جستجوی مقالات مرتبط با کلیدواژه "اسیدهای فنولیک" در نشریات گروه "کشاورزی"

In the present study, the effect of drying methods on the bioactive compounds of the two salvia spieces,Salviaofficinalis  andsalvia nemorosa,was investigated. The experiment was performed as a factorial experiment with two factors in a randomized complete block design with three replications. The first factor was two species of salvia and the second factor was drying method in 4 levels of shade drying for 144 hours, drying under the sun irradiation for 78 hours and drying in oven at 40 and 70°C for 37 and 6 hours, respectively. With concidering two levels for the first factor and four levels for the second factor, 8 treatments were studied in the experiment. The results showed that the highest extract yield (11%) was obtained from samples which dried in the oven with 70°C and in both species with a higher rate inS.nemorosa. The percentage of weight loss was not affected by drying methods but it affected by species andS.officinalis had the highest weight loss compared to another specie. High value of total phenolic compounds, total flavonoids, total tannin and antioxidant properties of two speiceswere found in samples dried in shade, and the lowest value of these traits were recorded in plants which dried in the oven at 70°C. High contents of phenolic acids including chlorogenic acid, caffeic acid, rosmarinic acid and salvainolic acidwere recorded  in both species which dried at shade condition and the lowest amount were found in samples dried in oven at 70°C. Also, salvainolicacid and rosmarinic acid was recorded at high level of phenolic acids in samples dried at shad condition.By comparing breeded (S. officinalis) and native species (S. nemorosa), it was found that the native species can have outstanding features for domestication, improvement and further research.

The phonological stage in which the abotic stress occurs is effective in determining the content of secondary metabolites in medicinal plants. This research deals with the effects of imposing drought stress at different phenological stages on growth and some physiological and phytochemical responses of Nepeta crispa L as a split plot design in Bu-Ali Sina University during 2019. Drought stress at three levels, including mild, moderate, and severe stress (with 80%, 60%, and 40% of field capacity, respectively) has been applied at two phenological stages (seedling establishment stage with 6 true leaves and pre-flowering stages). Results from statistical analysis show that drought stress has had a significant effect on all evaluated growth traits and phytochemical parameters of the plant including proline content, relative water content (RWC) of leaves, total phenols, flavonoids, tannins, antioxidant activities, and phenolic acids. Imposing drought stress at both phenological stages reduce plant growth, decreasing chlorophyll content and RWC. However, production of phenolic compounds and phenolic acids (including rosmarinic, chlorogenic and caffeic acids) at high level and accumulation of proline through imposing drought stress reduce the adverse effects of stress and increase the medicinal properties of the Nepeta crispa. Also, the effect of drought stress imposing at pre-flowering stage has been greater than its application in the seedling establishment stage. According to the results, it is recommended to impose moderate drought stress at pre-flowering stage to increase biosynthesis of some phytochemical compounds in Nepeta crispa medicinal plants.