Search

Echinoderms, a diverse group of marine invertebrates including starfish, sea urchins, and sea cucumbers, have been recognized as prolific sources of structurally diverse natural products. In the past five years, remarkable progress has been made in the isolation, structural elucidation, and pharmacological assessment of these bioactive compounds. These metabolites, including polysaccharides, triterpenoids, steroids, and peptides, demonstrate potent bioactivities such as anticancer, anti-inflammatory, antiviral, and antimicrobial effects, providing valuable insights and scaffolds for drug discovery. This review highlights the structural diversity and biological activities of natural products derived from echinoderms over the last five years, with a particular focus on their structure–activity relationships and therapeutic potential. It also outlines the prospects and challenges for future research, aiming to stimulate further exploration in marine drug discovery. [ABSTRACT FROM AUTHOR]

Two new cembrane-derived tricyclic diterpenes belonging to the sarcophytin family, namely 4a-hydroxy-chatancin (1) and sarcotoroid (2), together with two known related ones (3 and 4), were isolated from the soft coral Sarcophyton tortuosum collected off Ximao Island in the South China Sea. The structures of the new compounds were elucidated by extensive spectroscopic analysis, a quantum mechanical nuclear magnetic resonance (QM-NMR) method, a time-dependent density functional theory electronic circular dichroism (TDDFT-ECD) calculation, X-ray diffraction analysis, and comparison with the reported data in the literature. A plausible biosynthetic pathway of compounds 1–4 was proposed, involving undergoing a transannular Diels–Alder cycloaddition. In the bioassay, the new compound 1 displayed significant inhibitory activities against the fish pathogens Streptococcus parauberis KSP28, oxytetracycline-resistant Streptococcus parauberis SPOF3K, and Photobacterium damselae FP2244, with MIC values of 9.1, 9.1, and 18.2 μg/mL, respectively. Furthermore, by conducting a luciferase reporter assay on rat liver Ac2F cells, compounds 1, 3, and 4 were evaluated for peroxisome proliferator-activated receptor (PPAR) transcriptional activity, and compound 3 showed selective PPAR-β agonist activity at a concentration of 10 μΜ. [ABSTRACT FROM AUTHOR]

A novel amide alkaloid, bursatamide A (1), featuring an unprecedented propyl-hexahydronaphthalene carbon framework, was isolated from the infrequently studied sea hare Bursatella leachi , alongside a new 3-phenoxypropanenitrile alkaloid, bursatellin B (2), and twelve known compounds. The structures of 1 and 2 were elucidated through comprehensive spectroscopic data analyses, while their relative and absolute configurations (ACs) were established through total synthesis and a series of quantum chemical calculations, including calculated electronic circular dichroism (ECD) spectra, optical rotatory dispersion (ORD) methods, and DP4+ probability analyses. Bursatamide A (1) demonstrated inhibitory effects against the human pathogenic bacteria Listeria monocytogenes and Vibrio cholerae. Erythro -bursatellin B (21), a diastereoisomer of 2 , exhibited notable antibacterial activity against the fish pathogenic bacterium Streptococcus parauberis FP KSP28, with an MIC 90 value of 0.0472 μg·mL−1. [ABSTRACT FROM AUTHOR]

Several studies have investigated the relationship of greenspace with blood pressure (BP) and hypertension, but the results were inconsistent. We aimed to assess the relationship of greenspace with BP/hypertension. We searched PubMed, Embase and Web of Science on greenspace and BP/hypertension published before 5 April 2023. The methodological quality and risk of bias were evaluated. Twenty-seven articles were included. Our results suggested that higher normalized difference vegetation index (NDVI) was associated with lower odds of hypertension and levels of SBP [for every 10% increase of NDVI 500-m and NDVI 1000-m, the ORs were 0.95 (95% CI: 0.90–0.99) and 0.95 (95% CI: 0.90–0.99), the ꞵwas -1.32 (95% CI: -2.18, -0.45) and -1.41 (95% CI: -2.57, -0.25), respectively]. This study indicated that higher exposure to greenspace might be associated with lower levels of BP and risk of hypertension. Increase green spaces should be regarded as an important public health intervention.. [ABSTRACT FROM AUTHOR]

[Objectives] With the wide application of Carbon Fiber Reinforced Polymer (CFRP) in industry,the problem of poor lightning strike protection has become more and more serious. In order to study the lightning strike protection effect of coatings with different conductivity,[Methods] based on the shock current generation device and the lightning damage effect test bench,a comparative test is carried out on three types of CFRP samples by using 8/20 μs double-exponential pulse with the peak value of 100 kA,and the damage mechanism of CFRP subject to lightning strikes is analyzed.[Results] The test results show that,the CFRP structure is more severely damaged after lightning strikes and the lightning strike protection fails to be achieved if a material with low conductivity such as epoxy resin is used as the protective coating;but the damage of the CFRP structure caused by the lightning strikes can be effectively reduced if a material with high conductivity such as copper mesh is used as the protective coating.[Conclusions] The study results can provide technical support for the follow-up CFRP lightning strike protection researches.

In this letter, the authors present a novel compact waveguide filtering twist that can be readily fabricated from metal using the computer numerical control (CNC) machining process. This filtering twist comprises four coupled resonators that are rotationally deformed to provide the desired 90° twist. Such resonator structures eliminate the use of curved features and therefore are ideally suitable for conventional CNC machining. The proposed design offers appealing advantages, including great compactness, easy fabrication, and good scalability to millimetre‐wave and terahertz frequencies. The design is demonstrated at X‐band and has a fourth‐order Chebyshev filter response (bandwidth 0.4 GHz, centred at 10 GHz). The good agreement between simulation and measurement results validates the proposed concept. [ABSTRACT FROM AUTHOR]

Abstract Background The natural product Emodin demonstrates a wide range of pharmacological properties including anticancer, anti-inflammatory, antiproliferation, vasorelaxant and anti-H. pylori activities. Although its H. pylori inhibition was discovered, no acting target information against Emodin has been revealed to date. Results Here we reported that Emodin functioned as a competitive inhibitor against the recombinant β-hydroxyacyl-ACP dehydratase from Helicobacter pylori (HpFabZ), and strongly inhibited the growth of H. pylori strains SS1 and ATCC 43504. Surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC) based assays have suggested the kinetic and thermodynamic features of Emodin/HpFabZ interaction. Additionally, to inspect the binding characters of Emodin against HpFabZ at atomic level, the crystal structure of HpFabZ-Emodin complex was also examined. The results showed that Emodin inhibition against HpFabZ could be implemented either through its occupying the entrance of the tunnel or embedding into the tunnel to prevent the substrate from accessing the active site. Conclusion Our work is expected to provide useful information for illumination of Emodin inhibition mechanism against HpFabZ, while Emodin itself could be used as a potential lead compound for further anti-bacterial drug discovery.