| Summary: | 碩士 === 國立臺灣大學 === 化學研究所 === 93 === Chamaecyparis formosensis Matsum. is indigenous in the north and central parts of Taiwan at 1000~3000 meters, often forming pure stands or mixed with Chamaecyparis obtusa var. formosana. This trees can attain 1500 years of age, and sometime it can live about 4000 years old , Their longevity is attributable to the tree''s inherent ability to withstand erosion and prevent the growth of bacteria on its bark.
The methanol extract from the bark of Chamaecyparis formosensis Matsum. was concentrated to give residue which was partitioned between ethyl acetate and water. The ethyl acetate layer was separated by column chromatography on silica gel and HPLC afforded twenty-eight compounds. Of these compounds, ten compounds are new and one compound are isolated for the first time from natural sources.
Waltheria americana L. grows throughout the tropics and warmer subtropics. It is a short-lived shrub or subshrub and usually has a single, strong stem emerging from the ground, but frequently branches near the ground. However, in some environments, it may grow in a semiprostrate habit. This plant has several medicinal applications. For example, in Polynesia the root bark is chewed upon for sore throat, while in Hawaii it is used internally for arthritis, neuralgia, and asthma.
Fractionation and chromatography of the acetone extract from Waltheria americana L. afforded eighteen compounds. From these compounds, two compounds are isolated for the first time from natural sources.
The structure of these compounds were elucidated by comparison of their spectral data with related literature values and spectroscopic methods including 1D and 2D NMR.
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