A comparative study on the essential oil composition and antibacterial activities of different organs of wild growing Paeonia daurica subsp. tomentosa from Iran.

Paeonia daurica subsp. tomentosa (Lomakin) D.Y.Hong is an herbaceous perennial and flowering plant from the Paeoniaceae family. In this research, the roots, stems, leaves and fruits of P. daurica subsp. tomentosa were investigated for a comparative identification of essential oil composition. The essential oils constituents were identified by GC/MS and then compared. The study leads to the identification of 31, 57, 66, and 57 components in the essential oils obtained from the roots, stems, leaves and fruits, respectively. These chemicals make up more than 99% of the essential oil. Some of the identified compounds (α-Pinene, 4-ethyloctane, 5-methylnonane, benzaldehyde, myrtanal, 4,7-dimethyl benzofuran, n-decane, cuminaldehyde, cis-p-mentha-6,8-diene-2-ol, salicylaldehyde, tetradecane, tetradecanal, and n-tricosane) occurred in all parts of the plant. The existence of compounds such as cembrene (1.1%), 13-epi-manool (1.5%), 2-hydroxy methyl benzoate (10.1%), and tridecanal (0.7%), however, were confirmed exclusively in the fruit, stem, root, and leaf, respectively. The antibacterial activities (MIC) of the oils obtained from the four studied Paeonia parts against Escherichia coli and Staphylococcus aureus was studied. Staphylococcus aureus was the most sensitive microorganism to the oil obtained from the fruits of P. daurica subsp. tomentosa with the value of 0.04 ± 0.005 mg mL-1 .