Heterologous production of bioactive xenoacremone analogs in Aspergillus nidulans / 中国天然药物

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.

Tricarbocyclic core formation of tyrosine-decahydrofluorenes implies a three-enzyme cascade with XenF-mediated sigmatropic rearrangement as a prerequisite

Tyrosine-decahydrofluorene derivatives feature a fused [6.5.6] tricarbocyclic core and a 13-membered

Diversity and communities of culturable endophytic fungi from different tree peonies (geoherbs and non-geoherbs), and their biosynthetic potential analysis

Abstract To know more about the potential roles of endophytic fungi in the formation mechanism of Daodi medicinal material, diversity and communities of culturable endophytic fungi in three types of tree peonies were investigated. Endophytic fungi of three types of tree peonies were isolated and identified. The diversity was analyzed. Bayesian trees constructed by MrBayes 3.2.6 after phylogenetic analysis of the ITS sequences. The endophytic fungi potential for synthesis of natural products was assessed by means of detecting NRPS and PKS gene sequences. In total, 364 endophytic fungi isolates representing 26 genera were recovered from Paeonia ostii 'Feng Dan', Paeonia ostii 'Luoyang Feng Dan', and Paeonia suffruticosa 'Luoyang Hong'. More culturable endophytic fungi appeared in P. suffruticosa 'Luoyang Hong' (206) compared with P. ostii 'Feng Dan' (60) and P. ostii 'Luoyang Feng Dan' (98). The fungal community of P. ostii 'Feng Dan' had the highest richness and diversity. PKSs and NRPS detection rates of endophytic fungi from P. ostii 'Feng Dan' are both the highest among the three types of tree peonies. Results indicate that endophytic fungus is an important factor of Daodi Cortex Moutan forming, and endophytic fungi in peony are related to genuineness of Cortex Moutan.

Diversity and communities of culturable endophytic fungi from different tree peonies (geoherbs and non-geoherbs), and their biosynthetic potential analysis

Abstract To know more about the potential roles of endophytic fungi in the formation mechanism of Daodi medicinal material, diversity and communities of culturable endophytic fungi in three types of tree peonies were investigated. Endophytic fungi of three types of tree peonies were isolated and identified. The diversity was analyzed. Bayesian trees constructed by MrBayes 3.2.6 after phylogenetic analysis of the ITS sequences. The endophytic fungi potential for synthesis of natural products was assessed by means of detecting NRPS and PKS gene sequences. In total, 364 endophytic fungi isolates representing 26 genera were recovered from Paeonia ostii Feng Dan, Paeonia ostii Luoyang Feng Dan, and Paeonia suffruticosa Luoyang Hong. More culturable endophytic fungi appeared in P. suffruticosa Luoyang Hong (206) compared with P. ostii Feng Dan (60) and P. ostii Luoyang Feng Dan (98). The fungal community of P. ostii Feng Dan had the highest richness and diversity. PKSs and NRPS detection rates of endophytic fungi from P. ostii Feng Dan are both the highest among the three types of tree peonies. Results indicate that endophytic fungus is an important factor of Daodi Cortex Moutan forming, and endophytic fungi in peony are related to genuineness of Cortex Moutan.

Antimicrobial activity and identification of endophytic actinomycetes strain 13-85 isolated from Acanthopanax senticosus / 中草药

Objective: To studies the antimicrobial activity and stability of fermentation extracts produced by endophytic actinomycete strain 13-85 from Acanthopanax senticosus; Secondary metabolite biosynthesis genes were detected. Meanwhile, the strain was identified. Methods: Paper disc diffusion method was used to test the antimicrobial activity and stability of strain 13-85, the biosynthesis genes (PKS I, PKS II, NRPS, Halo, and CYP) were obtained by PCR, and sequences were analyzed. The strain was identified by phenotypic characteristics and molecular characteristics. Results: The fermentation broth of the strain showed broad-spectrum, strong activity, and stability against pathogenic microbes. The strain contains PKS II gene and NRPS gene. The PKS II sequence had 89% homology compared with Streptomyces fradiae PKS gene (Accession Number: AFO70128.1). The NRPS gene sequence had 95% homology with S. virginiae NRPS gene (Accession Number: WP_033225509.1). The sequence of 16S rRNA of the strain had 99.85% homology with S. amritsarensis (Accession Number: GQ906975). Conclusion: Metabolites of the actinomycete strain 13-85 with broad-spectrum antibacterial activity and better stability, have a value for development and application. The strain 13-85 was identified as Streptomyces amritsarensis, a valid species of genus Streptomyces.

The introduction of PKS-NRPS databases / 中国药学杂志

Polyketide synthases (PKSs) and nonribosomal peptide synthetases (NRPSs) are two kinds of multi-modular enzymes, which biosynthesize highly complex polyketides and nonribosonmal peptides, respectively. Both of these two secondary metabolites are of considerable pharmaceutical relevance and are thought to cover diverse biological functions. With the development of sequencing and bioinformatics, data about PKS/NRPS are increasing rapidly. New PKS/NRPS databases are created to analyze gene sequence and predict the functions and structures of natural products. In this article, we introduce five newest databases including PKMiner, NRPSsp, NaPDoS, ClusterMine360, and IMG-ABC, with the goal to help researchers choose databases.

Inheritance in endophytic fungi from Melia toosendan and diversity of genes of PKS and NRPS / 中草药

Objective: To explore the inheritance in endophytic fungi from Melia toosendan and the diversity of the genes of PKS and NRPS and to lay the foundation of looking for the synthesis of the potential strains of bioactive substances. Methods: To identify the morphology of 39 strains of endophytic fungi separated from the medicinal plant M. toosendan; The ITS sequences and the genes of PKS and NRPS were obtained using PCR method, compared by BLAST and analyzed by phylogenesis after sequencing. Results: The morphological identification and phylogenetic analysis on 39 strains showed that all strains of endophytic fungi from M. toosendan belonged to 25 categories, mainly Penicillium, Aspergillus, and Trichoderma. The dominant fungus species were Aspergillus (17.9%), and Penicillium (15.4%). PKS (12) and NRPS (6) genes were detected in this study, All NRPS genes were Penicillium. Conclusion: The endophytic fungi of M. toosendan have a rich genetic diversity and strong potential of synthesis of bioactive substances. Further research on Penicillium and Aspergillus should be carried out.