Essential oil, flavonoids and anthocyanins profiling of some Iranian damask rose (Rosa damascena Mill.) genotypes

Increasing production efficiency is necessary for the industrialization of plant cultivation which includes the type and content of metabolites in medicinal and aromatic plants. In the present study, the metabolic diversity of twenty-four Iranian Rosa damascena genotypes (G1-G24) was studied. The essential oils isolated from fresh flowers and methanolic extracts from dried petal samples were analyzed by chromatographic techniques. In total, forty-three chemical compounds were identified in the essential oil samples. Geraniol (0.2-45.8%), 13-citronellol (1.9-22.3%), and nerol (1.4-15.2%) were the major compounds identified in the studied oils especially in G5, G7, and G22, respectively. Twelve flavonoids and four anthocyanins were identified in the extracts. The highest flavonoid content (48.9 mg/g DW) was recorded in G2. Kaempferol 3-O-glucoside (6.1-12.9 mg/g DW), quercetin 3-O-glucoside (0.9-11.4 mg/g DW), and quercetin 7-(6"-galloylglucoside) (0.3-9.2 mg/g DW) were identified as the main flavonoids in the studied genotypes. The highest content of anthocyanin (37.0 mg/g DW) was observed in G1. Cyanidin 3,5-O-diglucoside was found only in G17 and G18, while cyanidin 3-O-sambubioside was unique in G1. 13-Citronellol and methyl eugenol had positive (8 > 0.5) and negative (8 > - 0.6) correlations with flavonoids kaempferol 3-O-galactoside 7-O-rhamnoside (K3g7r) and Q3g in the studied samples, respectively; so, this finding can be interestingly used as a phytochemical marker to select the damask rose genotypes producing high-quality essential oil. In conclusion, G21, G2, and G1 can be distinguished and used as adequate genotypes for further commercial cultivation to obtain the essential oil, flavonoids, and anthocyanins, respectively.