Comparison of Different Isolation Methods of Essential Oil from Vitexpseudo-negundo :Hydrodistillation and Microwave-assist Hydrodistillaton

There are many methods to obtain essential oils from the plant materials [۱]. The main methodsto obtain essential oils from the plant materials are hydrodistillation, steam distillation, steam andwater distillation [۲].Microwave-assisted hydrodistillation is one way of using microwaves in anextraction process where a higher extraction rate (i.e. a shorter extraction time) along with alower cost of operation can be obtained [۳].Microwave-assisted hydrodistillation was used to isolate an essential oil from the aerial parts ofVitex pseudo-negundo, and the results compared with those obtained by conventionalhydrodistillation. The composition of the oil indicated that some difference between the amountsand number of these components in microwave-assisted hydrodistillation oil, compared with thehydrodistillation oil. The two oils recovered from hydrodistillation and microwave-assisthydrodistillaton extraction contained the same dominant components:à-Thujene(۲۹.۱۰% ,۲۴.۵۱%); à-Terpineol acetate(۱۷.۲۶%, ۱۷.۴۸%);ë-Himachalene(۱۴.۶۵%, ۱۶.۷۴%)andSylvestrene(۱۱.۷۵%, ۱۰.۰۵%) respectively.The method of essential oil extraction affects theirchemical compositions and biological activities.