Phenolic constituents with potent α-glucosidase inhibitory and cytotoxic activities from Rumex nepalensis var. remotiflorus.

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-ß-D-glucoside-6'-[(2E)-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 IC50 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 IC50 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.

Four new phenolic constituents from the roots of Rumex dentatus L.

Four new phenolic compounds, including two naphthalenes, musizin-8-O-ß-D-(6'-O-malonyl-3''-methoxy)glucopyranoside (1) and 2-acetyl-3-methyl-1,4-naphtho-quinone-8-O-ß-D-glucopyranoside (2), one chromone, (2'R)-7-hydroxy-2-(2'-hydroxypropyl)-5-methyl acetate chromone (3), and one xanthone, 2,8-dimethyl-3,6-dihydroxyxanthone (4) were isolated from the roots of Rumex dentatus L. (Polygonaceae). In addition, five known including four naphthalenes (5-8) and one chromone (9) were also obtained. Their structures were determined by means of extensive spectroscopic analysis and acidic hydrolysis. Compound 1 showed moderate antifungal activity against Epidermophyton floccosum, with inhibitory rate of 39.539 ± 0.412% at a concentration of 100 µM.

New seco-anthraquinone glucoside from the roots of Rumex crispus.

A new seco-anthraquinone, crispuside A (1), and three new 3,4-dihydronaphthalen-1(2H)-ones, napthalenones A-C (2-4), were isolated from the roots of Rumex crispus L., along with 10 known anthraquinones (6-14) and naphthalenone (5). Their structures were fully determined by extensive spectroscopic analyses, including ECD, and X-ray crystallography in case of compound 5, whose absolute configuration was determined for the first time. The isolates 1, 6-14 were evaluated for their anti-inflammatory and anti-fungal activity against three skin fungi, e.g., Epidermophyton floccosum, Trichophyton rubrum, and Microsporum gypseum. Most of the isolates showed weak anti-fungal and anti-inflammatory activity. Only compound 9 exhibited obvious anti-fungal activity against E. floccosum (MIC50 = 2.467 ± 0.03 µM) and M. gypseum (MIC50 = 4.673 ± 0.077 µM), while the MIC50 values of the positive control terbinafine were 1.287 ± 0.012 and 0.077 ± 0.00258 µM, respectively. The results indicated that simple emodin type anthraquinone is more potential against skin fungi than its oxyglucosyl, C-glucosyl and glycosylated seco analogues.

The genus Rumex (Polygonaceae): an ethnobotanical, phytochemical and pharmacological review.

Rumex L., a genus in Polygonaceae family with about 200 species, is growing widely around the world. Some Rumex species, called "sorrel" or "dock", have been used as food application and treatment of skin diseases and hemostasis after trauma by the local people of its growing areas for centuries. To date, 29 Rumex species have been studied to contain about 268 substances, including anthraquinones, flavonoids, naphthalenes, stilbenes, diterpene alkaloids, terpenes, lignans, and tannins. Crude extract of Rumex spp. and the pure isolates displayed various bioactivities, such as antibacterial, anti-inflammatory, antitumor, antioxidant, cardiovascular protection and antiaging activities. Rumex species have important potential to become a clinical medicinal source in future. This review covers research articles from 1900 to 2022, fetched from SciFinder, Web of Science, ResearchGate, CNKI and Google Scholar, using "Rumex" as a search term ("all fields") with no specific time frame set for the search. Thirty-five Rumex species were selected and summarized on their geographical distribution, edible parts, traditional uses, chemical research and pharmacological properties.

Ectopic expression of a phytochrome B gene from Chinese cabbage (Brassica rapa L. ssp. pekinensis) in Arabidopsis thaliana promotes seedling de-etiolation, dwarfing in mature plants, and delayed flowering.

Phytochrome B (phyB) is an essential red light receptor that predominantly mediates seedling de-etiolation, shade-avoidance response, and flowering time. In this study, we isolate a full-length cDNA of PHYB, designated BrPHYB, from Chinese cabbage (Brassica rapa L. ssp. pekinensis), and we find that BrphyB protein has high amino acid sequence similarity and the closest evolutionary relationship to Arabidopsis thaliana phyB (i.e., AtphyB). Quantitative reverse transcription (RT)-PCR results indicate that the BrPHYB gene is ubiquitously expressed in different tissues under all light conditions. Constitutive expression of the BrPHYB gene in A. thaliana significantly enhances seedling de-etiolation under red- and white-light conditions, and causes dwarf stature in mature plants. Unexpectedly, overexpression of BrPHYB in transgenic A. thaliana resulted in reduced expression of gibberellins biosynthesis genes and delayed flowering under short-day conditions, whereas AtPHYB overexpression caused enhanced expression of FLOWERING LOCUS T and earlier flowering. Our results suggest that BrphyB might play an important role in regulating the development of Chinese cabbage. BrphyB and AtphyB have conserved functions during de-etiolation and vegetative plant growth and divergent functions in the regulation of flowering time.

[Biological properties of lateritic red soil and their relationships with soil fertility in Southern China under different land use types].

Taking the lateritic red soil on a typical slopeland in Southern China as test object, this paper studied the soil microbial properties, enzyme activities, and their relationships with soil fertility under four land use types (newly cultivated dryland, shrub land, Eucalyptus land, and orchard). There existed significant differences in the soil biological properties under different land use types, among which, orchard soil had the highest microbial quantity and enzyme activities, newly cultivated dryland soil had the fastest soil respiration rate, the fewest soil microorganism quantity, and the lowest enzyme activities, whereas shrub land and woodland soils had the biological properties ranged between newly cultivated dryland and orchard soils, and there was a high similarity in the biological properties between shrub land and woodland soils. Under different land use types, the soil microbial quantity and enzyme activities were positively correlated with soil organic carbon and most of the soil nutrients. It was suggested the soils with high soil organic matter content and high fertility level were beneficial to the soil microbial growth and enzyme activities.

[Effects of herb residue vermicompost on maize growth and soil fertility].

A pot experiment was conducted to evaluate the effects of herb residue vermicompost on maize growth and soil fertility. With the increasing application rate of vermicompost, the plant height, stem diameter, leaf area, and chlorophyll content of maize all increased significantly. After 60 days growth of maize, the soil bulk density in most vermicompost treatments decreased significantly. The soil pH in vermicompost treatments was significantly higher than that in CK and in chemical fertilization treatments. In addition, the soil total nitrogen and organic matter contents in vermicompost treatments were obviously higher than those in chemical fertilization treatments. It was suggested that herb residue vermicompost could be used as an efficient and high-quality organic fertilizer, and its appropriate application could improve soil physical structure, alleviate soil acidification, increase soil organic matter and nitrogen contents, and promote crop growth.

[Expression and clinical significance of P-gp in colonic gland of chronic schistosomiasis patients].

OBJECTIVE: To study the expression of P-glycoprotein (P-gp) in patients with chronic schistosomiasis and its relationship with gender and age, and to explore its clinical significance. METHODS: The colonic mucosa specimens of 50 chronic schistosomiasis patients and 4 persons who had a family history of colon cancer but their physical examinations were normal (as a control group) were selected and the expressions of P-gp in the colonic gland of these samples were detected with the immunohistochemical staining method. RESULTS: Compared with the control group, the mean gray value of the positive particles of P-gp of colonic epithelial cells of the chronic schistosomiasis group was significantly reduced (P < 0.05), but positive unit values were significantly increased (P < 0.05), which meant the P-gp expression in colonic gland of the patients with chronic schistosomiasis was significantly increased, but this increase had no relationship with sex and age. CONCLUSION: Chronic schistosomiasis may induce the increase of P-gp expression which may be a compensatory protection mechanism due to the stimulation of schistosome eggs to the colon tissues.

Second harmonic generation in one-dimensional nonlinear photonic crystals solved by the transfer matrix method.

The transfer matrix method has been widely used to calculate the scattering of electromagnetic waves. In this paper, we develop the conventional transfer matrix method to analyze the problem of second harmonic generation in a one-dimensional multilayer nonlinear optical structure. In the designed nonlinear photonic crystal structure, the linear and nonlinear optical parameters are both periodically modulated. We have taken into account the multiple reflection and interference effects of both the linear and nonlinear optical waves during the construction of the transfer matrix for each composite layer. Application of this method to multilayer nonlinear photonic crystal structures with different refractive indices indicates that the proposed method is an exact approach and can simulate the generation of the second harmonic field precisely. In an optimum structure, the second harmonic generation efficiency can be several orders of magnitude larger than in a conventional quasi-phase-matched nonlinear structure with the same sample length. The reason is that, due to the presence of photonic band gap edges, the density of states of the electromagnetic fields is large, the group velocity is small, and the local field is enhanced. All three factors contribute to significant enhancement of the nonlinear optical interactions.

[Plant epicuticular wax and drought resistance as well as its molecular biology].

Plant epicuticular wax is a collective term used to describe the organic components of the cuticle which covers the outer surface of aerial plant tissues. It is also the last defensive barrier of plant, playing important roles in plant growth and development. The components, transport, crystal formation and morpho-ultrastructure of plant epicuticular wax as well as the investigations concerning the relationship between epicuticular wax and adaptations to environment are reviewed. Especially, we systematically summarized the relationships among wax, cutin transpiration, leaf WUE and yield and the progresses in the physiological and molecular biology research regarding wax; we also discussed the problems existing in wax research.