Anti-influenza Sesquiterpene from the Roots of Reynoutria japonica

• Published in: Natural product communications 2014-03, Vol.9 (3), p.315-318
• Main Authors: Nhiem, Nguyen Xuan, Van Kiem, Phan, Van Minh, Chau, Hoai, Nguyen Thi, Duc, Ho Viet, Tai, Bui Huu, Quang, Tran Hong, Le Tuan Anh, Hoang, Yeo, Sang-Gu, Song, Jae-Hyoung, Cheon, Doo-Sung, Park, Moon Ho, Ko, Hyun-Jeong, Kim, Seung Hyun
• Format: Article
• Language: English
• Subjects: Animals; Antiviral Agents - isolation & purification; Dogs; Influenza A virus - drug effects; Madin Darby Canine Kidney Cells; Microbial Sensitivity Tests; Oseltamivir; Plant Roots - chemistry; Plants, Medicinal - chemistry; Polygonaceae - chemistry; Sesquiterpenes - isolation & purification; Sesquiterpenes - pharmacology; Toxicity Tests
• ISSN: 1934-578X; 1555-9475
• DOI: 10.1177/1934578X1400900308

One new flavonol glycoside, 4′-O-methylmyricitrin 3′-O-β-D-glucopyranoside (1), one new sesquiterpene, reynoudiol (11), as well as the 12 known compounds (2–10, 12–14) quercetin 3-O-methyl ether (2), quercitrin (3), isorhamnetin 3-α-L-rhamnopyranoside (4), tamarixetin 3-α-L-rhamnopyranoside (5), myricitrin (6), 4′-O-methylmyricitrin (7), isorhamnetin 3-O-β-D-xylopyranosyl (1→2)-O-β-D-glucopyranoside (8), isorhamnetin 3-O-β-D-apiofuranosyl-(1→2)-O-β-D-glucopyranoside (9), (+)-catechin (10), 7-drimene-3,11,12-triol (12), clovane-2β,9α-diol (13), and α-cadinol (14), were isolated from the methanol extract of Reynoutria japonica roots. Based on in vitro screening of the anti-influenza activity of the isolated compounds, reynoudiol showed significantly higher activity than that of oseltamivir phosphate at the same concentration, and did not induce any detectable cytopathic effect in MDCK cells. The CC50 of reynoudiol was above 50 μM and could inhibit influenza virus infection with an IC50 of 0.29 ± 0.01 μM. The therapeutic index (TI) of reynoudiol against influenza infection was 172.4, and thus, this compound can be potentially used to treat oseltamivir-resistant influenza virus infection.