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Aqueous and hydro-ethanolic extracts of Bauhinia microstachya leaves (AEBM and HEBM) were investigated for their phenolic content and phytochemical profile (by spectrophotometry and HPLC), and for their antioxidant activities and free radical scavenging potential in different in vitro systems (TRAP, TEAC, TBARS, nitric oxide, superoxide and hydroxyl radical). HEBM presented a 27.4% higher content of phenolics when compared to AEBM and a distinct phytochemical profile was observed. Our work suggests that both extracts have potent antioxidant activities and that their antioxidant capacity and efficiency vary according to the radical-generating system. In general, HEBM was more effective than AEBM in avoiding ROS-generating damage and in scavenging the various radicals formed. Nevertheless, when results were normalized to total phenolic content, a different profile of antioxidant activities and free radical scavenging potential was observed, particularly against oxidative lipid damage and superoxide radical. B. microstachya extracts may be considered an interesting source of natural antioxidants as well as other phenolic-rich plants.

Fruits of Myrcianthes pungens Berg. Legr. (Myrtaceae), known as guabiju, are widely consumed fresh as well as dried, processed into jam, marmalade, and juices. In this study, chemical composition and antichemotactic and antioxidant activities of fruits from a wild type (GB) and 2 genotypes, PL2 and PL1, of guabiju were investigated. Total anthocyanins for the genotypes ranged from 334 to 531 mg/100 g dry weight (dwt). Total flavonoids and polyphenols ranged from 79.8 to 154 mg/100 g and 2438 to 4613 mg/100 g (dwt), respectively. A reversed phase liquid chromatography method with photodiode array detection was used to determine chemical profiles of the main anthocyanins found in the extracts. An HPLC method for the quantification of flavonoids is proposed, providing a simple procedure with rapid sample preparation. All samples contained 5 identical anthocyanidins, distributed differently, with cyanidin as the main compound. Identified flavonoids were quercitrin, hyperoside, and isoquercitrin; their relative amounts varied among the extracts. The antioxidant activity of guabiju methanolic extract was comparable to that of Trolox, and at a test concentration of 0.25 mg/mL, GB and PL2 activities were higher than those exhibited by Trolox. Total dry extracts of guabiju exhibited greater inhibition of chemotaxis at a concentration of 4 μg/mL, except for GBH (wild-type hydrolyzed extract) which already presented high values at a concentration of 2 μg/mL. These results suggest that the consumption of this fruit, rich in polyphenols, may be beneficial to human health. Practical Application: The paper is the first attempt on the improvement of this native fruit, since it is widely consumed regularly as part of the South American diet. The content of phenolic compounds demonstrates that consumption of guabiju would be beneficial to human health. Differences among samples, originating from open pollination of plants growing on the same site, lead to the conclusion that improvements can be made in the chemical composition and beneficial activity of guabiju fruits by simply selecting genotypes for these characteristics among open-pollinated seedlings. [ABSTRACT FROM AUTHOR]