Influence of environmental factors on composition of phenolic antioxidants of Achillea collina Becker ex Rchb

The effects of environmental growth conditions on the antioxidant capacity, total phenolic content and composition of Achillea collina Becker ex Rchb. were investigated. Methanol extracts and infusions obtained from leaves and inflorescences of plants cultivated in the Italian Alps at two different altitudes (600 and 1050 m a.s.l.) were evaluated. Infusions exhibited the highest antioxidant capacity (1/IC50 values from 4.35 ± 0.72 to 8.90 ± 0.74), total phenolic content (from 31.39 ± 4.92 to 49.36 ± 5.70 mg gallic acid equivalents g-1 DW), chlorogenic acid (from 9.21 ± 1.52 to 31.27 ± 6.88 mg g -1 DW), 3,5-di-O-caffeoylquinic acid (from 12.28 ± 3.25 to 25.13 ± 1.99 mg g -1 DW) and 4,5-di-O-caffeoylquinic acid (from 7.38 ± 1.01 to 12.78 ± 2.61 mg g -1 DW) content. Climate (as influenced by altitude) was shown to be the main environmental factor influencing yarrow’s composition and properties. Leaf extracts from the higher experimental site showed a 2-4-fold increase of chlorogenic acid level. A. collina can be considered as a very good source of bioactive phenolic compounds, and growing it at high altitude may constitute an effective way to enhance significantly its quality for both medicinal and nutritional uses.