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Xu Y, Zhao N, Li F, Wang C, Xie H, Wu J, Cheng L, Wang L, Wang Z. Application of Vitreoscilla Hemoglobin as a Green and Efficient Biocatalyst for the Synthesis of Benzoxazoles in Water. Chembiochem 2024; 25:e202300609. [PMID: 37877236 DOI: 10.1002/cbic.202300609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 10/23/2023] [Accepted: 10/24/2023] [Indexed: 10/26/2023]
Abstract
We report an efficient and eco-friendly method for the Vitreoscilla hemoglobin (VHb)-catalyzed synthesis of benzoxazoles in water at room temperature. tert-Butyl hydroperoxide and 2,2,6,6-tetramethyl-1-piperidinyloxy were used as oxidant and radical scavenger, respectively. A total of 27 functionally diverse benzoxazoles were prepared in moderate to high yields (62 %-94 %) by the annulation reaction of phenols with amines in the presence of VHb in 1 h. Thus, this method is highly viable for practical applications. This work broadens the application of hemoglobin to organic synthesis.
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Affiliation(s)
- Yaning Xu
- Key Laboratory of Molecular Enzymology and Engineering of Ministry of Education, College of Life Sciences, Jilin University, Changchun, 130023, P. R. China
| | - Nan Zhao
- Key Laboratory of Molecular Enzymology and Engineering of Ministry of Education, College of Life Sciences, Jilin University, Changchun, 130023, P. R. China
| | - Fengxi Li
- Key Laboratory of Molecular Enzymology and Engineering of Ministry of Education, College of Life Sciences, Jilin University, Changchun, 130023, P. R. China
| | - Chunyu Wang
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, 130023, P. R. China
| | - Hanqing Xie
- Key Laboratory of Molecular Enzymology and Engineering of Ministry of Education, College of Life Sciences, Jilin University, Changchun, 130023, P. R. China
| | - Junhao Wu
- Key Laboratory of Molecular Enzymology and Engineering of Ministry of Education, College of Life Sciences, Jilin University, Changchun, 130023, P. R. China
| | - Lei Cheng
- Key Laboratory of Molecular Enzymology and Engineering of Ministry of Education, College of Life Sciences, Jilin University, Changchun, 130023, P. R. China
| | - Lei Wang
- Key Laboratory of Molecular Enzymology and Engineering of Ministry of Education, College of Life Sciences, Jilin University, Changchun, 130023, P. R. China
| | - Zhi Wang
- Key Laboratory of Molecular Enzymology and Engineering of Ministry of Education, College of Life Sciences, Jilin University, Changchun, 130023, P. R. China
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Makowska A, Sączewski F, Bednarski PJ, Gdaniec M, Balewski Ł, Warmbier M, Kornicka A. Synthesis, Structure and Cytotoxic Properties of Copper(II) Complexes of 2-Iminocoumarins Bearing a 1,3,5-Triazine or Benzoxazole/Benzothiazole Moiety. Molecules 2022; 27. [PMID: 36363982 DOI: 10.3390/molecules27217155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 10/19/2022] [Accepted: 10/20/2022] [Indexed: 12/05/2022]
Abstract
A series of copper(II) complexes of 2-imino-2H-chromen-3-yl-1,3,5-triazines 2a-h, 3-(benzoxazol-2-yl)-2H-chromen-2-imines 4a-b, and 3-(benzothiazol-2-yl)-2H-chromen-2-imines 6a-c were obtained by reacting of appropriate 2-iminocoumarin ligands L1a-h, L3a-b, and L5a-c with 3-fold molar excess of copper(II) chloride. The structure of these compounds was confirmed by IR spectroscopy, elemental analysis, and single-crystal X-ray diffraction data (2f, 2g, 2h, and 6c). All the synthesized complexes were screened for their activity against five human cancer cell lines: DAN-G, A-427, LCLC-103H, SISO, and RT-4 by using a crystal violet microtiter plate assay and relationships between structure and in vitro cytotoxic activity are discussed. The coordination of 2-iminocoumarins with copper(II) ions resulted in complexes 2a-h, 4a-b, and 6a-c with significant inhibitory properties toward tested tumor cell lines with IC50 values ranging from 0.04 μM to 15.66 μM. In comparison to the free ligands L1a-h, L3a-b, and L5a-c, the newly prepared Cu(II) complexes often displayed increased activity. In the series of copper(II) complexes of 2-imino-2H-chromen-3-yl-1,3,5-triazines 2a-h the most potent compound 2g contained a 4-phenylpiperazine moiety at position 6 of the 1,3,5-triazine ring and an electron-donating diethylamino group at position 7' of the 2-iminocoumarin scaffold. Among the Cu(II) complexes of 3-(benzoxazol-2-yl)-2H-chromen-2-imines 4a-b and 3-(benzothiazol-2-yl)-2H-chromen-2-imines 6a-c the most active was benzoxazole-2-iminocoumarin 4b that also possessed a diethylamino group at position 7' of the 2-iminocoumarin moiety. Moreover, compound 4b was found to be the most prominent agent and displayed the higher potency than cisplatin against tested cell lines.
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Fuentes-Aguilar A, Merino-Montiel P, Montiel-Smith S, Meza-Reyes S, Vega-Báez JL, Puerta A, Fernandes MX, Padrón JM, Petreni A, Nocentini A, Supuran CT, López Ó, Fernández-Bolaños JG. 2-Aminobenzoxazole-appended coumarins as potent and selective inhibitors of tumour-associated carbonic anhydrases. J Enzyme Inhib Med Chem 2021; 37:168-177. [PMID: 34894971 PMCID: PMC8667885 DOI: 10.1080/14756366.2021.1998026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We have carried out the design, synthesis, and evaluation of a small library of 2-aminobenzoxazole-appended coumarins as novel inhibitors of tumour-related CAs IX and XII. Substituents on C-3 and/or C-4 positions of the coumarin scaffold, and on the benzoxazole moiety, together with the length of the linker connecting both units were modified to obtain useful structure-activity relationships. CA inhibition studies revealed a good selectivity towards tumour-associated CAs IX and XII (Ki within the mid-nanomolar range in most of the cases) in comparison with CAs I, II, IV, and VII (Ki > 10 µM); CA IX was found to be slightly more sensitive towards structural changes. Docking calculations suggested that the coumarin scaffold might act as a prodrug, binding to the CAs in its hydrolysed form, which is in turn obtained due to the esterase activity of CAs. An increase of the tether length and of the substituents steric hindrance was found to be detrimental to in vitro antiproliferative activities. Incorporation of a chlorine atom on C-3 of the coumarin moiety achieved the strongest antiproliferative agent, with activities within the low micromolar range for the panel of tumour cell lines tested.
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Affiliation(s)
- Alma Fuentes-Aguilar
- Facultad de Ciencias Químicas, Ciudad Universitaria, Benemérita Universidad Autónoma de Puebla, Puebla, México
| | - Penélope Merino-Montiel
- Facultad de Ciencias Químicas, Ciudad Universitaria, Benemérita Universidad Autónoma de Puebla, Puebla, México
| | - Sara Montiel-Smith
- Facultad de Ciencias Químicas, Ciudad Universitaria, Benemérita Universidad Autónoma de Puebla, Puebla, México
| | - Socorro Meza-Reyes
- Facultad de Ciencias Químicas, Ciudad Universitaria, Benemérita Universidad Autónoma de Puebla, Puebla, México
| | - José Luis Vega-Báez
- Facultad de Ciencias Químicas, Ciudad Universitaria, Benemérita Universidad Autónoma de Puebla, Puebla, México
| | - Adrián Puerta
- BioLab, Instituto Universitario de Bio-Orgánica "Antonio González" (IUBO-AG), Universidad de La Laguna, La Laguna, Spain
| | - Miguel X Fernandes
- BioLab, Instituto Universitario de Bio-Orgánica "Antonio González" (IUBO-AG), Universidad de La Laguna, La Laguna, Spain
| | - José M Padrón
- BioLab, Instituto Universitario de Bio-Orgánica "Antonio González" (IUBO-AG), Universidad de La Laguna, La Laguna, Spain
| | - Andrea Petreni
- NEUROFARBA Department, Sezione di Scienze Farmaceutiche e Nutraceutiche, University of Florence, Florence, Italy
| | - Alessio Nocentini
- NEUROFARBA Department, Sezione di Scienze Farmaceutiche e Nutraceutiche, University of Florence, Florence, Italy
| | - Claudiu T Supuran
- NEUROFARBA Department, Sezione di Scienze Farmaceutiche e Nutraceutiche, University of Florence, Florence, Italy
| | - Óscar López
- Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, Seville, Spain
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Jackson AC, Pinter TBJ, Talley DC, Baker-Agha A, Patel D, Smith PJ, Franz KJ. Benzimidazole and Benzoxazole Zinc Chelators as Inhibitors of Metallo-β-Lactamase NDM-1. ChemMedChem 2021; 16:654-661. [PMID: 33211374 PMCID: PMC8114186 DOI: 10.1002/cmdc.202000607] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Indexed: 12/11/2022]
Abstract
Bacterial expression of β-lactamases, which hydrolyze β-lactam antibiotics, contributes to the growing threat of antibacterial drug resistance. Metallo-β-lactamases, such as NDM-1, use catalytic zinc ions in their active sites and hydrolyze nearly all clinically available β-lactam antibiotics. Inhibitors of metallo-β-lactamases are urgently needed to overcome this resistance mechanism. Zinc-binding compounds are promising leads for inhibitor development, as many NDM-1 inhibitors contain zinc-binding pharmacophores. Here, we evaluated 13 chelating agents containing benzimidazole and benzoxazole scaffolds as NDM-1 inhibitors. Six of the compounds showed potent inhibitory activity with IC50 values as low as 0.38 μM, and several compounds restored the meropenem susceptibility of NDM-1-expressing E. coli. Spectroscopic and docking studies suggest ternary complex formation as the mechanism of inhibition, making these compounds promising for development as NDM-1 inhibitors.
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Affiliation(s)
| | | | - Daniel C Talley
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, MD 21250, USA
| | - Adnan Baker-Agha
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, MD 21250, USA
| | - Dhruvil Patel
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, MD 21250, USA
| | - Paul J Smith
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, MD 21250, USA
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Li M, Li M, Tang Y, Sun Y, Qu L, Mao Z. Cu(II)/Vasicine Promoted Intramolecular C-O Formation: Synthesis of Benzoxazoles in EtOH. Curr Org Synth 2020; 18:310-315. [PMID: 33167843 DOI: 10.2174/1570179417666201109151752] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 10/12/2020] [Accepted: 10/15/2020] [Indexed: 11/22/2022]
Abstract
AIMS AND OBJECTIVES Benzoxazoles are valuable bicyclic aromatic compounds; the construction of benzoxazoles via C-O cross-coupling reactions has attracted more and more attention. MATERIALS AND METHODS The best condition of C-O bond formation from o-haloanilides was carried out, taking Cu(OTf)2 (5 mol%) and vasicine (10 mol%) as the catalysts in EtOH in the presence of K2CO3 (2 eq.) for 12 h at 90°C. RESULTS A series of 2-substituted benzoxazoles have been prepared in high yields from 2-bromoanilides and 2- iodioanilides under mild conditions. CONCLUSION We have developed an efficient Cu-vasicine catalytic system for intramolecular C-O bond formation. This strategy is applicable to the synthesis of a wide variety of 2-substituted benzoxazoles by intramolecular O-arylation of o-haloanilides.
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Affiliation(s)
- Minxin Li
- College of Pharmaceutical Science, Yunnan University of Chinese Medicine, Kunming 650500, China
| | - Meiling Li
- College of Pharmaceutical Science, Yunnan University of Chinese Medicine, Kunming 650500, China
| | - Yanling Tang
- College of Pharmaceutical Science, Yunnan University of Chinese Medicine, Kunming 650500, China
| | - Yun Sun
- College of Pharmaceutical Science, Yunnan University of Chinese Medicine, Kunming 650500, China
| | - Lu Qu
- College of Pharmaceutical Science, Yunnan University of Chinese Medicine, Kunming 650500, China
| | - Zewei Mao
- College of Pharmaceutical Science, Yunnan University of Chinese Medicine, Kunming 650500, China
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Zi M, Liu F, Wu D, Li K, Zhang D, Zhu C, Zhang Z, Li L, Zhang C, Xie M, Lin J, Zhang J, Jin Y. Discovery of 6-Arylurea-2-arylbenzoxazole and 6-Arylurea-2-arylbenzimidazole Derivatives as Angiogenesis Inhibitors: Design, Synthesis and in vitro Biological Evaluation. ChemMedChem 2019; 14:1291-1302. [PMID: 31131561 DOI: 10.1002/cmdc.201900216] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 05/22/2019] [Indexed: 12/15/2022]
Abstract
We embarked on a structural optimization campaign aimed at the discovery of novel anti-angiogenesis agents with previously reported imidazole kinase inhibitors as a lead compound. A library of 29 compounds was synthesized. Several title compounds exhibited selective inhibitory activities against vascular endothelial growth factor receptor 2 (VEGFR-2) over epidermal growth factor receptor (EGFR) kinase; these compounds also displayed selective and potent antiproliferative activity against three cancer cell lines. The newly synthesized compounds were evaluated for anti-angiogenesis activity by chick chorioallantoic membrane (CAM) assay. Among them, 1-(2-(2-chlorophenyl)benzo[d]oxazol-5-yl)-3-(4-(trifluoromethoxy)phenyl)urea (compound 5 n) showed the most potent anti-angiogenesis capacity, efficient cytotoxic activities (in vitro against human umbilical vein endothelial cells (HUVEC), H1975, A549, and HeLa cell lines, with respective IC50 values of 8.46, 1.40, 7.61, and 0.28 μm), and an acceptable level of VEGFR-2 kinase inhibition (IC50 =0.25 μm). Molecular docking analysis revealed 5 n to be a type II inhibitor of VEGFR-2 kinase. In general, these results indicate that these 6-arylurea-2-arylbenzoxazole/benzimidazole derivatives are promising inhibitors of VEGFR-2 kinase for potential development into anti-angiogenesis drugs.
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Affiliation(s)
- Mengli Zi
- Key Laboratory of Medicinal Chemistry for Natural Resources, Ministry of Education and Yunnan Province, School of Chemical Science and Technology, Yunnan University, Kunming, 650091, P.R. China
| | - Feifei Liu
- Laboratory of Molecular Genetics of Aging and Tumors, Medical School, Kunming University of Science and Technology, Kunming, 650500, P.R. China
| | - Di Wu
- Key Laboratory of Medicinal Chemistry for Natural Resources, Ministry of Education and Yunnan Province, School of Chemical Science and Technology, Yunnan University, Kunming, 650091, P.R. China
| | - Ke Li
- Biomedical Department, Yunnan Cancer Hospital, Third Affiliated Hospital of Kunming Medical University, Kunming, 650118, P.R. China
| | - Da Zhang
- Key Laboratory of Medicinal Chemistry for Natural Resources, Ministry of Education and Yunnan Province, School of Chemical Science and Technology, Yunnan University, Kunming, 650091, P.R. China
| | - Changcheng Zhu
- Institute of Drug Research and Development, Kunming Pharmaceutical Corporation, Kunming, 650100, P.R. China
| | - Zhiyun Zhang
- Department of Anorectal, Kunming Municipal Hospital of Traditional Chinese Medicine, Kunming, 650011, P.R. China
| | - Linghua Li
- Department of Anorectal, Kunming Municipal Hospital of Traditional Chinese Medicine, Kunming, 650011, P.R. China
| | - Conghai Zhang
- Key Laboratory of Medicinal Chemistry for Natural Resources, Ministry of Education and Yunnan Province, School of Chemical Science and Technology, Yunnan University, Kunming, 650091, P.R. China
| | - Mingjin Xie
- Key Laboratory of Medicinal Chemistry for Natural Resources, Ministry of Education and Yunnan Province, School of Chemical Science and Technology, Yunnan University, Kunming, 650091, P.R. China
| | - Jun Lin
- Key Laboratory of Medicinal Chemistry for Natural Resources, Ministry of Education and Yunnan Province, School of Chemical Science and Technology, Yunnan University, Kunming, 650091, P.R. China
| | - Jihong Zhang
- Laboratory of Molecular Genetics of Aging and Tumors, Medical School, Kunming University of Science and Technology, Kunming, 650500, P.R. China
| | - Yi Jin
- Key Laboratory of Medicinal Chemistry for Natural Resources, Ministry of Education and Yunnan Province, School of Chemical Science and Technology, Yunnan University, Kunming, 650091, P.R. China
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Sangi DP, Meira YG, Moreira NM, Lopes TA, Leite MP, Pereira-Flores ME, Alvarenga ES. Benzoxazoles as novel herbicidal agents. Pest Manag Sci 2019; 75:262-269. [PMID: 29885098 DOI: 10.1002/ps.5111] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 05/22/2018] [Accepted: 06/04/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Despite the need to develop new herbicides with different modes of action, due to weed resistance, many important classes of compounds have been studied poorly for this purpose. Benzoxazoles are considered privileged structures because of their biological activities, but their phytotoxic activities have not received a lot of attention until now. RESULTS Double vinylic substitution reactions were carried out to furnish four 2-nitromethylbenzoxazoles and one oxazolidine. Benzoxazol-2-ylmethanamine was obtained by reduction of compound 3a. These compounds were evaluated for their phytotoxicity in Allium cepa (onion), Solanum lycopersicum (tomato), Cucumis sativus (cucumber) and Sorghum bicolor (sorghum). Comparison with oxazolidine analogue allowed us to understand that the benzoxazolic structure is very important for the herbicidal activity. CONCLUSION All the synthesized compounds exhibited biological activity on seed germination. The four 2-nitromethylbenzoxazoles showed phytotoxic activity and the 5-chloro-2-(nitromethyl)benzo[d]oxazole (3b) exhibited higher inhibition than the commercial herbicide against all four plant species tested. © 2018 Society of Chemical Industry.
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Affiliation(s)
- Diego P Sangi
- Chemistry Department, Universidade Federal Fluminense, Volta Redonda, Brazil
| | - Yuri G Meira
- Chemistry Department, Universidade Federal Fluminense, Volta Redonda, Brazil
| | - Natália M Moreira
- Chemistry Department, Universidade Federal Fluminense, Volta Redonda, Brazil
| | - Thais A Lopes
- Chemistry Department, Universidade Federal Fluminense, Volta Redonda, Brazil
| | - Mathias P Leite
- Chemistry Department, Universidade Federal Fluminense, Volta Redonda, Brazil
| | - Milton E Pereira-Flores
- Department of Agricultural and Environmental Engineering, Universidade Federal de Viçosa, Brazil
| | - Elson S Alvarenga
- Chemistry Department, Universidade Federal de Viçosa, Viçosa, Brazil
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Glamočlija U, Padhye S, Špirtović-Halilović S, Osmanović A, Veljović E, Roca S, Novaković I, Mandić B, Turel I, Kljun J, Trifunović S, Kahrović E, Kraljević Pavelić S, Harej A, Klobučar M, Završnik D. Synthesis, Biological Evaluation and Docking Studies of Benzoxazoles Derived from Thymoquinone. Molecules 2018; 23:molecules23123297. [PMID: 30545123 PMCID: PMC6321291 DOI: 10.3390/molecules23123297] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 11/30/2018] [Accepted: 12/02/2018] [Indexed: 11/29/2022] Open
Abstract
Thymoquinone (TQ), a natural compound with antimicrobial and antitumor activity, was used as the starting molecule for the preparation of 3-aminothymoquinone (ATQ) from which ten novel benzoxazole derivatives were prepared and characterized by elemental analysis, IR spectroscopy, mass spectrometry and NMR (1H, 13C) spectroscopy in solution. The crystal structure of 4-methyl-2-phenyl-7-isopropyl-1,3-benzoxazole-5-ol (1a) has been determined by X-ray diffraction. All compounds were tested for their antibacterial, antifungal and antitumor activities. TQ and ATQ showed better antibacterial activity against tested Gram-positive and Gram-negative bacterial strains than benzoxazoles. ATQ had the most potent antifungal effect against Candida albicans, Saccharomyces cerevisiae and Aspergillus brasiliensis. Three benzoxazole derivatives and ATQ showed the highest antitumor activities. The most potent was 2-(4-fluorophenyl)-4-methyl-7-isopropyl-1,3-benzoxazole-5-ol (1f). Western blot analyses have shown that this compound inhibited phosphorylation of protein kinase B (Akt) and Insulin-like Growth Factor-1 Receptor (IGF1R β) in HeLa and HepG2 cells. The least toxic compound against normal fibroblast cells, which maintains similar antitumor activities as TQ, was 2-(4-chlorophenyl)-4-methyl-7-isopropyl-1,3-benzoxazole-5-ol (1e). Docking studies indicated that 1e and 1f have significant effects against selected receptors playing important roles in tumour survival.
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Affiliation(s)
- Una Glamočlija
- Scientific Research Department, Bosnalijek JSC, Jukićeva 53, 71000 Sarajevo, Bosnia and Herzegovina.
- School of Medicine, University of Mostar, Bijeli Brijeg bb, 88000 Mostar, Bosnia and Herzegovina.
- Faculty of Pharmacy, University of Sarajevo, Zmaja od Bosne 8, 71000 Sarajevo, Bosnia and Herzegovina.
| | - Subhash Padhye
- Interdisciplinary Science and Technology Research Academy, University of Pune, 2390-B, Hidayatullah Road, 411001 Pune, India.
| | - Selma Špirtović-Halilović
- Faculty of Pharmacy, University of Sarajevo, Zmaja od Bosne 8, 71000 Sarajevo, Bosnia and Herzegovina.
| | - Amar Osmanović
- Faculty of Pharmacy, University of Sarajevo, Zmaja od Bosne 8, 71000 Sarajevo, Bosnia and Herzegovina.
| | - Elma Veljović
- Faculty of Pharmacy, University of Sarajevo, Zmaja od Bosne 8, 71000 Sarajevo, Bosnia and Herzegovina.
| | - Sunčica Roca
- NMR Centre, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia.
| | - Irena Novaković
- ICTM, Center for Chemistry, University of Belgrade, Njegoševa 12, 11000 Belgrade, Serbia.
| | - Boris Mandić
- Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, 11000 Belgrade, Serbia.
| | - Iztok Turel
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, 1000 Ljubljana, Slovenia.
| | - Jakob Kljun
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, 1000 Ljubljana, Slovenia.
| | - Snežana Trifunović
- Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, 11000 Belgrade, Serbia.
| | - Emira Kahrović
- Department of Chemistry, Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo, Bosnia and Herzegovina.
| | - Sandra Kraljević Pavelić
- Centre for High-throughput Technologies, Department of Biotechnology, University of Rijeka, Radmile Matejčić 2, 51000 Rijeka, Croatia.
| | - Anja Harej
- Centre for High-throughput Technologies, Department of Biotechnology, University of Rijeka, Radmile Matejčić 2, 51000 Rijeka, Croatia.
| | - Marko Klobučar
- Centre for High-throughput Technologies, Department of Biotechnology, University of Rijeka, Radmile Matejčić 2, 51000 Rijeka, Croatia.
| | - Davorka Završnik
- Faculty of Pharmacy, University of Sarajevo, Zmaja od Bosne 8, 71000 Sarajevo, Bosnia and Herzegovina.
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Pierens GK, Venkatachalam TK, Reutens DC. Comparison of experimental and DFT-calculated NMR chemical shifts of 2-amino and 2-hydroxyl substituted phenyl benzimidazoles, benzoxazoles and benzothiazoles in four solvents using the IEF-PCM solvation model. Magn Reson Chem 2016; 54:298-307. [PMID: 26478462 DOI: 10.1002/mrc.4374] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 09/18/2015] [Accepted: 09/23/2015] [Indexed: 06/05/2023]
Abstract
A comparative study of experimental and calculated NMR chemical shifts of six compounds comprising 2-amino and 2-hydroxy phenyl benzoxazoles/benzothiazoles/benzimidazoles in four solvents is reported. The benzimidazoles showed interesting spectral characteristics, which are discussed. The proton and carbon chemical shifts were similar for all solvents. The largest chemical shift deviations were observed in benzene. The chemical shifts were calculated with density functional theory using a suite of four functionals and basis set combinations. The calculated chemical shifts revealed a good match to the experimentally observed values in most of the solvents. The mean absolute error was used as the primary metric. The use of an additional metric is suggested, which is based on the order of chemical shifts. The DP4 probability measures were also used to compare the experimental and calculated chemical shifts for each compound in the four solvents. Copyright © 2015 John Wiley & Sons, Ltd.
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Affiliation(s)
- Gregory K Pierens
- The Centre for Advanced Imaging, The University of Queensland, Building 57, Research Road, St Lucia, QLD, 4072, Australia
| | - T K Venkatachalam
- The Centre for Advanced Imaging, The University of Queensland, Building 57, Research Road, St Lucia, QLD, 4072, Australia
| | - David C Reutens
- The Centre for Advanced Imaging, The University of Queensland, Building 57, Research Road, St Lucia, QLD, 4072, Australia
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Cano-Prieto C, Losada AA, Braña AF, Méndez C, Salas JA, Olano C. Crosstalk of Nataxazole Pathway with Chorismate-Derived Ionophore Biosynthesis Pathways in Streptomyces sp. Tü 6176. Chembiochem 2015; 16:1925-1932. [PMID: 26083234 DOI: 10.1002/cbic.201500261] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Indexed: 11/12/2022]
Abstract
Streptomyces sp. Tü 6176, producer of cytotoxic benzoxazoles AJI9561, nataxazole, and 5-hydroxy-nataxazole, has been found to produce a fourth benzoxazole, UK-1. All derive from 3-hydroxy-anthranilate synthesized by the nataxazole biosynthesis machinery. However, biosynthesis of AJI9561, nataxazole, and 5-hydroxy-nataxazole requires 6-methylsalicylic acid also provided by nataxazole biosynthesis pathway, while biosynthesis of UK-1 utilizes salicylic acid produced by a salicylate synthase from the coelibactin biosynthesis pathway. This clearly suggests crosstalk between nataxazole and coelibactin pathways. Overproduction of UK-1 was obtained by growing a nataxazole non-producing mutant (lacking 6-methylsalicylate synthase, NatPK) in a zinc-deficient medium. Furthermore, Streptomyces sp. Tü 6176 also produces the siderophore enterobactin in an iron-free medium. Enterobactin production can be induced in an iron-independent manner by inactivating natAN, which encodes an anthranilate synthase involved in nataxazole production. The results indicate a close relationship between nataxazole, enterobactin and coelibactin pathways through the shikimate pathway, the source of their common precursor, chorismate.
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Affiliation(s)
- Carolina Cano-Prieto
- Departamento de Biología Funcional, Instituto Universitario de Oncología del Principado de Asturias (I.U.O.P.A), Universidad de Oviedo, C/ Julian Clavería, s/n, 33006 Oviedo (Spain)
| | - Armando A Losada
- Departamento de Biología Funcional, Instituto Universitario de Oncología del Principado de Asturias (I.U.O.P.A), Universidad de Oviedo, C/ Julian Clavería, s/n, 33006 Oviedo (Spain)
| | - Alfredo F Braña
- Departamento de Biología Funcional, Instituto Universitario de Oncología del Principado de Asturias (I.U.O.P.A), Universidad de Oviedo, C/ Julian Clavería, s/n, 33006 Oviedo (Spain)
| | - Carmen Méndez
- Departamento de Biología Funcional, Instituto Universitario de Oncología del Principado de Asturias (I.U.O.P.A), Universidad de Oviedo, C/ Julian Clavería, s/n, 33006 Oviedo (Spain)
| | - José A Salas
- Departamento de Biología Funcional, Instituto Universitario de Oncología del Principado de Asturias (I.U.O.P.A), Universidad de Oviedo, C/ Julian Clavería, s/n, 33006 Oviedo (Spain)
| | - Carlos Olano
- Departamento de Biología Funcional, Instituto Universitario de Oncología del Principado de Asturias (I.U.O.P.A), Universidad de Oviedo, C/ Julian Clavería, s/n, 33006 Oviedo (Spain)
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