Latest ArticlesFive new megastigmanes (1-5) were isolated from a decoction of Uncaria rhynchophylla by separation techniques of column chromatography using a combination of multiple stationary phases, including macroporous adsorbent resin, MCI resin, silica gel, Sephadex LH-20, and Toyopearl HW-40F, and reversed phase HPLC. Their structures were characterized by spectroscopic data analysis of HR-ESI-MS, NMR, and CD, in combination with Mosher's mothed as well as ECD and NMR calculations. The new compounds were named uncarphyllonone A (1), uncarphyllonols A (2) and B (3), and uncarphabscisic acids A (4) and B (5). Although the structures of 3 and 4 were previously reported, the reported NMR spectroscopic data were incorrect or do not support the assigned structures in literatures. This is also the first report of discovery of new megastigmane natural products from the Uncaria genus.
Mitochondrial oxidative stress has been recognized as a preliminary and critical factor that aggravates the pathological cascade of Alzheimer's disease, which induces the production of β-amyloid protein, upregulates the expression of phosphorylated tau protein and triggers oxidative damage to lipids, proteins and mitochondrial deoxyribonucleic acid. Central neurons are more vulnerable to oxidative stress than non-neuronal cells due to their high oxygen demand, abundant unsaturated fatty acids and antioxidant enzymes deficiency. On this account, this review introduces the causes of mitochondrial oxidative stress, and analyzes the important role of mitochondrial oxidative stress in the pathogenesis of Alzheimer's disease. Meanwhile, the review focuses on the design and intervention strategies of drug delivery systems targeting mitochondrial oxidative stress in neurons, aiming to provide new ideas for the prevention and treatment of Alzheimer's disease.
Four compounds were isolated from the 70% EtOH extract of Ardisia crispa by using various chromatographic techniques, including silica gel, ODS and semi-preparative HPLC. The structures of 1-4 were elucidated based on physicochemical properties and spectroscopic data. These compounds were defined as crispalactone A (1), (+)-pinoresinol (2), 3, 5-dimethoxy-4- hydroxyphenol-1-O-β-D-glucopyranoside (3) and (+)-schizandriside (4). Compound 1 is a new γ-valerolactone derivative, and compounds 2-4 are firstly isolated from Ardisia crispa.
Seven nucleoside compounds were isolated from the Oenothera biennis L. by various chromatographic techniques such as Diaion HP-20, silica gel, Sephadex LH-20, MCI and semi-preparative HPLC. Their structures were identified by analysis of physicochemical properties and spectral data, and determined as 9-(3′-carbonyl methyl)hydroxypurine (1), 1-(3′-carbonyl methyl)purine-6, 8-dione (2), N-methyl-2-pyridone-5-carboxamide (3), uracil (4), uridine (5), thymidine (6) and 2′-Ο-methoxy luridine (7). Compound 1 is a new nucleoside and compounds 2-7 were newly isolated from the Oenothera biennis L. Compounds 1-2 can significantly increase the viability of BEAS-2B cells induced by TGF-β1, showing potent anti-pulmonary fibrosis activity.
Molecular glues are a class of small molecules that induce the formation of protein-protein interactions to confer new biological function or therapeutic effects. As a unique pharmacological modality, molecular glues could target proteins without druggable binding pockets. It exhibits a variety of functions, including regulating signal transduction, stabilization or degradation of targeted proteins, through sticking different proteins together. This review will summarize the development and current status of molecular glues derived from natural products and analogs by illustrating the discovery and interaction mechanism. We hope to present a systematic view, provide valuable clues for researchers and encourage them to explore more efficient and rational molecular glue discovery strategies.
Although current synthetic anti-gout drugs have significant therapeutic effects in reducing serum uric acid levels, they have serious side effects such as allergic reactions and liver and kidney damage. Natural products with a wide range of uric acid-lowering and high safety have played a critical role in anti-gout drug discovery and development. This paper reviews the natural products with uric acid-lowering or anti-gout pharmacological effects and the investigation on their mechanisms of action, to provide information for drug discovery and development.
Saponins and sterones are two main characteristic components in Achyranthis Bidentatae Radix. In order to control the quality of Achyranthis Bidentatae Radix more effectively, a high-performance liquid chromatography (HPLC) method was established by using double external standards calibration method (DESCM) for simultaneous determination of the contents of achyranthoside C, achyranthoside D, β-ecdysterone, 25R-inokosterone and 25S-inokosterone in Achyranthis Bidentatae Radix. Chromatographic separation was achieved on an Agilent Poroshell 120 EC-C18 (150 mm × 4.6 mm, 2.7 μm) using 0.1% phosphoric acid in water and 0.1% phosphoric acid in acetonitrile as mobile phase. The flow rate was 0.8 mL·min-1 and the column temperature was set as 35 ℃, the injection volume was 5 μL and the total analytical time was 30 min. β-Ecdysterone was used as the reference to calculate the relative correction factors (RCF) and relative retention time (RRT) of 25R-inokosterone and 25S-inokosterone, achyranthoside D was used for achyranthoside C. The RCFs of 25R-inokosterone, 25S-inokosterone, and achyranthoside C were 1.116, 1.056, and 0.888 1, respectively. The double external standards calibration method (DESCM) and external standard method (ESM) were used to calculate the contents of five ingredients in Achyranthis Bidentatae Radix samples from different sources and the variation between the results was within acceptable limits (RE ≤ 5%). The results showed that the contents of two saponins and three sterones of Achyranthis Bidentatae Radix were 0.597%-1.916% and 0.044%-0.150% respectively. The total content of saponins was about 10 times that of sterones. In conclusion, the established DESCM allowed simultaneous determination of five ingredients (achyranthoside C, achyranthoside D, β-ecdysterone, 25R-inokosterone, and 25S-inokosterone) in Achyranthis Bidentatae Radix, providing a scientific and feasible overall quality evaluation method for Achyranthis Bidentatae Radix.
Glioblastoma is a malignant tumor in central nervous system, which has strong invasion, poor prognosis and short survival time. At present, the main treatment strategy of glioblastoma is surgical excision, supplemented by radiotherapy and chemotherapy. However, due to incomplete resection and high recurrence rate, it is urgent to find novel therapeutic method for glioblastoma. Photodynamic therapy, as a promising non-surgical treatment, provides a new strategy for postoperative adjuvant therapy of glioblastoma. This review summarizes the mechanism and clinical application of photodynamic therapy mediated by various photosensitizers in glioblastoma, in order to provide help for the treatment of glioblastoma.
Silk fibroin is a natural polymer with certain water solubility, structural modification, good biocompatibility and biodegradability, which can be used as a drug delivery carrier material. As a promising drug delivery system, drug-loaded silk fibroin nanoparticles can control drug release, reduce toxicity and improve therapeutic effects. In this paper, the basic characteristics of silk fibroin, the preparation methods of drug-loaded silk fibroin nanoparticles and the application of silk fibroin in nanoparticulate drug delivery systems are reviewed, and on this basis, the further development of drug-loaded silk fibroin nanoparticles is prospected.
Immune checkpoints (ICs) are immunosuppressive molecules expressed on immune cells, which can regulate immune cells' activation. Immune checkpoint inhibitors (ICIs) which can block the interaction of immune checkpoints and their ligands, improve the cytotoxic effect of the immune system on tumor cells. Immunotherapy such as employing ICIs has gradually become a conventional therapeutic strategy for cancer treatment. However, the low response rate and the emergence of drug resistance have seriously affected the clinical efficacy of ICIs. Reactive oxygen species (ROS) are electronic reduction products of active oxygen, as well as natural by-products of cell metabolism, which can be used as regulators of intercellular signals. Tumor microenvironment (TME) is often in the state of oxidative stress (OS), which is the imbalance between oxidative system and antioxidant system. ROS can affect the interaction with its ligands by regulating the expression and activity of immune checkpoints in TME, thus affecting the anti-tumor effect of immune cells. Accumulating studies have shown that ROS could regulate tumor immune checkpoints through several pathways. Due to different types and stages of tumor, it would be clinical beneficial to understand the mechanistic link of ROS on tumor immune checkpoint, and choose appropriate ROS regulators combined with immune checkpoint inhibitors to maximize anti-tumor effects. This article reviews the common metabolic sources and characteristics of ROS, the regulatory effect and mechanism of ROS on tumor immune checkpoints and its therapeutic application.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
