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De Grano RVR, Vashchenko EV, Nisar M, Sung HHY, Vashchenko VV, Williams ID. Crystal structures of the flavonoid Oroxylin A and the regioisomers Negletein and Wogonin. ACTA CRYSTALLOGRAPHICA SECTION C-STRUCTURAL CHEMISTRY 2020; 76:490-499. [PMID: 32367831 DOI: 10.1107/s2053229620005550] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 04/20/2020] [Indexed: 02/06/2023]
Abstract
The flavonoid Oroxylin A (6-methoxychrysin or 5,7-dihydroxy-6-methoxy-2-phenyl-4H-chromen-4-one, C16H12O5) and its regioisomers are of increasing interest for a variety of bioactive functions and their pharmaceutical formulation is of importance. Previous difficulties in the separation and misidentification of Oroxylin A from its regioisomers Wogonin (8-methoxychrysin or 5,7-dihydroxy-8-methoxy-2-phenyl-4H-chromen-4-one) and Negletein (5,6-dihydroxy-7-methoxyflavone or 5,6-dihydroxy-7-methoxy-2-phenyl-4H-chromen-4-one) render its full structural and powder X-ray characterization highly desirable. The low-temperature (100 K) crystal structures of Oroxylin A, Negletein and Wogonin sesquihydrate are reported for the first time. Wogonin crystallizes in two related but distinct hydrated forms. These have very similar powder diffractograms, indicating that such issues need to be addressed for its pharmaceutical formulation.
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Affiliation(s)
- Ruel Valerio Robles De Grano
- Department of Chemistry, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, People's Republic of China
| | - Elena V Vashchenko
- Department of Chemistry, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, People's Republic of China
| | - Madiha Nisar
- Department of Chemistry, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, People's Republic of China
| | - Herman H Y Sung
- Department of Chemistry, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, People's Republic of China
| | - Valerii V Vashchenko
- Department of Electrical and Computer Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, People's Republic of China
| | - Ian D Williams
- Department of Chemistry, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, People's Republic of China
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Baek SC, Park MH, Ryu HW, Lee JP, Kang MG, Park D, Park CM, Oh SR, Kim H. Rhamnocitrin isolated from Prunus padus var. seoulensis: A potent and selective reversible inhibitor of human monoamine oxidase A. Bioorg Chem 2018; 83:317-325. [PMID: 30396116 DOI: 10.1016/j.bioorg.2018.10.051] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 10/24/2018] [Accepted: 10/25/2018] [Indexed: 12/28/2022]
Abstract
Three flavanones and two flavones were isolated from the leaves of Prunus padus var. seoulensis by the activity-guided screening for new monoamine oxidase (MAO) inhibitors. Among the compounds isolated, rhamnocitrin (5) was found to potently and selectively inhibit human MAO-A (hMAO-A, IC50 = 0.051 µM) and effectively inhibit hMAO-B (IC50 = 2.97 µM). The IC50 value of 5 for hMAO-A was the lowest amongst all natural flavonoids reported to date, and the potency was 20.2 times higher than that of toloxatone (1.03 µM), a marketed drug. In addition, 5 reversibly and competitively inhibited hMAO-A and hMAO-B with Ki values of 0.030 and 0.91 µM, respectively. Genkwanin (4) was also observed to strongly inhibit hMAO-A and hMAO-B (IC50 = 0.14 and 0.35 µM, respectively), and competitively inhibit hMAO-A and hMAO-B (Ki = 0.097 and 0.12 µM, respectively). Molecular docking simulation reveals that the binding affinity of 5 with hMAO-A (-18.49 kcal/mol) is higher than that observed with hMAO-B (0.19 kcal/mol). Compound 5 interacts with hMAO-A at four possible residues (Asn181, Gln215, Thr336, and Tyr444), while hMAO-B forms a single hydrogen bond at Glu84. These findings suggest that compound 5 as well as 4 can be considered as novel potent and reversible hMAO-A and/or hMAO-B inhibitors or useful lead compounds for future development of hMAO inhibitors in neurological disorder therapies.
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Affiliation(s)
- Seung Cheol Baek
- Department of Pharmacy and Research Institute of Life Pharmaceutical Sciences, Sunchon National University, Suncheon 57922, Republic of Korea
| | - Mi Hyeon Park
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheong-ju si, Chungcheongbuk-do, 28116, Republic of Korea
| | - Hyung Won Ryu
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheong-ju si, Chungcheongbuk-do, 28116, Republic of Korea
| | - Jae Pil Lee
- Department of Pharmacy and Research Institute of Life Pharmaceutical Sciences, Sunchon National University, Suncheon 57922, Republic of Korea
| | - Myung-Gyun Kang
- Department of Predictive Toxicology, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea
| | - Daeui Park
- Department of Predictive Toxicology, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea
| | - Chul Min Park
- Center for Convergent Research of Emerging Virus Infection, Korea Research Institute of Chemical Technology, Daejeon 34114, Republic of Korea
| | - Sei-Ryang Oh
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheong-ju si, Chungcheongbuk-do, 28116, Republic of Korea
| | - Hoon Kim
- Department of Pharmacy and Research Institute of Life Pharmaceutical Sciences, Sunchon National University, Suncheon 57922, Republic of Korea.
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Yamashita Y, Biard A, Hanaya K, Shoji M, Sugai T. Short-step syntheses of naturally occurring polyoxygenated aromatics based on site-selective transformation. Biosci Biotechnol Biochem 2017; 81:1279-1284. [PMID: 28345416 DOI: 10.1080/09168451.2017.1303362] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Wogonin and astringin were synthesized from inexpensive chrysin and piceid in short steps. The key feature of these syntheses is site-selective transformation. The target molecules were obtained in 27 and 62% yields from the starting materials, respectively.
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Affiliation(s)
- Yasunobu Yamashita
- a Department of Pharmaceutical Sciences, Faculty of Pharmacy , Keio University , Tokyo , Japan
| | - Alan Biard
- a Department of Pharmaceutical Sciences, Faculty of Pharmacy , Keio University , Tokyo , Japan.,b Department of Chemistry , Graduate School of SIGMA Clermont , Aubiere Cedex , France
| | - Kengo Hanaya
- a Department of Pharmaceutical Sciences, Faculty of Pharmacy , Keio University , Tokyo , Japan
| | - Mitsuru Shoji
- a Department of Pharmaceutical Sciences, Faculty of Pharmacy , Keio University , Tokyo , Japan
| | - Takeshi Sugai
- a Department of Pharmaceutical Sciences, Faculty of Pharmacy , Keio University , Tokyo , Japan
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