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Wild species are widely used as potential sources of resistance of tomato to late blight (LB) (causal agent Phytophthora infestans). The biochemical response of wild and cultivated tomato genotypes with different levels of resistance to P. infestans was assessed through the total phenolic and flavonoid content and antioxidative capacity. In total, six genotypes were included in the research – three cultivated tomato varieties and three wild species. The wild genotypes Solanum pimpinellifolium S 220 and Solanum habrochaites had a significantly lower infection rate compared to the other tested genotypes. After disease assessment on the leaves, biochemical analyses were performed. Grouping of the wild accessions according to principal component analysis (PCA) analysis indicated similar reaction to LB infection. Furthermore, late blight trait is closer to cultivated genotypes. Although the phenolics and flavonoids have high importance in the reaction of tomato plants to late blight infection, these traits are not closely related to wild species and the disease. According to this study, the antioxidative tests that indicate a response of wild species to late blight infection are total antioxidant activity (TAA), ferric-reducing antioxidant power (FRAP) and radical cation scavenging activity (ABTS). [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 31030]

Plants are a good source of natural antioxidants and could provide protection against harmful free radicals. Phenolic compounds were found to be an important part of human diet and are considered as active principles in many medicinal and agricultural plants. Detailed information about health-promoting components of different soybean cultivars could lead to a better understanding and an increased consumption of this crop, including its use in functional foods. The objective of this study was to determine total phenolics, total tannins, total flavonoids and antioxidant capacity with different assays of five Serbian soybean cultivars (Merkur, Sava, Valjevka, Venera and Victoria) extracted with three different solvents (70% acetone, 70% ethanol and 70% methanol). Total phenolics varied among cultivars and among applied solvents. Antioxidant properties highly depended on a solvent used for extraction. Such results highlight an existing variability in soybean seeds and emphasise the need to evaluate diversity and to support conventional breeding programs to improve soybean nutritional value.

Late blight (LB) caused by the Phytophthora infestans is a devastating tomato disease, distributed worldwide. Tomato wild species could be a potential source of resistance, however, there are little data about their biochemical response to LB infection. Therefore the aim of the study was to evaluate total phenolic and total flavonoid content and antioxidative activity in the leaves of wild (Solanum pimpinellifolium) and cultivated genotype (Bizon) depending on disease severity. S. pimpinellifolium compared to Bizon was less susceptible and had five times lower disease severity index (11% and 55% respectively). Additionally, during the disease progression wild genotype showed a much slower decrease of total biochemical parameters compared to the cultivated one. Parameters such as total phenolic content (TP), DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging test and ABTS (2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)) radical scavenging activity in the symptomless leaves and the leaves infection 10-25% remained the same in S. pimpinellifolium. The susceptible genotype Bizon had about 40% of leaves with the disease severity 25-50%, and a rapid decrease of all biochemical parameters. A strong negative correlation was observed between late blight infection and biochemical parameters in Bizon, while in S. pimpinellifolium late blight infection negatively correlated only with TP, TF (total flavonoid content) and total antioxidant activity (TAA). [ABSTRACT FROM AUTHOR]

Plants which belong to Lamiaceae family are good potential sources of natural antioxidants useful for preventing oxidative stress-related diseases. The food industry is becoming increasingly interested in aromatic herbs, including plants from Lamiaceae family, because of their anti- inflammatory properties and antioxidant activities, due to growing consumer demands for healthy foods of natural origin. In the present investigation, the comparative antioxidant potential of aqueous and acetone extracts of three Lamiaceae species are described: Clinopodium menthifolium (Host), Satureja montana L., and Salvia sclarea L., using three methods: 2,2–azinobis (3–ethyl–benzothiazoline– 6–sulfonic acid) radical (ABTS) scavenging, 1,1–Diphenyl– 2–picrylhydrazyl radical (DPPH) scavenging, and ferric reducing antioxidant power (FRAP) assay and their correlations with total phenolic and flavonoid contents. Antioxidant capacity showed a positive relationship comparing three above mentioned tests. Antioxidant capacity detected by antioxidant ABTS, DPPH, and FRAP assays was positively correlated with total phenolics content. Aqueous extract of C. menthifolium showed greater antioxidant potential. [ABSTRACT FROM AUTHOR]

Phenolic compounds such as polyphenols, tannins and flavonoids as well as antioxidant activity, play an important role in the plant defense mechanisms. The above mentioned parameters were measured in four sunflower hybrids (NORH-34, HOB-2, IMI-3-911 and NS-H-111) inoculated with broomrape (sunflower root parasitic plant). The synthesis and accumulation of these compounds depended on genotype and broomrape inoculation. Total phenolic content in healthy sunflower root tissue ranged from 2.87 up to 10.53 mg, while in infected root tissue this parameter ranged from 6.06 to 12.66 mg gallic acid equivalents/g dry root weight. Total tannins content in healthy root ranged from 2.01 to 6.74 and in infected root from 4.30 to 8.17 mg gallic acid equivalents/g dry root weight. Total flavonoids in healthy root tissue were within the range 3.36-44.94 and in infected root tissue 35.35-83.89 mg of rutin equivalents/g dry root weight. Antioxidant activity in sunflower roots correlated with the total phenolic and total tannins and flavonoids content. [ABSTRACT FROM AUTHOR]

Sweet and sour cherries are a valuable natural source of somebioactive compounds important in human health preservation. Total phenolics,tannins, flavonoids and anthocyanins, and antioxidant capacity in a fruits of atwo selected sweet cherry genotypes (Szomolyai Gombolyii and Valerij Cskalov)and 2 sour cherry cultivars (Érdi bőtermő and Kántorjánosi) were investigated.Total phenolic content ranged from 76.05 up to 301.19 mg gallic acidequivalents/100 g fresh fruit weight and total tannins content ranged from32.33 to 236.61 mg gallic acid equivalents/100 g fresh fruit weight. Totalflavonoids were within the range 49.47-70.27 mg of rutin equivalents/100 gfresh fruit weight and total anthocyanins content were between 16.86 and51.16 mg cyanidin 3-glucoside equivalents/100 g fresh fruit weight. Antioxidantactivity of sweet and sour cherries is correlated with the total phenolics andtotal tannins content, and partially related with total anthocyanins, but not withthe total flavonoids. Fruits of sour cherries contains more phenolics than fruitsof sweet cherries and possess more potent antioxidant activity. [ABSTRACT FROM AUTHOR]