Nonalcoholic fatty liver disease (NAFLD) is one of the most common liver diseases which lacks ideal treatment options. Kaempferol and kaempferide, two natural flavonol compounds isolated from Hippophae rhamnoides L., were reported to exhibit a strong regulatory effect on lipid metabolism, for which the mechanism is largely unknown. In the present study, we investigated the effects of kaempferol and kaempferide on oleic acid (OA)-treated HepG2 cells, a widely used in vitro model of NAFLD. The results indicated an increased accumulation of lipid droplets and triacylglycerol (TG) by OA, which was attenuated by kaempferol and kaempferide (5, 10 and 20 μM). Western blot analysis demonstrated that kaempferol and kaempferide reduced expression of lipogenesis-related proteins, including sterol regulatory element-binding protein 1 (SREBP1), fatty acid synthase (FAS) and stearoyl-CoA desaturase 1 (SCD-1). Expression of peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT enhancer binding proteins β (C/EBPβ), two adipogenic transcription factors, was also decreased by kaempferol and kaempferide treatment. In addition, western blot analysis also demonstrated that kaempferol and kaempferide reduced expression of heme oxygenase-1 (HO-1) and nuclear transcription factor-erythroid 2-related factor 2 (Nrf2). Molecular docking was performed to identify the direct molecular targets of kaempferol and kaempferide, and their binding to SCD-1, a critical regulator in lipid metabolism, was revealed. Taken together, our findings demonstrate that kaempferol and kaempferide could attenuate OA-induced lipid accumulation and oxidative stress in HepG2 cells, which might benefit the treatment of NAFLD.

α-glucosidase is a major enzyme that is involved in starch digestion and type 2 diabetes mellitus. In this study, the inhibition of hypericin by α-glucosidase and its mechanism were firstly investigated using enzyme kinetics analysis, real-time interaction analysis between hypericin and α-glucosidase by surface plasmon resonance (SPR), and molecular docking simulation. The results showed that hypericin was a high potential reversible and competitive α-glucosidase inhibitor, with a maximum half inhibitory concentration (IC₅₀) of 4.66 ± 0.27 mg/L. The binding affinities of hypericin with α-glucosidase were assessed using an SPR detection system, which indicated that these were strong and fast, with balances dissociation constant (KD) values of 6.56 × 10⁻⁵ M and exhibited a slow dissociation reaction. Analysis by molecular docking further revealed that hydrophobic forces are generated by interactions between hypericin and amino acid residues Arg-315 and Tyr-316. In addition, hydrogen bonding occurred between hypericin and α-glucosidase amino acid residues Lys-156, Ser-157, Gly-160, Ser-240, His-280, Asp-242, and Asp-307. The structure and micro-environment of α-glucosidase enzymes were altered, which led to a decrease in α-glucosidase activity. This research identified that hypericin, an anthracene ketone compound, could be a novel α-glucosidase inhibitor and further applied to the development of potential anti-diabetic drugs.

A new visible-light-mediated protocol has been proposed for the synthesis of thiosulfonates via metal-free sulfonylation of thiols with aryldiazonium and sodium metabisulphite at room temperature. This mild three-component reaction simply utilizes readily available rhodamine 6G as the photocatalyst and cheap inorganic sulfite of sodium metabisulfite as a SO₂ surrogate and provides an attractive strategy to access various unsymmetrical thiosulfonates in moderate to good yields under oxidant- or strong acid-free conditions. Preliminary mechanistic studies indicated that a radical pathway was involved in the present transformation.

Biebersteiniaceae and Nitrariaceae, two small families, were classified in Sapindales recently. Taxonomic and phylogenetic relationships within Sapindales are still poorly resolved and controversial. In current study, we compared the chloroplast genomes of five species (Biebersteinia heterostemon, Peganum harmala, Nitraria roborowskii, Nitraria sibirica, and Nitraria tangutorum) from Biebersteiniaceae and Nitrariaceae. High similarity was detected in the gene order, content and orientation of the five chloroplast genomes; 13 highly variable regions were identified among the five species. An accelerated substitution rate was found in the protein-coding genes, especially clpP. The effective number of codons (EN_C), parity rule 2 (PR2), and neutrality plots together revealed that the codon usage bias is affected by mutation and selection. The phylogenetic analysis strongly supported (Nitrariaceae (Biebersteiniaceae + The Rest)) relationships in Sapindales. Our findings can provide useful information for analyzing phylogeny and molecular evolution within Biebersteiniaceae and Nitrariaceae.

Natural blue food colourant is rare. The aim of this work was to screen compounds from the common copigments that could improve the blue tones of anthocyanins (ACNs) and to investigate the effect of different copigments on the colour stability of anthocyanins in neutral species. International Commission on Illumination (CIE) colour space, UV, IR, NMR, atomic force microscopy (AFM) and computational chemistry methods were utilised to evaluate ACNs from Lycium ruthenicum Murr. (LR), which is complexed with food additives and biological agents. The results indicate that Pro−Xylane (PX), Ectoin (ECT) and dipotassium glycyrrhizinate (DG) enhance the blue colour of the ACNs. ACNs−PX presents a colour close to Oxford Blue and has a surface height of 2.13 ± 0.14 nm and slightly improved stability. The half−life of ACNs−DG is improved 24.5−fold and had the highest complexation energy (−50.63/49.15) kcal/mol, indicating hydrogen bonds and π−π stacking forces enhance stability. These findings offer a new perspective for anthocyanin utilisation as a blue colourant and contribute to the large−scale application of LR.

Amino acids are indispensable components of living organisms. The high amino acid content in Nitraria tangutorum Bobr. fruit distinguishes it from other berry plants and is of great significance to its nutritional value. Herein, using 10-ethyl-acridine-3-sulfonyl chloride as a fluorescent pre-column labeling reagent, a method for the efficient and rapid determination of amino acid content in N. tangutorum by pre-column fluorescence derivatization and on-line mass spectrometry was established and further validated. The limits of detection (signal-to-noise ratio = 3) were between 0.13 and 1.13 nmol/L, with a linear coefficient greater than 0.997 and a relative standard deviation between 1.37% and 2.64%. In addition, the method required a short analysis time, separating 19 amino acids within 20 min. Subsequently, the method was used to analyze the amino acid content of Nitraria tangutorum Bobr. from tissues retrieved from seven regions of the Qinghai-Tibet Plateau. Nitraria tangutorum Bobr. was shown to contain a large amount of amino acids, with the total content and main amino acid varying between the different tissues. This research supports the nutritional evaluation, quality control, and development and utilization of Nitraria tangutorum Bobr.