Inhibition of candidalysin production by methoxy-apo-enterobactin from Streptomyces ambofaciens CJD34 as a novel antifungal strategy against Candida albicans.

Opportunistic fungal pathogens, responsible for over 300 million severe cases and 1.5 million deaths annually, pose a serious global health threat, especially in immunocompromised individuals. Among these, Candida albicans is a major cause of both superficial and invasive infections, which can progress to systemic candidiasis.

Efficient Stereochemical Analysis of Hydroxy Fatty Acids Using PGME and PAME Derivatization.

We present a time-efficient and cost-effective approach for the stereochemical analysis of α- and β-hydroxy fatty acids (α-HFAs and β-HFAs) using chiral derivatizing agents, phenylglycine methyl ester (PGME) and phenylalanine methyl ester (PAME). Conventional methods for stereochemical analysis, such as X-ray crystallography and Mosher's ester derivatization, require pure samples and are laborious. In contrast, PGME and PAME derivatization enables direct LC-MS analysis of crude extracts without compound isolation or extensive sample preparation.

Discovery of Dual ROCK1/2 Inhibitors from sp. under Metal Stress.

Rho-associated protein kinase (ROCK) inhibitors are promising therapeutic agents for reducing elevated intraocular pressure in patients with glaucoma. We explored new ROCK inhibitors derived from bioactive metabolites produced by microbes, specifically cryptic metabolites from sp. MCY7, using a liquid chromatography-mass spectrometry-based chemical analysis approach integrated with metal stress-driven isolation.

Extraction, Isolation, and Structural Elucidation of Acylated Triterpene Saponins from Asteraceae Family.

Saponins represent specialized (secondary) metabolites primarily sourced from plants, typically characterized by an aglycone component of triterpenoids or steroids, often referred to as sapogenin, coupled with sugar moieties. Their structural intricacy and diversity, along with their manifold pharmacological properties, have garnered significant interest among researchers. Notwithstanding this interest, the study of saponins has been encumbered by challenges in their isolation, purification, and structural characterization.

Isolation and Characterization of Bioactive Compounds from sp. CMS18 and Their Antifungal Properties.

In this study, metagenomic analysis was employed to investigate the bacterial communities in the Muan tidal mudflat of the Republic of Korea. We used metagenomic analysis to identify the microbial community in tidal soil dominated by Proteobacteria. From this environment, the bacterial strain, sp.

Structural Elucidation and Antiviral Properties of Pannosides from the Halophyte L.

Four previously undescribed pentacyclic triterpenoid saponins, pannosides F-I (-), were isolated from the halophyte L. (), and their chemical structures were elucidated using 1D and 2D NMR spectroscopy and mass spectrometry. Comprehensive structural analysis revealed the presence of distinct aglycone and glycosidic moieties, along with complex acylation patterns.

Bacteria from the Amycolatopsis genus associated with a toxic bird secrete protective secondary metabolites.

Uropygial gland secretions of birds consist of host and bacteria derived compounds and play a major sanitary and feather-protective role. Here we report on our microbiome studies of the New Guinean toxic bird Pachycephala schlegelii and the isolation of a member of the Amycolatopsis genus from the uropygial gland secretions. Bioactivity studies in combination with co-cultures, MALDI imaging and HR-MS/MS-based network analyses unveil the basis of its activity against keratinolytic bacteria and fungal skin pathogens.

Nonthreaded Isomers of Sungsanpin and Ulleungdin Lasso Peptides Inhibit H1299 Cancer Cell Migration.

Lasso peptides are a structurally distinct class of biologically active natural products defined by their short sequences with impressively interlocked tertiary structures. Their characteristic peptide [1]rotaxane motif confers marked proteolytic and thermal resiliency, and reports on their diverse biological functions have been credited to their exceptional sequence variability. Because of these unique properties, taken together with improved technologies for their biosynthetic production, lasso peptides are emerging as a designable scaffold for peptide-based therapeutic discovery and development.

Discovery and structure elucidation of glycosyl and 5-hydroxy migrastatins from dung beetle gut Kitasatospora sp.

Unlabelled: Two new macrocyclic secondary metabolites, glycosyl-migrastatin (1) and 5-hydroxy-migrastatin (2), were isolated from a gut bacterium Kitasatospora sp. JL24 in dung beetle Onthophagus lenzii. Based on a comprehensive analysis of the nuclear magnetic resonance (NMR), MS, and UV spectroscopic data, the planar structures of 1 and 2 were successfully identified as new derivatives of migrastatin.

Heterologous expression of the cryptic gene cluster and structural revision of maduralactomycin A.

After conducting an analysis of the cryptic cluster region and performing transcriptomic studies, an integrative BAC Vector containing the gene sequence was constructed. The heterologous expression of the cluster in J1074 resulted in the production of the angucyclic product, seongomycin, which allowed for the assesment of its antibacterial, antiproliferative, and antiviral activities. Heterologous production was further confirmed by targeted knock-out experiments involving key regulators of the biosynthetic pathways.

Xinghamide A, a New Cyclic Nonapeptide Found in .

Xinghamide A (), a new nonapeptide, was discovered in isolated from a halophyte, (L.) Dumort. Based on high-resolution mass and NMR spectroscopic data, the planar structure of was established, and, in particular, the sequence of nine amino acids was determined with ROESY and HMBC NMR spectra.

3-Hydroxybutyrate-containing triterpenoid saponins from Brachyscome angustifolia and their immunogenic activity.

Three unique hydroxybutyrate-containing triterpenoid saponins, angustiside A-C (1-3), were isolated from the shoots of Brachyscome angustifolia (Asteraceae). The extensive spectroscopic study showed that their aglycone is a previously undescribed one, 16-hydroxy olean-18-en-28-oic acid, named as angustic acid (1a), and 2 and 3 contain hydroxybutyrate moiety in their side chains. The absolute configuration of 1a was determined to be (3R,5R,9R,13S,16S) by X-ray crystallography.

Chromatographic Determination of the Absolute Configuration in Sanjoinine A That Increases Nitric Oxide Production.

A chiral derivatization strategy with phenylglycine methyl ester (PGME) was employed to develop a straightforward method to determine the absolute configurations of ,-dimethyl amino acids. The PGME derivatives were analyzed using liquid chromatography-mass spectrometry to identify the absolute configurations of various ,-dimethyl amino acids based on their elution time and order. The established method was applied to assign the absolute configuration of the ,-dimethyl phenylalanine in sanjoinine A (), a cyclopeptide alkaloid isolated from Zizyphi Spinosi Semen widely used as herbal medicine for insomnia.

Metabolomic analysis of halotolerant endophytic bacterium isolated from (L.) dumort.

In this study, the strain was isolated from (L.) Dumort. collected in Sinan, Republic of Korea.

A comparative phytochemical study of nine Lauraceae species by using chemometric data analysis.

The diversity of secondary metabolites of individual plants results from multiple enzymatic processes in planta and various environmental factors, such as temperature, moisture, and soil conditions. Chemical composition analysis of plants can lead to a new method to understand relationship among comparable plants along with biological classification such as genetic and anatomical method. In this study, the chemical diversity of nine different Lauraceae species was investigated, and the plant samples were chemically analyzed and classified.

Cystargamides C and D, New Cyclic Lipopeptides From a Tidal Mudflat-Derived sp. JMS132.

Cystargamides C and D ( and ) were isolated from a marine actinomycete strain collected at Beolgyo, South Korea. The planar structures of the cystargamides were elucidated by 1/2D NMR, UV, and MS spectroscopic analyses. The absolute configurations of and were determined based on ROESY correlations and the advanced Marfey's methods.

Lobophorin Producing Endophytic JB1 Associated With (Thunb.) Moritzi & Zoll.

In this study, we focused on endophytes of (Thunb.) Moritzi & Zoll. and the plant-microbe interaction at metabolite levels.

Comparative Genomic and Metabolic Analysis of sp. RB110 Morphotypes Illuminates Genomic Rearrangements and Formation of a New 46-Membered Antimicrobial Macrolide.

Morphotype switches frequently occur in Actinobacteria and are often associated with disparate natural product production. Here, we report on differences in the secondary metabolomes of two morphotypes of a species, including the discovery of a novel antimicrobial glycosylated macrolide, which we named termidomycin A. While exhibiting an unusual 46-member polyene backbone, termidomycin A (1) shares structural features with the clinically important antifungal agents amphotericin B and nystatin A1.

GNPS-guided discovery of xylacremolide C and D, evaluation of their putative biosynthetic origin and bioactivity studies of xylacremolide A and B.

Targeted HRMS-GNPS-based metabolomic analysis of sp. X187, a fungal antagonist of the fungus-growing termite symbiosis, resulted in the identification of two lipopeptidic congeners of xylacremolides, named xylacremolide C and D, which are built from d-phenylalanine, l-proline and an acetyl-CoA starter unit elongated by four malonyl-CoA derived ketide units. The putative gene cluster was identified from a draft genome generated by Illumina and PacBio sequencing and RNAseq studies.

Targeted Isolation of Saalfelduracin B-D from Using LC-MS/MS-Based Molecular Networking.

High-resolution tandem mass spectrometry (HR-MS)-based metabolomic studies of , isolated from the "Saalfelder Feengrotten" caves in Germany, led to the isolation of three ribosomally synthesized and post-translationally modified type II thiopeptides, saalfelduracin B-D (-) and the known saalfelduracin A (). The structures of all four compounds were determined by comparative two-dimensional NMR analysis and high-resolution tandem mass spectrometry.

Targeted Discovery of Tetrapeptides and Cyclic Polyketide-Peptide Hybrids from a Fungal Antagonist of Farming Termites.

Herein, we report the targeted isolation and characterization of four linear nonribosomally synthesized tetrapeptides (pseudoxylaramide A-D) and two cyclic nonribosomal peptide synthetase-polyketide synthase-derived natural products (xylacremolide A and B) from the termite-associated stowaway fungus Pseudoxylaria sp. X187. The fungal strain was prioritized for further metabolic analysis based on its taxonomical position and morphological and bioassay data.

Coculture of Marine sp. With sp. Produces a New Piperazic Acid-Bearing Cyclic Peptide.

Microbial culture conditions in the laboratory, which conventionally involve the cultivation of one strain in one culture vessel, are vastly different from natural microbial environments. Even though perfectly mimicking natural microbial interactions is virtually impossible, the cocultivation of multiple microbial strains is a reasonable strategy to induce the production of secondary metabolites, which enables the discovery of new bioactive natural products. Our coculture of marine and strains isolated together from an intertidal mudflat led to discover a new metabolite, dentigerumycin E ().

Ohmyungsamycins promote antimicrobial responses through autophagy activation via AMP-activated protein kinase pathway.

The induction of host cell autophagy by various autophagy inducers contributes to the antimicrobial host defense against Mycobacterium tuberculosis (Mtb), a major pathogenic strain that causes human tuberculosis. In this study, we present a role for the newly identified cyclic peptides ohmyungsamycins (OMS) A and B in the antimicrobial responses against Mtb infections by activating autophagy in murine bone marrow-derived macrophages (BMDMs). OMS robustly activated autophagy, which was essentially required for the colocalization of LC3 autophagosomes with bacterial phagosomes and antimicrobial responses against Mtb in BMDMs.