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.
These results agree with those reported by Palacios et al., (2009) who detected alkaloids, amides, pyrones
, dihydrochalcones, flavonoids, phenylpropanoids, lignans, neolignans, tannins, saponins, coumarins belonging to the Piperaceae family to the same way flavonolic compounds like chalcones, dihydrochalcones, flavones and flavanones of the inflorescences of Piper hispidium Kunth (Plazas et al., 2008).
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.
Tawata, Essential oils, kava pyrones
and phenolic compounds from leaves and rhizomes of Alpinia zerumbet (Pers.) B.L.
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.