scholarly journals Zhaoshumycins A and B, Two Unprecedented Antimycin-Type Depsipeptides Produced by the Marine-Derived Streptomyces sp. ITBB-ZKa6

Marine Drugs ◽  
2021 ◽  
Vol 19 (11) ◽  
pp. 624
Author(s):  
Zhikai Guo ◽  
Shiying Ma ◽  
Salman Khan ◽  
Hongjie Zhu ◽  
Bo Zhang ◽  
...  

Marine actinomycetes are prolific chemical sources of complex and novel natural products, providing an excellent chance for new drug discovery. The chemical investigation of the marine-derived Streptomyces sp. ITBB-ZKa6, from Zhaoshu island, Hainan, led to the discovery of two unique antimycin-type depsipeptides, zhaoshumycins A (1) and B (2), along with the isolation of the four known neoantimycins A (3), F (4), D (5), and E (6). The structures of the new compounds 1 and 2 were elucidated on the basis of the analysis of diverse spectroscopic data and biogenetic consideration. Zhaoshumycins A (1) and B (2) represent a new class of depsipeptides, featuring two neoantimycin monomers (only neoantimycin D or neoantimycins D and E) linked to a 1,4-disubstituted benzene ring via an imino group. Initial toxicity tests of 1–6 in MCF7 human breast cancer cells revealed that compounds 5 and 6 possess weak cytotoxic activity. Further structure–activity relationship analysis suggested the importance of the NH2 group at C-34 in 5 and 6 for cytotoxicity in MCF7 cells.

2020 ◽  
Vol 16 (7) ◽  
pp. 958-968
Author(s):  
Yunrui Cai ◽  
Tong Chen ◽  
Huajian Zhu ◽  
Hongbin Zou

Background: The development of novel antineoplastic agents remains highly desirable. Objective: This study focuses on the design, synthesis, and antitumor evaluation of phenyl ureas bearing 5-fluoroindolin-2-one moiety. Methods: Three sets of phenylureas were designed and synthesized and their antiproliferative ability was measured against four human carcinoma cell lines (Hela, Eca-109, A549, and MCF-7) via MTT assay. In vivo anticancer activity was further evaluated in xenograft models of human breast cancer (MCF-7). Results: A total of twenty-one new compounds were synthesized and characterized by means of 1H and 13C NMR as well as HR-MS. Three sets of compounds (1a‒1c, 2a‒2c, and 3a‒3c) were initially constructed, and preliminary antiproliferative activities of these molecules were evaluated against Hela, Eca-109, A549 and MCF-7, highlighting the meta-substituted phenylureas (1a‒1c) as the most cytotoxic set. A series of meta-substituted phenylureas derivatives (1d‒1o) were then designed and synthesized for structure-activity relationship study. Most of the new compounds showed desirable cytotoxicity, among which compound 1g exhibited the most remarkable cytotoxic effects against the tested human cancer cells with IC50 values ranging from 1.47 to 6.79 μM. Further studies showed that compound 1g suppressed tumor growth in human breast cancer (MCF- 7) xenograft models without affecting the body weight of its recipients. Conclusion: In this study, twenty-one new compounds, containing the privileged structures of phenylurea and 5-fluoroindolin-2-one, were designed and synthesized. Subsequent structureactivity studies showed that 1g was the most bioactive antitumor agent among all tested compounds, hence a potentially promising lead compound once given further optimization.


Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 81
Author(s):  
Anna Carbone ◽  
Stella Cascioferro ◽  
Barbara Parrino ◽  
Daniela Carbone ◽  
Camilla Pecoraro ◽  
...  

Anti-virulence strategy is currently considered a promising approach to overcome the global threat of the antibiotic resistance. Among different bacterial virulence factors, the biofilm formation is recognized as one of the most relevant. Considering the high and growing percentage of multi-drug resistant infections that are biofilm-mediated, new therapeutic agents capable of counteracting the formation of biofilms are urgently required. In this scenario, a new series of 18 thiazole derivatives was efficiently synthesized and evaluated for its ability to inhibit biofilm formation against the Gram-positive bacterial reference strains Staphylococcus aureus ATCC 25923 and S. aureus ATCC 6538 and the Gram-negative strain Pseudomonas aeruginosa ATCC 15442. Most of the new compounds showed a marked selectivity against the Gram-positive strains. Remarkably, five compounds exhibited BIC50 values against S. aureus ATCC 25923 ranging from 1.0 to 9.1 µM. The new compounds, affecting the biofilm formation without any interference on microbial growth, can be considered promising lead compounds for the development of a new class of anti-virulence agents.


2014 ◽  
Vol 76 ◽  
pp. S128
Author(s):  
Tetsuro Kamiya ◽  
Aki Goto ◽  
Hirokazu Hara ◽  
Tetsuo Adachi

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2522 ◽  
Author(s):  
Gabriel Marc ◽  
Cătălin Araniciu ◽  
Smaranda Oniga ◽  
Laurian Vlase ◽  
Adrian Pîrnău ◽  
...  

C. albicans is the most frequently occurring fungal pathogen, and is becoming an increasing public health problem, especially in the context of increased microbial resistance. This opportunistic pathogen is characterized by a versatility explained mainly by its ability to form complex biofilm structures that lead to enhanced virulence and antibiotic resistance. In this context, a review of the known C. albicans biofilm formation inhibitors were performed and a new N-(oxazolylmethyl)-thiazolidinedione scaffold was constructed. 16 new compounds were synthesized and characterized in order to confirm their proposed structures. A general antimicrobial screening against Gram-positive and Gram-negative bacteria, as well as fungi, was performed and revealed that the compounds do not have direct antimicrobial activity. The anti-biofilm activity evaluation confirmed the compounds act as selective inhibitors of C. albicans biofilm formation. In an effort to substantiate this biologic profile, we used in silico investigations which suggest that the compounds could act by binding, and thus obstructing the functions of, the C. albicans Als surface proteins, especially Als1, Als3, Als5 and Als6. Considering the well documented role of Als1 and Als3 in biofilm formation, our new class of compounds that target these proteins could represent a new approach in C. albicans infection prevention and management.


2019 ◽  
Vol 7 (10) ◽  
pp. 394 ◽  
Author(s):  
Eduardo Almeida ◽  
Navdeep Kaur ◽  
Laurence Jennings ◽  
Andrés Felipe Carrillo Rincón ◽  
Stephen Jackson ◽  
...  

Much recent interest has arisen in investigating Streptomyces isolates derived from the marine environment in the search for new bioactive compounds, particularly those found in association with marine invertebrates, such as sponges. Among these new compounds recently identified from marine Streptomyces isolates are the octapeptidic surugamides, which have been shown to possess anticancer and antifungal activities. By employing genome mining followed by an one strain many compounds (OSMAC)-based approach, we have identified the previously unreported capability of a marine sponge-derived isolate, namely Streptomyces sp. SM17, to produce surugamide A. Phylogenomics analyses provided novel insights on the distribution and conservation of the surugamides biosynthetic gene cluster (sur BGC) and suggested a closer relatedness between marine-derived sur BGCs than their terrestrially derived counterparts. Subsequent analysis showed differential production of surugamide A when comparing the closely related marine and terrestrial isolates, namely Streptomyces sp. SM17 and Streptomyces albidoflavus J1074. SM17 produced higher levels of surugamide A than S. albidoflavus J1074 under all conditions tested, and in particular producing >13-fold higher levels when grown in YD and 3-fold higher levels in SYP-NaCl medium. In addition, surugamide A production was repressed in TSB and YD medium, suggesting that carbon catabolite repression (CCR) may influence the production of surugamides in these strains.


Author(s):  
YUNI SETYANINGSIH ◽  
ABDUL LATIF ◽  
HENDRI ASTUTY ◽  
DIN SYAFRUDDIN ◽  
PUJI BUDI SETIA ASIH

Objective: This research aims to study the activity of a Streptomyces sp. fermentation product as an antimalarial modality in HepG2 cells.Methods: The effects of the product against Plasmodium falciparum 3D7 were examined using an in vitro technique parasite. The potency of theStreptomyces sp. fermentation product was examined by determining the half maximal inhibitory concentration (IC50), and the mechanism wasstudied using transmission electron microscopy (TEM). Toxicity tests were also conducted.Results: The Streptomyces sp. fermentation product had an IC50 of 0.001 μg/ml against the parasite, versus values of 0.054 and 0.022 μg/ml forquinidine and prodigiosin, respectively. TEM revealed no formation of hemozoin. The Streptomyces sp. fermentation product was non-toxic in HepG2cells based on its cytotoxicity concentration 50% of 1.380 μg/ml.Conclusion: The Streptomyces sp. fermentation product has potential as a potent and non-toxic antimalarial therapy.


2020 ◽  
Vol 27 (8) ◽  
pp. 2164-2173
Author(s):  
Rais Ahmad Khan ◽  
Mohammad Rashid Khan ◽  
Mohammad Usman ◽  
Fatima Sayeed ◽  
Huda A. Alghamdi ◽  
...  

2012 ◽  
Vol 76 (7) ◽  
pp. 1322-1328 ◽  
Author(s):  
Chaoqing HUANG ◽  
Xiaoguang CHEN ◽  
Baolin GUO ◽  
Wenhua HUANG ◽  
Ting SHEN ◽  
...  

2012 ◽  
Vol 86 (16) ◽  
pp. 8730-8739 ◽  
Author(s):  
Hillary J. Stahla-Beek ◽  
Daniel G. April ◽  
Bejan J. Saeedi ◽  
Amanda M. Hannah ◽  
Susan M. Keenan ◽  
...  

Arthropod-borne flavivirus infection causes serious morbidity and mortality worldwide, but there are currently no effective antiflaviviral chemotherapeutics available for human use. Therefore, it is critical that new therapeutics against virus-specific targets be developed. To identify new compounds that may be used as broadly active flavivirus therapeutics, we have performed a high-throughput screening of 235,456 commercially available compounds for small-molecule inhibitors of the dengue virus NS5 RNA capping enzyme. We identified a family of compounds, the 2-thioxothiazolidin-4-ones, that show potent biochemical inhibition of capping enzyme GTP binding and guanylyltransferase function. During the course of structure-activity relationship analysis, a molecule within this family, (E)-{3-[5-(4-tert-butylbenzylidene)-4-oxo-2-thioxo-1,3-thiazolidin-3-yl]propanoic acid} (BG-323), was found to possess significant antiviral activity in a dengue virus subgenomic replicon assay. Further testing of BG-323 demonstrated that this molecule is able to reduce the replication of infectious West Nile virus and yellow fever virus in cell culture with low toxicity. The results of this study describe the first inhibitor that targets the GTP-binding/guanylyltransferase activity of the flavivirus RNA capping enzyme.


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