scholarly journals Plakinamine P, A Steroidal Alkaloid with Bactericidal Activity against Mycobacterium tuberculosis

Marine Drugs ◽  
2019 ◽  
Vol 17 (12) ◽  
pp. 707 ◽  
Author(s):  
Carolina Rodrigues Felix ◽  
Jill C. Roberts ◽  
Priscilla L. Winder ◽  
Rashmi Gupta ◽  
M. Cristina Diaz ◽  
...  

Tuberculosis is the leading cause of death due to infectious disease worldwide. There is an urgent need for more effective compounds against this pathogen to control the disease. Investigation of the anti-mycobacterial activity of a deep-water sponge of the genus Plakina revealed the presence of a new steroidal alkaloid of the plakinamine class, which we have given the common name plakinamine P. Its structure is most similar to plakinamine L, which also has an acyclic side chain. Careful dissection of the nuclear magnetic resonance data, collected in multiple solvents, suggests that the dimethyl amino group at the 3 position is in an equatorial rather than axial position unlike previously reported plakinamines. Plakinamine P was bactericidal against M. tuberculosis, and exhibited moderate activity against other mycobacterial pathogens, such as M. abscessus and M. avium. Furthermore, it had low toxicity against J774 macrophages, yielding a selectivity index (SI, or IC50/MIC) of 8.4. In conclusion, this work provides a promising scaffold to the tuberculosis drug discovery pipeline. Future work to determine the molecular target of this compound may reveal a pathway essential for M. tuberculosis survival during infection.

Author(s):  
A.N. Sagredos ◽  
R. Moser

AbstractBased on previous work (7) a method to simultaneously determine vamidothion [I], vamidothion-sulfoxide [II] and vamidothion sulfone [III] in tobacco has been developed. The compounds are extracted with water/acetone/acetic acid from the tobacco, cleansed over an aluminium oxide column and then determined on the gas chromatograph with the specific sulphur detector. Rates of recovery are 70 % - 92 %, the determination level is 0.1 ppm. Mass spectrometry and nuclear magnetic resonance data of vamidothion [I], vamidothion-sulfoxide [ II ] and vamidothion-sulfone [III] are given.


1980 ◽  
Vol 58 (19) ◽  
pp. 2069-2072 ◽  
Author(s):  
A. Stoessl ◽  
J. B. Stothers

The complement of sesquiterpenoidal stress compounds produced in the interaction of potato with the pathogenic fungus, Alternariasolani, includes representatives of a new stereochemical series, 2-epilubimin (1) and its reduction product, 15-dihydro-2-epilubimin (3). Their structures were deduced from 13C and 1H magnetic resonance data.


1967 ◽  
Vol 45 (3) ◽  
pp. 305-309 ◽  
Author(s):  
Harold MacLean ◽  
Koji Murakami

Proof of structure is presented for another lignan of the thujaplicatin series, 2,3-dihydroxy-2-(4″-hydroxy-3″,5″-dimethoxybenzyl)-3-(4′-hydroxy-3′-methoxybenzyl)-butyrolactone (I) (dihydroxythujaplicatin methyl ether). Analytical and spectral (ultraviolet, infrared, and nuclear magnetic resonance) data on derivatives and degradation products, in addition to the parent compound, are presented.


Author(s):  
Shubham Dubey ◽  
Biro Piroska ◽  
Manjulata Gautam

The world is changing rapidly, so is academics. E-learning has altered the area of academics and education. ICT enabled learning has given ideal services to students by providing any type of content on demand which is proportional to the performance of students. The concentration of learner has been found instinctive; thus there is a need of engaging mind towards course progress with its entirety till the objectives of the course will be achieved. There are several e-learning platforms available as EdX, Udacity, Khan Academy, Alison those have a number of learners registered for various courses. Studies suggest that these platforms suffer from the common problem of learners’ dropping out. Investigations also claim early leaving rate is increasing due to lack of quality of content, distraction factors, learners’ mind change, outdated and succinct information, and some more detraction factors. These issues have been observed on the basis of early leaving rates in various MOOCs. Thus there is a mammoth scope for minimizing the impact of these reasons on the learners’ mind. It can be achieved by identifying these factors affecting learners’ motivation during the course. This study is aiming on identifying these factors. The approach is to explore some certain keywords on previous literature (total 41) and then calculating their frequencies and co-factors associated with them. Both grouped factors contribution and individual factor contribution have been taken care. The study gives a direction for future work towards overcoming these actor and engaging learners in ICT enabled learning.


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