{"title":"Immunomodulatory natural products <i>via</i> toll-like receptor 2 signalling: from agonists to inhibitors across diverse natural sources.","authors":"Jeongho Lee","doi":"10.1039/d6np00080k","DOIUrl":"https://doi.org/10.1039/d6np00080k","url":null,"abstract":"<p><p>Covering: up to 2025Toll-like receptor 2 (TLR2) is a versatile pattern recognition receptor whose activity can be tuned in either direction-agonism or antagonism-to produce distinct therapeutic outcomes, ranging from vaccine adjuvants and cancer immunotherapeutics to anti-inflammatory agents for sepsis, neuroinflammation, and autoimmune disease. Natural products from bacteria, fungi, plants, and marine organisms have emerged as a structurally rich source of TLR2 modulators, encompassing acylated lipopeptides, glycolipids, polysaccharides, flavonoids, non-flavonoid polyphenols, an aromatic aldehyde, an aporphine alkaloid, and even large bacterial antagonist proteins. This review surveys these natural TLR2 agonists and inhibitors, highlighting how the effective allocation of hydrophobic chains between the TLR2 pocket and its partner receptor, rather than total acyl-chain number alone, combines with chain branching, stereochemical presentation and polar head-group interactions to govern TLR1/TLR6 heterodimer selectivity among bacterial and gut-commensal lipids, and how mechanistically distinct inhibitory strategies-direct receptor competition, transcriptional downregulation, and TIR-domain interference-converge on a shared druggable interface exploited independently by plant polyphenols and staphylococcal virulence factors alike. Persistent experimental challenges are also discussed, including microbial contamination of natural extracts and structural heterogeneity of isolated lipids, along with how total synthesis and chemically defined oligomers have resolved these ambiguities, underscoring natural products as a promising yet still underexploited chemical space for developing selective TLR2-targeted therapeutics.</p>","PeriodicalId":94,"journal":{"name":"Natural Product Reports","volume":" ","pages":""},"PeriodicalIF":12.5,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149331756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"YqcI/YcgG heme monooxygenases: a new fold for guanidine <i>N</i>-oxygenation in natural product biosynthesis.","authors":"Darwin D Lara, Yang Hai","doi":"10.1039/d6np00089d","DOIUrl":"https://doi.org/10.1039/d6np00089d","url":null,"abstract":"<p><p>Covering: up to 2026With the first crystal structure of a YqcI/YcgG enzyme now available, alongside biochemical characterization of multiple homologs, significant advances have been made toward understanding this previously uncharacterized protein family. Here, we review these recent discoveries and highlight the key questions that remain regarding YqcI/YcgG structure, function, and mechanism. Finally, we discuss emerging efforts to engineer this enzyme family and evaluate their potential as versatile biocatalytic platforms for selective guanidine <i>N</i>-oxygenation. Together, these studies establish YqcI/YcgG as a distinct class of heme-dependent enzymes and provide a framework for understanding and harnessing their unique catalytic capabilities.</p>","PeriodicalId":94,"journal":{"name":"Natural Product Reports","volume":" ","pages":""},"PeriodicalIF":12.5,"publicationDate":"2026-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149316151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hyeon-Seong Lee, Jungro Lee, Hoseong Hwang, Hyojune Park, Won Kyu Kim, Munhyung Bae, Jaeyoung Kwon
{"title":"Natural products from human-associated microbiota in human diseases.","authors":"Hyeon-Seong Lee, Jungro Lee, Hoseong Hwang, Hyojune Park, Won Kyu Kim, Munhyung Bae, Jaeyoung Kwon","doi":"10.1039/d6np00068a","DOIUrl":"https://doi.org/10.1039/d6np00068a","url":null,"abstract":"<p><p>Covering: 1985 to 2026The human microbiota harbors abundant metabolic capacity, producing and transforming a chemically diverse array of small molecules that range from well-characterized classes, such as short-chain fatty acids, secondary bile acids, and indoles, to structurally complex ribosomal and non-ribosomal peptides. Several of these metabolites act on defined host receptors and signaling pathways, linking microbial metabolic activity to a broad spectrum of human diseases. Although individual compounds have increasingly been linked to defined host targets, this rapidly growing evidence remains scattered across disease areas. Here, we review bioactive compounds produced or transformed by human-associated microbiota, together with microbiota-associated co-metabolites, across four major disease categories, namely metabolic diseases, cancers, immune regulation, and other systemic and extraintestinal diseases. For each, we discuss the microbial species implicated, the compounds they produce, and the mechanistic evidence connecting individual molecules to disease-relevant biological processes. Altogether, we highlight the therapeutic potential of microbiota-derived metabolites and the rich opportunities for discovery within the largely untapped microbial chemical space by integrating chemistry, microbiology, and disease mechanisms. Beyond the disease-centered organization, we compare these molecules across structural and biosynthetic origins, taxonomic producer patterns, and emerging discovery strategies to identify recurring principles that cut across individual disease categories.</p>","PeriodicalId":94,"journal":{"name":"Natural Product Reports","volume":" ","pages":""},"PeriodicalIF":12.5,"publicationDate":"2026-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149316150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Opines: origins, roles, structures with a nomenclature proposal, and syntheses.","authors":"Leon Otten, Patrick Pale","doi":"10.1039/d6np00028b","DOIUrl":"10.1039/d6np00028b","url":null,"abstract":"<p><p>Covering: 1927 to 2026.Although discovered almost a century ago, opines represent an ever-growing family of natural products, derived from a variety of organisms, including bacteria, fungi, plants, and marine invertebrates. Opines exhibit a wide variety of structures and play numerous biological roles, some of which have had significant implications in molecular biology, notably in the development of genetically modified organisms (GMOs) and in plant evolution with the recent discovery of natural GMOs. The opines structurally related to <i>N</i>-alkylated α-amino acids are useful chiral building blocks for the pharmaceutical and fine chemical industries, and some of the enzymes involved in their biosynthesis are now being exploited in these industries for drug development. This review first traces the history of opines from 1927 up to now in term of both chemical and biological views; then a new classification with clearer names is proposed mostly based on structural grounds. The various syntheses of opines are described and discussed according to this proposed classification, together with their known applications in biology, chemical biology and chemistry. Finally, several possible directions are highlighted as a roadmap for future research.</p>","PeriodicalId":94,"journal":{"name":"Natural Product Reports","volume":" ","pages":"2084-2124"},"PeriodicalIF":12.5,"publicationDate":"2026-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148596702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jabal Rahmat Haedar, Ying Shi, Mit A Bhatt, Jonathan R Chekan, Huan Wang, Chin-Soon Phan
{"title":"Radical-mediated cross-linking enzymes in RiPP biosynthesis.","authors":"Jabal Rahmat Haedar, Ying Shi, Mit A Bhatt, Jonathan R Chekan, Huan Wang, Chin-Soon Phan","doi":"10.1039/d6np00029k","DOIUrl":"10.1039/d6np00029k","url":null,"abstract":"<p><p>Covering: January 2020 to February 2026Ribosomally synthesized and post-translationally modified peptides (RiPPs) continue to be a rich source of chemically diverse and bioactive peptide natural products. In recent years, rapid progress has been made in the discovery of radical-mediated cross-linking enzymes involved in RiPP biosynthesis. These enzymes, such as radical SAM, P450, DUF3328, BURP-domain, and α-ketoglutarate-dependent enzymes have been found to catalyze various cross-linkings between one aromatic side chain and one aliphatic amino acid (monoaryl cyclophane) or between two aromatic side chains (biaryl cyclophane) on the precursor peptides. This highlight aims to summarize the latest development of these enzymes that catalyze the formation of cross-links involving two to five amino acids from bacteria, fungi and plants, with a particular focus on the cross-linked structure and radical enzymatic mechanism.</p>","PeriodicalId":94,"journal":{"name":"Natural Product Reports","volume":" ","pages":"1952-1961"},"PeriodicalIF":12.5,"publicationDate":"2026-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148560173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Unifying ten tryptophan dimer families: linkage diversity from bio-synthetic hypotheses to total synthesis and bioactivity.","authors":"Leiyang Bai, Haiping Liu, Xuefeng Jiang","doi":"10.1039/d6np00021e","DOIUrl":"10.1039/d6np00021e","url":null,"abstract":"<p><p>Covering: up to July 2026Dimeric tryptophan alkaloids represent a structurally diverse family of natural products whose three-dimensional architectures and biological activities are fundamentally dictated by the linkage patterns between the two tryptophan-derived units. In this review, we connect ten seemingly unrelated natural product families through the unifying principle of tryptophan dimerization, with biological activities varying considerably across linkage types. They are systematically classified according to their covalent connectivity-C-N, C-C, or mixed C-C/C-N linkages-covering ten distinct linkage types: C3-N1', C3a-C3a' (symmetric and unsymmetric), C3-C5', C5-C5', C3-C6', C3-C7', C6-N1', C7-N1', and N1-N1'. For each class, we critically compare total syntheses reported from 1999 to 2026, with an emphasis on strategic solutions to the formidable synthetic challenges faced, <i>e.g.</i> the stereocontrolled formation of congested quaternary centers, chemo- and regioselective installation of heterodimeric linkages, and construction of intricate polycyclic frameworks. We further present a unified biosynthetic hypothesis for all ten linkage types, grounded in radical- and cation-mediated dimerization pathways and supported by recent enzyme characterization and synthetic studies, which not only rationalizes the known linkages but can also guide the discovery of new dimerization modes and their total syntheses, aiming to provide a comprehensive and critical overview of these dimeric tryptophan alkaloids.</p>","PeriodicalId":94,"journal":{"name":"Natural Product Reports","volume":" ","pages":"2014-2048"},"PeriodicalIF":12.5,"publicationDate":"2026-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148547111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The golden decade of eburnamine-vincamine alkaloid synthesis: 2015 to present.","authors":"Huijing Wang, Jiayi Mu, Yangyang Zhong, Pei Tang, Fener Chen","doi":"10.1039/d6np00054a","DOIUrl":"10.1039/d6np00054a","url":null,"abstract":"<p><p>Covering: 2015 to 2026Eburnamine-vincamine alkaloids are unique monoterpenoid indole alkaloids with unprecedented structures and notable biological properties. Four eburnamine-vincamine alkaloids, namely vincamine, vinburnine, brovincamine, and vinpocetine have been approved for clinical treatment. In addition, numerous bioactive derivatives have been used in clinical trials. Since 2015, several synthetic strategies, particularly asymmetric approaches, have emerged to achieve significant progress in the total synthesis of eburnamine-vincamine alkaloids. The main synthetic challenge posed by their structures is the construction of the rigid polycyclic skeleton and installation of the C20/C21 (or C3/C14) contiguous stereocenters. These total synthesis endeavors are considered highly desirable and could fuel advances in medicinal chemistry of eburnamine-vincamine. In this review, recent reports (mainly from 2015 to 2026) on the total synthesis of eburnamine-vincamine natural products and their derivatives (eburnane-vincane, tacaman, schizozygane, and bisindole groups) are reported and discussed.</p>","PeriodicalId":94,"journal":{"name":"Natural Product Reports","volume":" ","pages":"1988-2013"},"PeriodicalIF":12.5,"publicationDate":"2026-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148416903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qianfei Huang, Xuxiang Chen, Shuhong Ma, Zilin Li, Peng Sun
{"title":"<i>Ortho</i>-alkyl phenylalkenoyl natural products: structural diversity, bioactivities and biosynthesis.","authors":"Qianfei Huang, Xuxiang Chen, Shuhong Ma, Zilin Li, Peng Sun","doi":"10.1039/d6np00053c","DOIUrl":"10.1039/d6np00053c","url":null,"abstract":"<p><p>Covering: up to 2026.<i>Ortho</i>-alkyl phenylalkenoyl-containing natural products, including cinnamoyl-containing nonribosomal peptides (CCNPs) and <i>ortho</i>-alkyl phenylalkenoic acids (APAs), are structurally and biologically diverse bacterial metabolites that have become a major focus of natural product research. These metabolites exhibit broad bioactivities, including antimicrobial, antiangiogenic, cytotoxic, anti-inflammatory, and nematicidal effects. Biosynthetically, CCNPs and APAs share a conserved, highly reduced (HR) type II polyketide synthase (PKS)-derived framework, featuring characteristic isoenzymes (ISOs) and specialised cyclases that assemble the <i>ortho</i>-alkyl phenylalkenoyl core. They diverge fundamentally in pathway architecture: CCNPs contain NRPS-synthesised peptide backbones, whereas APAs lack NRPS components and possess expanded KS/CLF pairs. Biosynthetic studies have revealed novel mechanisms (<i>e.g.</i>, isomerization, 6π-electrocyclisation) and multifunctional enzymes, providing valuable biocatalysts for synthetic biology. Although their biological activities depend strongly on structural context, emerging evidence highlights these metabolites as a promising source of lead compounds. Continued interdisciplinary efforts integrating natural product chemistry, biosynthesis, and medicinal chemistry are expected to unlock their therapeutic potential.</p>","PeriodicalId":94,"journal":{"name":"Natural Product Reports","volume":" ","pages":"2049-2083"},"PeriodicalIF":12.5,"publicationDate":"2026-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148589600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Hot off the Press.","authors":"Robert A Hill, Andrew Sutherland","doi":"10.1039/d6np90036d","DOIUrl":"10.1039/d6np90036d","url":null,"abstract":"<p><p>A personal selection of 32 recent papers is presented covering various aspects of current developments in bioorganic chemistry and novel natural products such as sacchaindol A from <i>Saccharopolyspora erythraea</i>.</p>","PeriodicalId":94,"journal":{"name":"Natural Product Reports","volume":" ","pages":"1935-1939"},"PeriodicalIF":12.5,"publicationDate":"2026-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149101171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Natural products shape microbial ecology and disease in the cystic fibrosis airway.","authors":"Niladri Bhowmik, Reed M Stubbendieck","doi":"10.1039/d6np00067c","DOIUrl":"10.1039/d6np00067c","url":null,"abstract":"<p><p>Covering up to 2026Cystic fibrosis (CF) is a life-shortening autosomal recessive genetic disorder caused by mutation in the gene encoding the CF transmembrane conductance regulator (CFTR). Dysfunction in CFTR leads to the accumulation of thick and dehydrated mucus in the respiratory tract, which serves as a substrate for a complex microbiota that includes commensal oral and respiratory bacteria and opportunistic pathogenic bacteria and fungi. During chronic infections, these microbes persist in the airways and contribute to progressive lung tissue damage, ultimately leading to respiratory failure and premature death. Within this environment, microbes synthesize a diverse repertoire of natural products, including antimicrobials, siderophores and other metallophores, signaling molecules, toxins, and other virulence factors. In this review, we thoroughly discuss natural products produced by members of the CF airway microbiota, primarily the bacterial pathogens <i>Burkholderia</i> spp., <i>Pseudomonas aeruginosa</i>, and <i>Staphylococcus aureus</i> and the fungal pathogens <i>Aspergillus fumigatus</i> and <i>Scedosporium</i> spp. When known, we describe the biosynthesis and roles of these natural products in microbial persistence, interspecies interactions, and virulence in the CF airway. When these roles are unknown, we infer potential roles based on evidence from the literature in different disease contexts. Finally, we briefly highlight natural products produced by the CF microbiota as novel sources for developing new antimicrobials and as drug targets to treat disease.</p>","PeriodicalId":94,"journal":{"name":"Natural Product Reports","volume":" ","pages":""},"PeriodicalIF":12.5,"publicationDate":"2026-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13684122/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149230867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}