High-resolution monophenolase/diphenolase/radical scavenging profiling for rapid screening of natural whitening candidates from Rosa rugosa cv. ‘Plena’

Antioxidants and tyrosinase inhibitory components were successfully screened and separated from Rosa rugosa cv. ‘Plena’ by high-performance liquid chromatography microfractionation bioactive screening combined with several separation and purification methods. Ethyl acetate extract of Rosa rugosa cv. ‘Plena’ showed high antioxidant activity and tyrosinase inhibitory activity. High-speed countercurrent chromatography, silica gel column chromatography, and semi-preparative high-performance liquid chromatography were used for the preparative separation of four bioactive components from ethyl acetate extract. Two tyrosinase-inhibiting active substances, flavogallonic acid, and N¹-N⁵-N¹⁰-tri-4-p-coumaroylspermidine, were isolated from Rosa rugosa cv. ‘Plena’, and they showed great monophenolase inhibition activity (half-maximal inhibitory concentration: 664.60 and 23.77 μg/ml, respectively) and excellent diphenolase inhibition activity (half-maximal inhibitory concentration: 23 614.61 and 16.80 μg/ml, respectively). Meanwhile, gallic acid, flavogallonic acid, and ellagic acid were shown to have excellent 1,1-diphenyl-2-picryl-hydrazyl antioxidant activity (half maximal inhibitory concentration: 6.66, 20.17, and 13.45 μg/ml), and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) antioxidant activity (half maximal inhibitory concentration: 3.53, 3.83, and 2.78 μg/ml). Molecular docking revealed that flavogallonic acid and N¹-N⁵-N¹⁰-tri-4-p-coumaroylspermidine had a strong binding affinity (–9.3 and –10 kcal/mol, respectively) to tyrosinase through hydrogen bonding and hydrophobic interactions.     

Rapid screening and purification of potential alkaloid neuraminidase inhibitors from Toddalia asiatica (Linn.) Lam. roots via ultrafiltration liquid chromatography combined with stepwise flow rate counter‐current chromatography

Toddalia asiatica (Linn.) Lam. is a medical plant traditionally used to treat coughs, fevers, and various diseases. Alkaloids are the main active ingredients in Toddalia asiatica (Linn.) Lam., but traditional methods for screening and separation are complex and labor‐intensive. In this work, an efficient strategy was developed to rapidly screen, identify, and separate neuraminidase inhibitors from Toddalia asiatica (Linn.) Lam. Ultrafiltration, high performance liquid chromatography, and time‐of‐flight mass spectrometry were employed for rapid screening and identification of neuraminidase inhibitors. A two‐phase solvent system comprising n‐hexane/ethyl acetate/methanol/water (5:5:3:7, v/v) was then selected for separation by high‐speed counter‐current chromatography. A sample loading of 200 mg and a stepwise flow rate were achieved by increasing the flow rate from 2 to 4 mL/min after 4 h. Three main fluoroquinoline alkaloids (haplopine, skimmianine, and 5‐methoxydictamnine) along with two coumarins were obtained via one‐step separation and their structures were determined by mass spectrometry and nuclear magnetic resonance. In vitro assays revealed skimmianine with half‐maximal inhibitory concentration of 16.2 ± 0.7 µmol/L was selected as the potential highest neuraminidase inhibitor. The results suggest that ultrafiltration high performance liquid chromatography–mass spectrometry combined with high‐speed counter‐current chromatography is efficient for the screening and isolation of neuraminidase inhibitors from complex natural products.     

Antioxidant,antibacterial and cytotoxic potential of the ripe fruits of Solanum lycocarpum A. St. Hil. (Solanaceae)

Ethanol extract (EE) and fractions obtained from the ripe fruits of Solanum lycocarpum were examined in order to determine their phenolic composition, antioxidant capacity, antibacterial activities and cytotoxic potential. High-performance liquid chromatography coupled with DAD analysis indicated that caffeic and chlorogenic acids were the main phenolic compounds present in the EE, dichloromethane (DCM) and ethyl acetate (Ac) fractions. The antioxidant activity assessed by the scavenging ability on 1,1-diphenyl-2-picrylhydrazyl radical was significantly more pronounced for DCM and Ac fractions than that of the commercial antioxidant 2,6-di-tert-butyl-4-methylphenol (BHT). EE and fractions exhibited selective antibacterial activity against Gram-positive bacteria, especially the hexane (Hex) and DCM fractions. EE and fractions exhibited low toxicity towards the LLC-MK2 cell line, especially the Hex, DCM and Ac fractions. This work provides the knowledge of phenolic composition in the extract and fractions from the ripe fruits of S. lycocarpum and their antioxidant, antibacterial and cytotoxic activities.     

Efficient strategies for preparative separation of iridoid glycosides and flavonoid glycosides from Hedyotis diffusa

Efficient strategies for the preparative separation of iridoid glycosides and flavonoid glycosides from Hedyotis diffusa using preparative high-performance liquid chromatography combined with appropriate pretreatment technologies were developed. Four fractions (Fr.1-1, Fr.1-2, Fr.1-3, and Fr.2-1) were firstly isolated from the crude extract of Hedyotis diffusa by column chromatography with C18, resin, and silica gel materials, respectively. Then, corresponding separation strategies were developed according to the polarity and chemical constituents. High-polar compounds of Fr.1-1 were purified by hydrophilic reversed-phase liquid chromatography and hydrophilic interaction liquid chromatography mode. The combination of C18 and phenyl columns realized the complementary separation of iridoid glycosides in Fr.1-2. Meanwhile, the improved selectivity caused by the change of organic solvent in the mobile phase was utilized to realize the purification of flavonoid glycosides in Fr.1-3 and Fr. 2-1. Finally, 27 compounds (purity > 95%) mainly involving nine iridoid glycosides and five flavonoid glycosides were obtained. A complete strategy was established for the separation of a complex sample with a wide polarity range, to jointly solve the problems of enrichment of target components and separation of structural analogs.     

A rapid assay to screen adenosine deaminase inhibitors from Ligustri Lucidi Fructus against metabolism of cordycepin utilizing ultra-high-performance liquid chromatography–tandem mass spectrometry

Cordycepin has recently received increased attention owing to its extensive pharmacological activity. Adenosine deaminase (ADA) is widely distributed in mammalian blood and tissues; as a result, cordycepin is quickly metabolized upon entering into the body and converted into the inactive metabolite 3′-deoxyinosine, thus limiting its activity when administered alone. We herein present a novel ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) method for screening ADA inhibitors against the metabolism of cordycepin. Cordycepin and 3′-deoxyinosine were chosen as substrate and product, respectively. A proper separation was achieved for all analytes within 3 min. 3′-Deoxyinosine was quantified in the presence or absence of potential ADA inhibitors to evaluate ADA activity. The assay can simultaneously determine substrate and product, with the endogenous substance and ADA inhibitors added not interfering in its activity. After optimizing the enzymatic incubation and UHPLC–MS/MS conditions, K_m and V_max values for ADA deamination of cordycepin were 95.18 ± 7.85 μm and 363.90 ± 12.16 μmol/min/unit, respectively. Oleanolic acid and ursolic acid from Ligustri Lucidi Fructus were chosen as ADA inhibitors with half maximal inhibitory concentration values of 21.82 ± 0.39 and 18.41 ± 0.14 μm , respectively. A non-competitive inhibition model was constructed and this assay can be used to screen other potential ADA inhibitors quickly and accurately.     

Isolation and Identification of Antioxidative Peptides from Frog (Hylarana guentheri) Protein Hydrolysate by Consecutive Chromatography and Electrospray Ionization Mass Spectrometry

Frog (Hylarana guentheri) proteins were hydrolyzed by papain and Flavourzyme to obtain antioxidative peptides. The antioxidant activities of the frog protein hydrolysates (FPHs) were measured, including 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (IC₅₀?=?9.94?±?0.13 mg/mL), reducing power (0.39?±?0.01 at 5.0 mg/mL), and oxygen radical absorbance capacity (ORAC) value (789.15?±?75.10 μmol Trolox equivalents/g). The hydrolysates were purified by ultrafiltration, ion exchange chromatography, gel filtration chromatography, and reverse-phase high-performance liquid chromatography (RP-HPLC). Through analysis of ESI-MS/MS, two dipeptides were identified as Leu/Ile-Lys (259.1607 Da) and Phe-Lys (293.1446 Da), respectively.     

Ligand fishing of anti‐neurodegenerative components from Lonicera japonica using magnetic nanoparticles immobilised with monoamine oxidase B

In this work, monoamine oxidase B was immobilised onto magnetic nanoparticles to prepare a new type of affinity solid‐phase extraction adsorbent, which was used to extract the possible anti‐neurodegenerative components from the Lonicera japonica flower extracts. Coupled with high‐performance liquid chromatography with mass spectrometry, two monoamine oxidase B ligands were fished‐out and identified as isochlorogenic acid A and isochlorogenic acid C, which were found to be inhibitors of the enzyme for the first time, with similar half maximal inhibitory concentration values of 29.05 ± 0.49 and 29.77 ± 1.03 μM, respectively. Furthermore, equilibrium‐dialysis dissociation assay of enzyme‐inhibitor complex showed that both compounds have reversible binding patterns to monoamine oxidase B, and kinetic analysis demonstrated that they were mixed‐type inhibitors for monoamine oxidase B, with K_i and K_is values of 9.55 and 37.24 μM for isochlorogenic acid A, 9.53 and 35.50 μM for isochlorogenic acid C, respectively. The results indicated that isochlorogenic acid A and isochlorogenic acid C were the major active components responsible for the anti‐degenerative activity of the flowers of L. japonica, while magnetic nanoparticles immobilised monoamine oxidase B could serve as an efficient solid‐phase extraction adsorbent to specifically extract monoamine oxidase B inhibitors from complex herbal extracts.     

Structures of novel norstilbene dimer, longusone A, and three new stilbene dimers, longusols A, B, and C, with antiallergic and radical scavenging activities from Egyptian natural medicine Cyperus longus

The methanolic extract of the whole plant of Cyperus longus originating in Egypt was found to show antiallergic effect on ear passive cutaneous anaphylaxis reactions in mice. By bioassay-guided separation, 11 stilbenes and stilbene dimers including a novel norstilbene dimer, longusone A, and three new stilbene dimers, longusols A, B, and C, were isolated. Their structures were elucidated on the basis of chemical and physicochemical evidence. Among the isolates, longusol B (IC(50)=96 μM), luteolin (3.0 μM), resveratrol (17 μM), piceatannol (24 μM), and cassigarols E (84 μM) and G (84 μM) were found to inhibit the release of β-hexosaminidase, as a marker of antigen-induced degranulations, in rat basophilic leukemia (RBL-2H3) cells. In addition, the methanolic extract and the constituents showed 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (SC(50)=22 μg/ml and 2.8-29 μM, respectively).     

Preparative High-Performance Liquid Chromatography Isolation of the True Proazulenes from Artemisia Arborescens L

Abstract

The use of the preparative medium-pressure liquid chromatography (prep-MPLC) and the preparative high-pressure liquid chromatography (prep-HPLC) techniques for the separation of the main true proazulenes from a purified extract of Artemisia arborescens L. are reported and discussed.     

Comprehensive evaluation of the antioxidant capacity of Sceptridium ternatum using multiple colorimetric methods and 1,1‐diphenyl‐2‐picrylhydrazyl–high‐performance liquid chromatography analysis

Sceptridium ternatum is a medicinal herb with multiple health benefits. However, its antioxidant activity and active components have not been clarified. In this study, the antioxidant capacity of S. ternatum was comprehensively investigated using multiple colorimetric methods and 1,1‐diphenyl‐2‐picrylhydrazyl–high‐performance liquid chromatography analysis. First, the phenolic content, flavonoid content, and radical scavenging ability of S. ternatum were parallelly determined using colorimetric methods performed in 96‐well microplates. The flavonoid content, rather than the phenolic content, was highly correlated with its antioxidant activity. Sceptridium ternatum was shown to be a rich source of flavonoids, with a highest flavonoid yield of 3.44 ± 0.11 mg/g. Subsequently, 1,1‐diphenyl‐2‐picrylhydrazyl–high‐performance liquid chromatography experiment and quadrupole time‐of‐flight mass spectrometry analyses were carried out for rapid screening of the individual antioxidants. A total of 14 O‐glycosyl flavonoids with quercetin or kaempferol aglycone have been characterized. Particularly, quercetin 3‐O‐rhamnoside‐7‐O‐glucoside exhibited the most potent antioxidant ability. Its half‐maximal effective concentrations for scavenging 1,1‐diphenyl‐2‐picrylhydrazyl and 2,2?‐azino‐bis (3‐ethylbenzthiazoline‐6‐sulfonic acid) radicals were 70.55 ± 2.69 and 106.90 ± 1.76 µg/mL, respectively, which were comparable with those of l ‐ascorbic acid. Our results indicated that the combined colorimetric and chromatographic methods provided a practical strategy for the discovery of bioactive compounds from natural products.     

Microcolumn liquid chromatography with thermionic detection of the enantiomers of O-ethyl S-2-diisopropylaminoethyl methylphosphonothioate (VX)

An improved interface for the on-line coupling of microcolumn liquid chromatography (micro-LC) with thermionic detection (TID) is described. Modifications have been made to enable separate adjustment of the eluent introduction and the detector flame temperature in order to improve the sensitivity and ease of use of the system. The micro-LC-TID was used for the chiral separation of the nerve agent O-ethyl S-2-diisopropylaminoethyl methylphosphonothioate (VX). Baseline separation for the enantiomers of VX was obtained on Chiralcel OD using 1% isopropanol in hexane as the eluent. The detection limit of VX using 60 nl injections is ca. 5 μg/ml (ppm range). However, when using large-volume injections (10 μl) the detection limit is ca. 25 ng/ml (ppb range).     

Screening,separation, and evaluation of xanthine oxidase inhibitors from Paeonia lactiflora using chromatography combined with a multi‐mode microplate reader

Natural products have become one of the most important resources for discovering novel xanthine oxidase inhibitors, which are commonly employed in the treatment of hyperuricemia and gout. However, to date, few reports exist regarding the use of monoterpene glycosides as xanthine oxidase inhibitors. Thus, we herein report the use of ultrafiltration coupled with liquid chromatography in the screening of monoterpene glycoside xanthine oxidase inhibitors from the extract of Paeonia lactiflora (P. lactiflora ), and both high‐performance counter‐current chromatography and medium‐pressure liquid chromatography were employed to separate the main constituents. Furthermore, the xanthine oxidase inhibitory activities and the mechanisms of inhibition of the isolated compounds were evaluated using a multi‐mode microplate reader by Molecular Devices. As a result, three monoterpene glycosides were separated by combined high‐performance counter‐current chromatography and medium‐pressure liquid chromatography in purities of 90.4, 98.0, and 86.3%, as determined by liquid chromatography. These three compounds were identified as albiflorin, paeoniflorin, and 1‐O‐β‐ᴅ‐glucopyranosyl‐8‐O‐benzoylpaeonisuffrone by electrospray ionization tandem mass spectrometry, and albiflorin and paeoniflorin were screened as potential xanthine oxidase inhibitors by ultrafiltration with liquid chromatography. The evaluation results of xanthine oxidase inhibitory activity corresponded with the screening results, as only albiflorin and paeoniflorin exhibited xanthine oxidase inhibitory activity.     

Determination of Phenolic Compounds and the Antioxidant Capacity of Ximenia parviflora Benth. var. parviflora (Olacaceae) Fruit by High-Performance Liquid Chromatography with Diode Array Detection

The total phenolic and flavonoid content, phenolic composition, and in vitro antioxidant capacity of ethanolic extracts of Ximenia parviflora Benth. var. parviflora fruits collected at Zinaparo, Michoacan (in central Mexico) were determined. Fruit extracts present a high scavenging activity of 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis[3-ethylbenzothiazoline-6-sulfonic acid] radicals (71.49?±?0.11% and 85.00?±?1.29% inhibition, respectively). The four phenolic compounds identified in fruit extracts by high-performance liquid chromatography with diode array detection were gallic acid, chlorogenic acid, caffeic acid, and quercetin. X. parviflora fruits may be used as a starting material for the extraction of high value antioxidant phenolic compounds with potential applications in the pharmaceutical and dietary supplement industries.     

PREPARATIVE ISOLATION AND PURIFICATION OF CHEMICAL CONSTITUENTS OF BELAMCANDA BY MPLC, HSCCC AND PREP-HPLC

Combined with medium-pressure liquid chromatography (MPLC) and preparative high-pressure liquid chromatography (Prep-HPLC), high-speed countercurrent chromatography (HSCCC) was successfully applied for separation and purification of isoflavonoids from the extract of belamcanda. HSCCC separation was performed on a two-phase solvent system composed of methyl tert-butyl ether -ethyl acetate - n-butyl alcohol - acetonitrile -0.1% aqueous trifluoroacetic acid at a volume radio of 1:2:1:1:5. Semi-purified peak fractions from HSCCC separation were further purified by Prep-HPLC. Nine well-separated fractions were analyzed by HPLC-UV absorption spectrometry to determine their purities and characterized with ESI-MS(n). Except for peaksland VII (unknown) seven compounds were identified as apocynin (peak II), mangiferin (peak III), 7-O-methylmangiferin (peak IV), hispidulin (peak V), 3'-hydroxyltectoridin (peak VI), iristectorin B (peak VII), isoiridin (peak IX).     

Halioxepine, a new meroditerpene from an Indonesian sponge Haliclona sp

Chemical investigations on a sponge Haliclona sp. found a meroditerpene 1 having a new carbon skeleton. By analyzing spectroscopic data, the structure was elucidated to comprise a substituted hydroquinone, a tetrahydrooxepine, and a cyclohexene, and these components were united with C1 and C2 units. Compound 1 showed moderate cytotoxicity against NBT-T2 cells with IC50 4.8 μg/ml and also antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) with IC50 3.2 μg/ml.     

Purification of polysaccharide from artificially cultivated Anoectochilus roxburghii (wall.) Lindl. by high‐speed counter current chromatography and its antitumor activity

To establish a systematic method for the extraction, purification, characterization and antitumor activity study of polysaccharide from artificially cultivated Anoectochilus roxburghii (wall.) Lindl. (AC‐ARPS). High‐speed counter current chromatography with two‐phase aqueous systems was successfully applied to purify AC‐ARPS after one‐step separation. The purity of the AC‐ARPS obtained by phenol/sulfuric acid method was 95.01%. The chemical structures of AC‐ARPS were identified by a series of analytical methods including high‐performance liquid chromatography and liquid chromatography with mass spectrometry. High‐performance liquid chromatography and liquid chromatography with mass spectrometry indicated that AC‐ARPS was mainly composed of mannose, ribose, glucose, galactose and arabinose with a molar ratio of 1.00:8.47:47.30:1.17:1.19. AC‐ARPS is a homogeneous polysaccharide with a molecular weight of 25 681 Da. The antitumor effect of AC‐ARPS was evaluated on lung cancer A549, osteosarcoma 143B, rat adrenal pheochromocytoma PC 12, breast cancer MCF‐7, acute leukemia HL 60, chronic leukemia K562, colon cancer SW620, esophageal cancer OE 19, liver cancer HepG2, and neuroglioma U251 cells in vitro. AC‐ARPS showed the best inhibitory effect on OE 19 cells, and the IC₅₀ value was 5.67 ± 0.831 μmol/L. Fluorescence analysis and flow cytometry results showed that AC‐ARPS induced apoptosis and G2/M phase arrest in OE 19 cells.     

Preparative isolation and analysis of alcohol dehydrogenase inhibitors from Glycyrrhiza uralensis root using ultrafiltration combined with high‐performance liquid chromatography and high‐speed countercurrent chromatography

A simple, rapid, and effective assay based on ultrafiltration combined with high‐performance liquid chromatography and high‐speed countercurrent chromatography was developed for screening and purifying alcohol dehydrogenase inhibitors from Glycyrrhiza uralensis root extract. Experiments were carried out to optimize binding conditions including alcohol dehydrogenase concentration, incubation time, temperature, and pH. By comparing the chromatograms, three compounds were found possessing alcohol dehydrogenase binding activity in Glycyrrhiza uralensis root. Under the target‐guidance of ultrafiltration combined with the high‐performance liquid chromatography experiment, liquiritin ( 1 ), isoliquiritin ( 2 ), and liquiritigenin ( 3 ) were separated by high‐speed countercurrent chromatography using ethyl acetate/methanol/water (5:1:4) as the solvent system. The alcohol dehydrogenase inhibitory activities of these three isolated compounds were assessed; compound 2 showed strongest inhibitory activity with an IC₅₀ of 8.95 μM. The results of the present study indicated that the combinative method using ultrafiltration, high‐performance liquid chromatography and high‐speed countercurrent chromatography could be widely applied for the rapid screening and isolation of enzyme inhibitors from complex mixtures.     

Tracking antiangiogenic components from Glycyrrhiza uralensis Fisch. based on zebrafish assays using high-speed countercurrent chromatography

Natural products are some of the most important sources of lead compounds for drug discovery. The advanced isolation technique of lead compounds of natural origin using therapeutically relevant bioassays is capable of enhancing work efficiency from complex multiconstituent extracts. In the present study, a bioassay-guided isolation strategy combined with bioactivity screening was used to identify novel angiogenesis inhibitors from licorice (Glycyrrhiza uralensis Fisch.) based on the zebrafish model and rapid preparative separation by high-speed countercurrent chromatography. Zebrafish embryos at 24 h postfertilization were chosen as the angiogenesis inhibition model for bioactivity screening. A solvent system (n-hexane-ethyl acetate-methanol-water) with different ratios was optimized and applied in the high-speed countercurrent chromatography separation of two fractions, Fr5 and Fr6, from the ethyl acetate extract of licorice. Blood circulation and vascular outgrowth in intersegmental vessels were found to be simultaneously inhibited by isoliquiritigenin and isolicoflavonol in a dose-dependent manner. Thus, these two compounds were identified and considered as active inhibitors against angiogenesis. These experimental results indicate that zebrafish bioassays combined with high-speed countercurrent chromatography may provide an alternative pathway for the rapid isolation of bioactive natural products.     

Major flavonoid components of heartsease (<Emphasis Type="Italic">Viola tricolor</Emphasis> L.) and their antioxidant activities

Sephadex LH-20 column chromatography was used to separate flavonoid components in a heartsease methanol extract. One of the main components was identified by NMR as violanthin (6-C-glucosyl-8-C-rhamnosylapigenin). As a first approximation, the other main flavonoid component was considered to be rutin (3-O-rhamnoglucosylquercetin), based on comprehensive comparison of retention times and UV spectra of reference molecules, as well as molecular mass and fragmentation patterns obtained by mass spectrometry. The minor flavonoids were separated by polyamide column and analyzed by LC-MS. The antioxidant capacity of different flavonoid fractions was determined using both Trolox equivalent antioxidant capacity (TEAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) in vitro antioxidant assays. The highest electron-donor capacity was found for the major flavonoid component (rutin), whereas one minor component-rich flavonoid fraction exhibited the highest hydrogen-donor activity.     

Identification and quantification of anthocyanins,flavonoids, and phenolic acids in flowers of Rhododendron arboreum and evaluation of their antioxidant potential

The current study aimed to investigate the anthocyanins, non-anthocyanins (flavonoids and phenolic acids), and free radicals scavenging potential in the flowers of Rhododendron arboreum using ultra high performance liquid chromatography with ion mobility quadrupole time of flight tandem mass spectrometry. A total of 25 constituents including nine anthocyanins, six phenolic acids, and ten flavonoids were identified in the flower extract. The major anthocyanins identified were cyanidin-3-O-β-galactoside ( 1 ), cyanidin-3-O-α-arabinoside ( 4 ), and cyanidin-3-O-rhamnoside ( 8 ), while quercetin glycosides were the main identified flavonoids in R. arboreum flowers. Additionally, ultra high performance liquid chromatography methods were developed and validated for the quantification of nine compounds (anthocyanins, flavonoid glycosides, and phenolic acids); five of them were quantified using internal standards. The extracts were analyzed for total phenolics (123.6 mg GAE/g), anthocyanin content (1.76% w/w), and evaluated for antioxidant properties against 2,2-diphenyl-1-picrylhydrazyl radical (IC₅₀: 102.06 and 96.92 μg/mL) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical cation (112.25 and 45.59 μM TE/g) assays. The profiling of R. arboreum for anthocyanins is reported for the first time. The findings suggest that the flowers are a promising source of bioactive constituents and could be used as functional food, antioxidants, and nutraceuticals.