Antiviral phenolics from the leaves of Cleistocalyx operculatus

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• 作者：Thi Kim Quy Ha^a ; Trong Tuan Dao^a ; Ngoc Hieu Nguyen^a ; Jiwon Kim^a ; Eunhee Kim^b ; Tae Oh. Cho^c ; Won Keun Oh^a ; ^{wkoh1@snu.ac.kr" class="auth_mail" title="E-mail the corresponding author}
• 关键词：H1N1 ; Influenza neuraminidase ; Cleistocalyx operculatus ; Myrtaceae
• 刊名：Fitoterapia
• 出版年：2016
• 出版时间：April 2016
• 年：2016
• 卷：110
• 期：Complete
• 页码：135-141
• 全文大小：858 K

文摘

During the screening program for anti-influenza agents from medicinal plants, the ethanolic extract of Cleistocalyx operculatus leaves was found to exhibit potential neuraminidase (NA) inhibitory activity. Bioassay-directed fractionation led to the isolation of two new acetophenones (1 and 2) and one new flavanone (3), along with six known compounds (4–9). The structures of all isolated compounds were elucidated using various spectroscopic methods and through comparison with the previous literature. Compounds 6 and 8 exhibited strong enzymatic inhibition on various neuraminidases from different influenza viruses, including H1N1, H9N2, novel H1N1, and oseltamivir-resistant novel H1N1 (H274Y mutation) expressed in HEK293 cells (IC₅₀ values ranging from 5.07 ± 0.94 μM to 9.34 ± 2.52 μM, respectively). Kinetic experiments revealed the non-competitive inhibitory mode of both compounds 6 and 8. Furthermore, these flavonoids reduced the cytopathic effect of the H1N1 virus in MDCK cells. The present study suggests the potential of two flavonoids (6 and 8) as new lead compounds for the development of novel NA inhibitors in the future.