جستجوی مقالات مرتبط با کلیدواژه « antioxidant compounds » در نشریات گروه « زیست شناسی »

In this research, in order to investigate the ethnopharmacological diversity, yield components and phytochemical characteristics of Viola species (Viola spp.) from 16 habitats in the north and northwest of Iran (Golestan, Mazandaran, Ardabil, East Azarbaijan and Kermanshah provinces), a research based on a completely Randomization was done with three replications. Ethnopharmacology information was obtained from local people and plant samples were collected from the mentioned habitats in the spring of 2018 at the time of flowering. At the same time, the samples of each barium were collected and prepared for identification at the species level and receiving the code. Soil samples were also taken from a depth of 0-30 for physical and chemical analysis, and the geographic coordinates and height were also recorded. The yield components and phytochemical characteristics (including chlorophyll a, b and total, carotenoid by spectrophotometer, total phenol by Folin-Siocatio colorimetric method, total flavonoid by aluminum-chloride colorimetric method, antioxidant compounds by ABTS and DPPH methods) of the collected samples were measured. As a result of the botanical investigation, it was found that 16 collected masses were related to five different species including V.odorata L., V.alba, V.suavis, V.sieheana and V.ignobilis. Ethnopharmacological results showed that in most regions this plant is called by the name of violet or something similar and it is used in the treatment of viral diseases such as colds. The analysis of the results showed that the characteristics of the habitat had a significant effect on all the components of the measured performance and phytochemical traits, so that the amount of chlorophyll and the dry weight of the aerial parts of the samples increased with the increase in the organic matter and nutrients of the soil. Also, with the increase in altitude, the amount of antioxidant compounds by ABTS and DPPH methods, phenolic and flavonoidic compounds increased in aerial parts, and the results of principal component analysis (PCA) also confirmed the obtained results. In the clustering that was done based on the two factors of yield and phytochemical components, it was found that the cluster decomposition for phytochemical characteristics was divided into 14 categories and for yield components into 9 categories at 0.2 Euclidean distance. The results of cluster analysis also showed that the climatic and edaphic characteristics of the habitat have a great effect on the yield components and phytochemical characteristics of the violet plant, which can determine the appropriate cultivation pattern.

Periploca aphylla is an evergreen plant and resistance to drought stress, which can grow in harsh environmental conditions in hot and dry areas of southern Kerman province, therefore, it plays an important role in preserving the environment as well as soil. In this study, soil ecological factors of plant distribution areas, plant morphology, and comparison of some antioxidant compounds in different plant organs were studied. The results showed that the plant distribution area possesses sandy, non-saline soils with neutral to slightly alkaline acidity and contains a good amount of macronutrients and micronutrients. The presence of relatively thick perianth with abundant hairs, in this plant, shows the adaptive properties to harsh environmental conditions. The released pollen grains from anther are tetrad and are bonded together by viscous materials to form pollinia. The gynoecium is a two-carpel that initially, the carpels are partially connected to each other and form two follicles fruits that develop at an angle of 180 degrees to each other. The highest total phenol and flavonoid content was observed in seeds and the highest total anthocyanin content was observed in flowers. Comparing the 8 phenolic compounds identified in different parts of the plant, the predominant phenolic compounds in shoots and seeds are hesperidin, in flowers and immature fruits, chlorogenic acid, and in mature fruits, Gallic acid. Comparing plant phenolic compounds, hesperidin and vanillin had the highest and lowest values, respectively. With respect to the fact that the various organs of this plant are rich in phenolic compounds; therefore, this plant species is introduced for use in the pharmaceutical industry.

Basil is an important medicinal plant, belonging to the Lamiaceae family. Basil is used for the treatment of different diseases such as stomachache, headache, constipation, fever and infections, as well as to reduce and regulate the blood sugar. Moreover, Basil is known for its antibacterial, antifungal and antioxidant properties. In this study, the impact of drought stress on phenols and flavonoids concentrations, as well as the antioxidant activities of leaf extract of three basil cultivars were investigated. Seeds of basil cultivars (mikhak, green, purple) were cultivated in sand-loamy soil and drought stresses (75%, 50% and 25% of the field capacity) were applied on six-leave plants. Experiments were conducted in a completely randomized design and three repeats. Total phenols, total flavonoids and flavonols concentrations of basil leaf extracts and their antioxidant activities were measured. The maximum values (with significant differences) of three groups of non-enzymatic antioxidants and the highest levels of antioxidant activities were observed for green cultivars under mild stresses (75% of the field capacity). It was observed that antioxidant activities were elevated by the increase of the concentration of the plant extract. Drought stress results in oxidative stress in basil plants. Phenols, flavonoids and flavonols are well-known as strong antioxidants have a role in the plant’s protection against the oxidative stress. In thrice cultivars of basil which were investigated, concentrations and abilities of these compounds to inhibit free radicals were decreased by the increase of the levels of drought stresses. It seems that both basil genotypes and drought stress levels affected the production of antioxidants studied and, consequently, have impacts on the plant inhibitory abilities against the oxidative stress.

Aim and Among more than 23,000 microbial secondary metabolites discovered, 42% of them are separated from actinobacteria. These secondary metabolites have wide range of biological activities such as antibacterial, antifungal, antiparasitic, antiviral, antitumor, immunosuppressive, insecticide, antiinflammatory, antioxidant and other activities. In the past few years, numerous studies have been conducted on these biological activities in the country, but no report has been published about the antioxidant activity of local actinomycetes resources. The purpose of this research is to achieve natural antioxidants with lower physiological hazards associated with local microbial resources. Fifty strains of native actinomycetes preserved at the University of Tehran Microorganism collection were selected randomly and after sporolation and prefermentation and fermentation, bacterial extracts were prepared. At first, antioxidant activity of the extracts was evaluated by DPPH method. These results were evaluated with synthetic antioxidants including ascorbic acid and BHA. Also cytotoxic activity of the extracts was measured on Artemia. Elected strains were recognized with molocular method. According to the results, 10% of extracts have no antioxidant activity, 20% of the extracts have high antioxidant activity (IC50<200), 32% of extracts with medium antioxidant activity (200

Metalloid arsenic is considered as one of the most important environmental contaminant compounds. Some plants with high concentrations of arsenic accumulation in their shoots، have the ability to purify arsenic-contaminated areas. Due to the chemical similarity between arsenic and phosphate، similar behavior has been observed by plant uptake system. In this study، hydroponic experiment was conducted on Isatis cappadocica، as a newly-discovered hyperaccumulator. Accordingly، we conducted this experiment to compare the interaction of arsenic and phosphorus on antioxidant compounds of I. cappadocica. Therefore، the plants were grown for 6 weeks in a medium، embedded with combinations of 50، 200، 800 and 1200 μmol arsenic and 5، 50، 200، 800 and 1600 μmol phosphorus، respectively. The dry weight، hydrogen peroxide، antioxidant compounds and the arsenic and phosphorus concentration of harvestable parts were determined. The highest concentration of arsenic was obtained in plants treated with 1200 μmol As and 5 μmol phosphorus. Along with a marked increase in arsenic concentration in the media، a built up hydrogen peroxide was observed. Increasing arsenic concentration in the medium lead to increase of antioxidant compounds (carotenoids، anthocyanin and flavonoid). The accumulation of more than 700 mg kg-1 arsenic in the shoots، demonstrated the high resistance of I. cappadocica to arsenic stress and the existence of efficient mechanisms for reduced oxidative stress.

Burdock (Arctium lappa L.) is an important medicinal plant containing arctiin and arctigenin، which are important secondary metabolits used as anticancer reagents. Due to the existence of important secondary metabolites in this plant، development of a reliable in vitro tissue culture and regeneration methods to facilitate genetic transformation in this plant is important. In the current study، for optimization of the callus induction، leaf، petiole and root explants of A. lappa were cultured in solid MS medium، which was supplemented with 0. 5% PVP (as an anti-oxidant) and different concentrations and combinations of BA and 2،4-D hormones. This study revealed that the petiole explants induced highest callus rate comparing to the other tested explants. In addition، two hormones combined concentrations of 0. 5 mg/L BA + 1. 0 mg/L 2،4-D and 1. 0 mg/L BA + 2. 0 mg/L 2،4-D، produced the highest amount of callus and were the most suitable treatments for the callus induction.