Aqueous extracts of walnut (Juglans regia L.) leaves: quantitative analyses of hydroxycinnamic and chlorogenic acids

Abstract

Identification of both hydroxycinnamic and chlorogenic acids present in aqueous extracts of walnut leaves (Juglans regia L.) were carried out by using, for the first time, standard compounds not commercially available for qualitative identification. In particular, in addition to caffeic, ferulic, p-coumaric and sinapic acids, cis and trans mono-caffeoylquinic, dicaffeoylquinic, mono-feruloylquinic and cis and trans mono-p-coumaroylquinic acid isomers were detected and quantified by Ultra High Pressure Liquid Chromatography and the seasonal variations of these secondary metabolites were investigated.

Hydroxycinnamoyl Amino Acids Conjugates: A Chiral Pool to Distinguish Commercially Exploited Coffea spp.

“…In the present Although only a few works reported the presence of HCAs in coffee beans, it was evidenced in the literature that these compounds were characteristic of the Robusta species [5,[13][14][15][16][17][18]. In the present work, compounds 1b-5b have been quantified in green coffee beans of C. arabica and C. canephora of different geographical origin, and for the first time of C. liberica, using an aqueous extraction procedure, as was already used in our previous works for the quantification of chlorogenic acids [21,22].…”

Chemical Profiling, Bioactive Properties, and Anticancer and Antimicrobial Potential of Juglans regia L. Leaves

“…It also appears that the discrepancies in the antimicrobial efficacy of the tested extracts may be due to the seasonal variability of antimicrobial active substances contained in the biomass of walnut leaves [ 33 ].…”

“…Therefore, these were tentatively identified as coumaroyl glucosides. In fact, coumaric acid derivatives are commonly found in walnut leaves [ 8 , 9 , 22 , 23 , 33 , 44 , 45 , 46 ]. Pseudomolecular ion [M-H]- at m / z 355 ( 12 ) was assigned to ferulic acid hexoside, based on the MS/MS m / z at 193 [M-H-162]- and the literature findings [ 22 , 44 ].…”

Novel synthesis of 1,2-diaza-1,3-dienes with potential biological activity from cinnamic acids and diazonium salts of anilines

“…Cinnamic acids are a class of compounds with a phenylpropanoid skeleton (C6–C3), which are largely present in the plant kingdom as free compounds or in a conjugated form. 4 Coffee beans, cocoa, tea, apples, brassica vegetables, grapes, citrus, pears are particularly rich of cinnamic acids, which are also present as ester conjugates with quinic acid, to give the class of compounds known as chlorogenic acids, 4–9 or esters with other acids, sugars or lipids, or forming amides with amino acids (Fig. 1).…”