Metabolomic Profiling and Antioxidant Activities of Breonadia salicina Using 1H-NMR and UPLC-QTOF-MS Analysis

Abstract

Breonadia salicina (Vahl) Hepper and J.R.I. Wood is widely used in South Africa and some other African countries for treatment of various infectious diseases such as diarrhea, fevers, cancer, diabetes and malaria. However, little is known about the active constituents associated with the biological activities. This study is aimed at exploring the metabolomics profile and antioxidant constituents of B. salicina. The chemical profiles of the leaf, stem bark and root of B. salicina were comprehensively characterized using proton nuclear magnetic resonance (1H-NMR) spectroscopy and ultra-performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS). The antioxidant activities of the crude extracts, fractions and pure compounds were determined using the DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging and reducing power assays. A total of 25 compounds were tentatively identified using the UPLC-QTOF-MS. Furthermore, the 1H-NMR fingerprint revealed that the different parts of plant had differences and similarities among the different crude extracts and fractions. The crude extracts and fractions of the root, stem bark and leaf showed the presence of α-glucose, β-glucose, glucose and fructose. However, catechin was not found in the stem bark crude extracts but was found in the fractions of the stem bark. Lupeol was present only in the root crude extract and fractions of the stem bark. Furthermore, 5-O-caffeoylquinic acid was identified in the methanol leaf extract and its respective fractions, while the crude extracts and fractions from the root and dichloromethane leaf revealed the presence of hexadecane. Column chromatography and preparative thin-layer chromatography were used to isolate kaempferol 3-O-(2″-O-galloyl)-glucuronide, lupeol, d-galactopyranose, bodinioside Q, 5-O-caffeoylquinic acid, sucrose, hexadecane and palmitic acid. The crude methanol stem bark showed the highest antioxidant activity in the DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging activity with an IC50 value of 41.7263 ± 7.6401 μg/mL, whereas the root crude extract had the highest reducing power activity with an IC0.5 value of 0.1481 ± 0.1441 μg/mL. Furthermore, the 1H-NMR and UPLC-QTOF-MS profiles showed the presence of hydroxycinnamic acids, polyphenols and flavonoids. According to a literature survey, these phytochemicals have been reported to display antioxidant activities. Therefore, the identified hydroxycinnamic acid (caffeic acid), polyphenol (ellagic acid) and flavonoids (catechin and (epi) gallocatechin) significantly contribute to the antioxidant activity of the different parts of plant of B. salicina. The results obtained in this study provides information about the phytochemistry and phytochemical compositions of Breonadia salicina, confirming that the species is promising in obtaining constituents with medicinal potential primarily antioxidant potential.

Effects of seasonal variation on phytochemicals contributing to the antimalarial and antitrypanosomal activities of Breonadia salicina using a metabolomic approach

“…Plasmodium falciparum (3D7 strain) malaria parasites (Manassas, VA, USA) were preserved as described before [ 27 ] with 2–4 % hematocrit human red blood cells. The seasonal crude extracts (50 μg/mL) were added in 96-well plates and incubated for 48 h in a 37 °C CO 2 incubator.…”

“…In recent times, metabolomics approaches have unravelled previous challenges in phytochemistry. For example, phytochemical studies of B. salicina have yielded compounds such as α -amyrin, ursolic acid, and lupeol; 2,4-dihydroxycinnamic acid and stigmasterol; coumarins like 7-hydroxycoumarin, 6-hydroxy-7-methoxycoumarin, and 7-( β - d -apiofuranosyl (1–6)- β - d -glucopyranosyl) umbelliferone; saturated fatty acids (hexadecane and palmitic acid), a disaccharide (sucrose), an oleanane triterpenoid saponin (bodinioside Q), a monosaccharide ( d -galactopyranose), a flavonoid (kaempferol 3- O -(2ʹʹ- O -galloyl)-glucuronide) and chlorogenic acid (5- O- caffeoylquinic acid) using a reductionist approach [ [24] , [25] , [26] , [27] ]. Although isolation of phytochemicals from B. salicina plant parts has been previously reported [ [24] , [25] , [26] ], not much has been disclosed of isolation techniques used.…”

Phytochemical constituents and pharmacological activities of Breonadia salicina (Vahl) Hepper and J.R.I.Wood (Rubiaceae)

“…Mahlo and Eloff (Mahlo and Eloff 2014) reported the isolation of ursolic acid (Table 1) from the acetone leaf extract of the plant, which displayed vigorous antifungal activity. Nvau et al (Nvau et al 2019) elucidated six other chemical compounds from the stem bark of the plant, while Tlhapi et al (Tlhapi et al 2021) has recently isolated another eight compounds from the same part. The compounds isolated and identified are 7-(β-d-apiofuranosyl-(1 → 6)-β-dglucopyranosyl)-umbelliferone and is called adicardin which is a two-sugar substituted coumarin that readily occurs in plants.…”

A Comprehensive Study to Identify Major Metabolites of an Amoxicillin–Sulbactam Hybrid Molecule in Rats and Its Metabolic Pathway Using UPLC-Q-TOF-MS/MS

“…The applicability of different types of mass spectrometry to metabolite mapping varies greatly [ 30 ]. The advantage of TOF–MS is that it can obtain detailed information on biotransformation sites and has high sensitivity, quality, accuracy, chromatographic compatibility, and data collection rates [ 31 ]. In addition, TOF–MS can collect more qualitative and quantitative information about drugs and their metabolites, and even endogenous biomarkers, from the same sample at the same time, simplifying the screening process.…”