831-61-8Relevant articles and documents
Biddle,Kelley
, p. 920 (1912)
The effect of solvent composition on grafting gallic acid onto chitosan via carbodiimide
Guo, Ping,Anderson, John D.,Bozell, Joseph J.,Zivanovic, Svetlana
, p. 171 - 180 (2016)
The primary antioxidant (AOX) activity of chitosan can be introduced by grafting of phenolic compound - gallic acid (GA) to its amino and/or hydroxyl groups. The objective of this study was to investigate the effect of ethanol (EtOH) concentration (0%, 25%, 50%, and 75% in water) on efficiency of grafting GA onto chitosan in the presence of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC)/N-hydroxysuccinimide (NHS). The grafting was confirmed by FTIR and the efficiency was quantified as Folin's total phenolics. When pure deionized water was used as a sole solvent (0% EtOH), GA was grafted to chitosan at the largest extent (285.9 mg GA/g chitosan). As the concentration of EtOH increased, the grafting efficiency proportionally decreased. NMR studies showed that EtOH inhibited grafting of GA by prohibiting the production of the intermediate - NHS ester. The results confirm that the concentration of EtOH in grafting solution significantly affects grafting efficiency of GA on chitosan.
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Iljin
, p. 459 (1910)
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Method for producing ester based on eco-friendly and high efficiency esterification by using base exchange of salt and the compound thereof
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Paragraph 0099-0105; 0107, (2021/07/07)
The present invention relates to an esterification reaction-based eco-friendly and high efficiency ester compound using ion exchange and an ester compound thereof. The esterification generally proceeds by reverse reaction with water, resulting in poor yield of the ester. In order to avoid hydrolysis, the esterification reaction was environmentally or non-limited due to the continuous supply of hydrochloric acid gas or the use of chlorinated thionyl chloride as a noxious substance. To the present invention, a continuous hydrochloric acid gas is provided by ion exchange of a salt, and magnesium sulfate acts as a dehydrating agent to remove water generated in esterification. In addition, the reactants are cheap and the product is also low in harmfulness and easier to handle and thus more efficient reaction is possible.
Polyhydroxybenzoic acid derivatives as potential new antimalarial agents
Degotte, Gilles,Francotte, Pierre,Pirotte, Bernard,Frédérich, Michel
, (2021/08/07)
With more than 200 million cases and 400,000 related deaths, malaria remains one of the deadliest infectious diseases of 2021. Unfortunately, despite the availability of efficient treatments, we have observed an increase in people infected with malaria since 2015 (from 211 million in 2015 to 229 million in 2019). This trend could partially be due to the development of resistance to all the current drugs. Therefore, there is an urgent need for new alternatives. We have, thus, selected common natural scaffolds, polyhydroxybenzoic acids, and synthesized a library of derivatives to better understand the structure–activity relationships explaining their antiplasmodial effect. Only gallic acid derivatives showed a noticeable potential for further developments. Indeed, they showed a selective inhibitory effect on Plasmodium (IC50 ~20 μM, SI > 5) often associated with interesting water solubility. Moreover, this has confirmed the critical importance of free phenolic functions (pyrogallol moiety) for the antimalarial effect. Methyl 4-benzoxy-3,5-dihydroxybenzoate (39) has, for the first time, been recognized as a potential lead for future research because of its marked inhibitory activity against Plasmodium falciparum and its significant hydrosolubility (3.72 mM).
