• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.5
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• pp.644-651
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• 2021

Viral hemorrhagic septicemia virus (VHSV) is a fish pathogen responsible for causing enormous economic loss to the aquaculture industry not only in Korea but worldwide. Thus, it is necessary to identify natural compounds that can be used to control the spread of VHSV. In this study, the anti-VHSV activities of five catechol derivatives, i.e., catechol, pyrogallol, 3-methyl catechol, veratrole, and 3-methyl veratrole-extracted from green tea-were assessed. The antiviral activities of these derivatives were found to be dependent on their structure, i.e., the hydroxyl or methoxyl group and their substituent groups-on the benzene ring. Catechol, pyrogallol, and 3-methyl catechol exhibited relatively high 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities than veratrole, and 3-methyl veratrole. Moreover, 3-methyl catechol harboring a methyl substituent group increased the viability of the virus-infected cells and resulted in a 2.86 log reduction in the gene copies of VHSV N (per mL) in real-time PCR analysis. In conclusion, the catechol derivatives harboring hydroxyl groups in their benzene ring exhibited higher antioxidant activities than those harboring the methoxyl groups. However, catechol derivatives with a methyl group at the 3'-position of the benzene ring exhibited higher antiviral activity than those harboring a hydroxyl group. To our knowledge, this is the first study to evaluate the relationship between the structure and the anti-VHSV activity of catechol derivatives.

• YAKHAK HOEJI
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• v.38 no.3
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• pp.345-350
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• 1994

Fourteen melandrin derivatives(I-XIV) were investigated on analgesic, anti-inflammatory and antiviral activities . Compound I [N-(p-hydroxybenzoyl)-5-hydroxyanthranilic acid methvl ester], Xll [N-(2-phenoxypropionyl)-5-hydroxy anthranilic acid propyl ester and XIV [N-(2-phenoxypropionyl)-5-hydroxyanthranilic acid exhibited analgesic activity in tail pressure and Randall-Selitto method. But no anti-inflammatory activity was shown. Compound I exhibited weak antiviral activity on Herpes simplex virus type I F strain by virus-induced cytopathic effect(CPE) assay and it's selectivity index(Sl) was 8.17.

• Archives of Pharmacal Research
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• v.23 no.4
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• pp.302-309
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• 2000

Based on (-)-neplanocin A with the 5'-hydroxyl substituted with fluoro, azido, or amino group, the corresponding xylo- and arabino derivatives were synthesized from D-ribose using the Mit-sunobu reaction as a key step. None of the final nucleosides did show either significant antiviral activities or cytotoxicities.

• Biomolecules & Therapeutics
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• v.23 no.5
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• pp.465-470
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• 2015

Chrysin is a 5,7-dihydroxyflavone and was recently shown to potently inhibit enterovirus 71 (EV71) by suppressing viral 3C protease ($3C^{pro}$ activity. In the current study, we investigated whether chrysin also shows antiviral activity against coxsackievirus B3 (CVB3), which belongs to the same genus (Enterovirus) as EV71, and assessed its ability to prevent the resulting acute pancreatitis and myocarditis. We found that chrysin showed antiviral activity against CVB3 at $10{\mu}M$, but exhibited mild cellular cytotoxicity at $50{\mu}M$, prompting us to synthesize derivatives of chrysin to increase the antiviral activity and reduce its cytotoxicity. Among four 4-substituted benzyl derivatives derived from C(5) benzyl-protected derivatives 7, 9-11 had significant antiviral activity and showed the most potent activity against CVB3 with low cytotoxicity in Vero cells. Intraperitoneal injection of CVB3 in BALB/c mice with $1{\times}10^6TCID_{50}$ (50% tissue culture infective dose) of CVB3 induced acute pancreatitis with ablation of acinar cells and increased serum CXCL1 levels, whereas the daily administration of 9 for 5 days significantly alleviated the pancreatic inflammation and reduced the elevation in serum CXCL1 levels. Collectively, we assessed the anti-CVB3 activities of chrysin and its derivatives, and found that among 4-substituted benzyl derivatives, 9 exhibited the highest activity against CVB3 in vivo, and protected mice from CVB3-induced pancreatic damage, simultaneously lowering serum CXCL1 levels.

• Journal of Life Science
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• v.19 no.7
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• pp.928-933
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• 2009

In an effort to discover an antiviral substance against noroviruse (NV), which causes gastroenteritis illness world-wide, several plants including spices and herbs were evaluated for their antiviral activities against feline calicivirus (FCV) as a surrogate for NV. Among them, methanolic extract of green tea (Camellia sinensis L.) exhibited significant antiviral activity against FCV. After treatment with green tea extract (3.13 mg/ml) for 1 hr, FCV was completely inactivated. The antiviral activity of green tea extract against FCV was also determined to be dose and time- dependent. The results obtained in this study suggested that green tea will be effective in the prevention of food-borne diseases caused by NV.

• Journal of Microbiology and Biotechnology
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• v.23 no.1
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• pp.125-130
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• 2013

Influenza viruses cause significant morbidity and mortality in humans through epidemics or pandemics. Currently, two classes of anti-influenza virus drugs, M2 ion-channel inhibitors (amantadin and rimantadine) and neuraminidase inhibitors (oseltamivir and zanamivir), have been used for the treatment of the influenza virus infection. Since the resistance to these drugs has been reported, the development of a new antiviral agent is necessary. In this study, we examined the antiviral efficacy of the plant extracts against the influenza A/PR/8/34 infection. In vitro, the antiviral activities of the plant extracts were investigated using the cell-based screening. Three plant extracts, Thuja orientalis, Aster spathulifolius, and Pinus thunbergii, were shown to induce a high cell viability rate after the infection with the influenza A/PR/8/34 virus. The antiviral activity of the plant extracts also increased as a function of the concentration of the extracts and these extracts significantly reduced the visible cytopathic effect caused by virus infections. Furthermore, the treatment with T. orientalis was shown to have a stronger inhibitory effect than that with A. spathulifolius or P. thunbergii. These results may suggest that T. orientalis has anti-influenza A/PR/8/34 activity.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.615-620
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• 2003

The sulfated exopolysaccharide p-KG03, which is produced by the marine microalga Gyrodinium impudicum strain KG03, exhibited impressive antiviral activity in vitro ($EC_{50}$ = 26.9 g/ml) against the encephalomyocarditis virus (EMCV). Depending on the p-KG03 concentration, the development of cytopathic effects in EMCV-infected HeLa cells was either inhibited completely or slowed. Moreover, p-KG03 did not show any cytotoxic effects on HeLa cells, even at concentrations up to 1,000 g/ml. The polysaccharide was purified by repeated precipitation in ethanol, followed by gel filtration. The p-KG03 polysaccharide had a molecular weight of $1.87\;{\times}\;10^6$, and was characterized as a homopolysaccharide of galactose with uronic acid (2.96%, w/w) and sulfate groups (10.32% w/w). The biological activities of p-KG03 suggest that sulfated metabolites from marine organisms are a rich source of antiviral agents. This is the first reported marine source of antiviral sulfated polysaccharides against EMCV. The p-KG03 polysaccharide may be useful for the development of marine bioactive exopolysaccharides for use in biotechnological and pharmaceutical products.

• Archives of Pharmacal Research
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• v.26 no.11
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• pp.960-966
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• 2003

Macrophages play an important role in host defenses by killing tumors and virus infections and producing secretory products. High mannuronic acid (HMA) containing alginate was examined to determine the mechanisms by which HMA-activated macrophages resist infection with HSV-1 and inhibit the growth of tumor cells. The ability of macro phages to resist infection with HSV-1 or to inhibit the growth of tumor cells was assessed following treatment with HMA alginate in the presence of either antibodies to various cytokines or inhibitors/scavengers of toxic macrophage products. Only antibodies to IFN-$\alpha$/$\beta$ were able to abrogate the protective effects of HMA alginate in macrophages infected with HSV-1, suggesting that the antiviral activity induced by this immunomodulator was mediated by the production of IFN-$\beta$. In contrast, anti-TNF-$\alpha$, anti-IFN and inhibitors of nitric oxide and reactive oxygen species were all able to partially abrogate HMA-induced cytostatic activity, suggesting that multiple mechanisms are involved in macrophage cytostasis. These results indicate that the HMA-induced intrinsic antiviral and extrinsic cytotoxic activites are mediated by different mechanisms.

• Applied Chemistry for Engineering
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• v.34 no.2
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• pp.192-198
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• 2023

In this study, the components of microwave-assisted extracts obtained from Thuja orientalis leaves were analyzed, and the cytotoxicity, antibacterial and antiviral activities were evaluated. The predominant components from microwave-assisted extraction were catechin, leucopelargonidin, arecatannin, quinolone, and kaempferol derivatives, which are classified in the flavonoid and tannin groups. We observed that the 0.11 mg/mL of extract concentration did not show cytotoxicity in HaCaT cells. The antibacterial activities were tested according to the guidelines of methods for determining the bactericidal activity of antimicrobial agents. The extracts showed 99.9% antibacterial efficiency against gram-positive S. aureus, while the antibacterial effect on gram-negative E. coli was insignificant. When the extract concentration and contact time with bacteria were increased, 99.9% antibacterial efficiency was observed for E. coli as well as S. aureus. Following the standard to assess the activity of microbicides against viruses in suspension (ASTM-E1052-20), the antiviral efficiency was more than 99.99% for influenza A (H1N1) and SARS-CoV-2. These results suggest its potential use in antiviral disinfectants, surface coatings, personal protective equipment, and textiles.

• Proceedings of the Microbiological Society of Korea Conference
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• 1998.04a
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• pp.41.1-41.1
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• 1998