scholarly journals Fungal biosynthesis of the bibenzoquinone oosporein to evade insect immunity

2015 ◽  
Vol 112 (36) ◽  
pp. 11365-11370 ◽  
Author(s):  
Peng Feng ◽  
Yanfang Shang ◽  
Kai Cen ◽  
Chengshu Wang
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Small Molecules ◽  
Polyketide Synthase ◽  
Biological Activities ◽  
Host Immunity ◽  
Insect Immunity ◽  
Pharmacological Activities ◽  
Fungal Virulence ◽  
Biosynthetic Machinery

Quinones are widely distributed in nature and exhibit diverse biological or pharmacological activities; however, their biosynthetic machineries are largely unknown. The bibenzoquinone oosporein was first identified from the ascomycete insect pathogen Beauveria bassiana >50 y ago. The toxin can also be produced by different plant pathogenic and endophytic fungi with an array of biological activities. Here, we report the oosporein biosynthetic machinery in fungi, a polyketide synthase (PKS) pathway including seven genes for quinone biosynthesis. The PKS oosporein synthase 1 (OpS1) produces orsellinic acid that is hydroxylated to benzenetriol by the hydroxylase OpS4. The intermediate is oxidized either nonenzymatically to 5,5′-dideoxy-oosporein or enzymatically to benzenetetrol by the putative dioxygenase OpS7. The latter is further dimerized to oosporein by the catalase OpS5. The transcription factor OpS3 regulates intrapathway gene expression. Insect bioassays revealed that oosporein is required for fungal virulence and acts by evading host immunity to facilitate fungal multiplication in insects. These results contribute to the known mechanisms of quinone biosynthesis and the understanding of small molecules deployed by fungi that interact with their hosts.

scholarly journals OligoTRAFTACs: A Generalizable Method for Transcription Factor Degradation

2021 ◽  
Author(s):  
Kusal T.G. Samarasinghe ◽  
Elvira An ◽  
Miriam Genuth ◽  
Ling Chu ◽  
Scott Holley ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Transcription Factors ◽  
Dna Binding ◽  
Small Molecules ◽  
Cell Lines ◽  
First Generation ◽  
Binding Ability ◽  
Key Players

Dysregulated transcription factors (TFs) that rewire gene expression circuitry are frequently identified as key players in disease. Although several TFs have been drugged with small molecules, the majority of oncogenic TFs are not currently pharmaceutically tractable due to their paucity of ligandable pockets. The first generation of transcription factor targeting chimeras (TRAFTACs) was developed to target TFs for proteasomal degradation by exploiting their DNA binding ability. In the current study, we have developed the second generation TRAFTACs (oligoTRAFTACs) comprised of a TF-binding oligonucleotide and an E3 ligase-recruiting ligand. Herein, we demonstrate the development of oligoTRAFTACs to induce the degradation of two oncogenic TFs, c-Myc and brachyury. In addition, we show that brachyury can be successfully degraded by oligoTRAFTACs in chordoma cell lines. Furthermore, zebrafish experiments demonstrate in vivo oligoTRAFTAC activity. Overall, our data demonstrate oligoTRAFTACs as a generalizable platform towards difficult-to-drug TFs and their degradability via the proteasomal pathway.

scholarly journals Importance of Fluorine in Benzazole Compounds

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4677
Author(s):  
Thuraya Al-Harthy ◽  
Wajdi Zoghaib ◽  
Raid Abdel-Jalil
Keyword(s):  
Small Molecules ◽  
Medicinal Chemistry ◽  
Biological Activities ◽  
Short Review ◽  
Significant Enhancement ◽  
Pharmacological Activities ◽  
The Past ◽  
To Receive

Fluorine-containing heterocycles continue to receive considerable attention due to their unique properties. In medicinal chemistry, the incorporation of fluorine in small molecules imparts a significant enhancement their biological activities compared to non-fluorinated molecules. In this short review, we will highlight the importance of incorporating fluorine as a basic appendage in benzothiazole and benzimidazole skeletons. The chemistry and pharmacological activities of heterocycles containing fluorine during the past years are compiled and discussed.

scholarly journals Functional Analysis of All Nonribosomal Peptide Synthetases in Cochliobolus heterostrophus Reveals a Factor, NPS6, Involved in Virulence and Resistance to Oxidative Stress

2005 ◽  
Vol 4 (3) ◽  
pp. 545-555 ◽  
Author(s):  
Bee-Na Lee ◽  
Scott Kroken ◽  
David Y. T. Chou ◽  
Barbara Robbertse ◽  
O. C. Yoder ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Polyketide Synthase ◽  
Biological Activities ◽  
Cochliobolus Heterostrophus ◽  
Pcr Analysis ◽  
Human Pathogens ◽  
Fungal Virulence ◽  
Nonribosomal Peptide ◽  
Nonribosomal Peptide Synthetases ◽  
Peptide Synthetases

ABSTRACT Nonribosomal peptides, made by nonribosomal peptide synthetases, have diverse biological activities, including roles as fungal virulence effectors. Inspection of the genome of Cochliobolus heterostrophus, a fungal pathogen of maize and a member of a genus noted for secondary metabolite production, revealed eight multimodular nonribosomal peptide synthase (NPS) genes and three monomodular NPS-like genes, one of which encodes a nonribosomal peptide synthetase/polyketide synthase hybrid enzyme presumed to be involved in synthesis of a peptide/polyketide molecule. Deletion of each NPS gene and phenotypic analyses showed that the product of only one of these genes, NPS6, is required for normal virulence on maize. NPS6 is also required for resistance to hydrogen peroxide, suggesting it may protect the fungus from oxidative stress. This and all other nps mutants had normal growth, mating ability, and appressoria. Real-time PCR analysis showed that expression of all NPS genes is low (relative to that of actin), that all (except possibly NPS2) are expressed during vegetative growth, and that expression is induced by nitrogen starvation. Only NPS6 is unfailingly conserved among euascomycete fungi, including plant and human pathogens and saprobes, suggesting the possibility that NPS6 activity provides oxidative stress protection during both saprobic and parasitic growth.

Tetrazoloquinolines: Synthesis, Reactions, and Applications

2020 ◽  
Vol 24 (4) ◽  
pp. 439-464 ◽  
Author(s):  
Rizk E. Khidre ◽  
Tahah A. Ameen ◽  
Mounir A. I. Salem
Keyword(s):  
Carboxylic Acid ◽  
Chemical Reactions ◽  
Sodium Azide ◽  
Biological Activities ◽  
Quinoline Derivatives ◽  
Pharmacological Activities ◽  
Synthesis Reactions ◽  
Intramolecular Cyclocondensation

This review summarizes the synthesis, reactions, and biological activities of tetrazolo[1,5-a]quinoline derivatives. These derivatives were synthesized by several methods such as i) from the reaction of 2-chloroquinoline with sodium azide ii) from diazotization 2-hydrazinylquinoline derivatives, and iii) from intramolecular cyclocondensation of 2-azidoarylidenes. Also, the chemical reactions and pharmacological activities of some tetrazoloquinolines such as tetrazolo[1,5-a]quinoline-4-carbaldehyde, 5-chlorotetrazolo[ 1,5-a]quinoline, 4-(chloromethyl)tetrazolo[1,5-a]quinoline, tetrazolo[1,5- a]quinoline-4-carboxylic acid, and 5-azidotetrazolo[1,5-a]quinoline were discussed.

Anticancer Activity of Natural Flavonoids: Inhibition of HIF-1α Signaling Pathway

2020 ◽  
Vol 23 (26) ◽  
pp. 2945-2959 ◽  
Author(s):  
Xiangping Deng ◽  
Yijiao Peng ◽  
Jingduo Zhao ◽  
Xiaoyong Lei ◽  
Xing Zheng ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Secondary Metabolites ◽  
Anticancer Agents ◽  
Hypoxia Inducible Factor ◽  
Tumor Hypoxia ◽  
Pharmacological Activities ◽  
Hypoxia Inducible Factor 1 ◽  
The Past ◽  
Low Toxicity ◽  
Tumor Blood Vessels

Rapid tumor growth is dependent on the capability of tumor blood vessels and glycolysis to provide oxygen and nutrients. Tumor hypoxia is a common characteristic of many solid tumors, and it essentially happens when the growth of the tumor exceeds the concomitant angiogenesis. Hypoxia-inducible factor 1 (HIF-1) as the critical transcription factor in hypoxia regulation is activated to adapt to this hypoxia situation. Flavonoids, widely distributed in plants, comprise many polyphenolic secondary metabolites, possessing broadspectrum pharmacological activities, including their potentiality as anticancer agents. Due to their low toxicity, intense efforts have been made for investigating natural flavonoids and their derivatives that can be used as HIF-1α inhibitors for cancer therapy during the past few decades. In this review, we sum up the findings concerning the inhibition of HIF-1α by natural flavonoids in the last few years and propose the idea of designing tumor vascular and glycolytic multi-target inhibitors with HIF-1α as one of the targets.

Naphthoquinone Derivatives Isolated from Plants: Recent Advances in Biological Activity

2020 ◽  
Vol 20 (19) ◽  
pp. 2019-2035
Author(s):  
Esmaeil Sheikh Ahmadi ◽  
Amir Tajbakhsh ◽  
Milad Iranshahy ◽  
Javad Asili ◽  
Nadine Kretschmer ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Biological Activity ◽  
Small Molecules ◽  
Anticancer Activity ◽  
Clinical Significance ◽  
Phase Ii ◽  
Biological Activities ◽  
Phase Ii Clinical Trials ◽  
Naturally Occurring ◽  
The Subject

Naturally occurring naphthoquinones (NQs) comprising highly reactive small molecules are the subject of increasing attention due to their promising biological activities such as antioxidant, antimicrobial, apoptosis-inducing activities, and especially anticancer activity. Lapachol, lapachone, and napabucasin belong to the NQs and are in phase II clinical trials for the treatment of many cancers. This review aims to provide a comprehensive and updated overview on the biological activities of several new NQs isolated from different species of plants reported from January 2013 to January 2020, their potential therapeutic applications and their clinical significance.

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