1.[Anti-dermaptophyte activity of phenolic compounds in "mokusaku-eki"].
Ikegami F1, Sekine T, Fujii Y. Yakugaku Zasshi. 1998 Jan;118(1):27-30.
"Mokusaku-eki," a kind of pyroligneous acid, is a dark brown color solution obtained from the charcoal burner of such Quercus spp. woods as a by-product. This is used as a folk medicine in water eczema. The n-hexane fraction of this solution contained several phenolic compounds such as 4-ethyl-2-methoxyphenol (3) and 2,6-dimethoxyphenol (4), which could not be found in the fresh woods. Among these compounds, 3 has the highest anti-dermaptophyte activity against Trichophyton mentagrophytes at minimum inhibitory concentration (MIC) 150 micrograms/ml.
2.Pyroligneous acid-the smoky acidic liquid from plant biomass.
Mathew S1, Zakaria ZA. Appl Microbiol Biotechnol. 2015 Jan;99(2):611-22. doi: 10.1007/s00253-014-6242-1. Epub 2014 Dec 3.
Pyroligneous acid (PA) is a complex highly oxygenated aqueous liquid fraction obtained by the condensation of pyrolysis vapors, which result from the thermochemical breakdown or pyrolysis of plant biomass components such as cellulose, hemicellulose, and lignin. PA produced by the slow pyrolysis of plant biomass is a yellowish brown or dark brown liquid with acidic pH and usually comprises a complex mixture of guaiacols, catechols, syringols, phenols, vanillins, furans, pyrans, carboxaldehydes, hydroxyketones, sugars, alkyl aryl ethers, nitrogenated derivatives, alcohols, acetic acid, and other carboxylic acids. The phenolic components, namely guaiacol, alkyl guaiacols, syringol, and alkyl syringols, contribute to the smoky odor of PA. PA finds application in diverse areas, as antioxidant, antimicrobial, antiinflammatory, plant growth stimulator, coagulant for natural rubber, and termiticidal and pesticidal agent; is a source for valuable chemicals; and imparts a smoky flavor for food.
3.Identification of methylglyoxal as a major mutagen in wood and bamboo pyroligneous acids.
Onoda A1, Asanoma M1, Nukaya H2. Biosci Biotechnol Biochem. 2016 Feb 12:1-7. [Epub ahead of print]
To identify the major mutagen in pyroligneous acid (PA), 10 wood and 10 bamboo pyroligneous acids were examined using the Ames test in Salmonella typhimurium strains TA100 and TA98. Subsequently, the mutagenic dicarbonyl compounds (DCs), glyoxal, methylglyoxal (MG), and diacetyl in PA were quantified using high-performance liquid chromatography, and the mutagenic contribution ratios for each DC were calculated relative to the mutagenicity of PA. Eighteen samples were positive for mutagens and showed the strongest mutagenicity in TA100 in the absence of S9 mix. MG had the highest mutagenic contribution ratio, and its presence was strongly correlated with the specific mutagenicity of PA. These data indicate that MG is the major mutagen in PA.
4.Identification of a germicidal compound against picornavirus in bamboo pyroligneous acid.
Marumoto S1, Yamamoto SP, Nishimura H, Onomoto K, Yatagai M, Yazaki K, Fujita T, Watanabe T. J Agric Food Chem. 2012 Sep 12;60(36):9106-11. doi: 10.1021/jf3021317. Epub 2012 Aug 29.
The germicidal activity of pyroligneous acid (PA) against a picornavirus, encephalomyocarditis virus (EMCV), was analyzed, and the component responsible for its disinfectant activity was identified. Bamboo PA (BPA) inactivated EMCV, but neutralization of BPA abolished this activity. Using liquid-liquid phase extraction and silica gel column chromatography, the hydrophobic active fraction of BPA was separated and its 12 major components were identified. The active fraction was reconstructed by mixing synthetic chemicals at the determined concentrations, and a subtraction series of one chemical from the complete mixture was prepared. An in vitro virus assay demonstrated that phenol was the sole germicidal component, and acetic acid augmented the phenol's inactivating activity resulting in >5-log decrease in EMCV infectivity. Considering the low environmental risk of PA, these findings suggest that BPA is a potentially useful agent for preventing viral epidemics in agricultural and human environments.