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Reactive oxygen species- (ROS) induced oxidation stress is a key cause of human health problems. Studies have shown that many diseases, such as Alzheimer's disease, Parkinson's disease, diabetes, carcinogenesis and inflammatory diseases, are associated with ROS. Plant polyphenols have the ability to remove these ROS in the human body, indicating their potential to improve human health. Zelkova serrata is a traditional medicinal plant in Taiwan and all of its plant parts have various health applications and even antioxidant activities. This study aimed to understand the antioxidant activities of bark polyphenols from Z. serrata and their active components. Results showed that the ethanolic extract of bark had free-radical scavenging abilities and reducing power. Although the extract barely had any flavonoids or condensed tannins, it comprised polar polyphenols with antioxidant activities. Furthermore, antioxidant activities in the extract originated mainly from lyoniresinol via hydrogen atom and electron transfer. These findings suggest that the bark extract of Z. serrata is also a potential resource for health improvement. [ABSTRACT FROM AUTHOR]

Cinnamomum kanehiraeHayata is an endemic tree species in Taiwan. Leaf essential oils from 26 sources ofC. kanehiraewere obtained by hydrodistillation and their chemical constituents were analyzed by gas chromatography-mass spectrometry (GC-MS). Fifty-eight compounds were identified fromC. kanehiraeleaf essential oils. The main constituents in leaf essential oils were linalool, 1,8-cineole, β-selinene, 1-hexadecyne, and α-cadinol. According to the chemical compositions of leaf essential oils and their relative contents obtained from GC-MS analyses, cluster analysis, and principal component analysis, the 26 sources examined were classified into five chemotypes: linalool type, linalool/1,8-cineole type, 1,8-cineole type, linalool/α-cadinol type, and mixed type. The biochemical correlations between the major constituents ofC. kanehiraewere examined and their relationship is discussed. [ABSTRACT FROM AUTHOR]

In this study antifungal activities of essential oils from wood and leaf and their constituents of Cunninghamia konishii against four wood decay fungi and six plant pathogenic fungi were investigated. GC and GC-MS analyses show that the major compounds of wood essential oil were cedrol and α-pinene, while those of leaf essential oil were α-pinene and p-cymene. Antifungal tests demonstrated the wood oil from C. konishii used against Trametes versicolor, Lenzites betulina, Laetiporus sulphureus, and Gloeophyllum trabeum and leaf oil from C. konishii used against L. sulphureus had strong antifungal activities. Moreover, wood oil used against Rhizoctonia solani, Fusarium solani, Pestalotiopsis funereal, and Ganoderma australe also had strong antifungal activities. Among the seven constituents of wood oil, cedrol displayed the best antifungal properties, indicating that it may be used as potential antifungal agents for the control of fungal diseases in plants. [ABSTRACT FROM AUTHOR]

In this study, inhibitory activities of leaf essential oils from Cinnamomum osmophloeum and Cinnamomum zeylanicum and their major constituents (trans-cinnamaldehyde and eugenol) against Rhizoctonia solani were investigated. Furthermore, the relationship between the antipathogenic activity and the chemical structure of trans-cinnamaldehyde and eugenol is discussed. Results demonstrated that leaf essential oils and their major constituents from C. osmophloeum and C. zeylanicum had strong antipathogenic activities against R. solani. Results obtained from the chemical structure-antipathogenic activity relationship study suggested that trans-cinnamaldehyde or (E)-cinnamic acid with an aldehyde (-CHO) or an acid (-COOH) group, a conjugated double bond, and a Length of CH chain outside the ring affect their antipathogenic activity. Furthermore, the presence of the methyl moiety in the ortho position may have a considerable influence on the inhibitory action against R. solani. In addition, compounds with a free phenolic hydroxyl (-OH) group and a double bond at the C7 position of the phenylpropenes also exhibited potent antipathogenic activity. [ABSTRACT FROM AUTHOR]