Obtaining a working standard sample of chalcone buteine and its quantitative determination in plant raw materials

Introduction. Butein ‒ 2',4',3,4-tetrahydroxychalcone is found in a number of plants that have a pronounced antimicrobial and antifungal effect: Butea monosperma Lam., hairy string ‒ Bidens pilosa L., tripartite string ‒ Bidens tripartita L., hydrophytum ‒ Hydnophytum formicarum Jack., early thyme ‒ Thymus praecox. Butein is not the dominant representative of the flavonoid class in plants, but it can serve as a marker compound for the analysis of raw materials containing this chalcone.

The purpose of the study is to synthesize and analyze a working standard sample of butein, as well as to develop a method for its quantitative determination in Cosmos bipinnate raw materials using solid-phase extraction.

Material and methods. Butein synthesis was carried out using the Claisen‒Schmidt reaction, the yield was 44,4%. Identification of the obtained butein was carried out using UV, IR and Mass spectroscopy. Quantitative determination of butein in the raw materials of Cosmos doubly persita was carried out by HPLC in combination with solid-phase extraction.

Results. The results obtained confirm that the test sample is butein (2',4',3,4-tetrahydroxychalcone). To determine butein in plant raw materials, a standard sample of this compound should be available, and therefore the substance of this chalcone was synthesized and on its basis, according to the state pharmacopoeia, a working standard sample was obtained (butein content in it is 99,62%). Identification of butein by HPLC was carried out by the retention time, which in the chromatogram of the test solution is 160,70 min, in the chromatogram of the standard solution – 160,07 min ± 2%. The butein content in the flowers of the cosmos bipinnate we studied in terms of dry raw materials is 0,043% ± 2%.

Conclusions. The synthesis of chalcone ‒ butein was carried out by alkaline condensation of resacetophenone with protocatechuic aldehyde. The yield of butein is 5,95 ± 0,0195 g (44,4%). A working standard sample was obtained based on the butein substance, the authenticity and purity of which was confirmed by melting point, as well as using HPLC, mass spectroscopy, UV and IR spectroscopy. The resulting standard working sample was further used to develop a method for the quantitative determination of butein in Cosmos bipinnate flowers using solid-phase extraction. The butein content in terms of dry raw materials is 0,043%±3%.