RUDN chemists improved the method of extracting natural antioxidants from bay leaves

RUDN chemists improved the method of extracting natural antioxidants from bay leaves

A chemist from RUDN University and his colleagues have proposed using residues from processing bay leaves as raw material for the production of chemically active substances, in particular antioxidants. Researchers have developed a mechanochemical method for the extraction of antioxidants, which reduces processing time by more than 10 times.

Isolation of the desired compounds from plant materials by traditional methods takes a lot of time and a large amount of solvent. One of the promising technologies is mechanochemical processing, in which raw materials are processed mechanically to destroy cell walls before extraction. This treatment does not require solvents and reduces production costs. However, there are still very few studies on the use of mechanochemistry for the extraction of natural compounds.

Rafael Luque, Director of the scientific center “Molecular Design and Synthesis of Innovative Compounds for Medicine”, RUDN University, and his colleagues from the University of Cordoba have developed a mechanochemical method that allows obtaining the right compounds from bay leaves processing waste.

At the first stage of the experiment, the researchers got the extract from leaves using three different solvents: ethanol, methanol and water. Then they used the ultrasonic, microwave, and mechanochemical extraction methods. In the case of the mechanochemical method, the chemists tested different variants of additives — carbonates.

For each of the methods, the authors measured the antioxidant activity of the obtained samples, the total amount of dissolved substances and the amount of phenols. It turned out that the specific antioxidant ability was greater for the extract in ethanol, so in a further study it was ethanol that was used as the main solvent.

Then the chemists investigated the properties of various carbonates as additives for mechanochemical processing. Without carbonates, the extraction is even better than with them, with the exception of lithium carbonate, therefore, Li2CO3 was used as an additive for mechanochemical extraction. The authors then compared mechanochemical processing with microwave and ultrasound processing. In the case of mechanochemical processing, the product yield is higher and the extraction takes less time.

Next, the chemists compared the composition of the extracts obtained by classical, mechanochemical, microwave and ultrasonic extraction. Apparently the main component of the extracts is the by-products formed during the degradation of cell walls. The extracts also contained such essential oils as eucalyptol, eugenol, linalool, and caryophyllene. Eucalyptol and linalool have antimicrobial activity, and eugenol and caryophyllene are among the strongest natural antioxidants. Most target substances and least by-products were extracted by microwave extraction.

The chemists note that mechanochemical extraction is the most promising method for the separation of chemical compounds from plant materials, because with the same content of the necessary substances, the extraction time is reduced by 10 times compared to other technologies. Replacing traditional methods with mechanochemical ones would be a big step forward, since this method meets all the principles of “green chemistry”.

The work was published in the journal Industrial Crops & Products.

News
All news
Science
23 Jun
Scientists Reveal the Water Column of the Yamal Lakes Can Be a Microbial Filter

Scientists from the Winogradsky Institute of Microbiology RAS, RUDN University, St. Petersburg State University and the Tyumen Scientific Centre SB RAS studied the microbial communities from several lakes of the Yamal Peninsula. It turned out that methanotrophs (bacteria that use methane as a source of energy) consume methane more actively in the deep mature lakes of the peninsula than in small thermokarst lakes. In this regard, methane emissions into the atmosphere from the surface of deep lakes are low, and only small (relatively younger thermokarst lakes with constitutional ground ice) can make a significant contribution to methane emissions in the north of Western Siberia. Thus, bacteria perform an important function for the climate balance — they reduce the emission of methane into the atmosphere.

Science
20 Jun
RUDN University Physicists Determine the Optimal Conditions for Holding High-Energy Plasma Clouds in Pyrotron

RUDN University physicists have described the conditions for the most efficient operation of long mirror-based variant of cyclotron in the autoresonance mode. These data will bring better understanding of plasma processes in magnetic traps.

Science
16 Jun
The new protocol will allow to obtain bioactive compounds bypassing by-products

Chemists from Russia and the USA have improved the method of creating bioactive indole-acetonitrile compounds. Previously, in the course of their synthesis, by-products were obtained — a new method allows them to be avoided. This increases the yield of the final product to 81%.