A new class of dimeric product isolated from the fungus Chaetomium globosum: evaluation of chemical structure and biological activity

2020 ◽  
Vol 73 (5) ◽  
pp. 320-323
Author(s):  
Christopher Sarmales-Murga ◽  
Fumito Akaoka ◽  
Michio Sato ◽  
Jun Takanishi ◽  
Takashi Mino ◽  
...  
Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 281
Author(s):  
Tomasz Jarosz ◽  
Przemyslaw Ledwon

Polypyrrole is a classical, well-known conjugated polymer that is produced from a simple heterocyclic system. Numerous pyrrole derivatives exhibit biological activity, and the repeat unit is a common building block present in the chemical structure of many polymeric materials, finding wide application, primarily in optoelectronics and sensing. In this work, we focus on the variety of copolymers and their material properties that can be produced electrochemically, even though all these systems are obtained from mixtures of the “simple” pyrrole monomer and its derivatives with different conjugated and non-conjugated species.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Camila M. B. Machado ◽  
Nathalia B. D. Lima ◽  
Sóstenes L. S. Lins ◽  
Alfredo M. Simas

AbstractWe address the use of Euler's theorem and topological algorithms to design 18 polyhedral hydrocarbons of general formula CnHn that exist up to 28 vertexes containing four- and six-membered rings only; compounds we call “nuggets”. Subsequently, we evaluated their energies to verify the likelihood of their chemical existence. Among these compounds, 13 are novel systems, of which 3 exhibit chirality. Further, the ability of all nuggets to perform fusion reactions either through their square faces, or through their hexagonal faces was evaluated. Indeed, they are potentially able to form bottom-up derived molecular hyperstructures with great potential for several applications. By considering these fusion abilities, the growth of the nuggets into 1D, 2D, and 3D-scaffolds was studied. The results indicate that nugget24a (C24H24) is predicted to be capable of carrying out fusion reactions. From nugget24a, we then designed 1D, 2D, and 3D-scaffolds that are predicted to be formed by favorable fusion reactions. Finally, a 3D-scaffold generated from nugget24a exhibited potential to be employed as a voxel with a chemical structure remarkably similar to that of MOF ZIF-8. And, such a voxel, could in principle be employed to generate any 3D sculpture with nugget24a as its level of finest granularity.


Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2256
Author(s):  
Serenella Nardi ◽  
Michela Schiavon ◽  
Ornella Francioso

Humic substances (HS) are dominant components of soil organic matter and are recognized as natural, effective growth promoters to be used in sustainable agriculture. In recent years, many efforts have been made to get insights on the relationship between HS chemical structure and their biological activity in plants using combinatory approaches. Relevant results highlight the existence of key functional groups in HS that might trigger positive local and systemic physiological responses via a complex network of hormone-like signaling pathways. The biological activity of HS finely relies on their dosage, origin, molecular size, degree of hydrophobicity and aromaticity, and spatial distribution of hydrophilic and hydrophobic domains. The molecular size of HS also impacts their mode of action in plants, as low molecular size HS can enter the root cells and directly elicit intracellular signals, while high molecular size HS bind to external cell receptors to induce molecular responses. Main targets of HS in plants are nutrient transporters, plasma membrane H+-ATPases, hormone routes, genes/enzymes involved in nitrogen assimilation, cell division, and development. This review aims to give a detailed survey of the mechanisms associated to the growth regulatory functions of HS in view of their use in sustainable technologies.


2007 ◽  
Vol 71 (1) ◽  
pp. 75-85 ◽  
Author(s):  
Adele Muscolo ◽  
Maria Sidari ◽  
Emilio Attinà ◽  
Ornella Francioso ◽  
Vitaliano Tugnoli ◽  
...  

N , N '-Diphenylurea was shown to have reproducible cytokinin activity . Some 500 ureas, mainly of the N -monosubstituted and N , N '-disubstituted types, were tested an d about one half of these were active. Attempts were made to correlate chemical structure with biological activity. Although there are some exceptions to nearly every generalization it has been possible to formulate some principles. (1) Phenyl urea was the simplest active compound. (2) An HNCONH bridge conferred higher activity than an HNCSNH linkage and any other tested arrangement of the bridge gave inactive com pounds. (3) Compounds in which both amino hydrogen atoms on one or both sides of the bridge were substituted were of low activity or were inactive. (4) Many com pounds of the type R NHCONH 2 in which R = a substituted phenyl ring were tested. Ring substitution generally increased the activity and the highest activity was associated with meta substitution and the lowest with ortho . Compounds with electron-attracting substituents were generally more active than those with electron-donating substituents. Pyridyl compounds were active but com pounds with non-planar rings were inactive. (5) In compounds of the type R NHCONH R ' in which R and R ' were phenyl or substituted phenyl groups the highest activities were usually found in com pounds with one unsubstituted phenyl ring. Those with two substituted phenyl groups generally had lower activity. Some ureas showed detectable activity at 0.1 parts/10 6 . This was about four times less active than kinetin when tested in the tobacco pith assay.


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