Antiviral phenolic compounds from the whole plants of Zostera marina against influenza A virus

Zostera marina L. is a perennial seagrass in the family Zosteraceae that lives in the nearshores of East Asia, Europe, and North America [1, 2]. Z. marina is known as a seaweed bed for fish and shellfish, and a traditional Chinese medicine [3, 4]. Previous phytochemical studies on Z. marina have afforded several phenolic compounds and lipids [4]. In the course of a search for anti-influenza viral compound from natural products, we have found that EtOAc and BuOH fractions of the EtOH extract of Z. marina have antiviral activity against influenza A virus, (IC₅₀: 4.95 µg/mL, SI: 14.80; IC₅₀: 68.93 µg/mL, SI: 8.15, respectively). The EtOAc and BuOH fractions, which exhibited comparatively higher activity than the other fractions, were subjected to column chromatographic separation. Six phenolic compounds were isolated and their structures were identified as luteolin, apigenin 7-glucoside, luteolin 7-glucoside, p-sulfoxy cinnamic acid, luteolin 7-sulfate, luteolin 7,3'-disulfate by spectral analysis. Antiviral activities for isolated compounds were evaluated using neutral red assay against influenza A/NWS/33 (H1N1) virus and neuraminidase inhibition assay in influenza A/NWS/33 virus.

References:

[1] Lee TB. Illustrated flora of Korea. Seoul: Hyangmoonsa; 1999: 74

[2] Kim JH, Cho YH, Park SM, Lee KE, Lee JJ, Lee BC, Pyo HB, Song KS, Park HD, Yun YP. Antioxidants and inhibitor of matrix metalloproteinase-1 expression from leaves of Zostera marina L. Arch Pharm Res 2004; 27: 177 – 183

[3] Wataru K, Kenji M, Yoshihiko A, Noruyasu I, Tadahiko K. Volatiles from Zostera marina. Phytochemistry 1998; 47: 27 – 29

[4] Zhonghuabencao Compilation Committee. Zhonghuabencao (8). Shanghai: Shanghai Science and Technologic Publisher; 1999: 19 – 20