Two new polyketides from Nocardiopsis lucentensis DSM 44048

Comprehensive updates on the biological features and metabolic potential of the versatile extremophilic actinomycete Nocardiopsis dassonvillei

Nocardiopsis dassonvillei prevails under harsh environmental conditions and the purpose of this review is to highlight its biological features and recent biotechnological applications. The organism prevails in salt-rich soils/marine systems and some strains endure extreme temperatures and pH. A few isolates are associated with marine organisms and others cause human diseases. Comparative genomic analysis indicates its versatility in producing biotechnologically relevant metabolites. Antimicrobial, cytotoxic, anticancer and growth promoting biomolecules are obtained from this organism. It also synthesizes biotechnologically important enzymes. Bioactive compounds and enzymes obtained from this actinomycete provide evidence regarding its metabolic competence and its potential economic value.

Metabolic profiling and biological potential of the marine sponge associated Nocardiopsis sp. UR67 along with docking studies

This work was performed to dig into the phytochemical composition and bioactivities of Nocardiopsis sp. UR67 associated with the marine sponge Callyspongia sp. It was fermented in suspension and immobilised in calcium alginate bead cultures. The ethyl acetate extracts, afforded from the broth in each case named EG-49 and J-48g, respectively, revealed 16 chemical principles mostly belonging to polyketides, macrolides, and peptides. EG-49 and J-48g displayed anti-Candida albicans activity with IC50 values of 8.1 and 8.3 µg/mL, and a substantial cytotoxic effect against lung adenocarcinoma H1650 at IC50 12.6 and 13.7 µg/mL, respectively. However, only EG-49 exhibited a noteworthy anti-trypanosomal activity at 7.5 µg/mL. Molecular docking of the characterised compounds against Trypanosoma brucei trypanothione reductase demonstrated the highest binding models of griseochelin-methyl ester (9) and filipin-II (11), which drew considerable significance of the metabolites derived from Nocardiopsis sp. UR67 developing potential T. brucei trypanothione reductase inhibitors.

Genus Nocardiopsis: A Prolific Producer of Natural Products

Actinomycetes are currently one of the major sources of bioactive secondary metabolites used for medicine development. Accumulating evidence has shown that Nocardiopsis, a key class of actinomycetes, has the ability to produce novel bioactive natural products. This review covers the sources, distribution, bioactivities, biosynthesis, and structural characteristics of compounds isolated from Nocardiopsis in the period between March 2018 and 2021. Our results reveal that 67% of Nocardiopsis-derived natural products are reported for the first time, and 73% of them are isolated from marine Nocardiopsis. The chemical structures of the Nocardiopsis-derived compounds have diverse skeletons, concentrating on the categories of polyketides, peptides, terphenyls, and alkaloids. Almost 50% of the natural products isolated from Nocardiopsis have been discovered to display various bioactivities. These results fully demonstrate the great potential of the genus Nocardiopsis to produce novel bioactive secondary metabolites that may serve as a structural foundation for the development of novel drugs.

Androsamide, a Cyclic Tetrapeptide from a Marine Nocardiopsis sp., Suppresses Motility of Colorectal Cancer Cells

A cyclic tetrapeptide, androsamide (1), was isolated from a marine actinomycete of the genus Nocardiopsis, strain CNT-189. The planar structure of 1 was assigned by the interpretation of 1D and 2D NMR spectroscopic data. The absolute configurations of constituent amino acids of 1 were determined by application of the Marfey's and advanced Marfey's methods. Androsamide (1) strongly suppressed the motility of Caco2 cells caused by epithelial-mesenchymal transition.

Molecules derived from the extremes of life: a decade later

Covering: Early 2008 until the end of 2019Microorganisms which survive (extreme-tolerant) or even prefer (extremophilic) living at the limits of pH, temperature, salinity and pressure found on earth have proven to be a rich source of novel structures. In this update we summarise the wide variety of new molecules which have been isolated from extremophilic and extreme-tolerant microorganisms since our original 2009 review, highlighting the range of bioactivities these molecules have been reported to possess.

Kenalactams A-E, Polyene Macrolactams Isolated from Nocardiopsis CG3

In our screening program for new biologically active secondary metabolites, a new strain, Nocardiopsis CG3 (DSM 106572), isolated from the saltpan of Kenadsa, was found to produce five new polyene macrolactams, the kenalactams A-E (1-5). Their structures were elucidated by spectral methods (NMR and HRESIMS), and the absolute configuration was derived by chemical derivatization (Mosher's method). Through a feeding experiment, alanine was proven to be the nitrogen-bearing starter unit involved in biosynthesis of the polyketide kenalactam A (1). Kenalactam E (5) was cytotoxic against human prostate cancer PC-3 cells with an IC₅₀ value of 2.1 μM.

A new diketopiperazine isolated from a Nocardiopsis strain TRM20105 guided by bioassay against Candida albicans

An actinomycete strain TRM20105 with antifungal activity was identified as Nocardiopsis dassonvillei subsp. dassonvillei DSM43111 (98.34% similarity) by 16S rDNA phylogenetic analysis and morphology observation. The fermentation broth of TRM20105 cultured with oat-soybean medium was subjected to discover bioactive compounds. Guided by antifungal bioassay against Candida albicans, a new diketopiperazine compound was purified via various column chromatographies together with pHPLC. The purified active compound was identified as 1-demethylnocazine A, (3Z,6Z)-5-methoxy-3,6-bis(4-methoxybenzylidene) -1,6-dihydropyrazin-2(3H)-one by the analyses of 1D & 2D NMR data.

Natural Product Potential of the Genus Nocardiopsis

Actinomycetes are a relevant source of novel bioactive compounds. One of the pharmaceutically and biotechnologically important genera that attract natural products research is the genus Nocardiopsis, mainly for its ability to produce a wide variety of secondary metabolites accounting for its wide range of biological activities. This review covers the literature from January 2015 until February 2018 making a complete survey of all the compounds that were isolated from the genus Nocardiopsis, their biological activities, and natural sources, whenever applicable.

Antibacterial Effect of Silver-Incorporated Flake-Shell Nanoparticles under Dual-Modality

Silver has been recognized as a broad-spectrum antimicrobial agent and extensively used in biomedical applications. Through a sequential one-pot synthesis strategy, we have successfully incorporated silver into flake-shell nanoparticles. Due to the simultaneous growth of networked nanostructures of silica and in situ reduction of silver ions, homogeneously distributed silver into the shell of the nanocapsule was formed. The antibacterial test indicated that the silver-incorporated silica nanocapsule exhibits effective antibacterial activity, inhibiting the bacterial growth by 75%. In addition, with the encapsulation of other antibiotic agent into the structure, an enhanced antibacterial effect under dual-modality could also be achieved.