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Laccase (benzenediol: oxygen oxidoreductase), is a multicopper polyphenol oxidase enzyme which has glycoprotein structure. The Researches are indicated that laccase enzyme can play role in detoxification of aromatic pollutants (as petroleum derivatives) and conversion them to less toxic compounds. On the other hand, because of its extensive, fibrous root system; Festuca arundinacea, creates an appropriate environment that causes increased catalysis of petroleum contaminants. Considering the fact that increasing in catalysis of pollutants can be provided by presence and changes in activity of various plant enzymes, in this research; the changes in laccase activity of Festuca's vegetative organs under soil pollution with different concentration of diesel fuel has been investigated. For this purpose, at first, the seeds of Festuca were cultivated in pots containing diesel fuel polluted soils and also control pots in greenhouse conditions. Then in specified time treatments, plants were harvested and plant extract containing laccase were extracted from aerial parts and roots of the plant, separately. After doing centrifuge, changes in enzyme activity were calculated by spectrophotometer. The results show that creation of soil pollution treatments compared with control samples, leads to increase in laccase activity in many cases. In other words, by increasing in laccase activity, the plant will increase its potency of decomposition and assimilation of pollutant hydrocarbons.

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in recent years, interest in use of plant sources due to function of Phytochemicals and antioxidant compound in maintenance of human health is increased, phenolic and flavonoid compounds are one of important compounds of plants that have antioxidant effects. Aim of the present study is to examine and comparison of phenolic and flavonoid compounds and antioxidant capacity of different organs of saffron, that every year a huge amount of them are wested during the processing of stigma. In this study, different parts of saffron were extracted by methanol (80%), then the amount of total phenol and flavonoid compounds was assayed by means of Folin-Ciocalteu and and Aluminium choloride methods respectively. The antioxidant activity was measured by DPPH free radical reduction. According to the results of this study, The highest content of total phenolic(6.43 mg GAE g-1 DW) and flavonoid (1.33 mg RU g-1 DW) was observed in stigma compared to other organs. The result of DPPH test also showed higher antioxidant capacity of stigma in comparison to other organs. Comparison of phenolic compounds in various organs showed that the content of these compounds and antioxidant activity could be different related to type of organs. Also, the higher antioxidant capacity in stigma and tepal compared to leaf and corm could be as a result of more phenolic compounds in these organs.