Supercritical Carbon Dioxide Antisolvent Fractionation for the Sustainable Concentration of Lavandula luisieri (Rozeira) Riv.- Mart Antimicrobial and Antioxidant Compounds and Comparison with Its Conventional Extracts

Abstract

Lavandula stoechas subsp. luisieri is a Spanish subspecies from the Lamiaceae family. Its essential oil has been traditionally used for several medical applications though little is known about other extracts. Similar to many other studies aiming to obtain traditional plant extracts to be used in different applications, this work evaluated the antioxidant and antimicrobial activities of Lavandula luisieri extracts and the correlation with their composition. Traditional hydrodistillation and ethanolic maceration were used to obtain the essential oil and the maceration extract, respectively. A green and sustainable methodology was applied to the maceration extract that was under a Supercritical Antisolvent Fractionation process to obtain a fine solid enriched in rosmarinic acid and the terpenes oleanolic and ursolic acids. Antimicrobial activities of all extracts and pure identified compounds (rosmarinic and ursolic acids) were evaluated against five bacterial strains; Listeria monocytogenes, Enterococcus faecium, Staphylococcus aureus, Salmonella Typhimurium and Escherichia coli and were compared with the pure compounds identified, rosmarinic and ursolic acids. All strains were sensitive against L. luisieri essential oil. The solid product obtained from the supercritical process was concentrated in the identified actives compared to the maceration extract, which resulted in higher antimicrobial and DPPH scavenging activities. The supercritical sustainable process provided L. luisieri compounds, with retention of their antimicrobial and antioxidant activities, in a powder exemptof organic solvents with potential application in the clinical, food or cosmetic fields.

Determination of Antimicrobial and Antioxidant Activities of Lavandula angustifolia Volatile Oil

“…At the same time, an antioxidant effect was observed as a result of the analysis made with the DPPH method. Research results (parallel to the present study) were found to have a lower effect than standards (Throlox and rosmarinic acid) (Giménez-Rota et al, 2019).…”

Novel bioactive extract from yarrow obtained by the supercritical antisolvent-assisted technique inhibits lipid metabolism in colorectal cancer

“…These results are consistent with the lower solubility of the polar phenolic compounds in the SCCO 2 –ethanol mixture, most of them being precipitated and recovered in the precipitate fraction. Giménez-Rota et al (2019) also reported a lower solubility of the polar phenolic compounds, such as rosmarinic acid, in the SCCO 2 –ethanol mixture ( Giménez-Rota et al, 2019 ).…”

“…At the end of the process, two fractions, the precipitate fraction and the separator fraction, are obtained containing compounds of different polarities. This technique can be considered as environmentally sustainable since it does not generate any type of waste ( Gimenez-Rota et al, 2019 ). Moreover, CO 2 creates an inert environment, reducing the degradation of bioactive compounds due to its low critical temperature.…”

Lavandula stoechas L. subsp. stoechas, a New Herbal Source for Ursolic Acid: Quantitative Analysis, Purification and Bioactivity Studies

“…The chemical structure of ursolic acid (Figure 2) isolated from the methanol, ethanol, and methanol-dichloromethane (1 : 1, v/ v) extracts of L. stoechas was confirmed by 1 H and 13 C-NMR spectroscopy and by comparing the spectral data previously reported in the literature. [43] Previously, ursolic acid was reported some Lavandula species such as L. spica, [44] L. luisieri, [45][46][47] L. augustifolia, [48] L. latifolia, [49] L. multifidi [50] and L. pubescens. [51] The spectral data of ursolic acid are given below.…”