HI-HPTLC-UV/Vis/FLD-HESI-HRMS and bioprofiling of steviol glycosides, steviol, and isosteviol in Stevia leaves and foods

Abstract

Food products and botanicals on the global market need to be investigated in a more comprehensive way to detect effects, falsifications or adulterations. This is especially true for such ones containing Stevia leaves, Stevia extracts, or steviol glycosides. A multi-imaging profiling was developed exploiting hydrophilic interaction liquid chromatography (HILIC). A minimalistic sample preparation, different mixtures of acetonitrile and water/buffer on the silica gel phase as well as derivatization reagents and optional hyphenation with high-resolution mass spectrometry were exploited. The hydrophilic interaction high-performance thin-layer chromatography (HI-HPTLC) development took 10 min for 48 analyses. It was used to screen Stevia leaf extracts and 20 different food products. For the first time, the biological and biochemical profiling of Stevia leaf products by HI-HPTLC-UV/ Vis/FLD-assay pointed to 19 different bioactive compound bands found in the more natural multicomponent Stevia leaf extracts, whereas most of these activities were not existent for the steviol glycosides. The chemically isolated, purified, and EU-regulated steviol glycosides ease risk assessment and food product development. However, multipotent botanicals may have subtle impact on homeostasis via several metabolic pathways, providing benefits for the consumer's health. Analyzed side by side by means of the effect-directed profiling, their individual activity profiles were visualized as image and individual substances of importance were pointed out. Multi-imaging (comprehensive detection) plus non-targeted bioprofiling (focus on known and unknown bioactivity) allows for a fast detection of questionable product changes that occur along the global food chain and are particularly related to food safety.

Is Our Natural Food Our Homeostasis? Array of a Thousand Effect-Directed Profiles of 68 Herbs and Spices

“…However, their multifactorial relevance in homeostasis is underexplored. It is evident that the use of the whole natural plant extract is more powerful for homeostasis due to the versatility of the gentle mechanisms of active compounds than the use of isolated compounds ( Morlock and Heil, 2020 ).…”

“…Also, generic chromatography-based high-resolution mass spectrometric methods were examined to cover as many substances as possible within a single analysis ( Díaz et al, 2012 ). However, one drawback is the high load of interfering matrix caused by the diversity and abundance of substances in such natural products as spices and herbs ( Caesar et al, 2019 ; Morlock and Heil, 2020 ). Elaborate sample preparation (which is selective and error-prone) would otherwise limit the validity and significance of the results.…”

Effect-Directed Profiling of Monofloral Honeys from Ethiopia by High-Performance Thin-Layer Chromatography and High-Resolution Mass Spectrometry

“…Each honey extract was applied (1–9 µL/band, as listed in the respective figure) in an 8 mm band (track distance 15 mm, distance from left edge 15 mm, distance from bottom edge 8 mm, and dosage speed 150 nL/s; Automatic TLC Sampler ATS 4, CAMAG, Muttenz, Switzerland), dried in a stream of cold air (2 min, hair dryer), and developed with ethyl acetate–methanol 3:2 ( V /V ) up to a migration distance of 60 mm (which took 14 min) in a twin trough chamber (20 × 10 cm, CAMAG), dried (3 min), and documented at white light illumination (Vis), UV 254 nm, and FLD 366 nm (TLC Visualizer, CAMAG). For derivatization, the plate was immersed in the respective reagent as described elsewhere [ 21 , 24 , 38 , 39 ]. Instruments were operated and data were processed with winCATS, version 1.4.7.2018, or visionCATS, version 3.1.21109.3 software (CAMAG).…”

Quality Assessment of Apple and Grape Juices from Serbian and German Markets by Planar Chromatography—Chemometrics

“…For the tyrosinase inhibition assay detecting enzyme inhibitors as colorless or bright bands against a purple background [48], the neutralized HPTLC chromatograms were first sprayed (Derivatizer) with 1 mL of substrate solution (45 mg of levodopa, 25 mg of CHAPS, and 75 mg of PEG 8000 were dissolved in 10 mL of phosphate buffer, consisting of 1.4 mg/mL of dipotassium hydrogen phosphate trihydrate and 1.68 mg/mL of disodium hydrogen phosphate, pH 6.8), then after drying, sprayed with 1 mL of enzyme solution (400 U/mL in phosphate buffer) and incubated in a humid box for 20 min. Images were recorded under white light illumination in reflectance mode.…”