Latest ArticlesFifteen compounds were isolated from fruits of Cornus officinalis by various chromatographic techniques such as Toyopearl HW-40C, Sephadex LH-20, silica gel, and the semi-preparative HPLC. Their chemical structures were identified by analysis of physicochemical properties and spectral data, and determined as neolignan A (1), caffeic acid (2), trans-p-hydroxy cinnamic acid (3), esculetin (4), scopoletin (5), benzyl-7-O-β-D-glucopyranoside (6), tachioside (7), 6-O-(4-hydroxybenzoyl) arbutin (8), 2-(3′, 4′-dihydroxyphenyl)-1, 3-benzodioxole-5-carboxaldehyde (9), (-)-pinoresinol-4-O-β-D-glucopyranoside (10), (7S, 8R)-dihydrodehydrodiconiferyl alcohol-9-O-β-D-glucopyranoside (11), (7S, 8R)-dihydrodehydrodiconiferyl alcohol-9′-O-β-D-glucopyranoside (12), (+)-lyoniresinol (13), (+)-isolariciresinol-9-O-β-D-glucopyranoside (14), and isolariciresinol-9′-O-β-D-glucopyranoside (15). Compound 1 was a new compound and named as neolignan A, and compounds 6-9 and 14 were isolated from Cornus officinalis for the first time. Compounds 2, 3 and 15 efficiently alleviated the PC12 cells injury induced by Aβ25-35, suggesting their potential anti-Alzheimer's disease activity.
To investigate the chemical constituents of Anisodus tanguticus, silica gel column chromatography, Sephadex LH-20 column chromatography, preparative thin layer chromatography, and semi-preparative HPLC were used to separate and purify the chemical constituents from the extract of A. tanguticus. The planar structure of the isolated compound was identified by HRMS, IR, and 2D NMR experiments. The absolute configuration of the isolated compound was determined by a combination of NOESY, coupling constant, circular dichroism (CD), and transition metal chelate reagent dimolybdenum tetraacetate [Mo2(OAc)4]-induced circular dichroism (ICD) data analysis. A new compound of the anisotane-type sesquiterpene (1) was isolated, which was determined to be (1R, 2S, 3R, 4R, 6R, 7R, 9R)-anisotane-11(13)-ene-3, 4, 9-triol and named anisotanol F. This is the second report of anisotane-type sesquiterpene, which has previously been reported as a novel sesquiterpenoid skeleton by our research group. Furthermore, the cytotoxicity against HUVECs and inhibitory effect on NO release in LPS-induced RAW264.7 cells of compound 1 were investigated. However, the results showed that it was inactive. Compound 1 is a new compound isolated from A. tanguticus. It belongs to the unusual anisotane-type sesquiterpene. This result enriches the chemical composition of A. tanguticus.
An analytical method was developed for determination of 7 aminoglycosides antibiotics in bear bile powder by hydrophilic interaction liquid chromatography tandem mass spectrometry. The samples were purified by mix-mode weak cation exchange and reversed-phase SPE. Waters ACQUITY UPLC BEH Amide column (100 mm × 3.0 mm, 1.7 μm) was used with 0.2% formic acid aqueous solution-0.2% formic acid acetonitrile solution as mobile phases by gradient elution. The aminoglycosides were detected by electrospray ionization mass spectrometry in positive mode with multiple reaction monitoring (MRM) mode. Spectinomycin, streptomycin, amikacin, kanamycin, tobramycin, apramycin and neomycin possessed good linear correlation in the respective concentration ranges, with the correlation coefficients more than 0.99. The mean recoveries at 3 spiked levels were in the range of 61.3%~127.3%, and the RSDs were 0.1%~1.9%. The limits of quantification were 0.2~1.0 mg·kg-1. The method had been applied to the analysis of actual samples.
Hepatotoxicity induced by herbal medicines such as Gynura japonica, which contains large amount of pyrrolizidine alkaloids (PAs) such as senecionine (SEN), is among the most serious problems of herbal drug-induced liver injury, yet there is no effective treatment in clinic. We have previously reported that ritonavir (the well-known CYP3A4 inhibitor) protected rats against Gynura japonica-induced liver injury in rats, which was closely related to the inhibition of the metabolic activation of PAs. A large number of lignans have been identified in Schisandrae Chinensis Fructis and are reported to attenuate drug-induced liver injuries by modulating the drug metabolism enzymes. Therefore, the present study investigated the protective effect and potential mechanism of schisandrol A (SoA, a representative lignan identified in Schisandrae Chinensis Fructis) against SEN-induced hepatotoxicity in mice. All experiments were approved by the Animal Research Committee of Shanghai University of Traditional Chinese Medicine (PZSHUTCM210604002). Animal welfare and the animal experimental protocols were strictly consistent with related ethics regulations of Shanghai University of Traditional Chinese Medicine. Liver injury was induced by a single gavage of SEN (150 μmol·kg-1); mice in the protection group were gavaged with SoA (116 μmol·kg-1) 7 days before SEN treatment. The results show that SoA dramatically alleviated SEN-induced liver injury in mice. Mice in the protection group showed decreased serum activities for alanine aminotransferase and aspartate aminotransferase; in addition, the hepatic necrosis and sinusoidal hemorrhage in SEN-treated mice were markedly attenuated in the protection group. The serum contents of SEN metabolites in mice were decreased. In vitro studies were performed by using human liver microsomes and proved that SoA inhibits CYP3A4 to decrease the metabolism of SEN. These studies indicate that SoA attenuated SEN-induced liver injury in mice, which was closely related to the inhibition of the metabolic activation of SEN. These results provide a better understanding of the relationship between CYP3A4 and PA-induced toxicity. This work also will be helpful in developing effective treatments for SEN-induced liver injury based on inhibition of its metabolic activation, and in making reasonable evaluations of the safety of herbal medicines containing PAs such as G. japonica.
The biological behavior of carbon dots, especially the mechanism of cellular uptake and intracellular distribution, is the basis of its biomedical applications. In this paper, blue fluorescent carbon quantum dots were synthesized by hydrothermal method with Poria cocos polysaccharide as raw material, and the specific biological behavior of carbon dots entering cells was explored to evaluate its biological activity. It was characterized by transmission electron microscopy, UV-vis absorption spectroscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Two different cell lines, immunocytes-RAW264.7 cells (mouse mononuclear macrophages cells) and cancer cells-4T1 cells (mouse breast cancer cells), were used as the research objects to study the uptake kinetics, uptake pathway, distribution and efflux of polysaccharide carbon dots in cells. The results showed that the carbon dots have a size distribution of 2 to 10 nm, and the average size was 6.85 nm. The carbon dots were mainly composed of C, O and N elements, with abundant surface functional groups such as -OH, C=O, C-N and C=C, and the fluorescence quantum yield was 4.72%. Carbon dots enter cells in a certain concentration and time dependence. Different cell lines have different uptake pathways. RAW264.7 cells enter the cells mainly by macrophage-specific phagocytosis, and a small part of the endocytosis is mediated by caveolin, while 4T1 cells are mainly mediated by grid protein endocytosis and giant cell drinking process. In summary, the synthesized carbon dots have good fluorescence properties, low cytotoxicity and excellent biocompatibility, which can be used for cell imaging applications.
In this study, the molecular mechanism of Cinnamomi Cortex-Rehmanniae Radix (CR) in the prevention and treatment of osteoporosis (OP) was investigated by integrating compatibility analysis of compound, bioinformatics and metabolomics. The rat OP models were established, and the Micro-CT indexes and pathological sections were comprehensively evaluated. The results showed that compared with the model group, the indexes such as bone mineral density (BMD) and bone volume/tissue volume (BV/TV) were significantly increased after CR treatment (P < 0.05), and the bone trabeculae were arranged into mesh. The results of UHPLC-Q-TOF/MS mainly involved amino acid metabolism, lipid metabolism and estrogen metabolism pathways. Integrating bioinformatics and metabolomics analysis, it was finally found that: ① cinnamic acid and ethylcinnamate inhibit inflammatory factors such as TNF, IL-1β, and IL-13, thereby preventing and treating OP; ② multiple active ingredients of CR target ESR2, PPARG, and CYP19A1, GABRA1 and other targets, regulate cAMP synthesis, AMPK signaling pathway and lipid metabolism, thereby regulating estrogen levels to prevent and treat OP; ③ oleic acid, arachic acid, etc. act on AR, VDR and other targets, and regulate HIF-1 signaling pathway and AGE-RAGE signaling pathway, thereby regulating osteoblasts and osteoclasts, and affecting calcium and phosphorus absorption to maintain bone homeostasis. This study clarified the molecular mechanism of CR in preventing and treating OP from the perspective of multi-directional regulation of inflammatory factors, estrogen and bone homeostasis, and provided theoretical basis for the clinical application of CR and the development of compound. This experiment complied with the ethical standards of animal experiments and was approved by the Animal Ethics Committee of Shaanxi University of Chinese Medicine (No. SUCMDL20210309002).
To investigate the metabolites of a new synthetic cannabinoid 3, 3-dimethyl-2-[1-(4-cyanobutyl)indazole-3-formamimino]methyl butyrate (4CN-MDMB-BUTINACA) in vitro, a human liver microsome incubation model was established to analyze the metabolic biotransformation of synthetic cannabinoids using ultra-high performance liquid chromatography coupled to quadrupole-orbitrap high-resolution mass spectrometry. Nontarget metabolomic results showed that the metabolites of 4CN-MDMB-BUTINACA included hydroxylation, ester hydrolysis, ester hydrolysis with hydroxylation reaction, pentane oxidation and ester hydrolysis with pentane oxidation reaction, among which M1-a, M2 and M4 were potential metabolic markers. The research results provide a theoretical basis and technical support for the biomonitoring and metabolic characterisation of the cannabinoid 4CN-MDMB-BUTINACA.
In this study, black phosphorus nanosheets (BP) were prepared by the ordinary liquid phase method, and resveratrol was loaded on the BP after being modified by polyethylene glycol. The brain targeting of BP was investigated by fluorescent protein labeling, and the effects of black phosphorus on cerebral ischemia/reperfusion injury were studied by 2, 3, 5-triphenyltetrazolium chloride (TTC) staining, neurobehavioral evaluation, and brain edema. Protein immunoblotting analysis was used to explore the molecular mechanism of the BP drug delivery system on ischemic brain injury. Hemolysis test and hematoxylin-eosin (H & E) staining were used to evaluate its biocompatibility. The results showed that BP had excellent drug loading capacity, uniform drug loading system structure and particle size, stable drug release curve, and excellent photothermal effect. Through the analysis and comparison of fluorescence intensity, it was found that BP can increase the permeability of blood-brain barrier (BBB) under the condition of near-infrared light assisted irradiation, and make drugs more pass through the BBB. In addition, the black phosphorus nano tablet drug delivery system can significantly improve the neurobehavioral disorder of mice after modeling, and the cerebral infarction area and brain edema degree are significantly decreased. Western blot experiments showed that the drug delivery system could play an anti-ischemic brain injury role by activating the expression of antioxidant signaling pathway proteins nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). The hemolysis test and H & E test results of the BP drug carrier system showed that it had no obvious toxicity and high safety. In conclusion, the BP prepared in this study had high drug loading, good photothermal performance, and high safety. Under the near-infrared condition, they also have certain brain targeting ability, which can improve the therapeutic effect of drugs in the brain. Animal welfare and experimental procedures were following the regulations of the Animal Ethics Committee of the First Affiliated Hospital of Shihezi University.
Phenylalanine ammonia lyase (PAL) can catalyze L-phenylalanine to produce trans-cinnamic acid, which is widely used in the fields of pharmacy, food and agriculture. In particular, phenylalanine ammonia lyase from Anabaena variabilis (AvPAL) is the only protein drug for the treatment of phenylketonuria. However, the poor activity and low stability limit the application in industry of AvPAL. In this study, the key amino acids of substrate-binding cavity in AvPAL were identified by screening the single site saturation mutagenesis library. Subsequently, the impact of replacing M222 with the additional 19 amino acids on activity was also evaluated by site-directed mutagenesis. It was found that the kcat values of mutants M222L and M222V were 90% and 60% higher than that of AvPAL, and the kcat/Km was 1.4 and 1.5 times as that of AvPAL. Molecular docking results revealed that the higher activity of M222L and M222V may be due to the increase of hydrophobicity favorable for the substrate-binding cavity. This study is important for elucidating the structure-function relationship of AvPAL.
2-Oxoglutarate/Fe(II)-dependent dioxygenases (2-ODD) play an important role in plant primary and secondary metabolism. Based on the high-throughput sequencing platform Illumina NovaSeq 6000, the transcriptome of Salvia apiana Jepson was sequenced, and the obtained reads were de novo assembled. A total of 38 534 unigenes were obtained from the transcriptome. The assembled unigenes were annotated and 29 982 unigenes were given functional annotations. The 2-ODD genes were identified from the assembled S. apiana transcriptome database by bioinformatics methods, and the genes were analyzed, including the homology of the sequences, physicochemical characteristics, signal peptides, transmembrane domains, subcellular localization, secondary structure and tertiary structure, etc. The evolutionary relationships and the expression patterns of the identified 2-ODD genes were also analyzed. 39 full-length 2-ODD genes were identified from the transcriptome of S. apiana. The average length of these 2-ODD encoding proteins was 320 amino acids, the molecular weight was about 36.00 kDa, and most of them were hydrophilic proteins. Phylogenetic analysis divided these 2-ODD genes into several subfamilies. Gene expression analysis indicated that the 2-ODD genes were expressed in different parts of S. apiana, and the expression level of most genes was much higher in roots than that in leaves. This study can lay a foundation for further study of 2-ODD genes in S. apiana.