Antioxidant Activity Of Metabolites Research Articles

Seasonal variation influences flavonoid biosynthesis path and content, and antioxidant activity of metabolites in Tetrastigma hemsleyanum Diels & Gilg.

Environmental conditions contribute to plant growth and metabolism. This study aimed to determine a suitable environment and climate for large-scale artificial cultivation of an endangered plant, Tetrastigma hemsleyanum, by investigating the seasonal variations influencing the flavonoid biosynthetic selectivity and antioxidant activity of its major metabolites. Under conditions of precipitation (2.0~6.6 mm), temperature (17.5~24.1°C), humidity (67.3~80.2%), and sunshine duration (3.4~5.8 h) from April to May, the total flavonoid content in T. hemsleyanum reached higher levels between 281.3 and 392.8 μg/g. In the second half of April, the production selectivity (PS) of isoorientin (IsoO), orientin (Or), rutin (Rut), isoquercitin (IsoQ), kaempferol-3-O-rutinoside (Km3rut), astragalin (Ast), quercetin (Qu), apigenin (Ap), and kaempferol (Km) were 0.30, 0.06, 0.07, 0.07, 0.00, 0.04, 0.38, 0.05, and 0.03, respectively. Naringenin was dehydrogenated or hydroxylated to initiate two parallel reaction pathways for flavonoid biosynthesis in T. hemsleyanum: path I subsequently generated flavone derivatives including apigenin, luteolin, orientin, and isoorientin, and path II subsequently generated flavonol derivatives including Km, Qu, IsoQ, Rut, Ast, and Km3rut. The reaction selectivity of path II (RPSII) from January 1 to September 30 was considerably higher than that of path I (RPSI), except for March 16–31. In addition, either the content or antioxidant activity of three major metabolites in T. hemsleyanum followed the order of phenolic compounds > polysaccharides > sterols, and exhibited dynamic correlations with environmental factors. Naringenin favored hydroxylation and derived six flavonol compounds from January to September, and favored dehydrogenation and derived three flavone compounds from October to December. In most months of a year, Km preferentially favored hydroxylation rather than glucosylation.

Chemical composition and nutritional function of olive (Olea europaea L.): a review

The olive (Olea europaea L.) is a widely-distributed plant that originated in the Mediterranean region. Its fruit is commonly used to produce olive oil, table olives, and other by-products. The main nutrient of the olive fruit is fat, predominantly monounsaturated fatty acids (MUFA). Olives are also rich in carbohydrates, vitamins, and minerals. Increasing numbers of investigations show that the health benefits of the ‘Mediterranean diet’ are associated with lower incidences of chronic degenerative diseases and higher life expectancy. These benefits have been attributed to the dietary consumption of olive oil. Furthermore, epidemiological data suggest that phenolic components and other antioxidants in olive oil are responsible for some of these benefits. Remarkably, these minor components play significant roles in reducing the incidences of atherosclerosis, cardiovascular disease, neurodegenerative diseases, and certain types of cancer. We reviewed the main olive products and the nutritional composition of olive oil focusing on fatty acids, phenolic compounds, and other antioxidants. We also discuss the chief chemical constituents relevant to the biological activity of olive oil, the metabolism and bioavailability of olive oil phenolic compounds, and the antioxidant activity of metabolites. Finally, we outline recent advances, potential applications, and limitations of developments in the olive oil industry, aiming to provide a theoretical basis for further research and to broaden the prospect of its application to healthy diets.

Anti-phytopathogen, multi-target acetylcholinesterase inhibitory and antioxidant activities of metabolites from endophytic Chaetomium globosum

Fourteen metabolites with various structure types were isolated from endophytic Chaetomium globosum. Five compounds were separated from genus Chaetomium for the first time. Some compounds exhibited remarkable inhibition against phytopathogenic fungi causing root rot of Panax notoginseng. Compounds 1–5 had significant DPPH-free radical-scavenging activity. Compounds 3 and 5 indicated significant inhibitions against the acetylcholinesterase (AChE). From preliminary structure–activity relationship, it was found that the oxygenic five-membered ring of 3 and 5 was crucial in the anti-AChE activity. These structures provide new templates for the potential treatment and management of plant diseases and Alzheimer disease.