Search results for "Ethyl caffeate"
showing 4 items of 4 documents
Characterization and purification of a bacterial chlorogenic acid esterase detected during the extraction of chlorogenic acid from arbuscular mycorrh…
2016
International audience; A Gram-negative bacterium able to grow using chlorogenic acid (5-caffeoylquinic acid) as sole carbon source has been isolated from the roots of tomato plants inoculated with the arbuscular mycorrhizal fungus Rhizophagus irregularis. An intracellular esterase exhibiting very high affinity (K-m = 2 mu M) for chlorogenic acid has been extracted and purified by FPLC from the chlorogenate-grown cultures of this bacterium. The molecular mass of the purified esterase determined by SDS-PAGE was 61 kDa and its isoelectric point determined by chromatofocusing was 7.75. The esterase hydrolysed chlorogenic acid analogues (caffeoylshikimate, and the 4- and 3-caffeoylquinic acid i…
Nanosponges for the protection and release of the natural phenolic antioxidants quercetin, curcumin and phenethyl caffeate
2020
The inclusion of polyphenols into nanoporous materials may significantly improve their application as radical trapping agents for therapeutic purposes. In the present work, nanosponges based on hypercross- linked cyclodextrins and calixarenes (NS1–NS3) were used as carriers of three natural phenolic antioxidants: quercetin (Que), curcumin (Cur) and phenethyl caffeate (Phec). Good w/w loadings, namely 7.3% for the Que–NS1 composite, 17.3% for Cur–NS2 and 12.9% for Phec–NS3, were achieved. The release kinetics and the inhibition rate constants (kinh) of the reaction with alkylperoxyl radicals (ROO.) in 0.1 M phosphate buffer solutions at pH 7.4 were studied and indicated better antioxidant ac…
Detection of a plant enzyme exhibiting chlorogenate-dependant caffeoyltransferase activity in methanolic extracts of arbuscular mycorrhizal tomato ro…
2012
When Glomus intraradices-colonised tomato roots were extracted in methanol at 6 degrees C, chlorogenic acid (5-caffeoylquinic acid), naturally present in the extract, was slowly converted by transesterification into methyl caffeate. The progress of the reaction could be monitored by HPLC. The reaction only occurred when the ground roots were left in contact with the hydro-alcoholic extract and required the presence of 15-35% water in the mixture. When the roots were extracted in ethanol, chlorogenic acid was transformed to ethyl caffeate in the same conditions. The reaction was also detected in Glomus mosseae-colonised tomato root extracts. It was also detectable in non-mycorrhizal root ext…
Phenolic and acetylenic metabolites from Artemisia assoana
1987
Abstract Nine flavones, three coumarins, two flavone glycosides, p-hydroxyacetophenone and methyl caffeate have been isolated from the aerial parts of Artemisia assoana. Six diacetylenic spiroketal enol-ethers, a mixture of n-alkyl p-coumarates and a new phenylpropanoid metabolite, sinapyl alcohol diisovalerate, have been isolated from root extracts of the same plant. 1H and 13C NMR spectra of some of these compounds are given and taxonomic aspects are discussed.