Changes in major bioactive compounds with antioxidant activity of Agastache foeniculum, Lavandula angustifolia, Melissa officinalis and Nepeta cataria: Effect of harvest time and plant species

• Published in: Industrial crops and products 2015-12, Vol.77, p.499-507
• Main Authors: Duda, Simona Carmen, Mărghitaş, Liviu Alexandru, Dezmirean, Daniel, Duda, Marcel, Mărgăoan, Rodica, Bobiş, Otilia
• Format: Article
• Language: English
• Subjects: Agastache foeniculum; Antioxidant activity; Bioactive compounds; Harvest period; Lavandula angustifolia; Melissa officinalis; Nepeta cataria
• ISSN: 0926-6690; 1872-633X
• DOI: 10.1016/j.indcrop.2015.09.045

[Display omitted] •The present study reports the bioactive compounds from four Lamiaceae family plants: Agastache foeniculum, Lavandula angustifolia, Melissa officinalis and Nepeta cataria in two different stages of development and harvested in two distinctive periods of the day.•Methanol extracts were analyzed for total polyphenolic and flavone/flavonol content using UV–vis spectrometry.•Chromatographic profile of phenolic acids and flavonoids were determined using high performance liquid chromatography PDA detection.•Antioxidant activity was evaluated using two different spectrophotometric methods.•Optimum period of harvesting for maximum amount of bioactive compounds was determined. The continuous interest in medicinal plants has brought about todays modern processing and usage of different plants. Extracts obtained from the aerial parts of Agastache foeniculum, Lavandula angustifolia, Melissa officinalis and Nepeta cataria were investigated for their antioxidant activity and polyphenolic content. The extracts were prepared from plants harvested in two phenological phases of development (beginning of blooming and full bloom) and in two distinctive time points (11a.m. and 4p.m.). Different amounts of total phenolic content were measured (12.44–76.43mgGAE/g dry plant) and correlated with botanical origin, phenophase and harvesting hour. Flavone/flavonol content presented higher amounts than total polyphenol content in A. foeniculum extracts (36.87mgQE/g compared to 27.19mgGAE/g). All plants exhibit high antioxidant activity (73.14–81.74% inhibition and 0.265–0.554mM Trolox equivalents), measured with DPPH and FRAP method. Fingerprint of biologically active compounds highlights the potential of using these plants as value-added products, because of their content in phenolic acids and flavonoids with antioxidant activity. The quantity and profile of polyphenols was influenced by harvesting period and hour. The best moment for harvesting these plants in order to have maximum amount of bioactive compounds, was established to be in the first decade of June (beginning of blooming) and in the afternoon.