Eucryphia cordifolia extracts: Phytochemical screening, antibacterial and antioxidant activities

Abstract

Eucryphia cordifolia is a native and dominant species from the Temperate Forest in the southern region of Chile. It is a crucial melliferous species producing unifloral honey with outstanding antibacterial properties with great commercial value at international markets. A phytochemical screening was developed by colorimetric and gravimetric methods.Antioxidant activities were assessed by using 2,2diphenyl-1-picrylhydrazyl (DPPH), 2,2azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and ferric ion reducing antioxidant power (FRAP) method. The minimum bactericidal concentration (MBC) was the method used to determine the antibacterial activity. The results revealed the highest antioxidant activity for the methanolic extracts of branches (IC50 35.7 µg/mL for DPPH, IC50 11.0 µg/mL for ABTS, and 4.6 mM FeSO4•7H2O/g in FRAP), attributed to its high content of total phenols (332.8 mg GAE/g). The quantification of the MBC led to values in the range of 0.78-12.5 mg/mL for S. aureus and S. pyogenes, and 6.25-50 mg/mL for E. coli and P. aeruginosa, respectively. The presented work provides valuable first in vitro evidence regarding the potential application of E. cordifolia extracts as antioxidants and antibacterial agents in the nutraceutical and phytopharmaceutical industry.

Chemical, antioxidant, and antifungal analysis of oregano and thyme essential oils from Ecuador: Effect of thyme against Lasiodiplodia theobromae and its application in banana rot

“…Subsequently, absorbance was measured at 517 nm in a microplate reader (Cytation™ 5, BioTek). A calibration curve with Trolox was used, and the results were expressed in mg Trolox equivalent/g extract, calculated according to the equation y = 0.6467X + 31.252 (R 2 = 0.9939) adding the blank [ 28 ]. To calculate the IC 50 of the essential oils, a serial dilution (4000 at 31.5 ppm) was performed, plotting a curve with the logarithm of the concentration versus the percentage of antioxidant activity.…”

“…Antioxidant capacity was measured using the iron reduction method described by Viteri et al [ 28 ]. The FRAP complex was prepared using 300 mM acetate buffer (pH 3.6), a solution of TPTZ (10 mM) dissolved in 40 mM hydrochloric acid, and a solution of ferric chloride (20 mM), in a 10:1:1 ratio (v/v/v).…”

Estudio de la variabilidad en el tiempo y espacio de la actividad antioxidante y composición bioquímica de Kappaphycus alvarezii en diferentes densidades de siembra

“…El contenido de flavonoides se estimó según el método de Avramova et al 40 . Se hicieron reaccionar 20 µL de muestra con 200 μl de la mezcla de reactivos preparado por separado con etanol absoluto, cloruro de aluminio al 10 %, Figura 2.…”

Condiciones óptimas de extracción de compuestos antioxidante del alga roja Acanthophora spicifera

“…Se midió la capacidad de captación de radicales libres DPPH de los extractos descrita por Viteri et al,2021 20 en una placa de 96 posillos, después de 30 minutos de incubación en oscuridad se midió la absorbancia a 517 ηm usando un Lector multi-modal Synergy HTX con detector UV-VIS (Biotek).…”

“…Se midio la actividad inhibidora del radical catiónico ABTS de los extractos descrita por Viteri et al,2021 20 en una placa de 96 posillos, se incubo durante 30 min y se midió la absorbancia en una longitud de onda de 732 ηm. Los resultados de la actividad antioxidante fueron expresados como µmol equivalentes de Trolox por gramo de peso seco (µmol TE).…”