<b>AIMb>To identify the components of acetylleucomycin and its hydrolytic products by LC-MS.

<b>METHODSb>Acetylleucomycin was separated on a Diamonsil C18 column with 0.1 mol x L(-1) ammonium acetate-acetontrile (35 : 65) as mobile phase. The LC-MS was equipped with an electorspray ion source (ESI), which was set at the positive ion mode, and the mass spectra of each component in chromatogram were obtained with difference cone voltage.

<b>RESULTSb>The components of acetylleucomycin and its hydrolytic products can be separated by HPLC. The components were identified according to the molecular weight and its major mass fragment ions. The major components identified in domastic acetylleucomycin were acetylleucomycin A4, A5; acetylleucomycin A1, A3; acetylleucomycin A6, A7, and acetylleucomycin A13. The hydrolytic products of acetylleucomycin were not kitasamycin, but some non-complete hydrolytic product.

<b>CONCLUSIONb>The method is rapid, sensitive and specific. It' s suitable to application in the fields of multi-components antibiotics analysis.

Chromatography, Liquid ; methods ; Hydrolysis ; Josamycin ; analysis ; chemistry ; Kitasamycin ; analogs & derivatives ; analysis ; chemistry ; Leucomycins ; analysis ; chemistry ; Macrolides ; analysis ; chemistry ; Spectrometry, Mass, Electrospray Ionization ; methods

Angucyclines/angucyclinones are a large group of polycyclic aromatic polyketides and their producers are widely distributed in nature. This family of natural products attracts great attention because of their diverse biological activities and unique chemical structures. With the development of synthetic biology and the exploitation of the actinomycetes from previously unexplored environments, angucyclines/angucyclinones-like natural products with new skeletons were continuously discovered, thus enriching the structural diversity of this family. In this review we summarize the new angucyclines/angucyclinones analogues discovered in the last decade (2010-2020) by using different strategies, such as changing cultivation conditions, genetic modification, genome mining, bioactivity-guided compound isolation, and fermentation of actinomycetes from underexplored environments. We also discuss the role of synthetic biology in the discovery and development of new compounds of the angucycline/angucyclinone family.
Anthraquinones ; Biological Products ; Polyketides ; Streptomyces

We introduce a computational approach for analysis of glycosylation in Post-PKS tailoring steps. It is a computational method to predict the deoxysugar biosynthesis unit pathway and the substrate specificity of glycosyltransferases involved in the glycosylation of polyketides. In this work, a directed and weighted graph is introduced to represent and predict the deoxysugar biosynthesis unit pathway. In addition, a homology based gene clustering method is used to predict the substrate specificity of glycosyltransferases. It is useful for the rational design of polyketide natural products, which leads to in silico drug discovery.
Biological Agents ; Computer Simulation ; Glycosylation ; Glycosyltransferases ; Polyketides ; Substrate Specificity

Diaporthe sp. fungi is one of the important sources of active natural products. Polyketides, alkaloids, terpenes, anthraquinones and other types of novel metabolic products are found from this genus, and many of them have significant anti-tumor, antibacterial, anti-hyperlipidemia, inhibition of pulmonary fibrosis, antioxidant and other biological activities. This paper reviewed source, structure and biological activity of natural products from Diaporthe sp. in the past two decades, and provided a reference for in-depth study of natural product of this genus fungus and innovative drug development.
Anti-Bacterial Agents ; Biological Products/pharmacology* ; Fungi ; Polyketides ; Terpenes

Over-expression of the pathway specific positive regulator gene is an effective way to activate silent gene cluster. In the curret study, the SARP family regulatory gene, vasR2, was over-expressed in strain Verrucosispora sp. NS0172 and the cryptic gene cluster responsible for the biosynthesis of pentaketide ansamycin was partially activated. Two tetraketides (1 and 2) and a triketide (3) ansamycins, together with five known compounds (4-8), were isolated and elucidated from strain NS0172OEvasR2. Their NMR data were completely assigned by analysis of their HR-ESI-MS and
Micromonosporaceae/metabolism* ; Multigene Family ; Polyketides/metabolism* ; Rifabutin/metabolism*

Two new polyketides, lasobutone A(1) and lasobutone B(2), along with three known compounds, guignardianone C(3), guignardic acid(4), and 4-hydroxy-17R-methylincisterol(5), were isolated from the endophytic fungi Xylaria sp. by silica gel, MCI, and preparative HPLC, which was separated from the Chinese medicinal material Coptis chinensis and cultivated through solid fermentation with rice. Their structures were elucidated on the basis of spectroscopic methods, such as MS, NMR, IR, UV, and ECD. Compounds 2 and 4 showed inhibitory activities against the nitric oxide(NO) production in the LPS-induced macrophage RAW264.7 with IC_(50) values of 58.7 and 42.5 μmol·L~(-1) respectively, while compound 5 exhibited cytotoxic activities against HT-29 with IC_(50) value of 14.3 μmol·L~(-1).
Antineoplastic Agents ; Coptis chinensis ; Endophytes/chemistry* ; Fungi ; Polyketides/chemistry*

Two new polyketides, chinoketides A and B (1 – 2) with a known compound xylarphthalide A (3), were isolated from the solid medium of the endophytes from the leaves of the relic plant Distylium chinense with the “black-box” co-culture method, and the structures of two new compounds were elucidated by NMR, MS and CD spectra. And the absolute configurations of chinoketides A (1) and B (2) were determined as 2R,3R,8S and 5R,6S by calculating their ECD spectra to compare with the experimental CD spectra. Finally, the antimicrobial activities were evaluated to Erwinia carotovora sub sp. Carotovora (Jones) Bersey et al, and the results showed that compounds 1 – 3 displayed the antimicrobial activities with MIC value at 20.5, 30.4 and 10.2 µg/mL.
Coculture Techniques ; Endophytes ; Methods ; Pectobacterium carotovorum ; Plants ; Polyketides

Based on polyketide syntheses gene (PKS) and non-ribosomal peptide synthetases gene (NRPS), one strain with high anti-pathogenic activity was screened from 77 strains isolated from Arctic marine sediments and identified. By optimizing the composition of culture medium and fermentation conditions, the production of this strain's active metabolites was improved and the main metabolites were identified by HRMS, ¹H NMR and ¹³C NMR. The antibacterial spectrum of the main metabolites and the effect of the metabolites on cucumber Fusarium wilt were also determined. The results showed that the strain was Bacillus velezensis and it showed growth promoting effect on plants. When the strain was cultured in 5 g/L maltose, 10 g/L tryptone, 10 g/L sodium chloride, at 30 ℃, 150 r/min for 60 h, the diameter of the inhibition zone increased from (16.23±0.42) to (24.42±0.57) mm. The metabolites of this strain mainly contain macrolide compound macrolactin A, which has antagonistic effect on a variety of pathogenic bacteria and fungi. Cucumber seedling experiments showed that the metabolites of this strain had a protective effect on cucumber Fusarium wilt, and showed a good potential for development and application as a biocontrol agent.
Polyketides/pharmacology* ; Fungi ; Bacteria ; Fusarium/genetics* ; Anti-Bacterial Agents/pharmacology* ; Peptide Synthases/genetics*

Marine microorganisms, especially marine fungi, have historically proven their value as a prolific source for structurally novel and pharmacologically active secondary metabolites (Deshmukh et al., 2018; Carroll et al., 2022). The corals constitute a dominant part of reefs with the highest biodiversity, and harbor highly diverse and abundant microbial symbionts in their tissue, skeleton, and mucus layer, with species-specific core members that are spatially partitioned across coral microhabitats (Wang WQ et al., 2022). The coral-associated fungi were very recently found to be vital producers of structurally diverse compounds, terpenes, alkaloids, peptides, aromatics, lactones, and steroids. They demonstrate a wide range of bioactivity such as anticancer, antimicrobial, and antifouling activity (Chen et al., 2022). The genetically powerful genus Emericella (Ascomycota), which has marine and terrestrial sources, includes over 30 species and is distributed worldwide. It is considered a rich source of diverse secondary metabolites with antimicrobial activity or cytotoxicity (Alburae et al., 2020). Notably, Emericella nidulans, the sexual state of a classic biosynthetic strain Aspergillus nidulans, was recently reported as an important source of highly methylated polyketides (Li et al., 2019) and isoindolone-containing meroterpenoids (Zhou et al., 2016) with unusual skeletons.
Animals ; Aspergillus nidulans ; Polyketides/chemistry* ; Anthozoa/microbiology* ; Anti-Infective Agents/pharmacology* ; Alkaloids

Tyrosine-decahydrofluorene derivatives are a class of hybrid compounds that integrate the properties of polyketides and nonribosomal peptides. These compounds feature a [6.5.6] tricarbocyclic core and a para-cyclophane ether moiety in their structures and exhibit anti-tumor and anti-microbial activities. In this study, we constructed the biosynthetic pathway of xenoacremones from Xenoacremonium sinensis ML-31 in the Aspergillus nidulans host, resulting in the identification of four novel tyrosine-decahydrofluorene analogs, xenoacremones I-L (1-4), along with two known analogs, xenoacremones A and B. Remarkably, compounds 3 and 4 contained a 12-membered para-cyclophane ring system, which is unprecedented among tyrosine-decahydrofluorene analogs in X. sinensis. The successful reconstruction of the biosynthetic pathway and the discovery of novel analogs demonstrate the utility of heterologous expression strategy for the generation of structurally diverse natural products with potential biological activities.
Aspergillus nidulans/metabolism* ; Biological Products/metabolism* ; Polyketides/metabolism* ; Peptides/metabolism* ; Biosynthetic Pathways ; Multigene Family