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Six seongsanamides were isolated from the culture broth of Bacillus safensis KCTC 12796BP, and their structures were elucidated by spectroscopic data analysis combined with Marfey's method, electronic circular dichroism calculations, and biosynthetic gene cluster analysis. Compounds 1-4 were bicyclic peptides with isodityrosine residues; 5 and 6 were monocyclic peptides. Only the bicyclic seongsanamides inhibited degranulation and LTC/PGD generation in IgE/Ag-stimulated bone marrow-derived mast cells. Oral administration of 1 suppressed mast cell-dependent passive cutaneous anaphylaxis reaction.
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http://dx.doi.org/10.1021/acs.orglett.8b03293 | DOI Listing |
J Org Chem
September 2025
College of Chemistry and Materials Science, Key Laboratory of Analytical Science and Technology of Hebei Province, and MOE Key Laboratory of Medicinal Chemistry and Molecular Diagnostics, Hebei University, Baoding 071002, Hebei, China.
In this work, the previously reported SeODR strategy was used successfully for the synthesis of bicyclic peptides (). with different rings bearing various thioether linkages were prepared through a one-pot reaction; 15 with satisfactory yields were achieved. Cross-linkers including xylylene dibromide (, 2,6-bis(bromomethyl)pyridine (, 4,4'-bis(bromomethyl)biphenyl (), 1,3-dichloroacetone (, and dichloro--tetrazine ( are all compatible with the SeODR approach used for deprotection of the S-acetamidomethyl (Acm) group in peptides.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
August 2025
Institute of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, D-12489, Berlin, Germany.
Chemical modification and nucleic acid self-assembly can be used to make protein receptor ligands form specific arrangements. While this property has been extensively exploited for probing of homomultivalent interactions, there has been comparatively little attention paid to the exploration of heteromultivalent interactions. In this study, we investigated the use of readily assemblable DNA duplexes for programming bispecific targeting of specific cell types.
View Article and Find Full Text PDFJ Nat Prod
August 2025
Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, Key Laboratory of Neurological Diseases of Hubei Province, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Multidrug resistance (MDR) remains a significant challenge in cancer chemotherapy. Seeking novel MDR modulators, we employed a molecular networking (MN)-guided strategy to explore the endophytic fungus . This led to the targeted isolation of an unprecedented cyclotetrapeptide, templicolamide A (, featuring a rare β-enamino acid), and four piperazine derivatives (-), including the new helvamide E () with a unique bicyclic scaffold.
View Article and Find Full Text PDFJ Org Chem
August 2025
Philipps-University Marburg, Department of Chemistry, Hans-Meerwein-Straße 4, 35043 Marburg, Germany.
We describe the first synthesis of the natural cyclic hexapeptide Fusahexin (-ala-Leu-ehr=Pro-leu-Leu) () containing the bicyclic dipeptide ehr=Pro, a tetrahydro-1,3-oxazin-4-one formed from erythronine and proline. Fusahexin and several other peptides were obtained either by using the bicyclic dipeptide Fmoc-ehr=Pro-OH () in SPPS or by late-stage oxidation of a precursor peptide aldehyde. In all cases studied, the bicyclic dipeptide ehr=Pro cyclizes by acid-promoted condensation, forming the bridge head of the fused bicyclic ring exclusively in configuration.
View Article and Find Full Text PDFDrug Deliv Transl Res
July 2025
Department of Bioengineering, Institut Químic de Sarrià, Universitat Ramon Llull, Barcelona, 08017, Spain.
Although nucleotide-based therapeutics hold promise for a variety of diseases, their clinical application is limited because of low stability and poor bioavailability. Among non-viral gene delivery vectors, poly(β-aminoester)s (pBAEs) stand out because of their low cytotoxicity, high transfection capacity, and adequate biodegradation profile. Oligopeptide end-Modified pBAEs (OM-pBAEs) enable enhanced polynucleotide encapsulation, cellular internalization, and transfection.
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