harzianum was not very clearly illustrated yet to date, the theory of metabolite as an inhibitor of pathogen growth has been supporting by many researchers (Dennis and Webster, 1971a, b; Okuda et al., 1982; Claydon et al., 1987; Ghisalberti et al., 1990), the inhibitor include simple aromatic compounds, some polyketides as pyrones
and butenolides, volatile terpenes, isocyano metabolites, and relatively non-polar substances.
In fact, some potential therapeutic actions, namely, anxiety, tension, and restlessness, of standardized extracts of kava-kava roots have been attributed to kava pyrones
, desmethoxyyangonin 6, and (+/-)-methysticin through inhibition of platelet MAO-B .
Hider, "Effects of the pyrones
, maltol and ethyl maltol, on iron absorption from the rat small intestine," Journal of Pharmacy and Pharmacology, vol.
produce many volatile (e.g., pyrones
, sesquiterpenes) and non-volatile secondary metabolites (e.g., peptabiols).Volatile secondary metabolites are responsible to play a key role in the mycoparasitic action (Vinale, F., et al 2008).
Computer-assisted optimiza tion in the development of a high-performance liquid chromatographic method for the analysis of kava pyrones
in Piper methysticum preparations.
and resin: studies on GABAA, GABAB and benzodiazepine binding sites in rodent brain.
Chemical studies carried out on Brazilian Piperaceae species have revealed the occurrence of pyrones
, lignoids and chromenes besides various amides bearing isobutyl, pyrrolidine, dihydropyridone and piperidine moieties (Parmar et al.
However, basidiomes may also contain high concentrations of toxins, such as phenols, pyrones
, and heterocyclic nitrogen complexes.
Pyrolysis rearranges guaiacols, catechols, syringols, vanillins, furancarboxaldehydes, isoeugenol, pyrones
, acetic acid, formic acid, and other carboxylic acids (Piskorz et al.
Surface acidity and basicity were calculated on the basis of the assumption that 0.05 M NaHC[O.sub.3] neutralises carboxyl groups only (the strongest acid fraction), 0.05 M NaOH neutralises acidic groups including carboxyl, lactones, and phenols, 0.25 M NaOH neutralises total acidity (carboxyl, lactones, phenols, carbonyls, and any other acidic species), and HCl neutralises all basic groups including ketones, pyrones
, and chromens (Boehm 1994; Chun et al.