Characterization of Flavonoids Profiles in Polar Extracts from Croton grewioides Baill. Using Ultra-High Resolution Mass Spectrometry

Abstract

Research to identify plant bioactive compounds led to the evolution of extraction methods. This study optimized ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) to extract the flavonoids of Croton grewioides Baill. species contributing to characterize the polar extract profile and understand the antioxidant potential of these plant constituents. The use of experimental design and statistical treatments enabled the determination of the ideal conditions for each technique. The extracts of five accessions of C. grewioides were obtained under the optimized extraction conditions and were analyzed using ultra high-resolution mass spectrometry (FT-Orbitrap MS) operating at negative ionization mode for flavonoids detection. The accurate experimental mass obtained to the main compounds was used to attribute the molecular formula. Chemical structures of the main compounds detected were proposed using structure data bases. Chemometric analysis were performed with two FT-Orbitrap MS spectra samples using the identified metabolites and, the antioxidant activity data, showing that for this species the MAE was most effective in extracting the antioxidant compounds. It was possible to propose the structures for forty compounds in the C. grewioides extracts, demonstrating the excellent performance of the FT-Orbitrap MS in providing information on the chemical profile of polar compounds in plant extracts.

Microwave and ultrasound extraction of antioxidant phenolic compounds from Lantana camara Linn. leaves: Optimization, comparative study, and FT‐Orbitrap MS analysis

“…This could be attributed to the effects of microwave radiation in the extraction medium, which favored a higher TPC value for this extract, since phenolic compounds have recognized antioxidant activities. 1,25,38 Similar results have been reported previously in the literature.…”

“…The MAE extract showed higher antioxidant activity values (DPPH, 423.51 μmol TE/g DW; ABTS, 414.50 μmol TE/g DW; FRAP, 838.69 μmol TE/g DW) compared to the other extracts. This could be attributed to the effects of microwave radiation in the extraction medium, which favored a higher TPC value for this extract, since phenolic compounds have recognized antioxidant activities 1,25,38 …”

“…The analyses were performed in HESI(−) mode, with a vaporization region temperature of 40°C, a spray voltage of 3.5 kV, a capillary temperature of 300°C, sheath gas at 12 a.u., sweep gas at 5 a.u., and auxiliary gas at 0 a.u. The mass spectra were acquired following methodologies described by Nascimento et al 1 The accurate masses of the various negative [M − H] − ions detected were converted into molecular formulas, such as C x H y N z O w S k .…”

“…Phenolic compounds, such as phenolic acids and flavonoids, stand out among the classes of compounds most studied in research on natural products, due to their wide range of biological effects including antioxidant, anti-inflammatory, anticholinesterase, and anticarcinogenic activities. [1][2][3][4][5] Due to their antioxidant capacity, these compounds can act in the capture of free radicals, in the inhibition of peroxides and enzymes responsible for the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS), and in the complexation of metals.…”

“…Phenolic compounds, such as phenolic acids and flavonoids, stand out among the classes of compounds most studied in research on natural products, due to their wide range of biological effects including antioxidant, anti‐inflammatory, anticholinesterase, and anticarcinogenic activities 1–5 …”