Neuropyrones A-E, five undescribed α-pyrone derivatives with tyrosinase inhibitory activity from the endophytic fungus Neurospora dictyophora WZ-497

Recent progress in chemistry and bioactivity of novel enzyme inhibitors from natural products: A comprehensive review

The essence of enzymes is to maintain the normal activities of living organisms by catalyzing metabolic reactions and regulating cells. Inhibiting enzyme activity can slow the progression of certain diseases and cure them, making enzymes one of the major targets for disease treatment. The search and development of novel enzyme inhibitors are of great significance for the treatment of certain major diseases. One of the most prominent features of natural products is their complex and diverse structures, which often compliments the synthetic capabilities of medicinal chemistry. Considering the biosynthetic processes of natural molecules in organisms, they exhibit higher similarity and binding potential with biological structures, enabling them to serve as ligands for various enzymes and receptors. In this review, we summarized a total of 226 novel natural products with enzyme inhibitory activity published in 49 articles over the past three years (2022-2024). These natural products (including terpenes, alkaloids, flavonoids, phenylpropanoids, polyketides, peptides, anthraquinones, etc.) are derived from plants, microorganisms, and marine organisms. We also discuss some synthetic analogs, with a focus on their structures and biological activities. This review provides useful information for the research and development of novel enzyme inhibitors.

Aster tataricus L. f.: a review on the botany, phytochemistry, ethnopharmacology, pharmacology, toxicology and comprehensive utilization

Aster tataricus L.f. (A.tataricus), a perennial herb of the genus Aster in the Asteraceae (Compositae) family. It is associated with a spicy, bitter, and warm nature and belongs to the Lung Meridian. The medicinal parts of A.tataricus are flowers, leaves, roots, and rhizomes. A.tataricus was first recorded in Shuo Wen under the alias "Zi Wan" (). Traditionally, it is utilised to clear lung qi, promote fluid flow, calm adverse-rising energy, relieve cough, resolve sputum, and regulate secretions. However, it is worth noting that A.tataricus has certain hepatotoxicity. Modern pharmacology indicates that A.tataricus can be used to treat various diseases, including those of the respiratory and urinary systems. In this review, all available information on A.tataricus was collected via academic databases such as PubMed, SciFinder Scholar, CNKI, iPlant, Google Scholar, Web of Science, GBIF, and Masterpieces of Traditional Chinese Medicine. To date, more than 200 metabolites have been isolated and characterized from A.tataricus, including terpenoids, flavonoids, polypeptides, and others. These compounds demonstrate a wide range of pharmacological activities, such as anti-inflammatory effects, antitussive and bronchodilatory properties, anticancer activity, antioxidant effects, treatment of osteolytic disorders, management of urinary system diseases, alleviation of acute lung injury, and enhancement of memory. Meanwhile, the different polarity extracts of A.tataricus also exhibit some toxicological characteristics, the astin has a similar structure to that of cyclochloridine, the hepatotoxic metabolite of penicillin; its saponins also have hemolytic effects. However, there are currently few studies on the toxicology of A.tataricus. Further in-depth research is needed to explore the potential mechanisms underlying the toxicity of A.tataricus. The toxicity of A.tataricus can be reduced through compatibility and processing, but this aspect has received little discussion and further research on quality standardization is needed. To ensure the sustainable development of A.tataricus, we have also summarized its artificial cultivation techniques. Shionone and astin are the characteristic components of A.tataricus. Their pharmacological effects have been deeply studied, but the research on other metabolites is relatively scarce. Therefore, this article focuses on botany, artificial cultivation, phytochemistry, ethnopharmacology, pharmacology, toxicology, and comprehensive utilization of A.tataricus. Discuss the future research prospects and existing problems of A.tataricus, and provide references for further research on A.tataricus and the establishment of quality control standards.

Discovery of Natural Resorcylic Acid Lactones as Novel Potent Copper Ionophores Covalently Targeting PRDX1 to Induce Cuproptosis for Triple-Negative Breast Cancer Therapy

Triple-negative breast cancer (TNBC) is a highly aggressive subtype of breast cancer. Cuproptosis, a novel identified cell death form, is triggered by the direct binding of copper to lipoylated components of the tricarboxylic acid cycle. Identifying new effective drug targets and copper ionophores inducing cuproptosis for TNBC therapy is an urgent clinical need. In this study, a total of 24 resorcylic acid lactones (RALs, 1-24), including 9 previously unreported ones, were isolated from the endophyte Ilyonectria sp. Various assays demonstrated that pochonin D (16, PoD) effectively inhibited the proliferation of TNBC cells in vivo and in vitro. Further investigations, including transcriptomics, proteomics, bioinformatics analysis, CMap, OTTER, clinical samples, and the use of PoD as molecular probe, revealed that PRDX1 is associated with cuproptosis and served as a potential target in TNBC. Mechanistically, PRDX1 was involved in the process of cuproptosis, and PoD bound to the Cys173 site of PRDX1, inhibited its enzymatic activity, and intervened with cuproptosis, thereby exerting anti-TNBC activity. Our study revealed that PRDX1 is not only a promising biomarker associated with cuproptosis but also a therapeutic target for TNBC, and PoD is a novel copper ionophore capable of inducing cuproptosis in TNBC cells by targeting PRDX1.

Identification of Novel Target DCTPP1 for Colorectal Cancer Therapy with the Natural Small-Molecule Inhibitors Regulating Metabolic Reprogramming

Colorectal cancer (CRC) is one of the most common malignant tumors. Identification of new effective drug targets for CRC and exploration of bioactive small-molecules are clinically urgent. The human dCTP pyrophosphatase 1 (DCTPP1) is a newly identified pyrophosphatase regulating the cellular nucleotide pool but remains unexplored as potential target for CRC treatment. Here, twelve unprecedented chemical architectures terpene-nonadride heterodimers (1-12) and their monomers (13-20) were isolated from endophyte Bipolaris victoriae S27. Compounds 1-12 represented the first example of terpene-nonadride heterodimers, in which nonadride monomers of 1 and 2 were also first example of 5/6 bicyclic nonadrides. A series of assays showed that 2 could repress proliferation and induce cell cycle arrest, apoptotic and autophagic CRC cell death in vitro and in vivo. Clinical cancer samples data revealed that DCTPP1 was a novel target associated with poor survival in CRC. DCTPP1 was also identified as a new target protein of 2. Mechanically, compound 2 bound to DCTPP1, inhibited its enzymatic activity, intervened with amino acid metabolic reprogramming, and exerted anti-CRC activity. Our study demonstrates that DCTPP1 was a novel potential biomarker and therapeutic target for CRC, and 2 was the first natural anti-CRC drug candidate targeting DCTPP1.

An updated and comprehensive review of the morphology, ethnomedicinal uses, phytochemistry, and pharmacological activity of Aster tataricus L. f

Ethnopharmacological relevance

Aster tataricus L.f., an extensively used herb in traditional Chinese medicine for more than 2000 years, is known as "Zi wan" or "Fan huncao". Its dried root and rhizome hold great promise in the treatment of cough, asthma, tumor, inflammation, etc.Aim of the study: This literature review summarizes the morphology characteristics, ethnopharmacological use, phytochemical properties, pharmacological effects, and potential applications of Aster tataricus. Furthermore, this review will discuss the future research trends and development prospects of this plant.

Materials and methods

Using "Aster tataricus L.f.", "Traditional medicinal usage", "Phytochemistry", "Pharmacological effects" as the keywords and gathered relevant data on Aster tataricus L.f. using electronic databases (Elsevier, PubMed, ACS, CNKI, Google Scholar, Baidu Scholar, Web of Science), relevant books, and classic literature about Chinese herb.

Result

A total of 186 compounds have been isolated and identified from Aster tataricus, including terpenes, organic acids, peptides, and flavonoids. And Aster tataricus has been widely used as a natural cough suppressant and has anti-oxidative, anti-inflammatory, anti-depressive, and anti-tumor effects. In addition, Aster tataricus has also been reported to have damaging effects on the liver as well as other toxicities were discussed in this review.

Conclusions

Aster tataricus is an ancient herbal medicine with a broad spectrum of pharmaco logical activities that has been used for thousands of years in China, and has shown remarkable effectiveness in the treatment of various diseases, especially cough, asthma, inflammation. Although its rich chemical constituents have various pharmacological activities, the underlying mechanisms, as well as its toxicity and safety, remains unclear and warrant further investigation.

A novel anti-inflammatory flavonoid from flowers of Hibiscus mutabilis L

Hibiscus mutabilis L. is a Traditional Chinese Medicinal plant of significant value. However, there has been limited research focusing specifically on its flowers. In this study, we report the isolation of one novel and nine known flavonoids from the flowers of H. mutabilis L. The structures of these compounds were elucidated using chemical and comprehensive spectral analysis, involving 1D, 2D NMR, and HRESIMS. The novel compound was further evaluated for its anti-inflammatory and cytotoxic activities using in vitro assays on RAW264.7 cells. Compound 1 at the concentration of 6.25 μM significantly inhibited the production of NO and TNF-α induced by LPS in RAW264.7 cells, exhibiting superior efficacy compared to the positive control dexamethasone, thus indicating its potential as an anti-inflammatory drug candidate.

Sativene Sesquiterpenoids from the Plant Endophytic Fungus Bipolaris victoriae S27 and Their Potential as Plant-Growth Regulators

Thirteen new sativene sesquiterpenoids (1 and 3-14), one new natural product (2), and 16 known compounds (15-30) were isolated from the endophytic fungus Bipolaris victoriae S27. Their structures were elucidated by extensive spectroscopic analysis, NMR and ECD calculations, and X-ray crystal diffractions. Compound 1 represented the first example of sativene sesquiterpenoids with a 6/5/3/5-caged tetracyclic ring system. All obtained compounds were evaluated for their plant-growth regulatory activity. The results showed that 1, 3, 4, 6, 8, 11, 12, 17, 19, 26, and 27 could suppress the growth of Arabidopsis thaliana, while 2, 5, 13, 15, 18, and 25 showed promoting effects. Among them, compound 3 showed the most potent plant-growth inhibitory activity, which is obviously superior to that of the marked herbicide glyphosate.

Experimental and theoretical studies on inhibition against tyrosinase activity and melanin biosynthesis by antioxidant ergothioneine

Ergothioneine, a natural derivative of histidine with a thiol/thine tautomeric structure, exhibits exceptional antioxidant properties and inhibition activities on tyrosinase. In this study, enzyme kinetics experiments and chromatographic spectral analysis revealed that ergothioneine inhibited tyrosinase in a reversible and non-competitive manner, with an inhibition constant of 0.554 mg/mL (2.41 mM). As the concentration of ergothioneine increased, the extremely flexible loop structure of tyrosinase extended from 40.1 % to 41.0 %, effectively covering the active center or binding site. Theoretical molecular docking simulation results show that ergothioneine forms complexes with tyrosinase through hydrogen bonding and salt bridges in the active center of Cu ions. Additionally, it was observed that ergothioneine's antioxidant had a stronger reducing impact on dopaquinone, an intermediate in melanin production, than the effect of ascorbic acid at an equivalent concentration (0.5 mg/mL). Ergothioneine reduced the intracellular reactive oxygen species to lower levels than the control group without UVA radiation and regulated the proliferation and differentiation in B16-F10 melanocytes. Clinical trials have shown that a 0.1 % concentration of ergothioneine can effectively suppress melanin production in irradiated skin. The significant reduction in melanin index and an increase in the individual type angle (ITA°) degree were measured after 4 weeks. These results collectively suggest that ergothioneine may be a promising inhibitor of natural antioxidant tyrosinase. Furthermore, due to its safety and efficacy, ergothioneine could be considered one of the bioactive substances for further study on diseases related to melanin production and tyrosinase activity which is of great significance for the cosmetics, medicine and food industries.