Background & Aim: The pigments inside the leaf chloroplasts receive sunlight energy and transport it to photosynthesis reaction center. The most important of these pigments is chlorophyll. In this study, the pigments existence in medicinal plant, sumac (Rhus coriaria L.), was investigated at Biotechnology Laboratory, Isfahan University of Technology. Experimental: Experiments were performed in three replicates by using the upper, middle and lower leaves of sumac. Pigments were extracted by 80% acetone from fresh leaves of the sumac. Extracts have been used for the reading at 645, 663 and 470 nm absorption wavelength for chlorophyll a, chlorophyll b and carotenoids, respectively. Results & Discussion: The results showed significant difference between the amounts of pigments in different seasons (p< 0.05). The amount of chlorophyll a, b, total chlorophyll and carotenoids was obtained in spring on average 0.78, 0.24, 1.02 and 3.32 mg/g of leaf, whereas it was 1.55, 0.46, 2.01 and 6.61 mg/g of leaf for winter, respectively. The total amount of carotenoid was higher than chlorophylls and both of them were high in early winter. Totally, chlorophyll a content was higher than chlorophyll b in both seasons, as well as other plants. Recommended applications/industries: Chlorophyll, carotenoids and their derivatives are important antioxidants that there are plenty of them in sumac, it reveals the potential for its use in the food industry. Manuscript profile

Background & Aim: Osmotic stress in plants lead to increase free radicals and plants use different mechanisms to scavenge these radicals. So, researchers apply stresses especially drought stress to increase secondary metabolites such as phenolics, and antioxidants. One of the valuable medicinal plants is yarrow (Achillea tenuifolia) which is a perennial plant with different medicinal applications.Experimental: In order to assess the effect of drought stress, four different treatments (25%, 50%, 75% and 100% of Field Capacity) with four replicates was done in plastic pots at greenhouse. After 30 days, leaves of samples were used to evaluate total phenolics, antioxidant activity using three model systems including 1,1-diphenyl-2-picrylhydrazy (DPPH), ferric thiocyanate (FTC), and β-carotene-linoleic acid assay. In addition, malone dialdehyde (MDA), and proline content were evaluated.Results & Discussion: Drought stress in A.tenuifolia significantly increased total phenoloics, and antioxidant activity (in DPPH and β-carotene-linoleic acid assay). In addition, proline and malone dialdehyde were elevated by stress, while according to FTC model, there was no significant differences between 25% and 50% FC treatments.Industrial and practical recommendations: According to the results of present study, the 50% FC treatment can be introduced as acceptable drought level to produce sufficient phenolics and acceptable plant yield. Finally, more studies suggested for assessing the effect of drought stress on amount of other compounds in this medicinal plant. Manuscript profile