Pehuén (Araucaria araucana) seed residues are a valuable source of natural antioxidants with nutraceutical, chemoprotective and metal corrosion-inhibiting properties

• Published in: Bioorganic chemistry 2020-11, Vol.104, p.104175, Article 104175
• Main Authors: Gallia, María C., Bachmeier, Evelin, Ferrari, Ana, Queralt, Ignasi, Mazzeo, Marcelo A., Bongiovanni, Guillermina A.
• Format: Article
• Language: English
• Subjects: Animals; Anticorrosive; Antioxidants - chemistry; Antioxidants - isolation & purification; Antioxidants - pharmacology; Araucaria araucana - chemistry; Biological Products - chemistry; Biological Products - isolation & purification; Biological Products - pharmacology; Biphenyl Compounds - antagonists & inhibitors; Chlorocebus aethiops; Circular economy; Corrosion; Corrosive inhibitor; Cyclophosphamide; Dietary Supplements; Dose-Response Relationship, Drug; EDXRF; Green chemistry; Male; Molecular Structure; Natural product; Picrates - antagonists & inhibitors; Protective Agents - chemistry; Protective Agents - isolation & purification; Protective Agents - pharmacology; Quercetin; Rats; Rats, Wistar; Seeds - chemistry; Structure-Activity Relationship; Tannins; Vero Cells; Waste
• ISSN: 0045-2068; 1090-2120
• DOI: 10.1016/j.bioorg.2020.104175

[Display omitted] •The Pehuén (Araucaria araucana) is a prehistoric tree adapted to hostile environments.•97% of antioxidant power in piñón were in its coat, which is discarded as waste.•Piñón coat extract increases antioxidant defenses of cyclophosphamide treated rats.•Piñón extract inhibits more than 60% of the acid corrosion of steel.•The valorization of piñón waste expands possible applications in industrial fields. In the last decade, green chemistry has been attracting great interest in many contexts, including, among others, natural antioxidants. However, only a few works deal with natural residue extracts and biowaste, which could be an efficient, economical and environmentally friendly source for the production of useful compounds. In this study, we look for antioxidant activity in Araucaria araucana seeds, an iconic pine species of the Argentine and Chilean Patagonia commonly known as “pehuén”. Piñones are the edible pehuén seeds, and it is estimated that approximately 40 tons of piñones are harvested annually in Argentina and Chile. The chemical composition, antioxidants, metal corrosion-inhibiting properties and biological activity of edible and discarded piñón tissues were determined. Acute toxicity was discarded by in vitro testing and double fluorescent staining. Biological activity was evaluated in vivo by determining redox markers in salivary glands from rats treated with Cyclophosphamide (an oncological drug). All piñón tissues had antioxidants and antioxidant activity, with the coats showing the highest levels (up to 404 µg ascorbic acid equivalent per mg). The coats, in particular, had high gallic acid, catechin, quercetin and tannin contents, and more antioxidant activity, polyphenols and flavonoids than berries from the region. Results by X-ray fluorescence spectrometry showed that Na, Mg, P, S, Cl, K, and Ca were majority elements in the coat, embryo and endosperm. Furthermore, coat extract also showed significant anti-corrosion activity and in vivo protection against oxidative damage. The results indicate that piñón biowaste is a low-cost attractive source of natural antioxidants with potential nutraceutical, medical and metal corrosion protection applications.