Deep Eutectic Solvents (DESs) are increasingly considered privileged media for the extraction of bioactive molecules from natural sources. In the recent past, they have been used for the development of analytical methods for the determination of food contaminants, such as ochratoxin A, with excellent results in terms of recovery in different matrices or to obtain polyphenols from food industry waste. Starting from these results, new methods have been developed to recover bioactive molecules produced by plants or microfungi using these green methods. In particular, in a preliminary study, Cabernet Sauvignon and Petit Verdot red grape pomaces, collected during 2023 vintage in Apulia (Italy), were used as starting secondary raw materials for bioactive molecule extractions. The extraction procedure was carried out, through shaking, using seven different DESs and hydroalcoholic solutions as reference solvents. The phenolic compounds’ profile of the resulted extracts has been obtained through HPLC-DAD analysis, in which up to eight out thirteen polyphenols studied were detected with a maximum concentration of 0.49 μg/g of quercetin in a single sample. DPPH photometric assays performed on the extracts showed significant antioxidant activity as well: the DES Choline Chloride/Urea 1:2 with 40% water resulted to be the best with a value of 14.9 mM Gallic Acid Equivalents for the sample obtained from dried Petit Verdot pomace. DESs were also used to recover Ochratoxins obtained in a preliminary massive production experiment from microfungi in liquid cultures as part of the PRIN 2022 PNRR project entitled "Nature- Inspired structures: Fungal metabolites for a sustainable semi-synthetic approach to the discovery of new multi-target anti-Alzheimer's drugs (NInFA)"3. Specifically, P. nordicum ITEM 9634 was grown on YES (yeast extract sucrose) with 2% NaCl at 25°C for 1 week and two different green solvents (DESs) were used for OTs extraction. Among these, Choline Chloride/Lactic Acid 1:2 with 25% of water showed the highest extraction efficiency, with an OTA and OTB content up to 50% of that obtained with acetonitrile:water (60:40, v/v), the most used VOC mixture reported in literature1. The same solvent was also used for the purification of lyophilized extracts containing OTA. In this case, their solubilization and subsequent addition of small quantities of water caused the quantitative precipitation of ochratoxin A as a light brown solid. The subsequent hydrolysis in acidic water led to ochratoxin alpha (OTα), a key intermediate in the semi-synthesis of multi-target hybrids for the possible treatment of Alzheimer's disease, the final goal of the NInFA project.
Green methods for the recovery of bioactive molecules from natural sources
Marco Paparella;Rosalba Leuci;Vincenzo Roselli;Antonio Laghezza;Massimo Ferrara;Lucia Gambacorta;Luca Piemontese
2025-01-01
Abstract
Deep Eutectic Solvents (DESs) are increasingly considered privileged media for the extraction of bioactive molecules from natural sources. In the recent past, they have been used for the development of analytical methods for the determination of food contaminants, such as ochratoxin A, with excellent results in terms of recovery in different matrices or to obtain polyphenols from food industry waste. Starting from these results, new methods have been developed to recover bioactive molecules produced by plants or microfungi using these green methods. In particular, in a preliminary study, Cabernet Sauvignon and Petit Verdot red grape pomaces, collected during 2023 vintage in Apulia (Italy), were used as starting secondary raw materials for bioactive molecule extractions. The extraction procedure was carried out, through shaking, using seven different DESs and hydroalcoholic solutions as reference solvents. The phenolic compounds’ profile of the resulted extracts has been obtained through HPLC-DAD analysis, in which up to eight out thirteen polyphenols studied were detected with a maximum concentration of 0.49 μg/g of quercetin in a single sample. DPPH photometric assays performed on the extracts showed significant antioxidant activity as well: the DES Choline Chloride/Urea 1:2 with 40% water resulted to be the best with a value of 14.9 mM Gallic Acid Equivalents for the sample obtained from dried Petit Verdot pomace. DESs were also used to recover Ochratoxins obtained in a preliminary massive production experiment from microfungi in liquid cultures as part of the PRIN 2022 PNRR project entitled "Nature- Inspired structures: Fungal metabolites for a sustainable semi-synthetic approach to the discovery of new multi-target anti-Alzheimer's drugs (NInFA)"3. Specifically, P. nordicum ITEM 9634 was grown on YES (yeast extract sucrose) with 2% NaCl at 25°C for 1 week and two different green solvents (DESs) were used for OTs extraction. Among these, Choline Chloride/Lactic Acid 1:2 with 25% of water showed the highest extraction efficiency, with an OTA and OTB content up to 50% of that obtained with acetonitrile:water (60:40, v/v), the most used VOC mixture reported in literature1. The same solvent was also used for the purification of lyophilized extracts containing OTA. In this case, their solubilization and subsequent addition of small quantities of water caused the quantitative precipitation of ochratoxin A as a light brown solid. The subsequent hydrolysis in acidic water led to ochratoxin alpha (OTα), a key intermediate in the semi-synthesis of multi-target hybrids for the possible treatment of Alzheimer's disease, the final goal of the NInFA project.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
