Abstract: The aim of this work is to study sustainable approaches to pure betulin using green low-polar solvents from natural feedstock pine monoterpenes and limonene. The conventional methods of extracting outer birch bark (OBB) lead to extracts that contain only 50%-75% of betulin, while refining processes of OBB extracts are usually labor consuming and employ toxic solvents. The extractions of OBB using monoterpenes and their hydrogenated analogs at boiling and microwave assisted conditions turned out to be insufficiently selective and lead to a significant uptake of extractants on the depleted bark. To obtain pure betulin, the sequence including energy-saving extraction of OBB with a green solvent (ethyl acetate, EtOAc), saponification of the extract, and purification of betulin in limonene or hydrogenated monoterpenes was proposed. The protocol of processing primary extracts with stable monoterpenes-limonene, pinane, and hydrogenated turpentine oil-ensured separation of pure betulin (95%-97%) with high yields (75%-82%) and the effective recycling of extractants (81%-87%). The refining of plant metabolites in monoterpenes can be regarded as a promising method, successfully competing with the known multistep processes and methods employing toxic solvents.

Cite: Grazhdannikov A.E. , Kornaukhova L.M. , Rodionov V.I. , Pankrushina N.A. , Shults E.E. , Fabiano-Tixier A.S. , Popov S.A. , Chemat F.
Selecting a Green Strategy on Extraction of Birch Bark and Isolation of Pure Betulin Using Monoterpenes
ACS Sustainable Chemistry and Engineering. 2018. V.6. N5. P.6281-6288. DOI: 10.1021/acssuschemeng.8b00086 WOS Scopus РИНЦ OpenAlex

Dates:

Published online:	Apr 6, 2018
Published print:	May 7, 2018

Identifiers:

Web of science:	WOS:000431927500068
Scopus:	2-s2.0-85046711765
Elibrary:	35492961
OpenAlex:	W2796359484

Citing:

DB	Citing
Web of science	17
Scopus	19
Elibrary	19
OpenAlex	22

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