scholarly journals Tulasporins A–D, 19-Residue Peptaibols from the Mycoparasitic Fungus Sepedonium tulasneanum

2016 ◽  
Vol 11 (12) ◽  
pp. 1934578X1601101 ◽  
Author(s):  
Alexander Otto ◽  
Annegret Laub ◽  
Mark Haid ◽  
Andrea Porzel ◽  
Jürgen Schmidt ◽  
...  

Four new 19-residue peptaibols, named tulasporins A–D (1–4), were isolated from the semi-solid cultures of Sepedonium tulasneanum. Their structures were elucidated on the basis of extensive ESI-HRMSn fragmentation studies as well as 1H NMR spectroscopic analyses. Interestingly, the structures of tulasporins A–D (1–4) resemble those of chrysospermins isolated earlier from cultures of S. chrysospermum. Previously, it was hypothesized that the peptaibol production by Sepedonium species correlates with the morphology of the aleurioconidia, as exclusively round-shaped aleurioconidia forming species produced peptaibols. Since the investigated Sepedonium tulasneanum produces oval aleurioconidia, this study can be considered as the first report of peptaibols from a Sepedonium strain with oval-shaped aleurioconidia. Thus, it could be demonstrated that both round as well as oval aleurioconidia forming Sepedonium species are able to produce peptaibols. Tulasporins A-D (1–4), when tested against phytopathogenic fungi, exhibited good growth inhibitory activity against both Botrytis cinerea and Phytophthora infestans, while they were devoid of significant activity against Septoria tritici.

2017 ◽  
Vol 1 (2) ◽  
pp. 31-32
Author(s):  
Assia Keniche ◽  
Samia Bellifa ◽  
Hafida Hassaine ◽  
Joseph Kajima Mulengi

Background: Antibiotics, as miraculous drugs, have been used extensively to confront fatal infection, even without prescriptions. However, the inappropriate and disproportionate use of antibiotics have led to the emergence of new drug-resistant bacteria1, which causes a high risk of serious diseases and dramatically aggravates the clinical complications in hospitals. Methods: By using the peptide coupling protocol, a simple straightforward synthesis of functionalized aziridines has been developed. By means of this synthetic strategy from readily available N-phtaloyl acide and 2-methylbenzosulfonate aziridine using DCC as coupling agent, new tosylates aziridines could be obtained. The coupling reactions occurred without a ring opening of the three membered ring. Results: This work describes new results of our ongoing research targeting new derivatives of biological interests. All the compounds were screened for their antibacterial activity; they all showed comparable moderate to good growth inhibitory activity with reference to tetracyclin and gentamicin. Conclusion: In conclusion, we reported the synthesis and a preliminary antibacterial evaluation of novel functionalized tosylaziridines. The synthetic strategy relies on the coupling reactions between tosylaziridines and amino acids. Moreover, and besides showing interesting antibacterial activities, the series of novel compounds can be further improved to serve as potential drug against nosocomial diseases.


2014 ◽  
Vol 9 (12) ◽  
pp. 1934578X1400901
Author(s):  
Alembert T. Tchinda ◽  
David E. Tsala ◽  
Nnanga Nga ◽  
Ewa Cieckiewicz ◽  
Robert Kiss ◽  
...  

Two new aromadendrane sesquiterpenoids (1β,4β,5β,6α,7α,11 S)-aromadendr-9-en-13,14-dioic acid (1) and (1β,4β,5β,6α,7α,11 S)-13-oxoaromadendr-9-en-14-oic acid (2) have been isolated from the stem bark of Alafia multiflora along with β-sitosterol and β-sitosterol glucoside. Their structures were established on the basis of spectroscopic analyses, including 1D and 2D NMR experiments (1H-1H COSY, NOESY, HSQC, HMBC). Compound 1 showed a weak growth inhibitory activity against the murine melanoma line B16F10 MTT.


2013 ◽  
Vol 91 (8) ◽  
pp. 649-655 ◽  
Author(s):  
Gaik-Lean Chee ◽  
Bharat Bhattarai ◽  
Jordan D. Nash ◽  
Kim Madec ◽  
Brian B. Hasinoff ◽  
...  

Certain dihydro-1,4-dithiin tetraoxides such as dimethipin, a commercial plant growth regulant, have been reported to exhibit highly selective biological activities depending on the type and number of substitutions on the α,β-unsaturated bond in the dithiin ring. Despite the abundant reports on this class of compounds, the study of chemical reactivity of the α,β-unsaturated bond in the dithiin ring has not been reported and the factors governing the biological selectivity of these compounds are still unknown. In this study, the reactivity of eight dithiin compounds substituted in varying degrees at the α,β-unsaturated bond towards biologically important nucleophilic groups at pH 7.4 were investigated using UV-vis, fluorescence, and 1H NMR spectroscopies. Their reactivity towards glutathione correlated strongly with their cell growth inhibitory activity and inhibition of DNA topoisomerase II, an enzyme containing critical sulfhydryl groups. On this basis, the mechanism by which these dithiins achieve the biological selectivity previously reported was proposed. Excellent correlations between glutathione reactivity and Taft’s polar substituent constants or electrostatic atomic charges of the dithiins were also demonstrated, suggesting that these descriptors might be useful for predicting the reactivity of other dithiins towards sulfhydryl nucleophiles.


2012 ◽  
Vol 7 (7) ◽  
pp. 1934578X1200700
Author(s):  
Chen-Lung Ho ◽  
Kuo-Feng Hua ◽  
Kuan-Ping Hsu ◽  
Eugene I-Chen Wang ◽  
Yu-Chang Su

In this study, antipathogenic activities of the twig essential oil and its constituents from Chamaecyparis formosensis Matsum were evaluated in vitro against six plant pathogenic fungi. The essential oil from the fresh twigs was isolated using hydrodistillation in a Clevenger-type apparatus, and characterized by GC-FID and GC-MS. Twenty-five compounds were identified, representing 98.9% of the oil. The main components were β-eudesmol (25.1%), τ-muurolol (21.6%), elemol (15.0%), totarol (14.9%), and α-cadinol (12.4%). The twig oil (500 μg/mL) showed growth inhibitory activity against the phytopathogenic fungi, Fusarium oxysporum, Pestalotiopsis funereal, and Ganoderma austral, with antifungal indices of 92.7%, 71.1%, and 87.7%, respectively. In addition, the oil suppressed totally the growth of Rhizoctonia solani, Colletotrichum gloeosporioides, and Fusarium solani. In order to ascertain the source compounds of these antipathogenic activities, the main components were individually evaluated. τ-Muurolol and α-cadinol exhibited excellent activity against F. oxysporum, R. solani, C. gloeosporioides, and F. solani, with IC50< 50 μg/mL. These compounds also efficiently inhibited the mycelial growths of P. funereal and G. austral. Thus, α-cadinol and τ-muurolol could be considered as potential natural fungicides for controlling fungal pathogens and worth.


2021 ◽  
Vol 14 (1) ◽  
pp. 49
Author(s):  
David Méndez-Luna ◽  
Loreley Araceli Morelos-Garnica ◽  
Juan Benjamín García-Vázquez ◽  
Martiniano Bello ◽  
Itzia Irene Padilla-Martínez ◽  
...  

The implementation of chemo- and bioinformatics tools is a crucial step in the design of structure-based drugs, enabling the identification of more specific and effective molecules against cancer without side effects. In this study, three new compounds were designed and synthesized with suitable absorption, distribution, metabolism, excretion and toxicity (ADME-tox) properties and high affinity for the G protein-coupled estrogen receptor (GPER) binding site by in silico methods, which correlated with the growth inhibitory activity tested in a cluster of cancer cell lines. Docking and molecular dynamics (MD) simulations accompanied by a molecular mechanics/generalized Born surface area (MMGBSA) approach yielded the binding modes and energetic features of the proposed compounds on GPER. These in silico studies showed that the compounds reached the GPER binding site, establishing interactions with a phenylalanine cluster (F206, F208 and F278) required for GPER molecular recognition of its agonist and antagonist ligands. Finally, a 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide (MTT) assay showed growth inhibitory activity of compounds 4, 5 and 7 in three different cancer cell lines—MIA Paca-2, RCC4-VA and Hep G2—at micromolar concentrations. These new molecules with specific chemical modifications of the GPER pharmacophore open up the possibility of generating new compounds capable of reaching the GPER binding site with potential growth inhibitory activities against nonconventional GPER cell models.


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1380
Author(s):  
Xiutao Wu ◽  
Lijie Gong ◽  
Chen Chen ◽  
Ye Tao ◽  
Wuxi Zhou ◽  
...  

Harringtonolide (HO), a natural product isolated from Cephalotaxus harringtonia, exhibits potent antiproliferative activity. However, little information has been reported on the systematic structure−activity relationship (SAR) of HO derivatives. Modifications on tropone, lactone, and allyl positions of HO (1) were carried out to provide 17 derivatives (2–13, 11a–11f). The in vitro antiproliferative activity against four cancer cell lines (HCT-116, A375, A549, and Huh-7) and one normal cell line (L-02) was tested. Amongst these novel derivatives, compound 6 exhibited comparable cell growth inhibitory activity to HO and displayed better selectivity index (SI = 56.5) between Huh-7 and L-02 cells. The SAR results revealed that the tropone and lactone moieties are essential for the cytotoxic activities, which provided useful suggestions for further structural optimization of HO.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1637
Author(s):  
Solida Long ◽  
Joana B. Loureiro ◽  
Carla Carvalho ◽  
Luís Gales ◽  
Lucília Saraiva ◽  
...  

The tumor suppressor p53 is inactivated by mutation in approximately 50% of human cancers. Small molecules that bind and stabilize those mutants may represent effective anticancer drugs. Herein, we report the tumor cell growth inhibitory activity of carbazole alkaloids and amino derivatives, as well as their potential activation of p53. Twelve aminocarbazole alkaloids were semi-synthesized from heptaphylline (1), 7-methoxy heptaphylline (2), and 7-methoxymukonal (3), isolated from Clausena harmandiana, using a reductive amination protocol. Naturally-occurring carbazoles 1–3 and their amino derivatives were evaluated for their potential effect on wild-type and mutant p53 activity using a yeast screening assay and on human tumor cell lines. Naturally-occurring carbazoles 1–3 showed the most potent growth inhibitory effects on wild-type p53-expressing cells, being heptaphylline (1) the most promising in all the investigated cell lines. However, compound 1 also showed growth inhibition against non-tumor cells. Conversely, semi-synthetic aminocarbazole 1d showed an interesting growth inhibitory activity in tumor cells expressing both wild-type and mutant p53, exhibiting low growth inhibition on non-tumor cells. The yeast assay showed a potential reactivation of mutant p53 by heptaphylline derivatives, including compound 1d. The results obtained indicate that carbazole alkaloids may represent a promising starting point to search for new mutp53-reactivating agents with promising applications in cancer therapy.


2021 ◽  
pp. 096032712110214
Author(s):  
JY Lee ◽  
HM Lim ◽  
CM Lee ◽  
S-H Park ◽  
MJ Nam

Indole-3-carbinol (I3C) is a phytochemical that exhibits growth-inhibitory activity against various cancer cells. However, there are limited studies on the effects of I3C on colon cancer cells. In this study, the growth-inhibitory activity of I3C against the human colorectal carcinoma cell line (LoVo) was examined. The results of the 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide, colony formation, and cell counting assays revealed that I3C suppressed the proliferation of LoVo cells. Microscopy and wound-healing analyses revealed that I3C affected the morphology and inhibited the migration of LoVo cells, respectively. I3C induced apoptosis and DNA fragmentation as evidenced by the results of fluorescein isothiocyanate-conjugated annexin V staining and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling assay, respectively. Additionally, I3C arrested the cell cycle at the G0/G1 phase and enhanced the reactive oxygen species levels. Western blotting analysis revealed that treatment with I3C resulted in the activation of apoptotic proteins, such as poly(ADP-ribose) polymerase, caspase-3, caspase-7, caspase-9, Bax, Bim, and p53 in LoVo cells. These results indicate that I3C induces apoptosis in LoVo cells by upregulating p53, leading to the activation of Bax and caspases. Taken together, I3C exerts cytotoxic effects on LoVo cells by activating apoptosis.


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