Natural Products and Bioprospecting最新文献

Thrombosis triggers various severe diseases, while antithrombotic drugs carry bleeding risks, making the development of novel natural anticoagulants a subject of widespread attention. Poecilobdella manillensis, a prevalent medicinal leech, exhibits remarkable anticoagulant and antithrombotic activities. However, the material basis underlying its anticoagulant effects remains insufficiently investigated. This study aims to mine anticoagulant peptides from P. manillensis by peptidomics analysis, elucidate the material basis of its anticoagulant activity, and provide candidate molecules for developing novel natural anticoagulant drugs. Proteins extracted from P. manillensis were enzymatically digested and fractionated using DEAE-52 and CN columns. The resulting peptide components were analyzed by UPLC-Q-Orbitrap HRMS, and peptide sequences were matched against proteomic databases using Proteome Discoverer. Anticoagulant peptides were predicted using the BIOPEP-UWM database and PeptideRanker server, followed by in vitro and in vivo activity validation. Results showed that the hydrolysate consisted predominantly of low-molecular-weight peptides. 1533 peptides with Mw < 3000 Da (length < 20 amino acids) were identified from the PM-A2 and PM-A3 fractions, accounting for 40.76% of the total. Four peptides selected through predictive screening demonstrated anticoagulant and antithrombotic activities in vitro. Among them, LE-11 significantly prolonged both APTT and TT (P < 0.0001). Furthermore, LE-11 effectively alleviated carrageenan-induced thrombosis in mice, outperforming the heparin control at the mid-concentration (20 mg/kg). In this study, the highly active anticoagulant peptide LE-11 was identified from P. manillensis through peptidomic analysis. These findings establish a solid foundation for developing anticoagulant drugs from this source and provide critical scientific support for its clinical application in treating thrombotic diseases.

Guided by the MS/MS-based molecular networking, eight previously undescribed clerodane diterpenoid glycosides, designated tinospinosides F-M (1-8), along with 12 known analogues (9-20), were isolated from the tuberous roots of Paratinospora sagittata. Structural elucidation of the undescribed compounds was achieved through comprehensive spectroscopic analyses (NMR, HRESIMS), with their absolute configurations confirmed via single-crystal X-ray diffraction, TD-DFT/ECD computational analyses, and chemical degradation. Immunomodulation evaluation on all the isolates revealed that compounds 6 and 7 exerted significant promoting effect toward NO production in RAW264.7 macrophages. Further study demonstrated that 6 could enhance the release of immune cytokines (e.g., TNF-α) and upregulate the protein expression of iNOS and COX-2, which was potentially mediated through the activation of NF-κB signaling pathway.

The new species Cortinarius mapuveronicae from Andean-Patagonian Nothofagus-forests is described in a polythetic approach combining chemical analysis of the anthraquinonoid secondary metabolites, microscopical and morphological characteristics, as well as molecular phylogeny. C. mapuveronicae exhibits an intense red color reaction of the basidiomata by treatment with KOH, whereas the basidiospores are turning purplish brown. As responsible compound, the new anthraquinonoid pigment clavorubin-8-O-methylether (1), together with the known monomeric and dimeric anthraquinones (+)-7,7-emodinphyscion (2), emodin (3), emodin-6,8-di-O-methylether (4), questin (5), (+)-(S)-skyrin (6), (+)-(S)-aurantioskyrin (7), hypericin (8), dermolutein (9), and endocrocin (10) could be identified, showing also remarkable activity in a (photo)antimicrobial and (photo)cytotoxic assay. Phylogenetic analysis (ITS, LSU, rpb1) demonstrates a sister group relationship with the holotype of C. rubrobasalis.

A screen of ~ 4000 actinomycetes strains identified Streptomyces sp. W3009 as a producer of the antituberculosis agent pyridomycin. Using a mass spectrometry-based metabolomics approach coupled with molecular networking, we identified seven pyridomycin derivatives, six of which were novel. Three of these novel compounds were linear, featuring a unique 3-hydroxypicolinic acid-L-threonine-3-(3-pyridyl)-L-alanine (3HP-T-3PA) scaffold. Their structures were elucidated via detailed NMR studies. While two cyclic derivatives (4 and 5) showed modest antitubercular activity, the three linear derivatives, despite possessing the key 3HP-T-3PA moiety, exhibited no inhibitory activity. This intensive MS-based approach demonstrates the important role of such techniques in the discovery of novel biologically active core structures and their natural derivatives.

Antibiotic-induced depletion of the gut microbiota facilitated the colonization of vancomycin-resistant Enterococci (VRE) in the gastrointestinal tract, and then increased patients' susceptibility to secondary infections. Ellagic acid, a major constituent of fruits and nuts, showed various bioactivities except for antibacterial. Interestingly, it promoted the recovery of gut microbiota, enhanced microbial diversity and stimulated the proliferation of probiotic gut microbes, and then ameliorated the overgrowth of pathogens in vivo in our experiment. Moreover, ellagic acid activated Gpr41 and Gpr43 mainly by promoting the production of short chain fatty acids (SCFAs) such as acetic acid and propionic acid to inhibit the NF-ĸB signaling pathway. Then the dietary supplement with ellagic acid might treat infected gut to avoid antibiotic-associated intestinal diseases, and the finding also provided a novel strategy for exploring antibacterial agent besides screening in vitro.