Identification and quantification of anthocyanins, flavonoids, and phenolic acids in flowers ofRhododendron arboreumand evaluation of their antioxidant potential

Abstract

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.

Mass spectrometry and NMR spectroscopy profiles of red and pink Rhododendron flower petals establish them as rich sources of bioactive secondary metabolites

“…Previously, Bhatt et al, 2022, reported the presence of different phenolic acids, flavonoids, and anthocyanins in the acidified methanolic extract of R. arboreum petals by using HPLC. Various proanthocyanidins, glycosides, and hydroxycinnamates were detected from the methanolic extracts of leaves from 14 Rhododendron species using LC-MS (Jaiswal et al, 2012).…”

“…R. arboreum has red-colored petals and are consumed by local inhabitants in various forms, such as juices, jams, pickles, and chutney (Gautam et al, 2020; Kumar et al, 2019). Traditionally, these red petals in various forms (fresh, dried, and juice) are used for the treatment of various ailments like diarrhea, blood dysentery, high altitude sickness, headaches, diabetes, rheumatism, etc (Bhatt et al, 2022; Lingwan et al, 2021). The young leaves of R. arboreum have medicinal properties and are applied on the forehead to relieve headaches but cause intoxication in large quantities (Watt, 1982).…”

“…The phytochemical profiling of R. arboreum flower petals indicated the potential presence of various phytochemicals such as quinic acid, chlorogenic acid, coumaroyl quinic acid, catechin, p-coumaric acid, etc., in the hot aqueous extract which has been reported to have potential antiviral and other health beneficial properties (Lingwan et al, 2021). Recently, Bhatt et al, 2022 identified anthocyanins (cyanidin-3-O-β-galactoside, cyanidin-3-O-α-arabinoside and cyanidin-3-O-rhamnoside), phenolic acids and flavonoids in R. arboreum flower petals.…”

Ultra‐performance liquid chromatography‐Quadrupole time‐of‐flight tandem mass spectrometry‐based metabolite profiling, quality evaluation, and marker analysis of Trachyspermum ammi (L.) Sprague by high‐performance thin‐layer chromatography

“…The TPC and TFC were estimated according to the method reported earlier from our laboratory with some modifications [23][24][25].…”

Wild Edible Flowers of Western Himalayas: Nutritional Characterization, UHPLC-QTOF-IMS-Based Phytochemical Profiling, Antioxidant Properties, and In Vitro Bioaccessibility of Polyphenols

“…Estimation of Total Anthocyanin Content. Total anthocyanin content (TAC) was estimated using the method described by Bhatt et al 75 The flower samples were extracted in acidified methanol (0.1 M HCl; 10 mL) under sonication at 35 °C for 30 min. The TAC was quantified using the pH differential method.…”