Green Methods for Extraction of Inulin and Antioxidants from Carlina acanthifolia L. Roots – A Comparative Study

Abstract

Green extraction methods present a perspective approach for the isolation of bioactive molecules. Together with an ecofriendly approach to extraction, there are many undervalued plants - a rich of source of prebiotics and phenolic compounds. Carlina acanthifolia L. roots possessed antimicrobial, anti-inflammatory, and anti-ulcer properties due to the diverse bioactive compounds in them. Detailed information about inulin-type fructan in its roots is still absent. The object of this work was to define inulin, sugars, and phenolic content, the antioxidant activity in the water, and 70 % ethanol extract resulting from ultrasound-assisted extraction (UAE) and pressure-liquid extraction (PLE). The results showed that the total fructans reached 12.6±0.2 g/100 g dw. Inulin was found in water extracts (6.82 g/100 g dw) in the prevalence of ultrasound-assisted extracts. Total phenolic content did to not exceed 15.25 mg GAE/g dw. Additionally, the antioxidant activities were in the range from 5.99 to 205.83 μM TE/g dw. In conclusion, water extracts from UAE demonstrated higher levels of bioactive compounds with antioxidantive properties, probably due to cavitation process. However, this study is the first detailed investigation for fructans and polyphenols content, as well as antioxidant activity of Carlina acanthifolia L. roots in extracts obtained by green methods. Therefore, this research enriched the information of bioactive compounds in Carlina acanthifolia L. roots.

Polyphenolic Compounds, Triterpenes, Carlina Oxide, Antioxidant Activity and Carbohydrate Profile of Different Vegetal Parts of Carlina vulgaris L., Carlina acanthifolia All. and Carlina corymbosa

“…In general, water extracts demonstrated higher antioxidant potential, especially by the CUPRAC method based on electron transfer, followed by the ABTS method based on a mixed mechanism. The obtained data were compared with our previous observation for C. acannthifolia ethanol and water root extracts 9 . There are some studies about the antioxidant potential of Carlina vulgaris extract, 24,36 as ethyl acetate fractions demonstrated the highest activity by the FRAP method, and the lowest values were found for water extract 36 .…”

“…A similar tendency for phenolic content to correlate highly with antioxidant activity was reported by other researchers. 9 A high correlation existed between TPC/TFC, TPC, and DPPH/ABTS, and TFC and DPPH/ABTS (r > 0 79, r > 0 61, and r > 0 68) was also reported. 23,24 Total fructans, inulin, and sugar content in Carlina thistles extracts The results for sugar composition and fructan content in different plant materials of Carlina corymbosa, Carlina acanthifolia, and Carlina vulgaris were summarized in Table 5.…”

“…(18-20 %), while a previous study by Petkova et al found that inulin content in commercial Carlina acanthifolia roots reached 5-6.8 g/100 g dw. 9 Furthermore, Table 5 shows that Carlina corymbosa roots contained a considerably lower amount of inulin in comparison to Carlina acanthifolia roots. The lowest values of inulin were detected in Carlina vulgaris roots and vegetal parts (< 0.3 g/100 g dw).…”