Characterisation of α-amylase inhibitors in marigold plants via bioassay-guided high-performance thin-layer chromatography and attenuated total reflectance-Fourier transform infrared spectroscopy

Snezana Agatonovic-Kustrin; Galina Ramenskaya; Ella Kustrin; David W Morton

doi:10.1016/j.jchromb.2021.122676

Characterisation of α-amylase inhibitors in marigold plants via bioassay-guided high-performance thin-layer chromatography and attenuated total reflectance-Fourier transform infrared spectroscopy

J Chromatogr B Analyt Technol Biomed Life Sci. 2021 Mar 29:1173:122676. doi: 10.1016/j.jchromb.2021.122676. Online ahead of print.

Authors

Snezana Agatonovic-Kustrin¹, Galina Ramenskaya², Ella Kustrin³, David W Morton⁴

Affiliations

¹ A.P. Arzamastsev Department of Pharmaceutical and Toxicological Chemistry, I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow 119991, Russian Federation; School of Pharmacy and Biomedical Sciences, La Trobe University, Edwards Rd, Bendigo 3550, Australia. Electronic address: snezana0801@gmail.com.
² A.P. Arzamastsev Department of Pharmaceutical and Toxicological Chemistry, I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow 119991, Russian Federation; Scientific Center for Expert Evaluation of Medicinal Products, Ministry of Health of the Russian Federation, 8/2 Petrovskii Blvd., Moscow 127051, Russian Federation.
³ Department of Creative Arts and English, La Trobe University, Edwards Rd, Bendigo 3550, Australia.
⁴ A.P. Arzamastsev Department of Pharmaceutical and Toxicological Chemistry, I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow 119991, Russian Federation; School of Pharmacy and Biomedical Sciences, La Trobe University, Edwards Rd, Bendigo 3550, Australia.

PMID: 33848802
DOI: 10.1016/j.jchromb.2021.122676

Abstract

A high-performance thin-layer chromatography with microchemical derivatization and bioassay guided detection was used for bioanalytical profiling of selected marigold plant extracts. Anisaldehyde/sulfuric acid reagent and thymol/sulfuric acid reagent were used to visualize separated components on the chromatograms. Antioxidant activity and α-amylase inhibition were assessed with 2 bioassays, DPPH assay to detect free radical scavengers and starch-iodineassay method to detect compounds that inhibit α-amylase. The highest antioxidant activity of 10.12 μg of gallic acid equivalents (GAE) per 20 µL of extract was measured in extract from Tagetes flowers and the lowest in the extract from Calendula leaves with 5.10 μg of GAE. Multiple zones of α-amylase inhibition were detected. A detailed analysis of the ATR-FTIR spectra from the bands at R_F = 0.24 suggest that faradiol esters and saturated fatty acids esters, palmitic acid, myristic acid, and lauric acid are responsible for α-amylase inhibition, unsaturated fatty acids for the band at R_F = 0.51 and phytoecdysteroids for the band at R_F = 0.53.

Keywords: ATR-FTIR chemical characterisation; Antidiabetic activity; Bioassay guided HPTLC screening; Marigolds.