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Sarkar A, Mandal RD, Chakraborty N, Das AR. Cascade [4 + 1] Annulation through Activation of the C(sp 2)-H Bond Enabling Benzothiadiazinoisoindolcarboxylate, Benzothiadiazinoisoindole, and Benzothiadiazinoisoindolepyrrolidinedione as Hybrid Spiro-Heterocyclic Frameworks†. J Org Chem 2024. [PMID: 38758359 DOI: 10.1021/acs.joc.4c00366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
Two structurally distinct and biologically privileged succinimide and isoindole heteroarenes bearing benzothiadiazinedioxide motif-centered hybrid conjugates are proficiently achieved through Rh(III)-catalyzed sequential C(sp2)-H bond activation, ortho-alkenylation and finally cascade intramolecular cyclization. The significant feature of this developed protocol is that the resulting diversely decorated heterocycles contain a quaternary carbon center and this has been coursed through atypical [4 + 1] annulation ignoring the prevalent [4 + 2]-cyclization pathway and interestingly the applied coupling partners (e.g., maleimide, maleate, and styrene) to materialize the protocol functioned only as C1 synthon. Furthermore, the selective reduction strategy enables to modify the hybrid conjugate of succinimide and benzothiazine dioxide to benzothiazine dioxide-based spirocyclic isoindolopyrrolidinedione skeleton following preferential reduction of one carbonyl group of imide functionality. Overall this methodology emerges to be easily handled, versatile, time-efficient, and manifests relatively unfamiliar spiro-cyclization and good functional group tolerance so easy to grab a library of the entirely new variant of decorated hybrid spiro-heterocyclic scaffolds.
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Affiliation(s)
- Anindita Sarkar
- Department of Chemistry, University of Calcutta, Kolkata 700009, India
| | - Rahul Dev Mandal
- Department of Chemistry, University of Calcutta, Kolkata 700009, India
| | | | - Asish R Das
- Department of Chemistry, University of Calcutta, Kolkata 700009, India
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2
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Alekseeva KA, Fedoseeva MA, Bakhanovich OV, Khrustalev VN, Potkin VI, Zhou H, Nikitina EV, Zaytsev VP, Zubkov FI. One-Pot Reaction Sequence: N-Acylation/Pictet-Spengler Reaction/Intramolecular [4 + 2] Cycloaddition/Aromatization in the Synthesis of β-Carboline Alkaloid Analogues. J Org Chem 2024; 89:3065-3071. [PMID: 38359403 DOI: 10.1021/acs.joc.3c02533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
One-pot synthesis of tetrahydro-β-carbolines, fused with an isoindole core, was proposed starting from maleic anhydride and azomethines easily available from tryptamines and 3-(hetaryl)acroleins. This sequence includes four key steps: an acylation of the aldimine with maleic anhydride, a Pictet-Spengler cyclization, an intramolecular Diels-Alder reaction, and a concluding [1,3]-H shift. As a result, six- or seven-nuclear alkaloid-like heterocyclic systems, containing a benzo[1,2]indolizino[8,7-b]indole fragment annulated with furan, thiophene, or pyrrole, are formed in a diastereoselective manner.
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Affiliation(s)
- Kseniya A Alekseeva
- Organic Chemistry Department, Faculty of Science, RUDN University, 6 Miklukho-Maklaya St., Moscow 117198, Russian Federation
| | - Milana A Fedoseeva
- Organic Chemistry Department, Faculty of Science, RUDN University, 6 Miklukho-Maklaya St., Moscow 117198, Russian Federation
| | - Olga V Bakhanovich
- Organic Chemistry Department, Faculty of Science, RUDN University, 6 Miklukho-Maklaya St., Moscow 117198, Russian Federation
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo náměstí 2, Prague 166 10, Czech Republic
| | - Victor N Khrustalev
- N. D. Zelinsky Institute of Organic Chemistry of Russian Academy of Sciences, Moscow 119991, Russia
- Inorganic Chemistry Department, Faculty of Science, RUDN University, 6 Miklukho-Maklaya St., Moscow 117198, Russian Federation
| | - Vladimir I Potkin
- Institute of Physical Organic Chemistry of National Academy of Sciences of Belarus, 13 Surganov Street, Minsk 220072, Belarus
| | - Hongwei Zhou
- Jiaxing University, 1 Jiahang Road, Jiaxing, Zhejiang 314001, China
| | - Eugenia V Nikitina
- Organic Chemistry Department, Faculty of Science, RUDN University, 6 Miklukho-Maklaya St., Moscow 117198, Russian Federation
| | - Vladimir P Zaytsev
- Organic Chemistry Department, Faculty of Science, RUDN University, 6 Miklukho-Maklaya St., Moscow 117198, Russian Federation
| | - Fedor I Zubkov
- Organic Chemistry Department, Faculty of Science, RUDN University, 6 Miklukho-Maklaya St., Moscow 117198, Russian Federation
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Annang FB, Pérez-Moreno G, Bosch-Navarrete C, González-Menéndez V, Martín J, Mackenzie TA, Ramos MC, Ruiz-Pérez LM, Genilloud O, González-Pacanowska D, Vicente F, Reyes F. Antiparasitic Meroterpenoids Isolated from Memnoniella dichroa CF-080171. Pharmaceutics 2023; 15:pharmaceutics15020492. [PMID: 36839814 PMCID: PMC9962372 DOI: 10.3390/pharmaceutics15020492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 01/26/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023] Open
Abstract
Memnoniella is a fungal genus from which a wide range of diverse biologically active compounds have been isolated. A Memnoniella dichroa CF-080171 extract was identified to exhibit potent activity against Plasmodium falciparum 3D7 and Trypanosoma cruzi Tulahuen whole parasites in a high-throughput screening (HTS) campaign of microbial extracts from the Fundación MEDINA's collection. Bioassay-guided isolation of the active metabolites from this extract afforded eight new meroterpenoids of varying potencies, namely, memnobotrins C-E (1-3), a glycosylated isobenzofuranone (4), a tricyclic isobenzofuranone (5), a tetracyclic benzopyrane (6), a tetracyclic isobenzofuranone (7), and a pentacyclic isobenzofuranone (8). The structures of the isolated compounds were established by (+)-ESI-TOF high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy. Compounds 1, 2, and 4 exhibited potent antiparasitic activity against P. falciparum 3D7 (EC50 0.04-0.243 μM) and T. cruzi Tulahuen (EC50 0.266-1.37 μM) parasites, as well as cytotoxic activity against HepG2 tumoral liver cells (EC50 1.20-4.84 μM). The remaining compounds (3, 5-8) showed moderate or no activity against the above-mentioned parasites and cells.
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Affiliation(s)
- Frederick Boye Annang
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores de Andalucía, Parque Tecnológico de Ciencias de la Salud, Avda. del Conocimiento 34, 18016 Granada, Spain
- Correspondence: (F.B.A.); (F.R.); Tel.: +34-958-993965 (F.R.)
| | - Guiomar Pérez-Moreno
- Instituto de Parasitología y Biomedicina “López-Neyra”, Consejo Superior de Investigaciones Científicas (CSIC) Avda. del Conocimiento 17, Armilla, 18016 Granada, Spain
| | - Cristina Bosch-Navarrete
- Instituto de Parasitología y Biomedicina “López-Neyra”, Consejo Superior de Investigaciones Científicas (CSIC) Avda. del Conocimiento 17, Armilla, 18016 Granada, Spain
| | - Victor González-Menéndez
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores de Andalucía, Parque Tecnológico de Ciencias de la Salud, Avda. del Conocimiento 34, 18016 Granada, Spain
| | - Jesús Martín
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores de Andalucía, Parque Tecnológico de Ciencias de la Salud, Avda. del Conocimiento 34, 18016 Granada, Spain
| | - Thomas A. Mackenzie
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores de Andalucía, Parque Tecnológico de Ciencias de la Salud, Avda. del Conocimiento 34, 18016 Granada, Spain
| | - Maria C. Ramos
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores de Andalucía, Parque Tecnológico de Ciencias de la Salud, Avda. del Conocimiento 34, 18016 Granada, Spain
| | - Luis M. Ruiz-Pérez
- Instituto de Parasitología y Biomedicina “López-Neyra”, Consejo Superior de Investigaciones Científicas (CSIC) Avda. del Conocimiento 17, Armilla, 18016 Granada, Spain
| | - Olga Genilloud
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores de Andalucía, Parque Tecnológico de Ciencias de la Salud, Avda. del Conocimiento 34, 18016 Granada, Spain
| | - Dolores González-Pacanowska
- Instituto de Parasitología y Biomedicina “López-Neyra”, Consejo Superior de Investigaciones Científicas (CSIC) Avda. del Conocimiento 17, Armilla, 18016 Granada, Spain
| | - Francisca Vicente
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores de Andalucía, Parque Tecnológico de Ciencias de la Salud, Avda. del Conocimiento 34, 18016 Granada, Spain
| | - Fernando Reyes
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores de Andalucía, Parque Tecnológico de Ciencias de la Salud, Avda. del Conocimiento 34, 18016 Granada, Spain
- Correspondence: (F.B.A.); (F.R.); Tel.: +34-958-993965 (F.R.)
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Karishma P, Mandal SK, Sakhuja R. Rhodium‐Catalyzed Spirocyclization of Maleimide with
N
‐Aryl‐2,3‐dihydrophthalazine‐1,4‐dione to Access Pentacyclic Spiro‐Succinimides. ASIAN J ORG CHEM 2021. [DOI: 10.1002/ajoc.202100384] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Pidiyara Karishma
- Department of Chemistry Birla Institute of Technology and Science Pilani Rajasthan 333031 India
| | - Sanjay K. Mandal
- Department of Chemical Sciences Indian Institute of Science Education and Research Mohali Sector 81, SAS Nagar, Manuali P.O. Mohali Punjab 140306 India
| | - Rajeev Sakhuja
- Department of Chemistry Birla Institute of Technology and Science Pilani Rajasthan 333031 India
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El Maddah F, Eguereva E, Kehraus S, König GM. Biosynthetic studies of novel polyketides from the marine sponge-derived fungusStachylidiumsp. 293K04. Org Biomol Chem 2019; 17:2747-2752. [DOI: 10.1039/c9ob00198k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A methylation of the acetate starter unit is part of the polyketide biosynthesis of phthalides and phthalimidines from the marine-derived fungusStachylidiumsp. 293K04.
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Affiliation(s)
- Fayrouz El Maddah
- Institute for Pharmaceutical Biology
- University of Bonn
- 53115 Bonn
- Germany
- Department of Pharmacognosy and Tissue Culture
| | | | - Stefan Kehraus
- Institute for Pharmaceutical Biology
- University of Bonn
- 53115 Bonn
- Germany
| | - Gabriele M. König
- Institute for Pharmaceutical Biology
- University of Bonn
- 53115 Bonn
- Germany
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6
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Phthalides: Distribution in Nature, Chemical Reactivity, Synthesis, and Biological Activity. PROGRESS IN THE CHEMISTRY OF ORGANIC NATURAL PRODUCTS 104 2017; 104:127-246. [DOI: 10.1007/978-3-319-45618-8_2] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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7
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Sharma S, Han SH, Jo H, Han S, Mishra NK, Choi M, Jeong T, Park J, Kim IS. Rhodium-Catalyzed Vinylic C-H Functionalization of Enol Carbamates with Maleimides. European J Org Chem 2016. [DOI: 10.1002/ejoc.201600558] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Satyasheel Sharma
- School of Pharmacy; Sungkyunkwan University; 440-746 Suwon Republic of Korea
| | - Sang Hoon Han
- School of Pharmacy; Sungkyunkwan University; 440-746 Suwon Republic of Korea
| | - Hyeim Jo
- School of Pharmacy; Sungkyunkwan University; 440-746 Suwon Republic of Korea
| | - Sangil Han
- School of Pharmacy; Sungkyunkwan University; 440-746 Suwon Republic of Korea
| | - Neeraj Kumar Mishra
- School of Pharmacy; Sungkyunkwan University; 440-746 Suwon Republic of Korea
| | - Miji Choi
- School of Pharmacy; Sungkyunkwan University; 440-746 Suwon Republic of Korea
| | - Taejoo Jeong
- School of Pharmacy; Sungkyunkwan University; 440-746 Suwon Republic of Korea
| | - Jihye Park
- School of Pharmacy; Sungkyunkwan University; 440-746 Suwon Republic of Korea
| | - In Su Kim
- School of Pharmacy; Sungkyunkwan University; 440-746 Suwon Republic of Korea
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8
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Wang K, Bao L, Qi Q, Zhao F, Ma K, Pei Y, Liu H. Erinacerins C-L, isoindolin-1-ones with α-glucosidase inhibitory activity from cultures of the medicinal mushroom Hericium erinaceus. JOURNAL OF NATURAL PRODUCTS 2015; 78:146-154. [PMID: 25565282 DOI: 10.1021/np5004388] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The well-known edible and medicinal mushroom Hericium erinaceus produces various bioactive secondary metabolites. Ten new isoindolin-1-ones, named erinacerins C-L (1-10), together with (E)-5-(3,7-dimethylocta-2,6-dien-1-yl)-4-hydroxy-6-methoxy-2-phenethylisoindolin-1-one (11) were isolated from the solid culture of H. erinaceus. The structures of new metabolites were established by spectroscopic methods. The absolute configurations of 3, 4, 9, and 10 were assigned by comparing their specific rotations with those of related phthalimidines (13-20). Compounds 5 and 6, 7 and 8, and 9 and 10 are double-bond positional isomers. In a α-glucosidase inhibition assay, compounds 2-11 showed inhibitory activity with IC50 values ranging from 5.3 to 145.1 μM. Preliminary structure-activity analysis indicated that the terpenoid side chain and the phenolic hydroxy groups contributed greatly to the α-glucosidase inhibitory activity of 1-11. In a cytotoxicity assay, compound 11 also presented weak cytotoxicity against two cell lines, A549 and HeLa, with IC50 values of 49.0 and 40.5 μM.
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Affiliation(s)
- Kai Wang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences , No. 1 Beichenxi Road, Chaoyang District, Beijing 100101, People's Republic of China
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9
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Liu H, Lau GPS, Dyson PJ. Palladium-Catalyzed Aminocarbonylation of Alkynes to Succinimides. J Org Chem 2014; 80:386-91. [DOI: 10.1021/jo502412v] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Huizhen Liu
- Institut des Sciences et
Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Genevieve P. S. Lau
- Institut des Sciences et
Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Paul J. Dyson
- Institut des Sciences et
Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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10
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Karmakar R, Pahari P, Mal D. Phthalides and Phthalans: Synthetic Methodologies and Their Applications in the Total Synthesis. Chem Rev 2014; 114:6213-84. [DOI: 10.1021/cr400524q] [Citation(s) in RCA: 249] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Raju Karmakar
- Department
of Chemistry, Indian Institute of Technology, Kharagpur 721302, India
- Technical University of Braunschweig, 38106 Braunschweig, Germany
| | - Pallab Pahari
- Department
of Chemistry, Indian Institute of Technology, Kharagpur 721302, India
- Synthetic
Organic Chemistry Division, CSIR-North East Institute of Science and Technology, Jorhat 785006, Assam, India
| | - Dipakranjan Mal
- Department
of Chemistry, Indian Institute of Technology, Kharagpur 721302, India
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Hintermann L, Ackerstaff J, Boeck F. Inner Workings of a Cinchona Alkaloid Catalyzed Oxa-Michael Cyclization: Evidence for a Concerted Hydrogen-Bond-Network Mechanism. Chemistry 2013; 19:2311-21. [DOI: 10.1002/chem.201203505] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Indexed: 11/09/2022]
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12
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Yang SX, Xiao J, Laatsch H, Holstein JJ, Dittrich B, Zhang Q, Gao JM. Fusarimine, a novel polyketide isoquinoline alkaloid, from the endophytic fungus Fusarium sp. LN12, isolated from Melia azedarach. Tetrahedron Lett 2012. [DOI: 10.1016/j.tetlet.2012.09.031] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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13
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Elsebai MF, Nazir M, Kehraus S, Egereva E, Ioset KN, Marcourt L, Jeannerat D, Gütschow M, Wolfender JL, König GM. Polyketide Skeletons from the Marine Alga-Derived FungusConiothyrium cereale. European J Org Chem 2012. [DOI: 10.1002/ejoc.201200700] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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14
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Almeida C, Hemberger Y, Schmitt SM, Bouhired S, Natesan L, Kehraus S, Dimas K, Gütschow M, Bringmann G, König GM. Marilines A-C: Novel Phthalimidines from the Sponge-Derived Fungus Stachylidium sp. Chemistry 2012; 18:8827-34. [DOI: 10.1002/chem.201103278] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 03/20/2012] [Indexed: 01/12/2023]
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Zhang J, Senthilkumar M, Ghosh S, Hong S. Synthesis of Cyclic Imides from Simple Diols. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.201002136] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Zhang J, Senthilkumar M, Ghosh S, Hong S. Synthesis of Cyclic Imides from Simple Diols. Angew Chem Int Ed Engl 2010; 49:6391-5. [DOI: 10.1002/anie.201002136] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Preparative isolation and purification of isobenzofuranone derivatives and saponins from seeds of Nigella glandulifera Freyn by high-speed counter-current chromatography combined with gel filtration. J Chromatogr A 2009; 1216:4258-62. [PMID: 19344906 DOI: 10.1016/j.chroma.2009.03.050] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2008] [Revised: 03/03/2009] [Accepted: 03/03/2009] [Indexed: 11/23/2022]
Abstract
Although the medicinal plant and food Nigella glandulifera Freyn has been researched for decades, isobenzofuranones have never been isolated before. Two isobenzofuranone derivatives and two saponins were successfully separated and purified from seeds of N. glandulifera Freyn by high-speed counter-current chromatography (HSCCC) with the optimized two-phase solvent system, n-hexane-ethyl acetate-methanol-water (7:3:5:5, v/v). Salfredin B(11) (22.1mg, HPLC purity 95.3%), 5, 7-dihydroxy-6-(3-methybut-2-enyl) isobenzofuran-1(3H)-one (18.9mg, HPLC purity 97.3%) and crude sample 2 (555mg) were separated from 600mg of ethyl acetate extract of N. glandulifera Freyn. Following a cleaning-up step by chromatography on Sephadex LH-20, hederagenin (12mg) and 3-O-[beta-d-xylopyranosyl-(1-->3)-alpha-l-rhamnopyranosyl-(1-->2)-alpha-l-arabinopyranosyl]-hederagenin (45mg) were separated from sample 2. All of the fractions before peak II were collected and subjected to a Sephadex LH-20 column and eluted by methanol, two of triterpene saponins (12mg of hederagenin and 45mg of 3-O-[beta-d-xylopyranosyl-(1-->3)-alpha-l-rhamnopyranosyl-(1-->2)-alpha-l-arabinopyranosyl]-hederagenin) were isolated. The structures of peak fractions were identified by IR, electron ionization MS, (1)H NMR and (13)C NMR. 5, 7-Dihydroxy-6-(3-methybut-2-enyl) isobenzofuran-1(3H)-one was isolated for the first time from higher plant and salfredin B11 was isolated for the first time in this plant.
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Affiliation(s)
- Ji-Kai Liu
- Kunming Institute of Botany, the Chinese Academy of Sciences, Kunming 650204, P. R. China.
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19
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Abstract
Kinetic studies on the aldose reductase protein (AR2) have shown that it does not behave as a classical enzyme in relation to ring aldose sugars. These results have been confirmed by X-ray crystallography studies, which have pinpointed binding sites for pharmacological "aklose reductase inhibitors" (ARIs). As with non-enzymic glycation reactions, there is probably a free-radical element involved derived from monosaccharide autoxidation. In the case of AR2, there is free radical oxidation of NADPH by autoxidising monosaccharides, enhanced in the presence of the NADPH-binding protein. Whatever the behaviour of AR2, many studies have showed that sorbitol production is not an initiating aetiological factor in the development of diabetic complications in humans. Vitamin E (alpha-tocopherol), other antioxidants and high fat diets can delay or prevent cataract in diabetic animals even though sorbitol and fructose levels are not modified; vitamin C acts as an AR1 in humans. Protein post-translational modification by glyc-oxidation or other events is probably the key factor in the aetiology of diabetic complications. There is now no need to invoke AR2 in xylitol biosynthesis. Xylitol can be produced in the lens from glucose, via a pathway involving the enzymes myo-inositol-oxygen oxidoreductase, D-glucuronate reductase. L-gulonate NAD(+)-3-oxidoreductase and L-iditol-NAD(+)-5-oxidoreductase, all of which have recently been found in bovine and rat lens. This chapter investigates the molecular events underlying AR2 and its binding and kinetics. Induction of the protein by osmotic response elements is discussed, with detailed analysis of recent in vitro and in vivo experiments on numerous ARIs. These have a number of actions in the cell which are not specific, and which do not involve them binding to AR2. These include peroxy-radical scavenging and recently discovered effects of metal ion chelation. In controlled experiments, it has been found that incubation of rat lens homogenate with glucose and the copper chelator o-phenanthroline abolishes production of sorbitol. Taken together, these results suggest AR2 is a vestigial NADPH-binding protein, perhaps similar in function to a number of non-mammalian crystallins which have been recruited into the lens. There is mounting evidence for the binding of reactive aldehyde moieties to the protein, and the involvement of AR2 either as a 'housekeeping' protein, or in a free-radial-mediated 'catalytic' role. Interfering with the NADPH binding and flux levels--possibly involving free radicals and metal ions--has a deleterious effect. We have yet to determine whether aldose reductase is the black sheep of the aldehyde reductase family, or whether it is a skeleton in the cupboard, waiting to be clothed in the flesh of new revelations in the interactions between proteins, metal ions and redox metabolites.
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Affiliation(s)
- M J Crabbe
- Wolfson Laboratory, Division of Cell and Molecular Biology, School of Animal and Microbial Sciences, University of Reading, Whiteknights, Berks, UK.
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20
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Affiliation(s)
- C Pearce
- MYCOsearch, Oncogene Science Inc. Durham, North Carolina 27707, USA
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