Effects of long-term blue light irradiation on carotenoid biosynthesis and antioxidant activities in Chinese cabbage (Brassica rapa L. ssp. pekinensis).

The aim of this study was to investigate the impact of long-term exposure to blue light-emitting diodes (LEDs) on the accumulation of indolic glucosinolates and carotenoids, as well as the plant growth and antioxidant activities in both orange and common Chinese cabbage (Brassica rapa L. ssp. pekinensis). Blue light treatment also induced higher ferric-reducing antioxidant power and 2,2-diphenyl-1-picrylhydrazyl by 20.66 % and 30.82 % and antioxidant enzyme activities catalase, peroxidase, superoxide dismutase, and the accumulation of non-enzymatic antioxidant substances (total phenols and total flavonoids) in the orange Chinese cabbage. Furthermore, long-term exposure to blue light had negative effects on the net photosynthetic rate and chlorophyll fluorescence levels. Meanwhile, blue light promoted accumulation of Indol-3-ylmethyl glucosinolate (I3M), ß-carotene, lutein and zeaxanthin due to the high expression of regulatory and biosynthetic genes of the above metabolic pathways. In particular, lycopene and ß-carotene content in orange Chinese cabbage increased by 60.14 % and 65.33 % compared to the ones in common line. The accumulation of carotenoid and increasing antioxidant levels in the orange cabbage line was influenced by long-term blue light irradiation, leading to better tolerance to low temperature and drought stresses. The up-regulation of transcription factors such as BrHY5-2, BrPIF4 and BrMYB12 may also contribute to the increased tolerance in orange Chinese cabbage to extreme environmental stresses. The BrHY5-2 gene could activate carotenoid biosynthetic genes and induce the accumulation of carotenoids. These findings suggested that long-term blue light irradiation could be a promising technique for increasing the nutrition value and enhancing tolerance to low temperature and drought stresses in Chinese cabbage.

Prenylated chromones and flavonoids isolated from the roots of Flemingia macrophylla and their anti-lung cancer activity.

BACKGROUND: The successful launch of icaritin, a therapeutic drug for liver cancer derived from Epimedium brevicornu, has provided new impetus for the development of prenylated flavonoids in the field of oncology. Flemingia macrophylla is reported to contain characteristic prenylated flavonoids which can regulate the p53 protein. We aimed to isolate these constituents and conduct activity evaluation, structure-activity relationship, and mechanism studies to provide candidate compounds for antitumor drug development. METHODS: In this study, chromatographic techniques combined with spectroscopic methods were used to separate, purify, and identify the constituents of Flemingia macrophylla methanol extract. The cytotoxic activity of the constituents was evaluated using an MTT assay with A549 and H1975 cells as the model. The binding mechanism between the compounds and the p53 protein was investigated with molecular docking and validated with cellular thermal shift assay (CETSA). Western blotting (WB) was employed to detect the expression of p53 protein and apoptosis-related proteins in cells. RESULTS: Chiral HPLC separation of racemates 1 and 7 provided two pairs of undescribed enantiomers (1a/1b and 7a/7b), along with eight known compounds (2 - 9) isolated from Flemingia macrophylla roots. Their structures were elucidated by spectroscopic analysis, and the absolute configurations of the enantiomers were determined from experimental and calculated electronic circular dichroism data. Compounds 1 - 7, and the non-prenyl analogues 10 - 13, were evaluated for cytotoxic activity against the human lung cancer A549 and H1975 cell line. Compounds 5 - 7 displayed better cytotoxicity than the positive control icaritin in A549 and H1975, with IC50 values ranging from 4.50 to 19.83 µmol·L-1 and < 5 µmol·L-1, respectively. The structure-activity relationships of the chromone or flavonoid analogues against A549 cells were discussed. Molecular docking results demonstrated that compound 7a has strong interaction with p53 and WB indicated that 7a induced apoptosis by increasing the p53 protein, decreasing the anti-apoptotic protein Bcl-2, and activating the caspase family in A549 cells. These results suggest that prenylated flavonoids are potential p53 protein activators. CONCLUSION: This study demonstrates that Flemingia macrophylla is rich in prenylated flavonoid constituents, among which compounds 5 and 7 exhibited significant cytotoxic activity against A549 cells and served as reference candidates for the design and development of prenylated compounds as antitumor therapeutic drugs.

The Accumulation of Health-Promoting Nutrients from Representative Organs across Multiple Developmental Stages in Orange Chinese Cabbage.

Orange Chinese cabbage (Brassica rapa L. ssp. pekinensis) is an excellent source of health-promoting nutrients that could reduce the risk of chronic diseases. This study mainly investigated the accumulation patterns of eight lines of orange Chinese cabbage for indolic glucosinolates (GLSs) and pigment content from representative plant organs across multiple developmental stages. The indolic GLSs were highly accumulated at the rosette stage (S2), especially in inner and middle leaves, and the order of indolic GLSs accumulation in non-edible organs was flower > seed > stem > silique. The expression levels of biosynthetic genes in light signaling, MEP, carotenoids, and GLS pathways were consistent with the metabolic accumulation patterns. The results of a principal component analysis show a clear separation of high indolic GLS lines (15S1094 and 18BC6) from low indolic GLS lines (20S530). A negative correlation between the accumulation of indolic GLS and carotenoids was identified in our study. Our work contributes to providing valuable knowledge required to breed, grow, and select orange Chinese cabbage varieties and their eatable organs with higher nutritional value.

The effects of short term blue light treatment on promoting nutrition value in Chinese cabbage.

Chinese cabbage is a nutrients-rich vegetable with diverse leaf colors. Here, we used widely-targeted metabolomics technology to study the metabolic responses of three Chinese cabbage varieties with representative leaf colors after blue light treatment. The inner leaf color of orange varieties 20S530 and 15S1094 changed from yellow to golden yellow, while no visible color change occurred in the common variety 14S23 after the treatment. A total of 844 metabolites were measured from the leaf samples of these three varieties in a time course study after short term blue light treatment, with kaempferol-4'-O-glucoside, isoquercitrin, hyperin, arbutin, sulforaphane as enriched nutritional metabolites. Orange Chinese cabbage varieties showed additional nutrition enhancement after the treatment. This study is the first to explore the global metabolic responses of Chinese cabbage after blue light treatment, and our findings provided valuable insights on how to effectively use lighting conditions to enhance specific groups of nutrients in vegetables.

Monoterpenoid indole alkaloids isolated from the stems and twigs of Strychnos cathayensis.

Seven undescribed monoterpenoid indole alkaloids, two N(4)-chloromethylation artifacts, and 10 known alkaloids were isolated from the stems and twigs of Strychnos cathayensis. The corresponding structures were elucidated via spectroscopic data interpretation and electronic circular dichroism. The absolute configuration of (17S)-12-hydroxy-11-methoxydiaboline, the major anomer of 12-hydroxy-11-methoxydiaboline, was characterized by X-ray diffraction analysis for the first time. At an intraperitoneal dose of 30 mg/kg, 12-hydroxy-11-methoxy-N(4)-chloromethyldiaboline and (-)-macusine A exhibited potential analgesic effects with prolongation rates of 99% and 47% for the latency time of hind-paw licking, respectively, compared to the blank control. 12-Hydroxy-11-methoxydiaboline, 12-hydroxy-11-methoxydiaboline N(4)-oxide, retuline N-oxide, and (-)-vincosamide exhibited antiviral activity against Coxsackie virus B3 (CVB3) with IC50 values of 33.33 µM.

Comparative Metabolic Study of Two Contrasting Chinese Cabbage Genotypes under Mild and Severe Drought Stress.

Chinese cabbage (Brassica rapa L. ssp. pekinensis) is an important leafy vegetable crop cultivated worldwide. Drought is one of the most important limiting factors for the growth, production and quality of Chinese cabbage due to its weak drought tolerance. In order to deepen the understanding of drought stress response in Chinese cabbage, metabolomics studies were conducted in drought-tolerant (DT) and drought-susceptible (DS) genotypes of Chinese cabbage under water deficit-simulated mild and severe drought stress conditions. A total of 777 metabolites were detected, wherein 90 of them were proposed as the drought-responsive metabolites in Chinese cabbage, with abscisic acid (ABA), serine, choline alfoscerate, and sphingosine as potential representative drought stress biomarkers. We also found that drought-tolerant and drought-susceptible genotypes showed differential metabolic accumulation patterns with contrasting drought response mechanisms. Notably, constitutively high levels of ABA and glutathione were detected in drought-tolerant genotype in all tested and control conditions. In addition, proline, sucrose, γ-aminobutyric acid, and glutathione were also found to be highly correlated to drought tolerance. This study is the first metabolomic study on how Chinese cabbage responds to drought stress, and could provide insights on how to develop and cultivate new drought-resistant varieties.

[Study on chemical constituents of stems and leaves of Sapium discolor].

Seventeen compounds were isolated from the 95% ethanol extract of the stems and leaves of Sapium discolor by using various chromatographic techniques,including silica gel,Sephadex LH-20,MCI,ODS,and semi-preparative HPLC. Their structures were elucidated as sapiumin F( 1),kadsulignan C( 2),ciwujiatone( 3),ethylbrevifolin carboxylate( 4),7-hydroxy-8-methoxycoumarin( 5),fraxetin( 6),fraxidin( 7),isofraxidin( 8),6,7,8-trimethoxycoumarin( 9),5,6,7,8-tetramethoxycoumarin( 10),8-hydroxy-5,6,7-trimethoxycoumarin( 11),3,3'-di-O-methylellagic acid( 12),3,3',4'-tri-O-methylellagic acid( 13),3'-methoxyellagic acid 4'-O-α-rhamnopyranoside( 14),4,5-didehydro-chebulic acid triethyl ester( 15),ent-kaurane-3-oxo-16α,17-diol( 16),and abscisic acid( 17) by spectroscopic data. Compound 1 is a new compound. Except for compounds 4,11,and 13,the remaining compounds were isolated from this plant for the first time. All the isolates were evaluated for their in vitro antineuroinflammatory activities,and the results showed that compounds 6 and 15 significantly inhibited nitric oxide production in lipopolysaccharide-induced BV-2 microglial cells,with IC50 values of 6. 06 and 6. 05 µmol·L-1,respectively.

Coumarinolignoids and Taraxerane Triterpenoids from Sapium discolor and Their Inhibitory Potential on Microglial Nitric Oxide Production.

Seventeen compounds, including three new pairs of coumarinolignoid enantiomers, (7' S,8' S)-sapiumins A-C (1a-3a) and (7' R,8' R)-sapiumins A-C (1b-3b), six new taraxerane triterpenoids, sapiumic acids A-F (4-9), and five known taraxerane triterpenoids (10-14), were isolated from an ethanol extract prepared from the stems and leaves of Sapium discolor. The structures of 1-9 and their relative configurations were determined by spectroscopic data analysis, and the absolute configurations of the coumarinolignoids 1a/1b-3a/3b and triterpenoids 6-9 were assigned using experimental and calculated ECD data. Compounds 1a/1b-3a/3b are the first coumarinolignoids to be reported from the genus Sapium. Among all the isolates, compounds 1b, 2a/2b, 3a/3b, and 6-9 inhibited nitric oxide production in lipopolysaccharide-stimulated BV-2 microglial cells, with IC50 values of 1.7-15.3 µM.

Cytisine-type alkaloids and flavonoids from the rhizomes of Sophora tonkinensis.

A new cytisine-type alkaloid, (-)-N-hexanoylcytisine (1), and a new isoflavan, (3S, 4R)-4-hydroxy-7,4'-dimethoxyisoflavan 3'-O-ß-d-glucopyranoside (2), along with 10 known compounds, were isolated from the rhizomes of Sophora tonkinensis. Their structures were determined by spectroscopic methods, chemical evidence, and ECD data analysis. All of the isolates were evaluated for their cytotoxic activities against four human tumor cell lines.

[Studies on chemical constituents of rhizomes of Sophora tonkinensis].

Thirteen compounds were isolated from the 95% aqueous EtOH extract of the rhizomes of Sophora tonkinensis by a combination of various chromatographic techniques including column chromatography over silica gel, Sphadex LH-20, MCI, ODS, and semi-preparative HPLC.Their structures were elucidated as 1-(6,7-dihydro-5H-pyrrolo[1,2-a]imidazol-3-yl)ethanone(1), cyclo(Pro-Pro)(2), nicotinic acid(3), p-hydroxybenzonic acid(4), p-methoxybenzonic acid(5), 4-hydroxymethyl-2,6-dimethoxyphenol-1-O-ß-D-glucopyranoside(6), coniferin(7), syringin(8),(-)-secoisolariciresinol-4-O-ß-D-glucopyranoside(9),(-)-syringaresinol-4-O-ß-D-glucopyranoside(10),(-)-syringaresinol-4,4'-di-O-ß-D-glucopyranoside(11),(-)-pinoresinol-4,4'-di-O-ß-D-glucopyranoside(12), and(6S,9R)-roseoside(13) by their physicochemical properties and spectroscopic data.Compound 1 was a new naturalproduct, and compounds 2,5,6,9,10,12 and 13 were obtained from the Sophora genus for the first time.Compound 1 possessed moderate cytotoxic activity against A549 human tumor cell [IC50（23.05 ± 0.46）µmol•L⁻¹].

Antiviral Matrine-Type Alkaloids from the Rhizomes of Sophora tonkinensis.

Three new matrine-type alkaloids, (+)-5α-hydroxyoxysophocarpine (1), (-)-12ß-hydroxyoxysophocarpine (2), and (+)-5α-hydroxylemannine (3), along with 14 known analogues, (-)-sophocarpine (4), (-)-5α-hydroxysophocarpine (5), (-)-9α-hydroxysophocarpine (6), (+)-12α-hydroxysophocarpine (7), (-)-12ß-hydroxysophocarpine (8), (+)-oxysophocarpine (9), (+)-matrine (10), (+)-sophoranol (11), (+)-9α-hydroxymatrine (12), (-)-14ß-hydroxymatrine (13), (+)-oxymatrine (14), (+)-5α-hydroxyoxymatrine (15), (-)-14ß-hydroxyoxymatrine (16), and (+)-sophoramine (17), were isolated from the rhizomes of Sophora tonkinensis. Their structures were elucidated via spectrometric data analyses, and the absolute configurations were established by single-crystal X-ray diffraction and ECD data. Alkaloids 2, 6, 11, and 13 exhibited antiviral activity against the Coxsackie virus B3 (CVB3), with IC50 values of 26.62-252.18 µM, and alkaloids 7, 8, and 17 inhibited influenza virus A/Hanfang/359/95 (H3N2) replication with IC50 values of 63.07-242.46 µM.