Bioactivity-guided isolation of antioxidant triterpenoids from Betula platyphylla var. japonica bark.

Autor: Eom HJ; School of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea., Kang HR; School of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea., Kim HK; School of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea., Jung EB; College of Korean Medicine, Gachon University, Seongnam 461-701, Republic of Korea., Park HB; Department of Chemistry, Yale University, New Haven, CT 06520, United States., Kang KS; College of Korean Medicine, Gachon University, Seongnam 461-701, Republic of Korea. Electronic address: kkang@gachon.ac.kr., Kim KH; School of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea. Electronic address: khkim83@skku.edu.
Jazyk: angličtina
Zdroj: Bioorganic chemistry [Bioorg Chem] 2016 Jun; Vol. 66, pp. 97-101. Date of Electronic Publication: 2016 Apr 01.
DOI: 10.1016/j.bioorg.2016.04.001
Abstrakt: The bark of Betula platyphylla var. japonica (Betulaceae) has been used to treat pneumonia, choloplania, nephritis, and chronic bronchitis. This study aimed to investigate the bioactive chemical constituents of the bark of B. platyphylla var. japonica. A bioassay-guided fractionation and chemical investigation of the bark of B. platyphylla var. japonica resulted in the isolation and identification of a new lupane-type triterpene, 27-hydroxybetunolic acid (1), along with 18 known triterpenoids (2-19). The structure of the new compound (1) was elucidated on the basis of 1D and 2D NMR spectroscopic data analysis as well as HR-ESIMS. Among the known compounds, chilianthin B (17), chilianthin C (18), and chilianthin A (19) were triterpene-lignan esters, which are rarely found in nature. Compounds 4, 6, 7, 17, 18, and 19 showed significant antioxidant activities with IC50 values in the range 4.48-43.02μM in a DPPH radical-scavenging assay. However, no compound showed significant inhibition of acetylcholine esterase (AChE). Unfortunately, the new compound (1) exhibited no significance in both biological activities. This study strongly suggests that B. platyphylla var. japonica bark is a potential source of natural antioxidants for use in pharmaceuticals and functional foods.
(Copyright © 2016 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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