No abstract

No abstract

No abstract

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

No abstract

Stachys schtschegleevii is an endemic species of Iran. It is a valuable medicinal plant which is widely used in herbal medicines. To obtain high‐quality essential oil from this plant, the type of the applied drying technique plays a key role. The current study was aimed to investigate the effects of different drying methods (shade, sunlight, oven 40°C, oven 60°C, and microwave) on yield and essential oil composition of S. Schtschegleevii. The results indicated that the highest essential oil yield was related to microwave drying technique. Furthermore, α‐pinene, germacrene‐D, bicyclogermacrene, β‐eudesmol, and spathulenol were found to be the major compounds. Drying method significantly changed major compounds percentage, for instance, monoterpene hydrocarbonssuch as α‐pinene, β‐pinene, germacrene‐D, and myrcene significantly decreased due to oven drying (60°C), microwave or sunlight drying techniques. Moreover, bicyclogermacrene and β‐eudesmol percentage significantly decreased due to direct sunlight‐drying method. Consequently, microwave drying technique was found to be the most efficient technique in order to achieve the highest oil yield and shortest drying time. Practical applications Hedge nettle (Stachys schtschegleevii Sosn) belongs to Lamiaceae family and is known as an important medicinal plant due to its flavoring, therapeutic, and preservative properties. Aerial parts of the plant are used to extract essential oil and hence type of the applied drying technique plays a key role in obtaining high‐quality essential oil. Therefore, the influences of different drying techniques on essential oil content of S. schtschegleevii were examined and overall, microwave drying technique was found to be the most efficient technique in order to obtain the highest oil yield and shortest drying time; however, some of the major compounds were decreased due to the employment of this technique.

The high demands for the consumption of edible oils have caused scientists to struggle in assessing wild plants as a new source of seed oils. Therefore, in this study, the oil yield, fatty acid and tocopherol compositions, antioxidant and antibacterial activities of the oils obtained from Iran's two endemic plants (Pyrus glabra and Pyrus syriaca) were investigated. The obtained oil yields from the P. glabra and P. syriaca seeds were 33 ± 0.51 and 26 ± 0.28 w/w%, respectively. Oleic acid (C18:1) with the amount of 49.51 ± 1.05% was the major fatty acid in the P. glabra oil, while the main fatty acids in the P. syriaca seed oil belonged to linoleic acid (C18:2) and oleic acid (C18:1) with the amounts of 46.99 ± 0.37 and 41.43 ± 0.23%, respectively. The analysis of tocopherols was done by HPLC, and the results indicated that the P. glabra and P. syriaca seed oils were rich in α‐tocopherol (69.80 ± 1.91 and 45.50 ± 1.86 mg/100 g oil, respectively), constituting 86.24 and 89.01% of total detected tocopherols, respectively. The study on the reducing capacity of the oils indicated that the P. glabra oil had more reducing capacity than the P. syriaca oil. Moreover, the antioxidant activity of the P. glabra seed oil (43.4 ± 0.7 µg/ml) was higher than the P. syriaca seed oil (46.3 ± 1.2 µg/ml). Also, the investigation of the antibacterial activities indicated that the P. glabra and P. syriaca oils have an inhibitory effect on the studied bacteria. The results indicate that the oils of these plants can be appropriate sources of plant oils which can act as natural antibacterial agents.

No abstract