巴西櫻桃 (Eugenia brasiliensis L.) 不同部位精油化學成份組 成之分析

Abstract

Eugenia brasiliensis L. is a species of flowering plants in the myrtle family Myrtaceae. It has a worldwide, although highly uneven distribution in tropical and subtropical regions. The fruit, which is consumed as food and beverages, provides a good source of vitamins and minerals, while the leaves and stems have many medicinal properties. The aim of this study was to investigate the chemical composition of the essential oils of leaves collected from summer and winter; different parts of E. brasiliensis (flowers, leaves, stems, and green fruit), and fruits of four ripen stages (green, yellow, red, and purple). The results were used to determine the optimum harvesting time for the different parts of E. brasiliensis in order to obtain the highest oil yield. It was found that the extraction rate of summer leaves and winter leaves were 8.9 mg and 22 mg of oil from 100 g of leaves, respectively. In the different parts of plants (flowers, leaves, stems and green fruit) were 11.0 mg, 91.7 mg, 7.5 mg and 73.6 mg of oil from 100 g of flowers, leaves, stems and green fruit, respectively. Finally, fruits at green, yellow, red and purple color stages were 60.9 mg, 36.4 mg, 16.5 mg and 4.3 mg of oil per 100 g of fruits, respectively. The major components of the essential oils extracted from summer and winter leaves were spathulenol, τ-cadina, and α-cadinol. The leaves oils from both seasons had dry, woody, fresh, sweet, floral-citrusy and spicy odor. Major components of the essential oil extracted from different parts of the plant were spathulenol, τ-cadina, and α-cadinol, except fruit. Oils from flower, leaves, and stem had dry, woody, resinous-piney, resinous, pine and spicy odor. Major components of essential oils extracted from fruits at different ripen stages were limonene and phenol. Nonadecane was found from fruits in green, red, and purple color stages, but it was not found in fruits at yellow color stage. Oils from fruits at their different ripen stages had fresh, sweet, and sweet cherry-like flavor. It was found that the best season for harvesting and acquiring the highest quantity and quality of compound of essential oil was winter. Moreover, essential oil extracted from leaves was found to have the highest yield. In brief, it was shown that the chemical composition of the essential oils vary from different parts of plant and the season of collection. Although most of these compounds are well documented as essential oil components in various plant species, to our knowledge, this is the first report of their presence in the essential oil of Eugenia brasiliensis L. in Taiwan. Moreover, several factors can affect the chamical composition and yield of the essential oil. In some instances it is difficult to segregate these factors from each other, since many are interdependent. These variables may include seasonal and maturity variation, geographical origin, genetic variation, growth stages, and parts of plant.