One injection to profile the chemical composition and dual-antioxidation activities of Rosa chinensis Jacq

Comparative study on metabolite variations of two rose teas by plant metabolomics and revealing their skin-whitening candidates by spectrum-effect relationship analysis

INTRODUCTION

Rosa rugosa var. plena Rehd (CBR) and Rosa chinensis cv. "JinBian" (JBR) are two common species used in rose tea among different original species. CBR, the officially documented original plant of the rose species for food and medicinal purposes, is more costly than JBR. With increasing demand for different rose teas, it is meaningful to compare the chemical constituents for their quality control and reveal their skin-whitening components that will provide in-depth insights for the expansion of the rose tea industry.

OBJECTIVE

This study aims to reveal the chemical variances between CBR and JBR and determine their skin-whitening components.

METHODOLOGY

A strategy obtained by combining MS-based plant-metabolomics with spectrum-effect relationship analysis has been proposed for unveiling chemical differences between CBR and JBR and further exploring their potential skin-whitening components.

RESULTS

A total of 2030 metabolites were found that revealed considerable differences between CBR and JBR. The results of bioactivity assay demonstrated that JBR exhibited stronger tyrosinase inhibition activity than CBR. Six potential skin-whitening compounds (di-O-galloyl-HHDP-glucoside, tri-O-galloyl-HHDP-glucoside, spiraeoside, quinic acid, rugosin A, and 1,2,3,6-tetra-O-galloyl-glucose) were discovered as potential tyrosinase inhibitors, via spectrum-effect relationship analysis. This is the first time that di-O-galloyl-HHDP-glucoside, tri-O-galloyl-HHDP-glucoside, rugosin A, and 1,2,3,6-tetra-O-galloyl-glucose have been reported with tyrosinase inhibitory activity. Additionally, molecular docking analysis was used to reveal the inhibition mechanism of these compounds toward tyrosinase.

CONCLUSION

The finding of this study will be of great importance for the quality control of the two types of rose teas, and the revealed active ingredients will provide in-depth insights for the expansion of the rose tea industry.

Phytochemical analysis, antioxidant and ALR2 inhibitory activity of Sorbus torminalis (L.) fruits at different maturity stages

Thirty four compounds were identified in Sorbus torminalis (L.) fruit extracts of different maturity types by means of LC-DAD-MS (ESI+) fragmentation analysis. Both immature and mature fruits were rich in flavonoid glycosides esterified with hydroxycinnamic, phenolic and dicarboxylic acids along with benzoic, phenylpropanoic and cinnamoyl quinic acid derivatives with many of them being detected for the first time in Sorbus species and in literature. Extracts and fractions were tested for their antioxidant activity (DPPH, chemiluminescence, Rancimat assays) and the estimation of the phenolic content was carried out through Folin-Ciocalteu reagent. Ethyl acetate fraction exhibited the highest scavenging activity determined as EC50 = 1.58 ± 0.22 μg/mL and EC50 = 1.64 ± 0.24 μg/mL for immature and mature fruits respectively with the DPPH test. Chemiluminescence test indicated the same fraction having the strongest antioxidant activity with an IC50 0.41 ± 0.06 μg/mL and IC50 0.50 ± 0.02 μg/mL in both maturity types. The ethyl acetate fraction of the mature fruits is considered the most potent Aldose Reductase 2 (ALR2) inhibitor with 79% demonstrating the high nutritional value of Sorbus torminalis (L.) mature fruits as a defense mechanism against the onset of diabetes mellitus secondary complications leading to the utilization of the plant for nutritional and pharmaceutical purposes.

Characterization of volatiles in flowers from four Rosa chinensis cultivars by HS-SPME-GC × GC-QTOFMS

Rosa chinensis cultivars with volatile aromas are important resources in the perfume industry. The four rose cultivars introduced to Guizhou province are rich in volatile substances. In this study, volatiles from four Rosa chinensis cultivars were extracted using headspace-solid phase microextraction (HS-SPME), and analyzed with two-dimensional gas chromatography quadrupole time of flight mass spectrometry (GC × GC-QTOFMS). A total of 122 volatiles were identified; the main compounds in these samples were benzyl alcohol, phenylethyl alcohol, citronellol, beta-myrcene and limonene. A total of 68, 78, 71, and 56 volatile compounds were identified in Rosa 'Blue River' (RBR), Rosa 'Crimson Glory' (RCG), Rosa 'Pink Panther' (RPP), and Rosa 'Funkuhr' (RF) samples, respectively. The total volatile contents were in the following order: RBR > RCG > RPP > RF. Four cultivars exhibited similar volatility profiles, with alcohols, alkanes, and esters as the major chemical groups, followed by aldehydes, aromatic hydrocarbons, ketones, benzene, and other compounds. Alcohols and aldehydes were quantitatively the two most abundant chemical groups that included the highest number and highest content of compounds. Different cultivars have different aromas, and RCG had high contents of phenyl acetate, rose oxide, trans-rose oxide, phenylethyl alcohol and 1,3,5-trimethoxybenzene, characterized by floral and rose descriptors. RBR contained a high content of phenylethyl alcohol, and RF contained a high content of 3,5-dimethoxytoluene. Hierarchical cluster analysis (HCA) of all volatiles showed that the three cultivars (RCG, RPP, and RF) had similar volatile characteristics and were significantly different from RBR. Differential metabolites among cultivars were screened based on the OPLS-DA model, and there were six main enriched pathways of differential metabolites: biosynthesis of secondary metabolites, monoterpenoid biosynthesis, metabolic pathways, limonene and pinene degradation, sesquiterpenoid and triterpenoid biosynthesis, and alpha-linolenic acid metabolism. The biosynthesis of secondary metabolites is the most differential metabolic pathway.

Rapid identification, quantitation, and antioxidant activity evaluation of the components in Guanxin Shutong capsule with liquid chromatography and mass spectrometry

Guanxin Shutong capsule (GSC) is a traditional Chinese medicinal prescription used in the treatment of coronary heart disease (CHD) and angina pectoris in clinic. However, the chemical profile of GSC is still uncovered, which hindered the progress of pharmacological study and clinical application. Herein, high performance liquid chromatography (HPLC) together with high resolution mass spectrometry (HR-MS) techniques were employed to analyze the quality consistency and to identify chemical components in GSC. As a result, a total of 111 compounds were tentatively annotated. Quantitative analysis based on HPLC-ultraviolet detection (UV) was performed for 6 main components and fingerprints of 10 different batches of GSC were established. The developed method was validated for linearity, precision, repeatability, stability, and recovery. The quality evaluation and similarity analysis of the 10 batches were also performed. Furthermore, in vitro antioxidant activity assays demonstrated that GSC exhibited potential DPPH and hydroxyl radical scavenging capacities. Especially, salvianolic acids showed the strongest free radical scavenging capacities, which might be the main component for quality control of GSC.

Online Extraction–DPPH–HPLC-DAD-QTOF-MS System for Efficient Screening and Identification of Antioxidants from Citrus aurantium L. Var. amara (Rutaceae): Integrating Sample Preparation and Antioxidants Profiling

The lack of a direct connection between solid edible or medical natural products and bioactive compound profiling is a bottleneck in natural product research and quality control. Here, a novel integrated system, online extraction (OLE)–2,2′-diphenyl-1-picrylhydrazyl (DPPH)–HPLC−DAD−QTOF-MS, was fabricated to extract, screen, and identify antioxidants from the whole fruit of Citrus aurantium L. var. amara (CAVA, Rutaceae) simply, rapidly, and efficiently. The system consumes less sample (1.0 mg of CAVA powder) and requires a shorter analytical time (45 min for sample extraction, antioxidants screening, separation, and identification). Eight antioxidant flavonoids were screened and identified, and six available flavanones were sensitively, precisely, and accurately quantified. Two major flavanone glycosides, naringin (50.37 ± 0.43 mg/g) and neohesperidin (38.20 ± 0.27 mg/g), exhibit potent DPPH scavenging activities with IC₅₀ values of 111.9 ± 10.06 and 178.55 ± 11.28 μg/mL. A minor flavanone aglycone, hesperitin (0.73 ± 0.06 mg/g), presents stronger DPPH scavenging activity (IC₅₀, 39.07 ± 2.51 μg/mL). Furthermore, density functional theory calculations demonstrated their electron transport ability and chemical reactivity, which confirmed the screened results. The results indicate that the developed OLE–DPPH–HPLC−DAD−QTOF-MS system provides new perspectives for analysis of antioxidants from complex natural products, which also contribute to the quality evaluation of CAVA.

Chemical constituents and pharmacological activities of medicinal plants from Rosa genus

The genus Rosa (Rosaceae family) includes about 200 species spread in the world, and this genus shows unique advantages in medicine and food. To date, several scholars concentrated on compounds belonging to flavonoids, triterpenes, tannins, polysaccharide, phenolic acids, fatty acids, organic acids, carotenoids, and vitamins. Pharmacological effects such as antineoplastic and anti-cancer properties, anti-inflammatory, antioxidant, liver protection, regulate blood sugar, antimicrobial activity, antiviral activity, as well as nervous system protection and cardiovascular protection were wildly reported. This article reviews the chemical constituents, pharmacological effects, applications and safety evaluations of Rosa plants, which provides a reference for the comprehensive utilization of medicine and food resources and gives a scientific basis for the development of medicinal plants of the genus Rosa.

(-)-Epicatechin-An Important Contributor to the Antioxidant Activity of Japanese Knotweed Rhizome Bark Extract as Determined by Antioxidant Activity-Guided Fractionation

The antioxidant activities of Japanese knotweed rhizome bark extracts, prepared with eight different solvents or solvent mixtures (water, methanol, 80% methanol_(aq), acetone, 70% acetone_(aq), ethanol, 70% ethanol_(aq), and 90% ethyl acetate_(aq)), were determined using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging assay. Low half maximal inhibitory concentration (IC₅₀) values (2.632–3.720 µg mL⁻¹) for all the extracts were in the range of the IC₅₀ value of the known antioxidant ascorbic acid at t₀ (3.115 µg mL⁻¹). Due to the highest extraction yield (~44%), 70% ethanol_(aq) was selected for the preparation of the extract for further investigations. The IC₅₀ value calculated for its antioxidant activity remained stable for at least 14 days, while the IC₅₀ of ascorbic acid increased over time. The stability study showed that the container material was of great importance for the light-protected storage of the ascorbic acid_(aq) solution in a refrigerator. Size exclusion–high-performance liquid chromatography (SEC-HPLC)–UV and reversed phase (RP)-HPLC-UV coupled with multistage mass spectrometry (MSⁿ) were developed for fractionation of the 70% ethanol_(aq) extract and for further compound identification, respectively. In the most potent antioxidant SEC fraction, determined using an on-line post-column SEC-HPLC-DPPH assay, epicatechin, resveratrol malonyl hexoside, and its in-source fragments (resveratrol and resveratrol acetyl hexoside) were tentatively identified by RP-HPLC-MSⁿ. Moreover, epicatechin was additionally confirmed by two orthogonal methods, SEC-HPLC-UV and high-performance thin-layer chromatography (HPTLC) coupled with densitometry. Finally, the latter technique enabled the identification of (−)-epicatechin. (−)-Epicatechin demonstrated potent and stable time-dependent antioxidant activity (IC₅₀ value ~1.5 µg mL⁻¹) for at least 14 days.