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In this study, antitermitic and antifungal activities of enantiopure linalool and linalool oxide (furanoid) in L. umbellata var. membranacea were evaluated with their racemates. Results of chiral analysis showed that linalool oxide in leaves dominated by (R)-linalool and in twigs dominated by (S)-linalool were (2R,5R)-trans- and (2R,5S)-cis-linalool oxide and (2S,5S)-trans- and (2S,5R)-cis-linalool oxide, respectively. All rac-, (R)-, and (S)-linalool at highest concentration showed termiticidal and antifeedant activities against Reticulitermes speratus. Antitermitic activities of linalool oxides differed depending on their stereostructures, and (2R,5R)-trans-linalool oxide showed the strongest termiticidal activity. (S)-linalool showed significantly stronger antifungal activity than that of rac- and (R)-linalool against Penicillium citrinum and Chaetomium globosum. Racemate of trans- and cis-linalool oxide showed potent activity against P. citrinum, Rhizopus oryzae, and C. globosum; however, the activity decreased in isolated pure enantiomers. These results suggest that linalool and linalool oxide exhibit different antitermitic and antifungal properties. [ABSTRACT FROM AUTHOR]

The reaction behavior of condensed tannins and related polyphenols with ammonia (NH3) water was examined. NH3 water treatment of pyrogallol, gallic acid, and epigallocatechin, which have a pyrogallol nucleus, caused regioselective amination in the presence of molecular oxygen (O2) to form 2-aminoresorcinol, 4-amino-3,5-dihydroxybenzoic acid and 4′- C-amino-epigallocatechin, respectively. In contrast, other polyphenols, such as catechol, protocatechuic acid, and epicatechin, which have a catechol nucleus, did not undergo amination even in the presence of O2. Under nitrogen atmosphere (in the absence of O2), epimerization at the C-2 position took place during NH3 treatment of epigallocatechin, in addition to amination. The same epimerization took place during NH3 treatment of epicatechin regardless of the presence or absence of O2. By NH3 treatment, pyrogallol-type B-rings of condensed tannin from Acacia mearnsii underwent regioselective amination to yield 4′-amino-3′,5′-dihydroxybenzene-type B-rings in the presence of O2, whereas catechol-type B-rings of condensed tannin from quebracho showed little amination regardless of the presence or absence of O2. From these results, it was concluded that amination of pyrogallol nucleus by NH3 treatment should proceed via oxidation and reduction, and therefore this reaction would be attributed to the oxidation property of condensed tannins and related polyphenols. [ABSTRACT FROM AUTHOR]

Bark of desert willow (Salix psammophila, Spsa) grown in Inner Mongolia was successively extracted with n-hexane, diethyl ether, acetone, methanol, and hot water to examine chemical components associated with its environmental adaptability to desert conditions. The yield of n-hexane extract (5.0% based on dry bark), mainly composed of wax, was higher than those of acetone and methanol extracts (3.7% and 4.2%, respectively), whereas the yields of n-hexane extract (1.4%) from willow bark grown in humid areas were much lower than those of acetone (17.4% and 19.9%) and methanol (12.5% and 14.0%) extracts. Unlike other willow bark samples, Spsa bark contained a certain amount of sugar alcohols. In particular, we identified arabinitol (0.21%), which has not previously been reported as a major component of extracts of willow bark. The high content of wax and sugar alcohol would be associated with the ability of Spsa to survive in desert conditions. Accumulation of wax on the outer bark surface would reduce water loss, while sugar alcohols might improve freezing tolerance.