, and treatment. This review investigates the potential of autophagy inhibition as a therapeutic strategy for cancer. A systematic search was conducted on Embase, PubMed, and Google Scholar databases from 1967 to 2024 to identify studies on autophagy inhibitors and their mechanisms in cancer therapy. The review includes original articles utilizing in vitro and in vivo experimental methods, literature reviews, and clinical trials. Key terms used were "Autophagy", "Inhibitors", "Molecular mechanism", "Cancer therapy", and "Clinical trials". Autophagy inhibitors such as chloroquine (CQ) and hydroxychloroquine (HCQ) have shown promise in preclinical studies by inhibiting lysosomal acidification and preventing autophagosome degradation. Other inhibitors like wortmannin and SAR405 target specific components of the autophagy pathway. Combining these inhibitors with chemotherapy has demonstrated enhanced efficacy, making cancer cells more susceptible to cytotoxic agents. Clinical trials involving CQ and HCQ have shown encouraging results, although further investigation is needed to optimize their use in cancer therapy. Autophagy exhibits a dual role in cancer, functioning as both a survival mechanism and a cell death pathway. Targeting autophagy presents a viable strategy for cancer therapy, particularly when integrated with existing treatments. However, the complexity of autophagy regulation and the potential side effects necessitate further research to develop precise and context-specific therapeutic approaches.
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Affiliation(s)
| | - Yuxin Zhao
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macao SAR 999078, China (X.C.)
| | - Xiuping Chen
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macao SAR 999078, China (X.C.)
- Department of Pharmaceutical Science, Faculty of Health Sciences, University of Macau, Taipa, Macao SAR 999078, China
| | - Chengwei He
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macao SAR 999078, China (X.C.)
- Department of Pharmaceutical Science, Faculty of Health Sciences, University of Macau, Taipa, Macao SAR 999078, China
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2
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Ratto A, Honek JF. Oxocarbon Acids and their Derivatives in Biological and Medicinal Chemistry. Curr Med Chem 2024; 31:1172-1213. [PMID: 36915986 DOI: 10.2174/0929867330666230313141452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 01/10/2023] [Accepted: 01/12/2023] [Indexed: 03/15/2023]
Abstract
The biological and medicinal chemistry of the oxocarbon acids 2,3- dihydroxycycloprop-2-en-1-one (deltic acid), 3,4-dihydroxycyclobut-3-ene-1,2-dione (squaric acid), 4,5-dihydroxy-4-cyclopentene-1,2,3-trione (croconic acid), 5,6-dihydroxycyclohex- 5-ene-1,2,3,4-tetrone (rhodizonic acid) and their derivatives is reviewed and their key chemical properties and reactions are discussed. Applications of these compounds as potential bioisosteres in biological and medicinal chemistry are examined. Reviewed areas include cell imaging, bioconjugation reactions, antiviral, antibacterial, anticancer, enzyme inhibition, and receptor pharmacology.
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Affiliation(s)
- Amanda Ratto
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada
| | - John F Honek
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada
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3
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Ruseva N, Atanasova M, Sbirkova-Dimitrova H, Marković A, Šmelcerović Ž, Šmelcerović A, Cherneva E, Bakalova A. Chloro-substituted pyridine squaramates as new DNase I inhibitors: Synthesis, structural characterization, in vitro evaluation and molecular docking studies. Chem Biol Interact 2023; 386:110772. [PMID: 37898285 DOI: 10.1016/j.cbi.2023.110772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 10/08/2023] [Accepted: 10/16/2023] [Indexed: 10/30/2023]
Abstract
Having continued our recent study on the synthesis and DNase I inhibition of several monosquaramides, two new chloro-substituted pyridine squaramates were synthesized and their structure was identified by X-ray. Their inhibitory properties towards deoxyribonuclease I (DNase I) and xanthine oxidase (XO) were evaluated in vitro. 3-(((6-Chloropyridin-3-yl)methyl)amino)-4-ethoxycyclobut-3-ene-1,2-dione (compound 3a) inhibited DNase I with an IC50 value of 43.82 ± 6.51 μM, thus standing out as one of the most potent small organic DNase I inhibitors tested to date. No cytotoxicity to human tumor cell lines (HL-60, MDA-MB-231 and MCF-7) was observed for the tested compounds. In order to investigate the drug-likeness of the squaramates, the ADME profile and pharmacokinetic properties were evaluated. Molecular docking was performed to reveal the binding mode of the studied compounds on DNase I.
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Affiliation(s)
- Nina Ruseva
- Department of Chemistry, Faculty of Pharmacy, Medical University of Sofia, 2 Dunav Str., 1000, Sofia, Bulgaria
| | - Mariyana Atanasova
- Department of Chemistry, Faculty of Pharmacy, Medical University of Sofia, 2 Dunav Str., 1000, Sofia, Bulgaria
| | - Hristina Sbirkova-Dimitrova
- Institute of Mineralogy and Crystallography "Akad. Ivan Kostov", Bulgarian Academy of Sciences, Acad. G. Bonchev Bl. 107, 1113, Sofia, Bulgaria
| | - Ana Marković
- Department of Pharmacy, Faculty of Medicine, University of Niš, Bulevar Zorana Ðindića 81, 18000, Niš, Serbia
| | - Žaklina Šmelcerović
- Center for Biomedicinal Science, Faculty of Medicine, University of Niš, Bulevar Zorana Ðindića 81, 18000, Niš, Serbia
| | - Andrija Šmelcerović
- Department of Chemistry, Faculty of Medicine, University of Niš, Bulevar Zorana Ðindića 81, 18000, Niš, Serbia.
| | - Emiliya Cherneva
- Department of Chemistry, Faculty of Pharmacy, Medical University of Sofia, 2 Dunav Str., 1000, Sofia, Bulgaria; Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Build. 9, 1113, Sofia, Bulgaria
| | - Adriana Bakalova
- Department of Chemistry, Faculty of Pharmacy, Medical University of Sofia, 2 Dunav Str., 1000, Sofia, Bulgaria.
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Ardevines S, Auria-Luna F, Romanos E, Fernández-Moreira V, Benedi A, Concepción Gimeno M, Marzo I, Marqués-López E, Herrera RP. 1-Benzamido-1,4-dihydropyridine derivatives as anticancer agents: in vitro and in vivo assays. ARAB J CHEM 2022. [DOI: 10.1016/j.arabjc.2022.104514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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5
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Marchetti LA, Krämer T, Elmes RBP. Amidosquaramides - a new anion binding motif with pH sensitive anion transport properties. Org Biomol Chem 2022; 20:7056-7066. [PMID: 35993191 DOI: 10.1039/d2ob01176j] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Stimuli responsive anion transport is becoming an important aspect of supramolecular anion recognition chemistry. Herein, we report the synthesis of a family of anion receptors that incorporate a new anion binding motif, amidosquaramides. We show using experimental and computational methods that these receptors have pKa values close to physiological pH but also display intramolecular H-bonding interactions that affect anion recognition. Moreover, moderate activity in a Cl-/NO3- exchange assay is observed at physiological pH that can be effectively 'switched on' when repeated under acidic conditions. The reported findings provide synthetic methods that can be used for the construction of more complex squaramide based anion receptors and also provide insight into the importance of conformational analysis when considering receptor design.
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Affiliation(s)
- Luke A Marchetti
- Department of Chemistry, National University of Ireland Maynooth, Maynooth, Ireland.
| | - Tobias Krämer
- Department of Chemistry, National University of Ireland Maynooth, Maynooth, Ireland.
| | - Robert B P Elmes
- Department of Chemistry, National University of Ireland Maynooth, Maynooth, Ireland. .,Synthesis and Solid State Pharmaceutical Centre (SSPC), Ireland
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Pósa SP, Dargó G, Nagy S, Kisszékelyi P, Garádi Z, Hámori L, Szakács G, Kupai J, Tóth S. Cytotoxicity of cinchona alkaloid organocatalysts against MES-SA and MES-SA/Dx5 multidrug-resistant uterine sarcoma cell lines. Bioorg Med Chem 2022; 67:116855. [PMID: 35640378 DOI: 10.1016/j.bmc.2022.116855] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 05/10/2022] [Accepted: 05/23/2022] [Indexed: 11/18/2022]
Abstract
Since the first application of natural quinine as an anti-malarial drug, cinchona alkaloids and their derivatives have been exhaustively studied for their biological activity. In our work, we tested 13 cinchona alkaloid organocatalysts, synthesised from quinine. These derivatives were screened against MES-SA and Dx5 uterine sarcoma cell lines for in vitro anticancer activity and to investigate their potential to overcome P-glycoprotein (P-gp) mediated multidrug resistance (MDR). Decorating quinine with hydrogen-bond donor units, such as thiourea and (thio)squaramide, resulted in decreased half-maximal growth inhibition values on both cell lines (1.3-21 µM) compared to quinine and other cinchona alcohols (47-111 µM). Further cytotoxicity studies conducted in the presence of the P-gp inhibitor tariquidar indicated that several analogues, especially cinchona amines and squaramides, but not thiosquaramide, were expelled from MDR cells by P-gp. Similarly to the established P-gp inhibitor quinine, 6 cinchona analogues were shown to inhibit calcein-AM efflux. Interestingly, quinine and didehydroquinine exhibited a marginally increased toxicity against the multidrug resistant Dx5 cells. Collateral sensitivity of the MDR cell line was more pronounced when the cinchona thiosquaramide was complexed with Cu(II) acetate. Based on the results, cinchona derivatives are good anticancer candidates for further drug development.
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Affiliation(s)
- Szonja Polett Pósa
- Department of Organic Chemistry & Technology, Budapest University of Technology & Economics, Műegyetem rakpart 3, H-1111 Budapest, Hungary; Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
| | - Gyula Dargó
- Department of Organic Chemistry & Technology, Budapest University of Technology & Economics, Műegyetem rakpart 3, H-1111 Budapest, Hungary
| | - Sándor Nagy
- Department of Organic Chemistry & Technology, Budapest University of Technology & Economics, Műegyetem rakpart 3, H-1111 Budapest, Hungary
| | - Péter Kisszékelyi
- Department of Organic Chemistry & Technology, Budapest University of Technology & Economics, Műegyetem rakpart 3, H-1111 Budapest, Hungary
| | - Zsófia Garádi
- Department of Pharmacognosy Semmelweis University, Üllői út. 26, H-1085 Budapest, Hungary
| | - Lilla Hámori
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
| | - Gergely Szakács
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary; Institute of Cancer Research, Medical University Vienna, Vienna, Austria
| | - József Kupai
- Department of Organic Chemistry & Technology, Budapest University of Technology & Economics, Műegyetem rakpart 3, H-1111 Budapest, Hungary.
| | - Szilárd Tóth
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary.
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7
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Horizons in Asymmetric Organocatalysis: En Route to the Sustainability and New Applications. Catalysts 2022. [DOI: 10.3390/catal12010101] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Nowadays, the development of new enantioselective processes is highly relevant in chemistry due to the relevance of chiral compounds in biomedicine (mainly drugs) and in other fields, such as agrochemistry, animal feed, and flavorings. Among them, organocatalytic methods have become an efficient and sustainable alternative since List and MacMillan pioneering contributions were published in 2000. These works established the term asymmetric organocatalysis to label this area of research, which has grown exponentially over the last two decades. Since then, the scientific community has attended to the discovery of a plethora of organic reactions and transformations carried out with excellent results in terms of both reactivity and enantioselectivity. Looking back to earlier times, we can find in the literature a few examples where small organic molecules and some natural products could act as effective catalysts. However, with the birth of this type of catalysis, new chemical architectures based on amines, thioureas, squaramides, cinchona alkaloids, quaternary ammonium salts, carbenes, guanidines and phosphoric acids, among many others, have been developed. These organocatalysts have provided a broad range of activation modes that allow privileged interactions between catalysts and substrates for the preparation of compounds with high added value in an enantioselective way. Here, we briefly cover the history of this chemistry, from our point of view, including our beginnings, how the field has evolved during these years of research, and the road ahead.
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Auria-Luna F, Marqués-López E, Romanos E, Fernández-Moreira V, Gimeno MC, Marzo I, Herrera RP. Novel ureido-dihydropyridine scaffolds as theranostic agents. Bioorg Chem 2020; 105:104364. [PMID: 33113409 DOI: 10.1016/j.bioorg.2020.104364] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 09/25/2020] [Accepted: 10/07/2020] [Indexed: 12/13/2022]
Abstract
In this work, the synthesis of interesting urea derivatives 5 based on 1,4-dihydropyridines 3 is described for the first time. Considering that both families exhibit potential as drugs to treat various diseases, their activity as anticancer agents has been evaluated in HeLa (cervix), Jurkat (leukaemia) and A549 (lung) cancer cell lines as well as on healthy mice in vivo. In general, whereas 1,4-dihydropyridines show a moderate cytotoxic activity, their urea analogues cause an extraordinary increase in their antiproliferative activity, specially towards HeLa cells. Because of the chiral nature of these compounds, enantiomerically enriched samples were also tested, showing different cytotoxic activity than the racemic mixture. Although the reason is not clear, it could be caused by a complex amalgam of physical and chemical contributions. The studied compounds also exhibit luminescent properties, which allow performing a biodistribution study in cancer cells. They have emission maxima between 420 and 471 nm, being the urea derivatives in general red shifted. Emission quenching was observed for those compounds containing a nitro group (3e,f and 5e,f). Fluorescence microscopy showed that 1,4-dihydropyridines 3a and 3g localised in the lysosomes, in contrast to the urea derivatives 5h that accumulated in the cell membrane. This different distribution could be key to explain the differences found in the cytotoxic activity and in the mechanism of action. Interestingly, a preliminary in vivo study regarding the acute toxicity of some of these compounds on healthy mice has been conducted, using a concentration up to 7200 times higher than the corresponding IC50 value. No downgrade in the welfare of the tested mice was observed, which could support their use in preclinical tumour models.
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Affiliation(s)
- Fernando Auria-Luna
- Laboratorio de Organocatálisis Asimétrica, Departamento de Química Orgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, C/ Pedro Cerbuna 12, E-50009 Zaragoza, Spain
| | - Eugenia Marqués-López
- Laboratorio de Organocatálisis Asimétrica, Departamento de Química Orgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, C/ Pedro Cerbuna 12, E-50009 Zaragoza, Spain
| | - Eduardo Romanos
- Laboratorio de Organocatálisis Asimétrica, Departamento de Química Orgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, C/ Pedro Cerbuna 12, E-50009 Zaragoza, Spain; Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, C/ Pedro Cerbuna 12, E-50009 Zaragoza, Spain; Departamento de Imagen y Fenotipado, Instituto Aragonés de Ciencias de la Salud, Centro de Investigación Biomédica de Aragón (CIBA), Avda. San Juan Bosco, 13, planta D, E-50009 Zaragoza, Spain
| | - Vanesa Fernández-Moreira
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, C/ Pedro Cerbuna 12, E-50009 Zaragoza, Spain.
| | - M Concepción Gimeno
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, C/ Pedro Cerbuna 12, E-50009 Zaragoza, Spain
| | - Isabel Marzo
- Departamento de Bioquímica y Biología Celular, Universidad de Zaragoza, C/ Pedro Cerbuna 12, E-50009 Zaragoza, Spain
| | - Raquel P Herrera
- Laboratorio de Organocatálisis Asimétrica, Departamento de Química Orgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, C/ Pedro Cerbuna 12, E-50009 Zaragoza, Spain.
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Chasák J, Šlachtová V, Urban M, Brulíková L. Squaric acid analogues in medicinal chemistry. Eur J Med Chem 2020; 209:112872. [PMID: 33035923 DOI: 10.1016/j.ejmech.2020.112872] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 09/12/2020] [Accepted: 09/21/2020] [Indexed: 12/16/2022]
Abstract
In this review, we summarize the published data on squaric acid analogues with a special focus on their use in medicinal chemistry and as potential drugs. Squaric acid is an interesting small molecule with an almost perfectly square shape, and its analogues have a variety of biological activities that are enabled by the presence of significant H-bond donors and acceptors. Unfortunately, most of these compounds also exhibit reactive functionalities, and this deters the majority of medicinal chemists and pharmacologists from trying to use them in drug development. However, this group of compounds is experiencing a renaissance, and large numbers of them are being tested for antiprotozoal, antibacterial, antifungal, and antiviral activities. The most useful of these compounds exhibited IC50 values in the nanomolar range, which makes them promising drug candidates. In addition to these activities, their interactions with living systems were intensively explored, revealing that squaric acid analogues inhibit various enzymes and often serve as receptor antagonists and that the squaric acid moiety may be used as a non-classical isosteric replacement for other functional groups such as carboxylate. In summary, this review is focused on squaric acid and its analogues and their use in medicinal chemistry and should serve as a guide for other researchers in the field to demonstrate the potential of these compounds based on previous research.
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Affiliation(s)
- Jan Chasák
- Department of Organic Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, 771 46, Olomouc, Czech Republic
| | - Veronika Šlachtová
- Department of Organic Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, 771 46, Olomouc, Czech Republic
| | - Milan Urban
- Medicinal Chemistry, Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University in Olomouc, Hněvotínská 5, 779 00, Olomouc, Czech Republic
| | - Lucie Brulíková
- Department of Organic Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, 771 46, Olomouc, Czech Republic.
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Shyamsivappan S, Vivek R, Saravanan A, Arasakumar T, Subashini G, Suresh T, Shankar R, Mohan PS. Synthesis and X-ray study of dispiro 8-nitroquinolone analogues and their cytotoxic properties against human cervical cancer HeLa cells. MEDCHEMCOMM 2019; 10:439-449. [PMID: 31015907 DOI: 10.1039/c8md00482j] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 01/15/2019] [Indexed: 12/25/2022]
Abstract
A series of unique dispiro analogues containing an oxindole pyrrolidine 8-nitroquinolone hybrid has been obtained through a one-pot three-component 1,3-dipolar cycloaddition of azomethine ylides generated in situ from the condensation of isatins and benzylamine with (E)-3-arylidene-2,3-dihydro-8-nitro-4-quinolones. The structures of the newly synthesized compounds were characterized by using different spectroscopic techniques and by X-ray diffraction studies of their regio- and stereochemistry. All the synthesized compounds were screened for in vitro cytotoxic activity against the human cervical cancer cell line HeLa. The compounds have exhibited potent inhibition against human cervical cancer cells and insignificant toxicity to normal cells. The compounds 6d, 6a, 6h, 6b, and 6e induced apoptosis of HeLa cells, through ROS influx. The expression levels of proteins involved in the mitochondrion-related pathways were detected, and Western blot analysis showed that apoptosis occurred via activation of caspase-3.
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Affiliation(s)
- Selvaraj Shyamsivappan
- School of Chemical Sciences , Bharathiar University , Coimbatore , Tamil Nadu , India . ;
| | - Raju Vivek
- Chemical Biology , Rajiv Gandhi Centre for Biotechnology , Thiruvananthapuram , Kerala , India
| | - Arjunan Saravanan
- DRDO-BU CLS , Bharathiar University Campus , Coimbatore , Tamil Nadu , India
| | - Thangaraj Arasakumar
- School of Chemical Sciences , Bharathiar University , Coimbatore , Tamil Nadu , India . ;
| | - Gopalan Subashini
- Department of Chemistry , P.S.G.R. Krishnammal College For Women , Coimbatore , Tamil Nadu , India
| | - Thangaraj Suresh
- School of Chemical Sciences , Bharathiar University , Coimbatore , Tamil Nadu , India . ;
| | - Ramasamy Shankar
- Department of Physics , Bharathiar University , Coimbatore , Tamil Nadu , India
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Squaraine dyes: The hierarchical synthesis and its application in optical detection. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2017. [DOI: 10.1016/j.jphotochemrev.2017.03.001] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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13
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Ximenis M, Bustelo E, Algarra AG, Vega M, Rotger C, Basallote MG, Costa A. Kinetic Analysis and Mechanism of the Hydrolytic Degradation of Squaramides and Squaramic Acids. J Org Chem 2017; 82:2160-2170. [PMID: 28107005 DOI: 10.1021/acs.joc.6b02963] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The hydrolytic degradation of squaramides and squaramic acids, the product of partial hydrolysis of squaramides, has been evaluated by UV spectroscopy at 37 °C in the pH range 3-10. Under these conditions, the compounds are kinetically stable over long time periods (>100 days). At pH >10, the hydrolysis of the squaramate anions shows first-order dependence on both squaramate and OH-. At the same temperature and [OH-], the hydrolysis of squaramides usually displays biphasic spectral changes (A → B → C kinetic model) with formation of squaramates as detectable reaction intermediates. The measured rates for the first step (k1 ≈ 10-4 M-1 s-1) are 2-3 orders of magnitude faster than those for the second step (k2 ≈ 10-6 M-1 s-1). Experiments at different temperatures provide activation parameters with values of ΔH⧧ ≈ 9-18 kcal mol-1 and ΔS⧧ ≈ -5 to -30 cal K-1 mol-1. DFT calculations show that the mechanism for the alkaline hydrolysis of squaramic acids is quite similar to that of amides.
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Affiliation(s)
- Marta Ximenis
- Department of Chemistry, Universitat de les Illes Balears , Palma 07122, Spain
| | - Emilio Bustelo
- Department of Materials Scientist, Metallurgic Engineering and Inorganic Chemistry, Universidad de Cádiz , Puerto Real, 11510 Cádiz, Spain
| | - Andrés G Algarra
- Department of Materials Scientist, Metallurgic Engineering and Inorganic Chemistry, Universidad de Cádiz , Puerto Real, 11510 Cádiz, Spain
| | - Manel Vega
- Department of Chemistry, Universitat de les Illes Balears , Palma 07122, Spain
| | - Carmen Rotger
- Department of Chemistry, Universitat de les Illes Balears , Palma 07122, Spain
| | - Manuel G Basallote
- Department of Materials Scientist, Metallurgic Engineering and Inorganic Chemistry, Universidad de Cádiz , Puerto Real, 11510 Cádiz, Spain
| | - Antonio Costa
- Department of Chemistry, Universitat de les Illes Balears , Palma 07122, Spain
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14
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Lu M, Lu QB, Honek JF. Squarate-based carbocyclic nucleosides: Syntheses, computational analyses and anticancer/antiviral evaluation. Bioorg Med Chem Lett 2017; 27:282-287. [DOI: 10.1016/j.bmcl.2016.11.058] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 11/20/2016] [Accepted: 11/21/2016] [Indexed: 12/31/2022]
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