Determination of heavy metals contamination in thyme products by inductively coupled plasma mass spectrometry.

Thyme herbs constitute a major part of the Mediterranean diet and are gaining worldwide popularity. However, their chemical contamination with toxic metals may put consumers at a health risk. The objective of this study was to assess the incidence of Arsenic (As), Cadmium (Cd), Lead (Pb) and Mercury (Hg) in thyme-containing products. Composite samples were collected twice at six-month interval. Samples were digested by microwave digestion oven and analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). 11%, 22%, and 86% of samples had unacceptable levels of As, Hg and Pb respectively according to the international standards set by Codex Alimentarius and all the samples had acceptable limits of Cd. This study highlighted the importance of monitoring and enforcing regulatory actions related to the contamination of the food chain with heavy metals.

Phenolic Compounds Recovery from Blood Orange Peels Using a Novel Green Infrared Technology Ired-Irrad®, and Their Effect on the Inhibition of Aspergillus flavus Proliferation and Aflatoxin B1 Production.

The intensification of total phenolic compound (TPC) extraction from blood orange peels was optimized using a novel green infrared-assisted extraction technique (IRAE, Ired-Irrad®) and compared to the conventional extraction using a water bath (WB). Response surface methodology (RSM) allowed for the optimization of ethanol concentration (E), time (t), and temperature (T) in terms of extracted TPC and their antiradical activity, for both WB extraction and IRAE. Using WB extraction, the multiple response optimums as obtained after 4 h at 73 °C and using 79% ethanol/water were 1.67 g GAE/100 g for TPC and 59% as DPPH inhibition percentage. IRAE increased the extraction of TPC by 18% using 52% ethanol/water after less than 1 h at 79 °C. This novel technology has the advantage of being easily scalable for industrial usage. HPLC analysis showed that IRAE enhanced the recovery of gallic acid, resveratrol, quercetin, caffeic acid, and hesperidin. IR extracts exhibited high bioactivity by inhibiting the production of Aflatoxin B1 by 98.9%.

Deciphering the therapeutical potentials of rosmarinic acid.

Lemon balm is herbal tea used for soothing stomach cramps, indigestion, and nausea. Rosmarinic acid (RA) is one of its chemical constituents known for its therapeutic potentials against cancer, inflammatory and neuronal diseases such as the treatment of neurofibromatosis or prevention from Alzheimer's diseases (AD). Despite efforts, recovery and purification of RA in high yields has not been entirely successful. Here, we report its aqueous extraction with optimal conditions and decipher the structure by nuclear magnetic resonance (NMR) spectroscopy. Using various physical-chemical and biological assays, we highlight its anti-aggregation inhibition potentials against the formation of Tau filaments, one of the hallmarks of AD. We then examine its anti-cancer potentials through reduction of the mitochondrial reductase activity in tumor cells and investigate its electrochemical properties by cyclic voltammetry. Our data demonstrates that RA is a prominent biologically active natural product with therapeutic potentials for drug discovery in AD, cancer therapy and inflammatory diseases.

Derivatization and combination therapy of current COVID-19 therapeutic agents: a review of mechanistic pathways, adverse effects, and binding sites.

Current treatment of patients with coronavirus 2019 (COVID-19) involves repurposed drugs that inhibit viral infection by either binding to their respective targets or via modulating cellular signal transduction. However, there is still a great deal of efficacy enhancement through combination therapy and derivatization. Combination therapy should involve agents with significant activity and different mechanisms of action. The structural map of the interaction between a drug and its target protein will help guide drug discovery for devising safe and effective ways to treat COVID-19. Herein, we report numerous synthetic designs based on enhanced affinity to the viral carbohydrate-rich protein spikes and protein-binding sites of COVID-19.

Intensification of polyphenols extraction from orange peels using infrared as a novel and energy saving pretreatment.

This study aims to evaluate the impact of a nonconventional pretreatment technique "infrareds free solvent" on the intensification of polyphenols extraction from orange peels. Orange peels were pretreated with infrared heating using a ceramic infrared transmitter from 5 to 25 min at 50 °C. After the addition of the solvent on the pretreated peels, ultrasound treatment was applied on the mixture using an ultrasound generator connected to a titanium ultrasound probe, from 5 to 30 min, at 50 °C. Results showed that the application of ultrasounds on untreated peels enhanced the extraction of polyphenols by 62.5% compared to the conventional solid-liquid extraction. Twenty minutes of infrared pretreatment improved the extraction of polyphenols by 47% with solid-liquid extraction, and 112% with ultrasounds after 30 min compared to solid-liquid extraction from untreated peels. Different combinations of infrared pretreatment and ultrasound assisted extraction were then applied on orange peels. The most advantageous combination in terms of energy consumption and polyphenols extraction has been found for a 20 min infrared pretreatment time and 5 min ultrasound assisted extraction of polyphenols. PRACTICAL APPLICATION: Orange peels are valuable sources of natural antioxidants such as polyphenols. Ultrasound-assisted extraction can improve the extraction of polyphenols compared to conventional solid-liquid extraction. To intensify the extraction process, infrared heating can be used as a simple, low cost, and energy saving method. The combined effect of "infrareds free solvent" and ultrasounds allowed the extraction of the highest yields of polyphenols with a high antiradical capacity and a low energy consumption in comparison to conventional extraction.

Green extraction of polyphenols from grapefruit peels using high voltage electrical discharges, deep eutectic solvents and aqueous glycerol.

Deep eutectic solvents (DES) and aqueous glycerol were proposed as green alternatives to conventional solvents for the extraction of polyphenols from grapefruit peels. In order to increase the extraction kinetics and yields of polyphenols, high voltage electrical discharges (HVED) were used as a pre-treatment technology (energy varied between 7.27 and 218 kJ/kg). Results showed that the HVED energy input can be reduced, when the subsequent solid-liquid extraction was performed in 20% (w/v) aqueous glycerol or in DES (lactic acid: glucose) instead of water. The addition of glycerol has reduced the energy of the pre-treatment by 6 times. The same diffusivity of polyphenols (4 × 10-11 m2/s) was obtained in water from HVED pre-treated peels at 218 kJ/kg and in aqueous glycerol from pre-treated peels at 36 kJ/kg. The solubility of naringin, the main flavonoid compound of grapefruit peels in the solvents, was investigated through a theoretical modelling of its Hansen solubility parameters.

High voltage electrical discharges combined with enzymatic hydrolysis for extraction of polyphenols and fermentable sugars from orange peels.

Orange peels are a biomass rich in carbohydrates and polyphenols and characterized by their low lignin content. This work focuses on finding the best combination between physical and biological treatments to enhance the extraction of fermentable sugars and polyphenols. High voltage electrical discharges (HVED) (0 to 900 kJ/kg) or enzymatic hydrolysis with Viscozyme® L (12 FBGU/g) were applied on fresh or defatted orange peels for the extraction of polyphenols and fermentable sugars. An HVED energy input of 222 kJ/kg was optimal for the extraction of reducing sugars (19 g/100 g DM) and polyphenols (0.7 g/100 g DM). However, enzymatic hydrolysis allowed a higher extraction of reducing sugars (50 g/100 g DM). HVED were then applied prior or simultaneously to enzymatic hydrolysis to maximize the extraction of biomolecules from orange peels. Thus, the results clearly showed that the HVED pretreatment of orange peels is efficient to enhance the accessibility of cellulosic biomass to enzymes. HVED (222 kJ/kg) prior to enzymatic hydrolysis (12 FBGU/g), was the most effective combination of these two processes to get an intensive extraction of biomolecules from orange peels.