Search

Quantitative analysis of Rumex nepalensis var. remotiflorus revealed that its roots contain rich anthraquinones, which has emodin, chrysophanol, and physcion contents of up to 0.30, 0.67, and 0.98 mg/g, respectively. Further phytochemical study led to the isolation and purification of seven undescribed phenolic constituents, including one flavan derivative with a 13-membered ring, polygorumin A (1), two dianthrone glucosides, polygonumnolides F and G (2 , 3), two diphenylmethanones, rumepalens A and B (4 , 5), and a pair of epimeric oxanthrone C -glucosides, rumejaposides K and L (6a , 6b) from the roots of R. nepalensis var. remotiflorus. Furthermore, 1 undescribed natural product, 1- β -D-glucoside-6′-[(2 E)-3-(4-hydroxy-3-methoxyphenyl)-2-propenoate]-3-hydroxy-5-methylphenyl (19), and 21 known phenolic compounds were obtained from the aforementioned plant for the first time. Their structures were elucidated through extensive spectroscopic data analysis. Notably, compounds 1 , 4 – 5 , and 7 – 9 exhibited inhibitory activity on α -glucosidase with IC 50 values ranging from 1.61 ± 0.17 to 32.41 ± 0.87 μM. In addition, the isolated dianthrone, chrysophanol bianthrone (14), showed obvious cytotoxicity against four human cancer cell lines (HL-60, SMMC-7721, A-549, and MDA-MB-231) with IC 50 values ranging from 3.81 ± 0.17 to 35.15 ± 2.24 μM. In silico target prediction and molecular docking studies demonstrated that the mechanism of the anticancer activity of 14 may be related to the interaction with protein kinase CK2. [Display omitted] • The chemical constituents of R. nepalensis var. remotiflorus were studied firstly. • Emodin, chrysophanol and physcion are major anthraquinones in the roots. • Seven undescribed phenols and one undescribed natural product were obtained. • Some isolates showed obvious inhibition on α -glucosidase and HL-60 cell lines. [ABSTRACT FROM AUTHOR]

Twenty-four compounds were obtained from Pteroxygonum giraldii and were classified as five triterpenes (1 – 5), two sterols (6 and 7), two quinones (8 and 11), three stilbenes (9 , 10 and 18) and twelve flavonoids (12 – 17 , 19 – 24). Seventeen of these compounds were obtained from the genus Pteroxygonum for the first time. The chemotaxonomic significance of this plant was also discussed. Compounds 10 , 12 and 23 can serve as the fingerprints for P. giraldii , and compounds 12 , 13 , 17 and 22–24 are recognized as typical metabolites of P. giraldii. Both Pteroxygonum and Polygonum might have the same origin and could be classified into the same tribe among Polygonaceae. Furthermore, due to the presence of stilbenes, Pteroxygonum may have some taxonomic relationships with Fallopia , Rumex and Reynoutria. • Twenty-four compounds are reported from Pteroxygonum giraldii. • The structures of these compounds were elucidated by spectroscopic methods and data comparison. • Seventeen of these compounds were isolated from Pteroxygonum for the first time. • Pteroxygonum may have some taxonomic relationship with Fallopia , Rumex and Reynoutria. • The compounds indicate relationships between Pteroxygonum giraldii and others within the family Polygonaceae. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • RP-UHPLC–DAD-ESI-QTOF-MS and MS/MS analysis of Hydromethanol extracts of Rumex tunetanus flowers and stems was performed. • 60 compounds from 12 families were tentatively identified for the first time in Rumex tunetanus. • Flavonoids and tannins were the principal groups. • Results suggest the potential of Rumex tunetanus as a source of bioactive ingredients. Abstract Rumex tunetanus is an untapped resource with no available information about their chemical composition. That is why, the present study has conducted comprehensive metabolites profiling of the hydromethanol extracts of the Rumex tunetanus flowers and stems using RP-UHPLC-ESI-QTOF-MS. As results, 60 compounds were characterized for the first time in Rumex tunetanus between them, 18 photochemical were firstly identified in the Polygonaceae family in negative ionization mode. In this regard, quercetin-3- O -glucuronide and (−)-epicatechin gallate were the most abundant phenolic compounds in flowers and stems, respectively. Moreover, positive correlations were found between the antioxidant activity measured by DPPH and FRAP assays with the total phenolic compounds (r = 0.98; r = 0.99, respectively) and the abundance of some phenolic subfamilies such as hydroxycinnamic acids, hydroxybenzoic acids, flavonols and flavones with r > 0.86. The compounds displaying significant (P < 0.01) and good correlations with the antioxidant activity (r > 0.93) were hydroxybenzoic acid, rutin, quercetin-3- O -glucuronide, quercetin-3- O -glucoside, quercetin and luteolin-7- O -rutinoside. In conclusion, Rumex tunetanus flowers and stems showed different bioactive compound profiles and significant antioxidant properties and could be further used in food and nutraceutical industries. [ABSTRACT FROM AUTHOR]

Antimicrobial bioactivity-guided isolation of the root extract of R umex dentatus L. resulted in the characterization of nineteen natural products, including three undescribed compounds (rumexs A−C). Rumexs A and B are rare anthraquinone-anthrone dimers consisting of an emodin-10-C-glycoside linked via C-10 to C-7 of a chrysophanol moiety. They differed only in their configuration at C-10; their absolute configurations were determined by NOESY and ECD analysis. LC-HRMS analysis was performed to identify nineteen compounds. Anthraquinone derivatives such as anthraquinone aglycone, oxanthrone C-glycoside, anthraquinone O -glycoside and anthraquinone dimer were found to be the dominant components of R. dentatus. In addition, naphthol, naphthoquinone, chromone, flavonoid, isocoumarin, and lignanamide derivatives were also identified. Chrysophanol and emodin were the most abundant compounds in the crude ethanol extract; their contents were determined by HPLC to be 7.38 and 5.74 mg/g, respectively. The fractions and isolated compounds were tested for their inhibitory activity against Staphylococcus aureus , Candida albicans , and Escherichia coli. Most of them showed inhibitory activity against S. aureus , some fractions and 2-methoxy-6-acetyl-7-methyljuglone exhibited moderate inhibitory activity against C. albicans, and 2-methoxy-6-acetyl-7-methyljuglone had moderate inhibitory effects against E. coli. Emodin exhibited inhibitory activity against NO release in LPS-reduced RAW264.7 cells in a concentration-dependent manner. [Display omitted] • Nineteen compounds were isolated and identified from the roots of Rumex dentatus guided by antimicrobial activity. • Rumexs A and B are rare anthraquinone-anthrone dimers, and rumex C is an undescribed isocoumarin. • Most of compounds exhibited inhibitory activity against S. aureus. • Emodin exhibited anti-inflammatory activity against NO production. • The contents of chrysophanol and emodin in the crude ethanol extract were determined by quantitative HPLC analysis. [ABSTRACT FROM AUTHOR]

Rumex tianschanicus x Rumex patientia is a prospective plant as a source of renewable energy and is also an important medicinal plant. In the present experiments an efficient and reproducible method for plant regeneration through the direct induction of shoot buds from hypocotyls was developed. The highest frequency of organogenetic response of explants was obtained on 7- and 12-day-old hypocotyls that had been cultured on the regeneration medium MS + 0.17 mg/l IAA + 2.2 mg/l BAP + 2% sucrose (44.06% and 48.88%, respectively). Successfully rooted plantlets were acclimated to in vivo conditions with more than a 90% survival rate. Histological analysis revealed direct organogenesis. Shoot buds arose from stele tissues and also from regenerated leaves (secondary organogenesis). Histological and SEM analyses showed a membranous-fibrillar structure, which was similar to the extracellular matrix (ECM), around non-morphogenic callus cells. The nuclear DNA content in leaves of plantlets regenerated in vitro , estimated using flow cytometry, was similar to donor plants (about 4.6 pg/2C). This is the first report concerning the micropropagation protocol for hybrid sorrel and the first DNA 2C-value estimation for this species. [ABSTRACT FROM AUTHOR]