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Main HMBC (indicated by blue arrows from ¹H to ¹³C) and H-H COSY correlations (indicated by bold lines) of compounds 1 and 2.
Source publication
Two new resveratrol trimer derivatives, named rheumlhasol A (1) and rheumlhasol B (2) were isolated from the methanolic extract of roots of Rheum lhasaense A. J. Li et P. K. Hsiao together with four known resveratrol dimer derivatives, including maximol A (3), gnetin C (4), ε-viniferin (5), and pallidol (6). The structures were determined by combin...
Citations
... Chromatographic fractionation of defatted fraction of aerial parts (ATD) led to the isolation and characterization of nine known compounds. The structures of the isolated compounds were identified upon spectral data analysis (Spectroscopic data of compounds were shown in supplementary materials) and confirmed by comparison with those published in the literature ( Fig. 1) as: 20-hdroxy ecdysone (1) [36], phytol (2) [37], β-sitosterol (3) [38], stigmasterol (4) [38], palmitic acid (5) [39], luteolin (6) [38,40], β-sitosterol-3-O-β-d-glucopyranoside (7) [40,41], pallidol (8) [42,43] and isorhamnetin 3-O-β-galactopyranoside (9) [44,45]. ...
Background
The plant kingdom has long been considered a valuable source for therapeutic agents, however, some plant species still untapped and need to be phytochemically and biologically explored. Although several Atriplex species have been investigated in depth, A. leucoclada, a halophytic plant native to Saudi Arabian desert, remains to be explored for its phytochemical content and biological potentials. Herein, the current study investigated the metabolic content and the anti-inflammatory potential of A. leucoclada.
Methods
Powdered aerial parts of the plant were defatted with n-hexane then the defatted powder was extracted with 80% methanol. n-Hexane extract (ATH) was analyzed using GC–MS, while the defatted extract (ATD) was subjected to different chromatographic methods to isolate the major phytoconstituents. The structures of the purified compounds were elucidated using different spectroscopic methods including advanced NMR techniques. Anti-inflammatory activity of both extracts against COX-1 and COX-2 enzymes were examined in vitro. Molecular docking of the identified compounds into the active sites of COX-1 and COX-2 enzymes was conducted using pdb entries 6Y3C and 5IKV, respectively.
Results
Phytochemical investigation of ATD extract led to purification and identification of nine compounds. Interestingly, all the compounds, except for 20-hydroxy ecdysone (1), are reported for the first time from A. leucoclada, also luteolin (6) and pallidol (8) are isolated for the first time from genus Atriplex. Inhibitory activity of ATD and ATH extracts against COX-1 and COX-2 enzymes revealed concentration dependent activity of both fractions with IC50 41.22, 14.40 μg/ml for ATD and 16.74 and 5.96 μg/ml for ATH against COX-1 and COX-2, respectively. Both extracts displayed selectivity indices of 2.86 and 2.80, respectively as compared to 2.56 for Ibuprofen indicating a promising selectivity towards COX-2. Molecular docking study supported in vitro testing results, where purified metabolites showed binding affinity scores ranged from -9 to -6.4 and -8.5 to -6.6 kcal/mol for COX-1 and 2, respectively, in addition the binding energies of GC–MS detected compounds ranged from -8.9 to -5.5 and -8.3 to -5.1 kcal/mol for COX-1 and 2, respectively as compared to Ibuprofen (-6.9 and -7.5 kcal/mol, respectively), indicating high binding affinities of most of the compounds. Analysis of the binding orientations revealed variable binding patterns depending on the nature of the compounds. Our study suggested A. leucoclada as a generous source for anti-inflammatory agents.
... In the literature, the RSV IC50 values obtained from the DPPH assay (the most widely used method for measuring its antioxidant activity) have been highly variable ( Figure 7). In our study, the RSV IC50 (81.92 ± 9.17 µM) was similar to that reported in the study of Ha [12][13][14][15][16]. Three studies reported VNF IC50 values between 52.6 and 92 µM, which was comparable to the VNF IC50 value in our study (80.12 ± 13.79 µM) [9,12,17]. No study was available for VB. ...
... In our study, the RSV IC 50 (81.92 ± 9.17 µM) was similar to that reported in the study of Ha [12][13][14][15][16]. Three studies reported VNF IC 50 values between 52.6 and 92 µM, which was comparable to the VNF IC 50 value in our study (80.12 ± 13.79 µM) [9,12,17]. No study was available for VB. ...
The control of oxidative stress with natural active substances could limit the development of numerous pathologies. Our objective was to study the antiradical effects of resveratrol (RSV), ε-viniferin (VNF), and vitisin B (VB) alone or in combination, and those of a standardized stilbene-enriched vine extract (SSVE). In the DPPH-, FRAP-, and NO-scavenging assays, RSV presented the highest activity with an IC50 of 81.92 ± 9.17, 13.36 ± 0.91, and 200.68 ± 15.40 µM, respectively. All binary combinations resulted in additive interactions in the DPPH- and NO-scavenging assays. In the FRAP assay, a synergic interaction for RSV + VNF, an additive for VNF + VB, and an antagonistic for RSV + VB were observed. The ternary combination of RSV + VNF + VB elicited an additive interaction in the DPPH assay and a synergic interaction in the FRAP- and NO-scavenging assays. There was no significant difference between the antioxidant activity of the SSVE and that of the combination of RSV + VNF. In conclusion, RSV presented the highest effects, followed by VNF and VB. The interactions revealed additive or synergistic effects, depending on the combination of the stilbenes and assay.
... Its dry roots are usually used as medicine to treat constipation, stomachache, hyperlipidemia, cardiovascular, and cerebrovascular disease (Dashang 1997;Lin et al. 2019). The root of R. lhasaense didn't contain anthraquinone, which is a significant difference between R. lhasaense and other Rheum species (Liu et al. 2013). Despite its importance in medicinal value, there is little genetic information reported for R. lhasaense. ...
Rheum lhasaense (Polygonaceae) is one of the genuine medicinal herbs in Qinghai-Tibet Plateau, China. Here we report the first chloroplast (cp) genome of R. lhasaense using Illumina NovaSeq 6000 platform. The length of its complete cp genome is 161,820 bp, containing four sub-regions. A large single copy region (LSC) of 87,086 bp and a small single copy region (SSC) of 12,814 bp are separated by a pair of inverted repeat regions (IRs) of 30,960 bp. The complete cp genome of R. lhasaense contains 130 genes, including 85 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The overall GC content of the cp genome is 37.4%. The phylogenetic analysis, based on 28 cp genomes, suggested that R. lhasaense is closely related to R. acuminatum and R. pumilum.
... Resveratrol oligomers are biosynthesized via regioselective oxidative coupling of 2 to 8 monomers [30]. The oligomers can be formed through several self-mergers done by numerous distinct CeC and CeO binding [31]. ...
Resveratrol has been extensively reported as a potential compound to treat some skin disorders, including skin cancer, photoaging, allergy, dermatitis, melanogenesis, and microbial infection. There has been an increasing interest in the discovery of cosmetic application using resveratrol as the active ingredient because of its anti-aging and skin lightening activities. The naturally occurring derivatives of resveratrol also exert a beneficial effect on the skin. There are four groups of resveratrol derivatives, including hydroxylated compounds, methoxylated compounds, glycosides, and oligomers. The major mechanism of resveratrol and its derivatives for attenuating cutaneous neoplasia, photoaging and inflammation, are related with its antioxidative activity to scavenge hydroxyl radical, nitric oxide and superoxide anion. A systematic review was conducted to describe the association between resveratrol-related compounds and their benefits on the skin. Firstly, the chemical classification of resveratrol and its derivatives was introduced. In this review the cases which were treated for different skin conditions by resveratrol and the derivatives were also described. The use of nanocarriers for efficient resveratrol skin delivery is also introduced here. This review summarizes the cutaneous application of resveratrol and the related compounds as observed in the cell-based, animal-based and clinical models. The research data in the present study relates to the management of resveratrol for treating skin disorders and suggesting a way forward to achieve advancement in using it for cosmetic and dermatological purpose. © 2021, Taiwan Food and Drug Administration. All rights reserved.
... In particular, the antioxidant properties of RE had been shown to correlate with the position of the hydroxyl groups [26]. In addition, the biological properties of RE had been expanded using several modifications, including hydroxylation, methylation, and isoprenylation, and also via the formation of di-, tri-, and oligomers [27]. Furthermore, the applications of RE and its derivatives had been expanded to the development of new anticancer agents. ...
To expand the applications and enhance the stability and bioactivity of resveratrol (RE), and to simultaneously include the potential health benefits of short chain fatty acids (SCFA) esters of RE were prepared by Steglich reactions with acetic, propionic, and butyric acids, respectively. RE and the esterified RE-SCFA products (including RAE, RPE, and RBE) were analyzed using nuclear magnetic resonance (NMR), Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), differential thermal analysis (DTA), and liquid chromatography–mass spectrometry (LC–MS). The FTIR and ¹³C NMR spectra of the esterified products included ester-characteristic peaks at 1751 cm⁻¹ and 171 ppm, respectively. Moreover, the peaks in the range of 1700 to 1600 cm⁻¹ in the FTIR spectra of the esterified products indicated that the esterification of RE-SCFA was successful. The TGA results revealed that the RE-SCFA esters decomposed at lower temperatures than RE. The peaks in the LC–MS profiles of the esterified products indicated the formation of mono- and diesters, and the calculated monoester synthesis rates ranged between 45.81 and 49.64%. The RE esters inhibited the Cu²⁺-induced low-density lipoprotein oxidation reaction, exhibited antioxidant activity in bulk oil, and effectively inhibited the hydroxyl radical-induced DNA scission. Moreover, the RE-SCFA esters had better hydrogen peroxide scavenging activity than RE. Our results are the first in the literature to successfully including short chain fatty acids in the esters of resveratrol, and the products could be used as a functional food ingredient in processed foods or can be used as dietary supplements to promote health.
... There are, however, a few investigations on the chemical compounds and pharmacological activities of R. lhasaense. So far, only 12 stilbenoids were isolated and identified from its root, some of which possessed significant antioxidant activity [5,6]. Based on previous studies on the chemical analysis of R. lhasaense, it was known that anthraquinone derivatives considered as one of the most representative components in plants of the genus Rheum were not contained in R. lhasaense [7]. ...
... Apart from the presence of four new compounds (5, 13, 14 and 16), another 15 known compounds were also isolated from ethyl acetate soluble parts. Based on the spectroscopic data and comparison to related references, 15 known compounds were confirmed as deoxyrhapontigenin (1) [11], desoxyrhaponticin (2) [11], gnetinC (3) [12], maximol A (4) [13], rheumlhasol A (6) [6], piceatannol-3′-O-glucoside (7) [14], catechin (8) [15], dibutylphthalate (9) [16], ε-viniferin (10) [6], 1,6-digalloylβ-d-glucose (11) [17], polydatin (12) [11], resveratrol (15) [18], piceatannol (17) [18], 1,2,6-tri-O-galloyl-β-d-glucose (18) [19], gallic acid (19) [20]. These reported compounds have also been isolated from other plants of the genus Rheum. ...
... Apart from the presence of four new compounds (5, 13, 14 and 16), another 15 known compounds were also isolated from ethyl acetate soluble parts. Based on the spectroscopic data and comparison to related references, 15 known compounds were confirmed as deoxyrhapontigenin (1) [11], desoxyrhaponticin (2) [11], gnetinC (3) [12], maximol A (4) [13], rheumlhasol A (6) [6], piceatannol-3′-O-glucoside (7) [14], catechin (8) [15], dibutylphthalate (9) [16], ε-viniferin (10) [6], 1,6-digalloylβ-d-glucose (11) [17], polydatin (12) [11], resveratrol (15) [18], piceatannol (17) [18], 1,2,6-tri-O-galloyl-β-d-glucose (18) [19], gallic acid (19) [20]. These reported compounds have also been isolated from other plants of the genus Rheum. ...
Four unknown stilbenoids, including one dimer, namely 4′-methoxy-scirpusin A (5) and three monomeric stilbene glycosides, namely piceatannol-3′-O-[2′′-(3,5-dihydroxy-4-methoxybenzoyl)]-β-d-glucopyranoside (13), piceatannol-3′-O-(2′′-galloyl)-β-d-glucopyranoside (14) and piceatannol-3′-O-(6″-p-coumaroyl)-β-d-glucopyranoside (16) together with 15 described compounds, were isolated from the ethyl acetate fraction of the ethanol extract of roots of Rheum lhasaense based on the guidance of the inhibitory effect on acetylcholinesterase. The structures of the unknown compounds were established by combined spectroscopic analysis and comparing their spectral data with compounds with similar structures. Some selected components were also investigated for their inhibitory abilities on acetylcholinesterase (AChE), indicating that compound 13 may be responsible for higher inhibitory activity of the ethyl acetate fraction on AChE.
... It has been shown that the position of the hydroxyl groups is directly involved in its antioxidant properties, [30] and the presence of 4 -OH together with the trans stereochemistry are involved in its inhibitory effect on cell proliferation [31]. In addition, the biological properties of resveratrol are expanded through several modifications, including hydroxylation, methylation, isoprenylation, and by the formation of dimers, trimers, and oligomers [32]. Accordingly, the applications of resveratrol and its derivatives are also expanded, including the development of new anticancer agents. ...
... It has been shown that the position of the hydroxyl groups is directly involved in its antioxidant properties, [30] and the presence of 4′-OH together with the trans stereochemistry are involved in its inhibitory effect on cell proliferation [31]. In addition, the biological properties of resveratrol are expanded through several modifications, including hydroxylation, methylation, isoprenylation, and by the formation of dimers, trimers, and oligomers [32]. Accordingly, the applications of resveratrol and its derivatives are also expanded, including the development of new anticancer agents. ...
To facilitate broad applications and enhance bioactivity, resveratrol was esterified to resveratrol butyrate esters (RBE). Esterification with butyric acid was conducted by the Steglich esterification method at room temperature with N-ethyl-N′-(3-dimethylaminopropyl) carbodiimide (EDC) and 4-dimethyl aminopyridine (DMAP). Our experiments demonstrated the synthesis of RBE through EDC- and DMAP-facilitated esterification was successful and that the FTIR spectra of RBE revealed absorption (1751 cm⁻¹) in the ester region. ¹³C-NMR spectrum of RBE showed a peak at 171 ppm corresponding to the ester group and peaks between 1700 and 1600 cm⁻¹ in the FTIR spectra. RBE treatment (25 or 50 μM) decreased oleic acid-induced lipid accumulation in HepG2 cells. This effect was stronger than that of resveratrol and mediated through the downregulation of p-ACC and SREBP-2 expression. This is the first study demonstrating RBE could be synthesized by the Steglich method and that resulting RBE could inhibit lipid accumulation in HepG2 cells. These results suggest that RBE could potentially serve as functional food ingredients and supplements for health promotion.
... Similar to the resveratrol dimer, 23 resveratrol trimers (46-68) have been obtained since 2010 from five plant families: Dipterocarpaceae, Vitaceae, Paeoniaceae, Gnetaceae and Polygonaceae. Dipterocarpaceaeis is the main source of resveratrol trimers, and 11 resveratrol trimers (46)(47)(48)(49)(50)(51)(52)(53)(54)(55)(56) were isolated from this family during this period (Table A1; Figure 4). During this period, only one new resveratrol dimer, named (−)-7a,8a-cis-ε-Viniferin (27), was isolated from the seeds of Paeonia lactiflora (Paeoniaceae). ...
... Similar to the resveratrol dimer, 23 resveratrol trimers (46-68) have been obtained since 2010 from five plant families: Dipterocarpaceae, Vitaceae, Paeoniaceae, Gnetaceae and Polygonaceae. Dipterocarpaceaeis is the main source of resveratrol trimers, and 11 resveratrol trimers (46)(47)(48)(49)(50)(51)(52)(53)(54)(55)(56) were isolated from this family during this period (Table A1; Figure 4). Dryobalanops is a unique genus in the Dipterocarpaceae family that only lives in the tropical forests of west Malysia with only seven species worldwide [39]. ...
... The biosynthetic pathway of rheumlhasol B (66) is the gnetin C oxidative coupling with another resveratrol monomer. This is the first time resveratrol trimers were discovered in the plants of Rheum [49]. ...
Resveratrol oligomers (REVs), a major class of stilbenoids, are biosynthesized by regioselective oxidative coupling of two to eight units of resveratrol monomer. Due to their unique structures and pleiotropic biological activities, natural product chemists are increasingly focusing on REVs in the last few decades. This study presents a detailed and thorough examination of REVs, including chemical structures, natural resources, and biological activities, during the period of 2010–2017. Ninety-two new REVs compounds, including 39 dimers, 23 trimers, 13 tetramers, six resveratrol monomers, six hexamers, four pentamers, and one octamer, have been reported from the families of Dipterocarpaceae, Paeoniaceae, Vitaceae, Leguminosae, Gnetaceae, Cyperaceae, Polygonaceae Gramineae, and Poaceae. Amongst these families, Dipterocarpaceae, with 50 REVs, accounts for the majority, and seven genera of Dipterocarpaceae are involved, including Vatica, Vateria, Shorea, Hopea, Neobalanocarpus, Dipterocarpus, and Dryobalanops. These REVs have shown a wide range of bioactivities. Pharmacological studies have mainly focused on potential efficacy on tumors, bacteria, Alzheimer’s disease, cardiovascular diseases, and others. The information updated in this review might assist further research and development of novel REVs as potential therapeutic agents.
... Gnetin-C is a resveratrol dimer that has been isolated from several species of the Gnetaceae family and from Rheum ilasaense. 28,29 The ethanol extracts from the fruits, leaves, and seeds of melinjo (G. gnemon), an edible plant native to Southeast Asia and the western Pacific islands, are rich in resveratrol and various stilbenes, including gnetin-C. ...
Resveratrol has been extensively studied to investigate its biological effects, including its chemopreventive potential against cancer. Over the past decade, various resveratrol oligomers, both naturally occurring and synthetic, have been described. These resveratrol oligomers result from the polymerization of two or more resveratrol units to form dimers, trimers, tetramers, or even more complex derivatives. Some oligomers appear to have antitumor activities that are similar or superior to monomeric resveratrol. In this review, we discuss resveratrol oligomers with anticancer potential, with emphasis on well-characterized compounds, such as the dimer gnetin-C and other oligomers from Gnetum gnemon, whose safety, pharmacokinetic, and biological activities have been studied in humans.
... The structure of compound 1 was in agreement with that of the reported vitisin A, which was previously isolated from Vitis coignetiae [20]. Compared the 1 H NMR and 13 C NMR data with the literature values, compound 2 was identified as-viniferin [21]. The 1 H NMR spectrum exhibited signals for two 4-hydroxybenzene moieties at 7.11 (2H, d, J = 8.4 Hz) and 6.73 (2H, d, J = 8.4 Hz), 7.11 (2H, d, J = 8.4 Hz) and 6.65 (2H, d, J = 8.4 Hz); one 3,5-dihydroxybenzene moieties at 6.03 (2H, d, J = 2.2 Hz) and 6.04 (1H, t, J = 2.2 Hz); two aliphatic protons of a dihydrobenzofuran ring at 5.32 (1H, d, J = 5.2 Hz) and 4.40 (1H, d, J = 5.2 Hz); two trans olefinic protons at 6.81 (1H, d, J = 16.2 ...
Grapevine canes represent a large source of waste derived from the wine industry with low added-value. In the current work, the cane stilbene composition of twenty two grape cultivars (including Vitis vinifera sativa, Vitis vinifera sylvestris and hybrid direct producers) was investigated. Ten stilbenes were identified and quantified: hopeaphenol, ampelopsin A, isohopeaphenol, piceatannol, trans-piceid, trans-resveratrol, miyabenol C, ε-viniferin, r-viniferin and ω-viniferin. Total stilbene concentration ranged from 2400 to 5800 mg/kg dry weight. Principal component analysis applied to stilbene concentration showed a separation of cultivars in five groups. Antioxidant capacity of the stilbene extracts varied from 1700 to 5300 μmol Trolox equivalent/g dry weight. No relationship was found between stilbene content and ORAC values. Finally, the effect of year on cane stilbene content was also studied in V. vinifera sylvestris grapevine. The effect of the year depended on the cultivar. Data reported sustain the use of grapevine cane byproducts as a low cost source of bioactive stilbenes for the development of natural fungicides as well as nutraceutical, as strategy for sustainable viticulture.
