<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

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

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

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*

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*

Usnea longissima has a long history of use as a traditional medicine. Several bioactive compounds, primarily belonging to the polyketide family, have been isolated from U. longissima. However, the genes for the biosynthesis of these compounds are yet to be identified. In the present study, three different types of non-reducing polyketide synthases (UlPKS2, UlPKS4, and UlPKS6) were identified from a cultured lichen-forming fungus of U. longissima. Phylogenetic analysis of product template domains showed that UlPKS2 and UlPKS4 belong to group IV, which includes the non-reducing polyketide synthases with an methyltransferase (MeT) domain that are involved in methylorcinol-based compound synthesis; UlPKS6 was found to belong to group I, which includes the non-reducing polyketide synthases that synthesize single aromatic ring polyketides, such as orsellinic acid. Reverse transcriptase-PCR analysis demonstrated that UlPKS2 and UlPKS4 were upregulated by sucrose; UlPKS6 was downregulated by asparagine, glycine, and alanine.
Alanine ; Asparagine ; Fungi* ; Glycine ; Humans ; Medicine, Traditional ; Polyketide Synthases ; Polyketides ; Sucrose ; Usnea*

Yarrowia lipolytica, as an important oleaginous yeast, has been widely used in metabolic engineering. Y. lipolytica is considered as an ideal host for the production of natural products such as terpenes, polyketides and flavonoids, due to its ability to utilize a variety of hydrophobic substrates, high stress tolerance to acid and salt, high flux of tricarboxylic acid cycle and the ability in providing abundant the common precursor acetyl-CoA. Recently, more and more tools for genetic editing, gene expression and regulation has been developed in Y. lipolytica, which facilitate the metabolic engineering of Y. lipolytica for bio-manufacturing. In this review, we summarized the recent progresses in developing gene expression and natural product synthesis in Y. lipolytica, and also discussed the challenges and possible solutions in heterologous synthesis of natural products in this yeast.
Biological Products/metabolism* ; Gene Editing ; Metabolic Engineering ; Polyketides/metabolism* ; Yarrowia/metabolism*

A new polyketide, coptaspin A(1), along with two known compounds 4-acetyl-3,4-dihydro-6,8-dihydroxy-3-methoxy-5-methylisocoumarin(2), and cytochalasin Z_(12)(3), was isolated from the endophytic fungi Aspergillus sp. ZJ-58, which was isolated from the genuine medicinal plant Coptis chinensis in Chongqing after solid-state fermentation on rice and silica gel, MCI, and HPLC-based separation. Their structures were elucidated by MS, NMR, IR, UV, and ECD. The newly isolated compound 1 showed moderate inhibitory activities against LPS-induced NO production in RAW264.7 macrophages with the IC_(50) value of 58.7 μmol·L~(-1), suggesting its potential anti-inflammatory activity.
Anti-Inflammatory Agents/pharmacology* ; Aspergillus/chemistry* ; Coptis chinensis ; Plants, Medicinal ; Polyketides/pharmacology*