Optimized Ultrasound-Assisted Extraction of Lignans from Linum Species with Green Solvents

Lignans are plant phenols derived from phenylpropanoids. They play a significant role in plant defense and have features that make them appealing for pharmaceutical applications. Lignans can be obtained by plant in vitro cultures; their production by adventitious and hairy roots of Linum species seems to be a promising alternative to chemical synthesis. In the context of large-scale production, it is necessary to optimize their extraction from plants tissue by choosing the more suitable solvent and extraction procedure, paying attention to the use of green media and methods. With the aim to select the best conditions for the extraction of two interesting lignans (justicidin B and 6-methoxypodophyllotoxin) from Linum tissues, different green solvents and the method of ultrasound-assisted extraction were tested. The results showed that ethyl methyl ketone and dimethyl carbonate were the best media to extract justicidin B and 6-methoxypodophyllotoxin, respectively, in terms of purity and recovery. Moreover, we showed that ultrasound-assisted extraction presents different advantages compared to conventional methods. Finally, the optimal experimental conditions to extract justicidin B from L. austriacum hairy roots using methyl ethyl ketone were also determined by the response surface method. The models obtained are reliable and accurate to estimate the purity and recovery of justicidin B.

Automated summary

Lignans, plant phenols derived from phenylpropanoids, have significant potential for pharmaceutical applications. This study investigated the extraction of two lignans from Linum tissues using green solvents and ultrasound-assisted extraction. Ethyl methyl ketone and dimethyl carbonate were found to be the most effective solvents for extracting justicidin B and 6-methoxypodophyllotoxin, respectively. Ultrasound-assisted extraction was shown to have advantages over conventional methods. Additionally, optimal experimental conditions for extracting justicidin B from Linum austriacum hairy roots were determined using the response surface method, and reliable models for estimating purity and recovery were obtained.