Diversity in seed fatty acid composition and petal pyrrolizidine alkaloid content in Echium amoenum Fisch. & C.A.Mey. populations.

backgroundEchium amoenum Fisch. & C.A. Mey. is an important medicinal plant rich in unsaturated fatty acids and pyrrolizidine alkaloids. This study examined seed fatty acid composition, pyrrolizidine alkaloids, and antioxidant activity in petals of different Iranian Echium populations. A randomized complete block design with three replications was used. Plant extracts were prepared with acidified methanol (5% formic acid). Seed fatty acids were quantified using gas chromatography (GC), while petal pyrrolizidine alkaloids were analyzed with an Ultimate 3000 UHPLC system coupled o an Orbitrap Fusion mass spectrometer. The antioxidant activity of the extracts was evaluated via DPPH radical scavenging assays.

resultsSeed oil content varied among populations collected from Fasa, Roodsar, Ghazvin, Sari, Vaznehsar, and Leron. In the first year, oil content ranged from 16.20% to 22.40%, with the highest value observed in the Leron population, whereas in the second year it ranged from 21.00% to 25.50%, with Sari showing the highest oil content. The major fatty acids identified in the seed oils during the first year were oleic acid 18.35%-19.40%, linoleic acid 23.80%-26.20%, and α-linolenic acid 32.30%-34.20%. In the second year, oleic acid 15.80%-19.30%, linoleic acid 21.55%-24.70%, and α-linolenic acid 32.34%-37.40% were the predominant fatty acids. Among the populations evaluated in the second year, Fasa exhibited higher contents of γ-linolenic and α-linolenic acids, Leron had the highest linoleic acid content, and Vaznehsar was rich in oleic acid (p ≤ 0.01). Population collected from Leron also exhibited the strongest antioxidant activity in petal (p≤0.01). On the other hand, the concentrations of echimidine N-oxide and intermedine N-oxide varied notably among petal populations. Population collected from Fasa and Roodsar exhibited high echimidine N-oxide levels in petal (p≤0.01) at the first year 1592.18 and 1255.91 µg kg⁻¹, respectively, which declined by more than 85% in the second year. Population collected from Sari showed greater stability 485.49 µg kg⁻¹, while intermedine N-oxide in petal remained consistently low and irregular across both years.

conclusionsThese findings reveal substantial diversity among Echium populations, reflected in the high unsaturated fatty acid content of seeds and strong antioxidant activity of petals. Notably, first-year Echium amoenum plants exhibited relatively higher levels of echimidine N-oxide in petals, which may pose potential food-safety concerns. In contrast, second-year plants contained significantly lower levels of this compound, suggesting that they may present a reduced risk for consumption and be more suitable for food-related applications. Nonetheless, the food-safety implications of pyrrolizidine alkaloid content warrant further investigation and should be assessed considering established legal limits and regulatory frameworks.