Influence of storage time and temperature on the chemical composition of the essential oil of Hyptis pectinata L. Poit

摘要

Hyptis pectinata , popularly known as a??sambacait??a??, is a native medicinal herb used by local people for treating disease. Its pharmacological, antimicrobial, and medicinal properties have been reported in several studies. The essential oil of the leaves is rich in terpene compounds responsible for its properties. Because there are factors that can influence the chemical composition of essential oils, the objective of this study was to evaluate the influence of storage on Hyptis pectinata essential oil for 360 days at two different temperatures. The essential oil was distilled from dried leaves of seven-month-old plants using the hydrodistillation method, and the chemical composition was determined using GC-MS and GC/FID. The effects of storage on the essential oil Hyptis pectinata were tested over the course of a year (0, 15, 30, 60, 90, 120, 150, 180, 240, 300, and 360 days), using two temperatures: room (?±32?oC) and freezer (-20?oC). The predominant compounds in the essential oil are ?2a??caryophyllene, caryophyllene oxide, and germancrene D. The concentration of the chemical constituents of the essential oil varied depending on the storage temperature, and over the 360 days. The storage of the essential oil at room temperature over one year resulted in higher concentrations of ?2-elemene, ?±-copaene, germacrene D, caryophyllene oxide, and (E,E)-?±-farnesene and lower content of ?±-humulene and ?2-caryophyllene, compared to the results obtained from storing the essential oil in a freezer. These results indicate that the essential oil should be stored in a freezer, which provides greater stability to the concentration of the chemical constituents.