Chemical Composition, Antimicrobial Activity, and Antioxidant Activity of Ocotea minarum (Nees & Mart.) Mez.

Abstract

Ocotea minarum is a native plant from Brazil, popularly known as “canelinha” or “canela vassoura.” The objective of this study was to investigate the chemical composition of the extracts of the bark and the leaves of O. minarum and to evaluate its antimicrobial and antioxidant activities. The phenolic compounds, flavonoids and tanins, were quantified with the reagents Folin-Ciocalteu, aluminium chloride, and vanillin. The chemical profile was performed by HPLC-DAD. The minimum inhibitory concentration was evaluated by the microdilution in a broth method. The antioxidant activity was measured by the capture of free radicals 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid). In addition, protection against oxidative hemolysis and generation of malondialdehyde were evaluated in human erythrocytes. The composition of the extracts included the caffeic acid, p-coumaric acid, and rosmarinic acid, besides the flavonoids quercetin and luteolin. The EEL showed bacteriostatic action of 1000 μg/mL for all evaluated Salmonella Typhimurium, Salmonella Enteritidis, Pseudomonas aeruginosa, and Proteus mirabilis, and the EHEB had a moderate antifungal action against Candida krusei and Cryptococcus gattii (250 μg/mL). IC50 values of 8.19 (EEL) and 4.51 μg/mL (EEB) in the assay with DPPH and 6.25 (EEL) and 2.87 μg/mL (EEB) in the assay with ABTS were obtained. Up to the 3rd hour of oxidative hemolysis testing induced by AAPH, the EEB and EEL had a protective action, reducing the malondialdehyde. In conclusion, the data indicate that the O. minarum extracts can be evaluated as bioactive supplies for the development of new drugs for the prevention and treatment of diseases related to oxidative stress and microbial infections.

Optimization of ultrasound‐assisted extraction conditions for phenolics, antioxidant, and tyrosinase inhibitory activities of Vietnamese brown seaweed (Padina australis)

“…Antioxidants are often used to control the production of these substances. They act by neutralizing or capturing oxidative species, thus minimizing oxidative tissue damage (Rodrigues et al., 2019). Generally, natural antioxidants have considerably low toxicity in addition to being readily biodegradable, making them an effective substitute for synthetic antioxidants.…”

Insecticidal activity of Ageratina adenophora (Asteraceae) extract against Limax maximus (Mollusca, Limacidae) at different developmental stages and its chemical constituent analysis

“…The corresponding reagent without rutin served as the blank reference. The absorbance (OD) value was read at 410 nm using a full-wavelength microplate reader, and the standard curve was calculated [ 16 ]. For the color operation, 1.0 mL of the sample solution was used, and the OD value was determined at a wavelength of 410 nm using a full-wavelength enzyme labeling instrument.…”

Insecticidal activity of Ageratina adenophora (Asteraceae) extract against Limax maximus (Mollusca, Limacidae) at different development stages and its chemical constituent analysis

“…In order to distinguish the types of tannins (condensed or hydrolyzed), colorimetric tests were carried out with ferric chloride (FeCl 3 ) at 2% concentration. In order to quantify condensed tannins, the Stiasny method [14] was used and repeated three times, and the existence of tannins was con rmed by the turbidity of the water extract.…”