Introduction: Rosemary is one of the most useful medicinal plants among different categories of plants due to its many medicinal properties. Nanoparticles as one of the non-bio-stresses by using their electrochemical properties cause interference in the biosynthetic pathway of compounds in plants. This research was conducted in the form of a completely random basic design with three replications in the agricultural greenhouses of Zanjan University in 2017–2018. Also, gold nanoparticles were produced by the chemical reduction method in the laboratory of Zabul University, and then their effect on the increase or decrease of compounds in rosemary plant oil was investigated in two time intervals of harvesting: 24 hours, 48 hours, and the control group.
Materials and Methods: Rosemary plant cuttings with lengths of 10–12 cm and a diameter of half a centimeter were rooted in small containers containing light, washed soil, and ionolite, and permitted at night temperatures of 10–17 degrees and 21–23 degrees during the day. Then the rooted cuttings were transferred to 5 -liter pots containing a combination of fertile agricultural soil and sand. The Chemical reduction method (sodium citrate) was used to extract nanoparticles (Leopold and Lendl, 2003). The gold nanoparticle mixture that had changed color (blue) was subjected to the absorption spectrum of the spectrophotometric device, and the results obtained from the output of the device were checked based on which the maximum absorption rate of the gold nanoparticle with a diameter of 13 nm is equal to the wavelength of 520 nm and for the gold nanoparticle with a diameter of 52 nm is equal to 533 nm. The samples were sent to Beam Gostar Taban (2016–2021) after extraction by the chemical reduction method for diffraction electron microscopy (SEM) investigations and the authenticity of the presence of gold nanoparticles in the obtained samples. The gold nanoparticle treatment with a concentration of 30 ppm was sprayed on the plant in two different time periods (24 hours and 48 hours) and in the control group (without any treatment group) when the cuttings were fully established in terms of rooting and leafing. After that, their aerial parts were harvested at specified intervals and dried at room temperature for mass spectrometer (GC-MS) analysis. About 400 microliters of effective substance were spectrometered by the device (N Agilent 6890 Agilent technology USA), which was equipped with an ion trap system. The leaf sample of the plant, which was dehydrated at room temperature, was placed in the Cloninger device on a heater for 3 hours at a temperature of 100 degrees Celsius. A Water solvent was used in this research.
Results and Discussion: In this study, gold nanoparticles were extracted based on the chemical reduction method, and the synthesis of gold nanoparticles was confirmed by electron microscope diffraction (SEM) and spectrophotometric analyses. The results obtained in this study showed significant changes in the compounds obtained by mass spectrometry (GC-MS) in rosemary oil, each of which has unique medicinal properties. Changes in secondary metabolites increase the plant's antioxidant defenses, which can be important in adapting to stresses. Verbonone is an effective compound in rosemary oil that, in this study, had a significant increase under the treatment of gold nanoparticles.
Conclusion: In general, investigations conducted on the expression of oily compounds in rosemary showed that gold nanoparticle treatment did not have a significant effect on all the compounds in rosemary oil, but it was able to significantly increase a number of important compounds. The composition of verbena, which has an anti-inflammatory and antimicrobial role, showed a significant increase in the oily compounds of the rosemary plant. Considering the changes in the important oil compounds of the rosemary plant, it may be possible to induce the maximum production of these compounds and mass production of nanoparticles in the future.