Green processes for the extraction of bioactives from Rosemary: Chemical and functional characterization via ultra-performance liquid chromatography-tandem mass spectrometry and in-vitro assays

Abstract

In this contribution, the performance of three different extraction procedures towards the extraction of antioxidants from rosemary (Rosmarinus officinalis) is presented. Namely, pressurized liquid extraction (PLE), using water and ethanol as solvents, supercritical fluid extraction (SFE), using neat CO(2) and supercritical CO(2) modified with ethanol, as well as a novel extraction process called Water Extraction and Particle formation On-line (WEPO) are directly compared. Different extraction conditions including temperatures, times and pressures have been studied. The produced extracts have been characterized in terms of extraction yield, antioxidant activity (using the DPPH radical scavenging method) and total phenols (using the Folin method). Besides, all the extracts have been chemically characterized using a new quantitative UPLC-MS/MS method. This method allowed the determination of the main antioxidants present in rosemary, including, among others, rosmarinic acid, carnosic acid and carnosol, attaining detection limits as low as 2ng/mL. The results obtained in this study show that PLE using ethanol at high temperatures (200 degrees C) was able to produce extracts with high antioxidant activity (EC(50) 8.8microg/mL) and high yield (ca. 40%) while efficiently extracting antioxidants of diverse polarity, among them, carnosic and rosmarinic acids, regarded as the most important antioxidants present in rosemary. Nevertheless, in this work, the ability of the three studied environmentally friendly extraction techniques to obtain bioactives from natural sources is demonstrated.

Effect of rosemary polyphenols on human colon cancer cells: transcriptomic profiling and functional enrichment analysis

“…Five rosemary extracts marked as rom1 to rom5 were obtained from dried rosemary leaves using either supercritical fluid extraction (SFE) or pressurized liquid extraction (PLE) as reported by Herrero et al (2010). The extracts obtained by PLE with a 100 bar pressure for 20 min under the following conditions of solvent and temperature were as follows: rom1, using water at 100°C; rom2, using ethanol at 150°C; and rom3, using water at 200°C.…”

“…On the other side, the extracts obtained by SFE at 40°C for 30 min were as follows: rom4, using supercritical CO 2 and 7 % ethanol at 150 bar; rom5, using supercritical CO 2 at 400 bar. Previous chemical characterization studies provided information on the major phenolic constituents in each extract (Herrero et al 2010). A major phenolic compound in rom1, rom2, and rom3 extracts was rosmarinic acid with concentrations of 14.19, 16.78, and 8.59 lg/mg extract.…”

“…Rom1 and rom3 contained similar concentration of carnosol (*45 lg/mg extract), and carnosic acid was present at concentrations of 0.01, 66.23, and 5.78 lg/mg in rom1, rom2, and rom3, respectively. The extracts have also been reported to show antioxidant activity (EC 50 ) ranging from 5.3 to 10.5 lg/mL (Herrero et al 2010). Extracts were diluted at the indicated concentrations using ethanol and their content in polyphenols determined as gallic acid equivalents (GAE), expressed as mg gallic acid/g extract.…”

“…The biological activities of rosemary (Rosmarinus officinalis) polyphenols have been investigated by several research groups (Herrero et al 2010). Carnosol, one of the main polyphenols in rosemary, poses strong antioxidant and chemopreventive activities.…”

Characterization of the phenolic and antioxidant profiles of selected culinary herbs and spices: caraway, turmeric, dill, marjoram and nutmeg

“…For instance, rosmarinic acid, along with other compounds present in rosemary (e.g. carnosol, rosmanol, and epi-rosmanol), has shown potent antioxidant activities (Herrero et al, 2010), as possess thyme, oregano and marjoram (Hinneburg, et al, 2006;Amarowicz et al, 2009). However, a comprehensive identification of the phenolic profile of caraway, turmeric, dill, marjoram and nutmeg is still lacking.…”