The Ultrasound-Assisted Extraction of Polyphenols from Mexican Firecracker (Hamelia patens Jacq.): Evaluation of Bioactivities and Identification of Phytochemicals by HPLC-ESI-MS

Abstract

The objective of the present work was to optimize the extraction of phytochemicals from Hamelia patens Jacq. by ultrasound-assisted extraction. Taguchi L9 orthogonal array was used to evaluate the factors solid/liquid ratio (1:8, 1:12, and 1:16), extraction time (10, 20, and 30 min), and ethanol concentration (0, 35, and 70%). Total polyphenols were the response variable. Chromatographic fractionation using Amberlite XAD-16 was carried out and the total polyphenols, flavonoids, and condensed tannins were quantified. The redox potential, the reduction of the 2,2-diphenyl-1-picrylhydrazyl (DPPH), and the lipid oxidation inhibition were determined. Anti-bacterial activity was evaluated. The phytochemicals were identified by liquid chromatography coupled to mass spectrometry. Optimal extraction conditions were a solid/liquid ratio of 1:16, ethanol of 35%, and 10 min of ultrasound-assisted extraction. Maximum polyphenol content in the crude extract was 1689.976 ± 86.430 mg of gallic acid equivalents (GAE)/100 g of dried plant material. The purified fraction showed a total polyphenols content of 3552.84 ± 7.25 mg of GAE, flavonoids 1316.17 ± 0.27 mg of catechin equivalents, and condensed tannins 1694.87 ± 22.21 mg of procyanidin B1 equivalents, all per 100 g of purified fraction. Its redox potential was 553.93 ± 1.22 mV, reducing 63.08 ± 0.42% of DPPH radical and inhibiting 77.78 ± 2.78% of lipid oxidation. The polyphenols demonstrated antibacterial activity against Escherichia coli, Klebsiella pneumonia, and Enterococcus faecalis. The HPLC-ESI-MS analysis revealed the presence of coumarins, hydroxycinnamic acids, and flavonoids.

The Insecticidal Activity of Azadirachta indica Leaf Extract: Optimization of the Microencapsulation Process by Complex Coacervation

“…The neem phytochemicals are extracted by using organic solvents such as ethanol, and the extracts have shown insecticidal activity [ 31 ]. Ethanol is a good option for the extraction of bioactive compounds since it is a no-harm solvent and is generally recognized as safe (GRAS) [ 29 ]. It is important to mention that in the present work, the organic solvent was fully recovered using a rotary evaporator.…”

“…The solid-to-liquid ratio is also an important factor in the extraction process. This factor ranges from 1:10–1:16 w / v for the extraction of phytochemicals [ 27 , 29 ]. Thus, in the present study, we decided to use a solid-to-liquid ratio of 1:12 w / v .…”

“…The filtrate was concentrated in a rotavapor (Model R-200, Buchi, Flawil, Switzerland) by completely evaporating the ethanol. The total polyphenols concentration of the extract was quantified as reported by [ 29 ]. The gallic acid standard curve (0–100 μg/mL) was used as a reference.…”

“…The methodology includes the use of orthogonal arrays that reduce the time and cost of the process by reducing the experimental runs. Furthermore, the Taguchi methodology improves the quality of the tested processes due to the versatile analyzing models [ 29 ].…”

Raspberry polyphenols alleviate neurodegenerative diseases: through gut microbiota and ROS signals

“…Catechins inhibit the proliferation of Bacteroides, improving the survival status of intestinal microbes in Parkinson's patients. 45,46 ALS patients have a higher abundance of E. coli and a lower abundance of total yeast, 93 but flavonoids and coumarins could alleviate ALS through restraining E. coli and Enterococcus faecalis, 94 as well as stimulating the growth of probiotic yeast. 95 RPPs can make a beneficial contribution in terms of increasing beneficial bacteria such as Ackermannia mucronate, and reducing pathogenic microbiota such as Staphylococcus aureus, Clostridium perfringens and Pseudomonas aeruginosa.…”