Antrocaryon amazonicum: An unexploited Amazonian fruit with high potential of scavenging reactive oxygen and nitrogen species.

Antrocaryon amazonicum fruits are unexploited sources of bioactive compounds found in the Amazonia region of Brazil. In this study, for the first time, the carotenoid and phenolic compound profiles of the pulp and peel of A. amazonicum fruits, from two varieties at two harvest periods, were determined by LC-MS. Additionally, the potential of the peel and pulp extracts to scavenge physiologically relevant reactive oxygen species (ROS) and reactive nitrogen species (RNS) was assessed. The major carotenoids in both parts of the fruits were lutein, accounting for ≈42% of the identified carotenoids in the peel and ≈25% in the pulp, whereas catechin and hydroxybenzoic acid derivatives were the major phenolics in both parts. The peel extract, which presented the highest bioactive compound contents, was more efficient to scavenge ROS than the pulp. The peel extract showed high scavenging efficiency (IC50 ) for singlet oxygen (1 O2 ; 16 µg/ml), hypochlorous acid (HOCl; 20 µg/ml), peroxynitrite (ONOO- ; 38 µg/ml), and superoxide radical (O2 •- ; 47 µg/ml), whereas the pulp extract exhibited high efficiency for ONOO- (13 µg/ml), followed by HOCl (30 µg/ml), ¹O2 (76 µg/ml), and less efficient for O2 •- (44 µg/ml). Therefore, A. amazonicum fruits can be seen as an expressive source of bioactive compounds with high antioxidant potential to be further investigated to inhibit or delay oxidative processes both in food and physiological systems triggered by ROS and RNS. PRACTICAL APPLICATION: Bioactive compound extracts of Antrocaryon amazonicum fruits have high potential to be exploited for inhibiting or delaying oxidative processes and increase food stability.

Profile of phenolic compounds and carotenoids of Arrabidaea chica leaves and the in vitro singlet oxygen quenching capacity of their hydrophilic extract.

Arrabidaea chica (Brazilian name = pariri) is a plant species that belongs to the Bignoniaceae family, occurring in tropical America and widespread in the Amazonian region of Brazil. In this study, the phenolic compound and carotenoid profiles of A. chica leaves were determined by HPLC-DAD-MS. Scutellarin was identified as the main phenolic compound (15,147.22 µg/g, dry basis, d.b.) and lutein (204.28 µg/g, d.b.), ß-carotene (129.5 µg/g, d.b.) and α-carotene (79.86 µg/g, d.b.) as the major carotenoids. Moreover, A. chica leaves presented 152.7 µg/g of ascorbic acid (fresh weight). For the first time, the carotenoid profile and ascorbic acid contents were reported for A. chica leaves. Regarding the antioxidant capacity, A. chica extract was able to scavenge ABTS radical (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)), and for the first time, the protective effect against singlet oxygen (1O2) was reported. The A. chica extract was efficient as ABTS radical scavenger (86.81 µM Trolox/g of fresh leaves) and inhibited the degradation of tryptophan by 1O2 in a concentration-dependent manner with an IC50 at 177 µg/mL. Thus, A. chica leaves can be exploited as a promising source of bioactive compounds that may be useful to human health or food systems against oxidative damage.