Latest ArticlesThe abuse of novel phenylcyclohexylpyridine drugs poses a significant threat to societal safety. The novel psychoactive substance 2-methyl-deschloroketamine (2-MDCK), belonging to the phenylcyclohexylpyridine class, has recently surfaced as a new compound. However, there is a lack of understanding regarding its metabolic pathways and the identification of suitable biomarkers. In this study, a human liver microsomal model was established, and ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) technology was applied to investigate the in vitro metabolism and products of 2-MDCK. The results indicate that 2-MDCK undergoes various metabolic reactions, including dehydrogenation, deamination, hydroxylation, and demethylation, leading to the formation of eight metabolites. By conducting actual testing on hair samples from 2-MDCK abusers, the existence of six metabolites was confirmed. Comparing the metabolic products in the liver microsomal in vitro model, M3.1 and M4.1 were identified as biomarkers for 2-MDCK consumption. Five samples of abusers of 2-methyl-dechloroketamine were provided by the Anti-Drug Brigade of the Hangzhou Public Security Bureau. Negative hair samples were provided by laboratory volunteers, and all samples were obtained with the informed consent of the volunteers. These findings provide a scientific basis for the detection and identification of 2-MDCK and its metabolites, as well as crucial support for the study of the metabolic mechanisms of similar novel psychoactive substances in the phenylcyclohexylpyridine class. This research holds significant importance in addressing the issue of abuse of new psychoactive substances.
Pentacyclic triterpenoids are a class of widespread natural compounds containing six isoprene structures with a wide range of pharmacological activities, including antibacterial, anti-inflammatory, antiviral, antitumor, immune regulation, etc. The structural modifications of pentacyclic triterpenoid natural products and the drug development have always been a hot research topic. This article reviews the recent progresses in the structural modifications, pharmacological effects, and clinical studies of different kinds of pentacyclic triterpenoid natural products.
Antisense oligonucleotides are a type of gene therapy that targets mRNA and inhibits gene expression. They have been applied in the treatment of various diseases, but there are still problems with poor enzyme stability and high dosage in vivo, due to the shortage of appropriate delivery system. Insulin-like growth factor 1 receptor (IGF1R) is a cell surface receptor with tyrosine kinase activity. Its expression is abnormal in a variety of malignant tumors. It mediates the malignant proliferation, migration and invasion of tumor cells through a variety of ways. In this study, an antisense oligonucleotide (ASO, N04) targeting IGF1R mRNA was designed and chemically modified (PS, 2'-OMOE), then neutral cytidine lipid DNCA and cystine backbone cationic lipid CLD (Mix) were used to encapsulate ASOs. The particle size, polymer dispersity index and ζ potential of the formulations were 151 nm, 0.18 and -3.9 mV. The nanoparticles entered liver cancer cells (HepG-2, Huh-7), silenced target mRNA, arrested cell cycle in S phase, promoted apoptosis, and inhibited the proliferation efficiently. These results indicate that Mix/N04MOE5 has great potential in tumor treatment, which provides a basis for further research on novel agents against hepatocellular carcinoma.
Eleven compounds were isolated from the twigs and leaves of Xylopia vielana Pierre by various chromatographic techniques such as silica gel, ODS and the semi-preparative HPLC. Their chemical structures were identified by HR-ESI-MS, NMR, ECD and other spectroscopic methods as vielana A (1), vielana B (2), vielana C (3), 10-oxo-isodauc-3-en-15-al (4), 1α-hydroxyisodauc-4-en-15-al (5), mokko lactone (6), 11β,13-dihydrocostunolide (7), eurylosesquiterpenol E (8), epi-α-cadinol (9), mustakone (10), 7-epi-amiteo (11). Among them, compounds 1-3 were new compounds, and the rest compounds were isolated from this plant for the first time. Compounds 1 and 2 increased the transcriptional activity of the farnesoid X receptor (FXR) downstream target gene BSEP promoter, indicating that they have potential of FXR activation.
An integrated evaluation model based on the combination of traditional trait identification and modern chemical analysis was used for the identification of key indexes of grade classification and the establishment of grade quality standard of Lycium barbarum fruits (LBF) from Ningxia genuine producing area. Under the guidance of herbal examination and market survey, particle size, skin color and imperfection were taken as the external trait indicators; focusing on the comprehensiveness and validity of the quality evaluation, 2-O-β-D-glucopyranosyl-L-ascorbic acid (AA-2βG), zeaxanthin dipalmitate (ZD) and volatile ether extractives were used as important parameters involving in quality evaluation in addition to the pharmacopoeia test items and determination indicators such as moisture, ash, water-soluble extractives, Lycium barbarum polysaccharide (LBP) and betaine. The quality differences between different traits and grades of LBF as well as the relevance between character and quality were further investigated by mathematical and statistical means such as t-test analysis, correlation analysis and principal component analysis (PCA). Furthermore, the activities of extractives from different grades of LBF were compared at cellular level. The results showed that LBF were mainly preferred for large and red ones; except for betaine, the other index components were relatively high (moisture and ash were low) in the first-grade and samples with bright-red skin color. Besides, there was a significant correlation between skin color and moisture, water-soluble extractives, LBP, AA-2βG and ZD contents. Considering the results of the study and the market situation, the present study took the grain size and skin color of LBF as the core of evaluation, and at the same time introduced the multi-indicator components including LBP, AA-2βG, ZD, water-soluble extractives and moisture to further guide the grading, and established the quality standard of LBF grades combining the trait indexes and the chemical composition. More importantly, in vitro cell models both preliminarily confirmed that the first-grade LBF played a more significant "nourishing liver and kidney" effect, which provided an experimental basis for the quality control of LBF and promoted the realization of high quality and good price.
Cation exchange chromatography, as a commonly used separation and purification technique in biopharmaceutical manufacturing, is often employed for downstream processes to separate target monoclonal antibodies from their charge variants. For samples with complex and poorly resolved charge variant profiles, the collection solely based on ultraviolet detection does not provide specific compositional information for individual charge variants, making it challenging to determine the range of pooled fractions directly. Subsequent laborious fractionation analysis is then required to guide collection according to production requirements. A mechanistic model for the cation exchange chromatography process of the target monoclonal antibody's critical components was established, and it was employed to assist in product collection. The model accurately predicted the elution peak shapes of the modeled variants, with a root mean square error between predicted and actual values below 0.009. In comparison to the online ultraviolet-based collection method, the model-assisted collection method not only visualized the chromatographic process but also increased the relative productivity by fourfold while ensuring compliance rate.
Combined radiation and burn injury (CRBI) is a severe syndrome, which is induced by the simultaneous or successive radiation and burn; but no appropriate clinical therapies are available. Loong oil (LO) is a traditional Chinese medicine oil composed of the oil extracts of cuttlebone, safflower, walnut oil, and rapeseed oil, which has been demonstrated to own anti-radiation and tissue healing functions. In this study, glyceryl monostearate (GMO) was used for the preparation of lyotropic liquid crystals that loaded LO to obtain Loong oil-lyotropic liquid crystals (LOL) for the treatment of skin CRBI. The hexagonal phase structure of LOL was proved by small X-ray scattering (SAXS) analysis with an approximate
Lipopolysaccharides (LPS) are major outer membrane components of Gram-negative bacteria. Unlike most Gram-negative bacteria, Acinetobacter baumannii can still survive and acquire polymyxin resistance after complete loss of LPS. Previous studies of LPS-deficient Acinetobacter baumannii mostly focused on LPS-deficient strains induced by polymyxin, whose background was complex and unstable. To investigate LPS loss-mediated polymyxin resistant-Acinetobacter baumannii, this study constructed a stable and clear background LPS-deficient strain by knocking out lpxC gene in Acinetobacter baumannii ATCC 19606 with CIRSPR/Cas9, and then studied the phenotypic changes of the lpxC-deficient strain including morphology, growth rate, antibiotic susceptibility, virulence, membrane permeability, and membrane potential. Animal experiments were approved by the Animal Care and Welfare Committee Institute of Medicinal Biotechnology, CAMS and PUMC (approval number: IMB-20240119D9). The results indicated that the lpxC gene of Acinetobacter baumannii ATCC 19606 was successfully knocked out. After losing the lpxC, the strain underwent the morphological change from rod-shaped to spherical. Furthermore, it leads to reduced growth rate, enhanced membrane permeability, decreased membrane potential, lower virulence, and increased antibiotic susceptibility to β-lactams, quinolones, aminoglycosides, macrolides, glycopeptides. The lpxC deletion results in significant changes in membrane homeostasis and adaptability of Acinetobacter baumannii. Understanding the phenotypic changes of colistin-resistant Acinetobacter baumannii mediated by LPS loss is useful for exploring the resistance mechanism of Acinetobacter baumannii and developing new therapeutic strategies.
The anti-inflammatory efficacy of Callicarpa nudiflora extract were evaluated upon lipopolysaccharide (LPS)-induced infective inflammation in rats. Pathological changes of lung and colon tissues observed with hematoxylin-eosin (H&E) staining, together with inflammatory factors in serum, including nitric oxide (NO), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), were applied to assess the mitigating effects of C. nudiflora water extract on model rats. The experimental protocol strictly adhered to the guidelines of the Ethics Committee of Animal Research of Guangdong Pharmaceutical University (Approval: gdpulac2022132). Quality markers with anti-inflammatory activities were recognized by network pharmacology analysis. Subsequently, a reliable method for simultaneously quantifying six components was established. As a result, the pathological injury on lung and colon tissues of model rats induced by LPS were improved by C. nudiflora water extract. Compared with model group, C. nudiflora extract had decreased the release of proinflammatory factors in serum, including TNF-α and IL-6, and reduced the NO (P < 0.01). Network pharmacological analysis obtained 83 chemical components, 466 component targets, 584 disease targets and 129 action targets, which were mainly concentrated in 624 biological processes such as inflammatory response and positive regulation of nitric oxide biosynthesis, as well as 162 pathways such as phosphatidylinositol-3-hydroxykinase-protein kinase (PI3K-Akt) signal pathway and Janus kinase-signal transducer and activator of transcription 3 (JAK-STAT3) signal pathway. Upon analyzing their specificity, effectiveness, detectability, and quantity transfer rule from herb to extract, 6-hydroxyluteolin 7-glucoside, cynaroside, caffeic acid, acteoside, isoacteoside, and forsythoaside B were identified as the quality markers. Their anti-inflammatory activities were verified with LPS-induced inflammation model of RAW264.7 cells. Then contents of these 6 quality markers in 16 batches of C. nudiflora were determined. Thereby, the anti-inflammatory efficacy of C. nudiflora extract were confirmed in vivo, 6-hydroxyluteolin 7-glucoside, cynaroside, caffeic acid, acteoside, isoacteoside, and forsythoaside B were identified as anti-inflammatory ingredients, which can be used as quality control indicators for the herb and related formulation.
Bacterial resistance has always been a challenge in the field of antibacterials research. As one of the most problematic pathogens causing nosocomial infections, Acinetobacter baumannii (A. baumannii) was a severe threaten to public health. In recent years, as the rate of multidrug-resistant, extensively drug-resistant, and even pan drug-resistant A. baumannii has been increasing, there is an urgent need to develop new strategies to combat this pathogen. Iron is an essential element for the survival and the infection process of A. baumannii. Bacteria have developed a series of iron uptake strategies to survive in conditions of the host iron starvation, including the secretion of siderophore for iron chelation, the uptake of ferroheme, and the transport of ferrous by Feo system. Developing antibacterial strategies to inhibit the iron uptake is an effective way to deal with A. baumannii infection. This article will review the mechanisms of iron uptake by A. baumannii and the antimicrobial strategies developed based on them.