This research investigated the effect of parthenolide on the proliferation and migration of human breast cancer cells and explored the molecular mechanism of that effect. Surface plasmon resonance and fluorescence resonance energy transfer melting were used to detect the binding and stabilizing ability of PTL and G-quadruplex. MTT assays were used to determine the effect of PTL on the proliferation of MCF-7 breast cancer cells. A wound healing assay was performed to detect the migration of MCF-7. The results indicate that PTL shows good binding and stabilizing activities with c-myc G-quadruplex with a K_D=13.1 μmol·L^-1. PTL inhibited the proliferation of MCF-7 cells with an IC₅₀ of 21.3 μmol·L^-1 (24 h), 14.5 μmol·L^-1 (48 h) and 9.1 μmol·L^-1 (72 h). PTL inhibited MCF-7 breast cancer cell proliferation and migration and down-regulated the transcription and expression level of c-myc by targeting G-quadruplex.

Shiraia bambusiccola is an important medicinal fungus in China. Hypocrellins with perylenequinone skeleton are main bioactive components of Shiraia bambusiccola, which are widely used in food, medicine, pesticide and other fields as natural photosensitizers. For example, "hypocrellin ointment" has already been used clinically. As a rare and vulnerable species, wild Shiraia bambusiccola resources are very limited. Due to the complex structure and chanllenge in chemical total synthesis of hypocrellins, it is urgent to find an effective strategy to rationally utilize its medicinal value while protecting the wild resources. In this study, a candidate gene cluster hpc was identified in Shiraia sp. cfcc 84681 based on careful bioinformatic analysis. A heterologous expression system for hpc gene cluster was successfully constructed and a mutant strain with high yield of hypocrellins was obtained, which mainly produced hypocrellin A and isohypocrellin A. The main ingredients in the mutant strain are consistent with that in the wild Shiraia bambusiccola. These results provide a new strategy to solve the shortage of wild Shiraia bambusiccola resources.

The chemical constituents of gorgonian Junceella fragilis Ridley, collected from Ximao Island, the South China Sea, were investigated. A new briarane-type diterpenoid, named fragilide Y (1), together with five known compounds (2-6), namely fragilide D (2), cholesterol (3), ergosterol peroxide (4), 2'-deoxythymidine (5) and cis-thyminenol (6), were isolated from the acetone extract of J. fragilis. The structure of the new compound 1 was elucidated by extensive spectroscopic analysis, while the known compounds were identified by comparison with the reported data. In bioassay, none of these compounds displayed obvious anti-inflammatory and cytotoxic effects.

This paper aimed to investigate the release efficiency of peptide at carbon terminal triggered by tetrazine bioorthogonal click-to-release reaction, and further explored the potential application of this reaction in functional modification and mild cleavage in solid-phase peptide synthesis. Thirteen peptide derivatives modified by trans-cyclooctene (TCO) were designed and synthesized, which were reacted with tetrazine to release the peptides. The results showed that the release rates of peptide were 90.0% to 97.7% in one hour. The strategy has good compatibility with the functional side-groups and the length of peptides, which expands the applications scope of tetrazine bioorthogonal click-to-release reaction. At the same time, a novel bifunctional trans-cyclooctene molecule was designed and synthesized. The active peptide GIRLRG was modified by fluorophore on the solid-phase resin, and released through tetrazine click-to-release reaction under mild condition, providing a new strategy for the solid-phase modification and release strategy of the peptide.

Obesity is an important cause of a panel of metabolic diseases, such as hypertension, hyperlipidemia, arteriosclerosis, type 2 diabetes and various cancers. Discovery of anti-obesity agents has always been a hot spot in the field of new drug research and development. Pancreatic lipase (PL, also named triacylglycerol acyl hydrolase), a key enzyme responsible for the hydrolysis of 50%-70% dietary fats in the gastrointestinal system, which has been recognized as a crucial target for the prevention and treatment of obesity. PL inhibitors can reduce the decomposition and absorption of dietary fat in the digestive organs by decreasing the hydrolytic activity of this key enzyme, which can alleviate the symptoms of metabolic diseases such as obesity and hyperlipidemia. Although a potent PL inhibitor (orlistat) has been marketed, it may trigger gastrointestinal side effects after long-term use. Therefore, it is necessary to develop more new PL inhibitors with strong inhibition potency and safety. In recent years, a large number of studies have found that some Chinese herbal extracts and their constituents can regulate lipid metabolism and treat obesity via inhibiting PL. In this paper, the research progress in the field pancreatic lipase inhibitors, as well as the extracts of Chinese herbs and their constituents with pancreatic lipase inhibitory effects were summarized. Meanwhile, the PL inhibition activities and inhibitory mechanisms of herbal constitutes were also summarized systematically. In addition, the authors also highlight the challenges in this field and the future research directions. All information and knowledge presented in this review will be very helpful for the medicinal chemists to find more potent PL inhibitors from herbs or to develop next generation anti-obesity drugs, as well as helpful for the prevention and treatment of obesity and other related metabolic diseases using herba medicines or related products.

Cardiac glycoside is a class of steroidal glycosides with significant physiological activities to the heart. Several drugs had been approved for the treatment of heart failure and atrial fibrillation. In recent studies, the researchers have found that cardiac glycoside can selectively inhibit the proliferation of human tumor cells and has potent antitumor efficacy. Unfortunately, the poor solubility and severe adverse effects of cardiac glycoside hindered further clinical application in the field of anticancer. It is an effective strategy to solve the "drug-like" problem of cardiac glycoside by changing the pharmacokinetics and distribution in vivo and reducing the dosage and side effects by virtue of modern preparations technology and treatment scheme. In this review, a brief introduction of the developmental course and mechanism of cardiac glycosides in anticancer field was made, and recent research progress of cardiac glycosides preparations were summarized and discussed. Finally, the further research direction was prospected.

This research investigated the mechanism by which bupivacaine inhibits glutamate-induced intracellular free Ca²⁺ increases in primary cultured hippocampal astrocytes. Immunofluorescence was used to demonstrate the expression of metabotropic glutamate receptor (mGluR5 receptor) on neurons and astrocytes. Calcium imaging was used to measure the alteration of intracellular free Ca²⁺ ([Ca²⁺]_i) in primary cultured rat hippocampal neurons and astrocytes. The animal experiments were approved by the Animal Experiments Ethical Committee of Hebei Medical University. The results showed that mGluR5 receptor was abundantly expressed in the primary cultured rat neurons and astrocytes. Bupivacaine (300 μmol·L^-1) significantly inhibited 1 mmol·L^-1 glutamate-induced[Ca²⁺]_i increase in astrocytes (P < 0.01). 2-Methyl-6-(2-phenylethynyl)-pyridine (MPEP) (10 μmol·L^-1) completely abolished the increase of[Ca²⁺]_i induced by 1 mmol·L^-1 glutamate in the astrocytes (P < 0.01), while the inhibitory effect on neurons was only 10%-20%. Bupivacaine (300 μmol·L^-1) completely inhibited the[Ca²⁺]_i increase induced by mGluR5 receptor agonists (RS)-3, 5-dihydroxyphenylglycine (DHPG) (50 μmol·L^-1) and (RS)-2-chloro-5-hydroxyphenylglycine sodium salt (CHPG) (1 mmol·L^-1) in astrocytes (P < 0.01). In addition, bupivacaine inhibited the CHPG-induced[Ca²⁺]_i increase in a dose-dependent manner in astrocytes with an IC₅₀ of 100 μmol·L^-1. The results from this study indicate that bupivacaine inhibits glutamate-induced[Ca²⁺]_i elevation by acting on the mGluR5 receptor in primary cultured hippocampal astrocytes.

In recent years, the incidence and mortality of invasive fungal infections has increased. It is highly desirable to develop novel antifungal agents with new modes of action. Targeting virulence factors represents a new strategy for antifungal drug discovery. Secreted aspartic protease 2 (SAP2), a kind of virulence factor, is an emerging antifungal target. However, discovery of small-molecule SAP2 inhibitors remains a significant challenge. Based on the structure-activity relationship of our previously identified triazine small-molecule SAP2 inhibitor, we were able to identify two potent inhibitors, 8a and 8c, which showed excellent in vivo antifungal activity for the treatment of C. albicans infection. Moreover, compounds 8a and 8b effectively inhibited fungal biofilm. Taken together, triazine SAP2 inhibitors represent promising lead compounds for the discovery of novel antifungal agents.

Inspired by the coordination effects between imidazole and metal ions in hemoglobin, biomimetic nanoparticles were constructed for photodynamic tumor therapy. The photosensitizer of protoporphyrin IX (PpIX) was modified with histidine, which could be self-assembled with Zn²⁺ to obtain the biomimetic nanoparticles (NPs). Under the conditions of high glutathione and low pH, the biomimetic nanoparticles could be degraded and released for enhanced photodynamic tumor therapy. The structures of NPs were characterized by dynamic light scattering (DLS), UV-visible spectrophotometer (UV-Vis), fluorescence microscope and transmission electron microscope (TEM). The reactive oxygen species (ROS) production ability of NPs was measured by singlet oxygen sensor green (SOSG) test kit. Mouse breast cancer cell lines (4T1 cells) were employed to investigate the subcellular organelle distribution and cytotoxicity of NPs. These results confirmed that NPs possessed a good dispersibility and stability with a uniform structure and particle size at 165 nm. Moreover, MTT assay and live/dead cell staining assay demonstrated that NPs could inhibit the proliferation of 4T1 cells and exhibit a good biocompatability. This research would promote the construction of intelligent biomedicine for tumor precision therapy.

Natural products have been a major source of leading compounds in drug discovery. How to effectively screen active compounds from complex matrix remains an interesting topic. In this review, we comprehensively summarized advanced liquid chromatography based approaches in natural products screening, including pre-column, on-column and post-column screening methods. Their advantages, disadvantages and prospect are also discussed.