A Comprehensive Study on the Chemical Characterization and Neuroprotective Evaluation of Pracaxi Nuts Extracts Obtained by a Sustainable Approach.

The Amazonian Pentaclethra macroloba (Willd.) Kuntze nuts contain a lipidic fraction with health-promoting effects, but little is known about the bioactivity of other constituents. In this study, the lipidic fraction obtained using supercritical fluid extraction (SFE) with CO2 was chemically characterized by using lipidomics techniques. The SFE-CO2 residue, named as pracaxi cake, was re-extracted by pressurized liquid extraction following a biorefinery approach. Using a response surface methodology and based on the extraction yield and different in vitro assays, two optimum conditions were obtained: 80% and 12.5% of ethanol at 180 °C. Under these conditions, extraction yield and different in vitro measurements related to neuroprotection were assessed. Chemical characterization of these extracts suggested the presence of triterpenoid saponins and spermidine phenolamides, which were not previously reported in pracaxi nuts. These results suggest that pracaxi oil extraction by-products are a valuable source of bioactive compounds with neuroprotective potential.

Chemical Fingerprinting, Aorta Endothelium Relaxation Effect, and Enzymatic Inhibition of Canelo (Drimys winteri J. R. Forst. & G. Forst, (D.C) A. Gray, Family Winteraceae) Fruits.

Drimys winteri J.R. Forst. & G. Forst (D.C) G. Gray, var. chilensis (canelo) is an endemic tree from Chile. Since pre-Columbian times, it has produced a fruit known as the canelo pepper, (pimienta de canelo) or Foye pepper, which can be used as a spice. The chemical and biological analysis of canelo fruits is reported for the first time in this study, that is, its phenolic fingerprinting by UHPLC-PDA- Q-orbitrap MS, the antioxidant activity, the enzymatic inhibitory activity, and its relaxation effects on rat aorta. The proximal composition and the mineral content (Ca: 1.45 ± 0.03 mg/100 g; Mg: 7.72 ± 0.03 mg/100 g; Fe: 4.54 ± 0.21 mg/100 g; Zn: 2.99 ± 0.02 mg/100 g; Mn: 1.08 ± 0.03 mg/100 g; Cu: 0.82 ± 0.02 mg/100 g; K: 53.03 ± 0.20 mg/100 g; Na: 0.087 ± 0.00 mg/100 g) are also reported. The canelo fruits showed a total phenolic content of 57.33 ± 0.82 mg GAE/g dry weight. In addition, the total flavonoid content was 38.42 ± 1.32 mg equivalent of QE/g dry weight. The antioxidant activity was evaluated by employing DPPH and ABTS methods (IC50 of 6.65 ± 0.5 and 9.5 ± 0.05 µg/mL, respectively), ORAC (25.33 ± 1.2 µmol Trolox/g dry plant) and FRAP (45.56 ± 1.32 µmol Trolox/g dry plant). The enzymatic inhibition of acetylcholinesterase, butyrylcholinesterase, and tyrosinase (IC50: 1.94 ± 0.07, 2.73 ± 0.05, and 9.92 ± 0.05 µg extract/mL, respectively) is also reported. Canelo extract led to an 89% relaxation of rat aorta. Our results confirm that D. winteri fruits are a rich source of secondary metabolites and can inhibit enzymes associated with neurodegenerative diseases; the results also suggest that canelo may induce a potentially hypotensive effect in rat aorta. The study demonstrates the medicinal properties of canelo fruit and spice.

UHPLC-MS Phenolic Fingerprinting, Aorta Endothelium Relaxation Effect, Antioxidant, and Enzyme Inhibition Activities of Azara dentata Ruiz & Pav Berries.

Azara dentata Ruiz & Pav. is a small Chilean native plant from Patagonia, a producer of small white reddish berries. For the first time, the proximal analysis of the fruits, phenolic fingerprinting, the antioxidant activity, and the enzymatic inhibition and relaxation effects in rat aorta induced by the ethanolic extract of these fruits were investigated. The proximal composition and the mineral (Ca: 2434 ± 40 mg/kg; Mg: 702 ± 13 mg/kg; Fe: 117.1 ± 1.6 mg/kg; Zn: 16.1 ± 0.4 mg/kg) and heavy metal (As: 121 ± 11 µg/kg; Cd: 152 ± 5 µg/kg; Hg: 7.7 ± 1.3 µg/kg; Pb 294 ± 4 µg/kg) contents were analyzed. Anthocyanins, flavonoids, phenolic acids, and coumarins were identified using UHPLC-PDA-QTOF-MS. The ethanolic extracts showed a total phenolic content of 23.50 ± 0.93 mg GAE/g extract. In addition, the antioxidant activity was assessed using both DPPH and TEAC (28.64 ± 1.87 and 34.72 ± 2.33 mg Trolox/g of dry fruit, respectively), FRAP (25.32 ± 0.23 mg Trolox equivalent/g dry fruit), and ORAC (64.95 ± 1.23 mg Trolox equivalents/g dry fruit). The inhibition of enzymatic activities (acetylcholinesterase IC50: 2.87 + 0.23 µg extract/mL, butyrylcholinesterase IC50: 6.73 + 0.07 µg extract/mL, amylase IC50: 5.6 ± 0.0 µg extract/mL, lipase IC50: 30.8 ± 0.0 µg extract/mL, and tyrosinase IC50: 9.25 ± 0.15 µg extract/mL) was also assessed. The extract showed 50-60% relaxation in rat aorta (intact), mediated thorough the release of endothelial nitric oxide. Our results suggest that A. dentata is a good source of compounds with the capacity to inhibit important enzymes, can be hypotensive, and can thus have good potentiality as supplements in the amelioration of neurodegenerative diseases and could also have potential to be used to develop new functional foods. The study highlights the benefits of these neglected small fruits and could boost their consumption.

Phenolic Fingerprinting and Bioactivity Profiling of Extracts and Isolated Compounds from Gypothamnium pinifolium Phil.

Gypothamnium pinifolium Phil. (Asteraceae) is a small shrub that grows in the Paposo Valley of the II Antofagasta Region of Chile. This initial study is of the high-resolution phenolic fingerprinting, antioxidant activity, the relaxation effects in rat aorta, the inhibitory enzyme potential, plus the antiproliferative activity of the ethyl acetate and n-hexane extract from G. pinifolium and its two major isolated secondary metabolites (one coumarin: 2-nor-1,2-secolycoserone, and one diterpene: ent-labda-8,13-E-diene-15-ol). The study involves using ultra-high-performance liquid chromatography todiode array detection coupled with Q-Orbitrap mass spectrometry analysis (UHPLC-PDA-Orbi-trap-MS), in which various compounds were identified, including specific coumarins. The n-hexane extract showed total phenolic and flavonoid contents of 517.4 ± 12.5 mg GAE/100 g extract and 72.3 ± 3.7 mg QE/100 g extract, respectively. In addition, the antioxidant activity of the n-hexane extract was assessed using in-vitro assays such as bleaching of DPPH and ABTS (IC50: 14.3 ± 0.52 and 2.51 ± 0.43 µg extract/mL, respectively), FRAP (347.12 ± 1.15 µmol Trolox equivalent/g extract), and ORAC (287.3 ± 1.54 µmol Trolox equivalents/g extract). Furthermore, the inhibition against cholinesterases (acetylcholinesterase (AChE) 4.58 ± 0.04 µg/mL, butyrylcholinesterase (BChE) IC50: 23.44 ± 0.03 µg/mL) and tyrosinase (IC50: 9.25 ± 0.15 µg/mL) enzymes of the n-hexane extract, and main compounds (IC50: 1.21 ± 0.03 µg/mL, 11.23 ± 0.02 µg/mL, 3.23 ± 0.12 µg/mL, and 103.43 ± 16.86 µg/mL, correspondingly for the most active coumarin 1) were measured. The antiproliferative potential of the extracts and the two principal compounds against several solid human cancer cells was investigated. All of them showed good activity against cancer cells. Label-free live-cell imaging studies on HeLa cells exposed to the isolated coumarin and the diterpene enabled the observation of cell death and several apoptotic hallmarks. Our results indicate that G. pinifolium Phil. is a valuable source of secondary metabolites with potential activity against noncommunicable diseases.

Chemical Fingerprinting and Biological Evaluation of the Endemic Chilean Fruit Greigia sphacelata (Ruiz and Pav.) Regel (Bromeliaceae) by UHPLC-PDA-Orbitrap-Mass Spectrometry.

Greigia sphacelata (Ruiz and Pav.) Regel (Bromeliaceae) is a Chilean endemic plant popularly known as "quiscal" and produces an edible fruit consumed by the local Mapuche communities named as "chupón". In this study, several metabolites including phenolic acids, organic acids, sugar derivatives, catechins, proanthocyanidins, fatty acids, iridoids, coumarins, benzophenone, flavonoids, and terpenes were identified in G. sphacelata fruits using ultrahigh performance liquid chromatography-photodiode array detection coupled with a Orbitrap mass spectrometry (UHPLC-PDA-Orbitrap-MS) analysis for the first time. The fruits showed moderate antioxidant capacities (i.e., 487.11 ± 26.22 µmol TE/g dry weight) in the stable radical DPPH assay, 169.08 ± 9.81 TE/g dry weight in the ferric reducing power assay, 190.32 ± 6.23 TE/g dry weight in the ABTS assay, and 76.46 ± 3.18% inhibition in the superoxide anion scavenging assay. The cholinesterase inhibitory potential was evaluated against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). From the findings, promising results were observed for pulp and seeds. Our findings suggest that G. sphacelata fruits are a rich source of diverse secondary metabolites with antioxidant capacities. In addition, the inhibitory effects against AChE and BChE suggest that natural products or food supplements derived from G. sphacelata fruits are of interest for their neuroprotective potential.

Chemical Fingerprinting, Isolation and Characterization of Polyphenol Compounds from Heliotropium taltalense (Phil.) I.M. Johnst and Its Endothelium-Dependent Vascular Relaxation Effect in Rat Aorta.

Heliotropium taltalense is an endemic species of the northern coast of Chile and is used as folk medicine. The polyphenolic composition of the methanolic and aqueous extract of the endemic Chilean species was investigated using Ultrahigh-Performance Liquid Chromatography, Heated Electrospray Ionization and Mass Spectrometry (UHPLC-Orbitrap-HESI-MS). Fifty-three compounds were detected, mainly derivatives of benzoic acid, flavonoids, and some phenolic acids. Furthermore, five major compounds were isolated by column chromatography from the extract, including four flavonoids and one geranyl benzoic acid derivative, which showed vascular relaxation and were in part responsible for the activity of the extracts. Since aqueous extract of H. taltalense (83% ± 9%, 100 µg/mL) produced vascular relaxation through an endothelium-dependent mechanism in rat aorta, and the compounds rhamnocitrin (89% ± 7%; 10-4 M) and sakuranetin (80% ± 6%; 10-4 M) also caused vascular relaxation similar to the extracts of H. taltalense, these pure compounds are, to some extent, responsible for the vascular relaxation.