Mechanochromic Luminescence of 2,6-Bis(4-biphenyl)isonicotinic Acid via Interconversion of Classical/Frustrated Brönsted Pair

2021 ◽  
Vol 86 (18) ◽  
pp. 12591-12596
Author(s):  
Hongyan Zhao ◽  
Linwei Huang ◽  
Yedong Wang ◽  
Kai Feng ◽  
Yunhao Chang ◽  
...  
2020 ◽  
Vol 17 (3) ◽  
pp. 365-375
Author(s):  
Vasyl Kovalishyn ◽  
Diana Hodyna ◽  
Vitaliy O. Sinenko ◽  
Volodymyr Blagodatny ◽  
Ivan Semenyuta ◽  
...  

Background: Tuberculosis (TB) is an infection disease caused by Mycobacterium tuberculosis (Mtb) bacteria. One of the main causes of mortality from TB is the problem of Mtb resistance to known drugs. Objective: The goal of this work is to identify potent small molecule anti-TB agents by machine learning, synthesis and biological evaluation. Methods: The On-line Chemical Database and Modeling Environment (OCHEM) was used to build predictive machine learning models. Seven compounds were synthesized and tested in vitro for their antitubercular activity against H37Rv and resistant Mtb strains. Results: A set of predictive models was built with OCHEM based on a set of previously synthesized isoniazid (INH) derivatives containing a thiazole core and tested against Mtb. The predictive ability of the models was tested by a 5-fold cross-validation, and resulted in balanced accuracies (BA) of 61–78% for the binary classifiers. Test set validation showed that the models could be instrumental in predicting anti- TB activity with a reasonable accuracy (with BA = 67–79 %) within the applicability domain. Seven designed compounds were synthesized and demonstrated activity against both the H37Rv and multidrugresistant (MDR) Mtb strains resistant to rifampicin and isoniazid. According to the acute toxicity evaluation in Daphnia magna neonates, six compounds were classified as moderately toxic (LD50 in the range of 10−100 mg/L) and one as practically harmless (LD50 in the range of 100−1000 mg/L). Conclusion: The newly identified compounds may represent a starting point for further development of therapies against Mtb. The developed models are available online at OCHEM http://ochem.eu/article/11 1066 and can be used to virtually screen for potential compounds with anti-TB activity.


2019 ◽  
Vol 21 (27) ◽  
pp. 14728-14733 ◽  
Author(s):  
Xiao Ma ◽  
Jipeng Li ◽  
Chensheng Lin ◽  
Guoliang Chai ◽  
Yangbin Xie ◽  
...  

For a pyridinium-based emitter with fluorescence–phosphorescence dual emission, mechanical grinding induces phosphorescence disappearance and mechanical pressing induces extraordinary phosphorescence enhancement.


1954 ◽  
Vol 209 (2) ◽  
pp. 467-484 ◽  
Author(s):  
Leonard J. Zatman ◽  
Nathan O. Kaplan ◽  
Sidney P. Colowick ◽  
Margaret M. Ciotti

2021 ◽  
pp. 109484
Author(s):  
Shan Xue ◽  
Mengwei Li ◽  
Yi Han ◽  
Yulan Chen

Author(s):  
Shiqi Cheng ◽  
Zhao Chen ◽  
Ya Yin ◽  
Yue Sun ◽  
Shenghua Liu

1987 ◽  
Vol 105 (3) ◽  
pp. 1463-1469 ◽  
Author(s):  
C Fornieri ◽  
M Baccarani-Contri ◽  
D Quaglino ◽  
I Pasquali-Ronchetti

Hydrophobic tropoelastin molecules aggregate in vitro in physiological conditions and form fibers very similar to natural ones (Bressan, G. M., I. Pasquali Ronchetti, C. Fornieri, F. Mattioli, I. Castellani, and D. Volpin, 1986, J. Ultrastruct. Molec. Struct. Res., 94:209-216). Similar hydrophobic interactions might be operative in in vivo fibrogenesis. Data are presented suggesting that matrix glycosaminoglycans (GAGs) prevent spontaneous tropoelastin aggregation in vivo, at least up to the deamination of lysine residues on tropoelastin by matrix lysyl oxidase. Lysyl oxidase inhibitors beta-aminopropionitrile, aminoacetonitrile, semicarbazide, and isonicotinic acid hydrazide were given to newborn chicks, to chick embryos, and to newborn rats, and the ultrastructural alterations of the aortic elastic fibers were analyzed and compared with the extent of the enzyme inhibition. When inhibition was greater than 65% all chemicals induced alterations of elastic fibers in the form of lateral aggregates of elastin, which were always permeated by cytochemically and immunologically recognizable GAGs. The number and size of the abnormal elastin/GAGs aggregates were proportional to the extent of lysyl oxidase inhibition. The phenomenon was independent of the animal species. All data suggest that, upon inhibition of lysyl oxidase, matrix GAGs remain among elastin molecules during fibrogenesis by binding to positively charged amino groups on elastin. Newly synthesized and secreted tropoelastin has the highest number of free epsilon amino groups, and, therefore, the highest capability of binding to GAGs. These polyanions, by virtue of their great hydration and dispersing power, could prevent random spontaneous aggregation of hydrophobic tropoelastin in the extracellular space.


2011 ◽  
Vol 21 (23) ◽  
pp. 8401 ◽  
Author(s):  
Tiandong Liu ◽  
Alan D. Chien ◽  
Jiwei Lu ◽  
Guoqing Zhang ◽  
Cassandra L. Fraser

2011 ◽  
Vol 4 (3) ◽  
pp. 211-217 ◽  
Author(s):  
Asha B. Thomas ◽  
Piyoosh A. Sharma ◽  
Preeti N. Tupe ◽  
Ravindra V. Badhe ◽  
Rabindra K. Nanda ◽  
...  

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