Antiviral Activity of Phenolic Derivatives in Pyroligneous Acid from Hardwood, Softwood, and Bamboo

Abstract

Pyroligneous acids (PA) from hardwood, softwood, and bamboo significantly disinfected encephalomyocarditis virus (EMCV). Twenty-five kinds of phenolic derivatives in the PAs were identified and quantified. The total amounts of phenolic compounds in bamboo PA is higher than those in the PAs from softwood and hardwood. Phenol, 2-methoxyphenol, 2-methoxy-4-methylphenol, and 2-methoxy-4-ethylphenol are the most abundant compounds in the PAs examined. The activities of all the phenolic compounds against the encephalomyocarditis virus were assessed. The number of phenolic hydroxyl groups significantly affects the antiviral activity, and catechol and its derivatives exhibit higher viral inhibition effects than other phenolic derivatives. In addition, substituents affect the antiviral activity of the compounds. Phenolic compounds with a methyl group show higher activities than with a methoxyl group (e.g., 2-methylphenol > 2-methoxyphenol). Moreover, the relative position of functional groups also plays a key role in the viral inhibition activity (e.g., 2,6-dimethoxyphenol > 3,4-dimethoxyphenol). Thus, PAs contain phenol derivatives with considerable structural diversity and viral inhibition activities, providing a new strategy for virus-inactivation treatment through the optimization of PA-derived phenol structures.

High Amplification of the Antiviral Activity of Curcumin through Transformation into Carbon Quantum Dots

“…Therefore, highly abundant of curcumin fragmented components such guaiacol and anisole (methoxybenzene) on the surfaces of Cur‐CQDs can effectively inhibit the ROS generation by EV71, which is evident from Figure S20, enhancing its defense against the virus. Phenolic derivatives such as guaiacol, a major surface component of the Cur‐CQDs‐180, has also been reported to exhibit antiviral activity against encephalomyocarditis virus (EMCV) and its activity depends on the number, structure, and position of the substituents . In addition, the phenolic compounds with unsaturated carbon side chains have higher efficiency to inactivate the virus than unsubstituted phenols .…”

“…Phenolic derivatives such as guaiacol, a major surface component of the Cur‐CQDs‐180, has also been reported to exhibit antiviral activity against encephalomyocarditis virus (EMCV) and its activity depends on the number, structure, and position of the substituents . In addition, the phenolic compounds with unsaturated carbon side chains have higher efficiency to inactivate the virus than unsubstituted phenols . Therefore, we believe that our Cur‐CQDs‐180 has plenty of unsaturated carbon due to the partial carbonization process and the phenolic molecules attached to these carbons could have a major role in the antiviral activity.…”

Structure-dependent antiviral activity of catechol derivatives in pyroligneous acid against the encephalomycarditis virus

“…WV derived from Japanese larch (Larix kaempferi) was obtained from Shimokawa Forest Association (Hokkaido, Japan), which was produced according to the guidelines of the Japan Mokusaku-eki Association. 18,19 The concentration of acetic acid was 1.2% (weight percentage) and the pH was 3.22 at 20 C. Catechol, 3-methylcatechol, 4-methylcatechol, and 1,2,4-trimethoxybenzene were obtained from Tokyo Chemical Industry Co., Ltd. (Tokyo, Japan). 2-Methoxy-4-methylphenol, 4-ethylcatechol, and 2-methyl-1,4-benzenediol were purchased from Wako Pure Chemical Industry Co., Ltd. (Osaka, Japan).…”

“…The original WV and fractions were analyzed by gas chromatography-mass spectrometry (GC-MS) according to previous report. 19 The chemical compounds in the WV were identied by comparing their retention time and the mass spectra peaks with authentic standards. Catechol, 3-methylcatechol, 4-methylcatechol, and 4-ethylcatechol were quantied by GC-MS using butylated hydroxytoluene (BHT) as an internal standard.…”

“…L929 cells (murine broblast cell line purchased from ATCC) were by using the same procedure reported previously. 19 Viral inactivation assay EMCV was propagated in Vero cells, and its titer was determined by standard plaque assay on L929 cells as described previously. 20 For the inactivation assay, 10 mL of medium (MEM) containing 1 Â 10 5 pfu EMCV was incubated with 10 mL of PA or catechol derivatives on ice for 1 h. Methanol (for catechol derivatives) or H 2 O (for wood PAs) was used as a solvent control.…”