Synthesis of p -coumaroylquinic acids and analysis of their interconversion

Abstract

The synthesis of four isomers of p-coumaroylquinic acids was performed by esterification of pacetylcoumaroylchloride with a suitable protected (-)-quinic acid. All isomers have been characterized by means of NMR spectroscopy and circular dichroism. Acyl migration was observed in the synthesis of 3-O-p-coumaroylquinic acid and 4-O-p-coumaroylquinic acid. Calculations on the most stable conformations of all isomers have also been performed to explain the acyl migration observed during the synthesis procedure.

Potential Use of Vacuum Impregnation and High-Pressure Homogenization to Obtain Functional Products from Lulo Fruit (Solanum quitoense Lam.)

“…Compounds 5, 6, and 7 were assigned as p -coumaroylquinic acid, 4- p -coumaroylquinic acid, and 5- p -coumaroylquinic acid, respectively, with molecular mass [M-H] - = 337 and with a MS 2 fragment at m/z 191,163 as reported by Pereira et al [ 58 ], Gutiérrez Ortiz et al [ 59 ], Brahem et al [ 52 ], Mikulic-Petkovsek et al [ 60 ], Gómez-Romero et al [ 55 ], and Rodríguez-Medina et al [ 61 ]. Compounds 8 and 9 were, respectively, identified as quercetin-3-O-rhamnoside ([M-H] − = 447 MS 2 fragment at m/z 301) and quercetin-3- O -rutinoside ([M-H] − = 606 MS 2 fragment at m/z 300).…”

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

“…Not commercially available standards such as feruloylquinic acids (FQAs) and pCoQA were obtained by carrying out their chemical synthesis from condensation reactions between a quinic acid derivative and the corresponding acyl chloride. The identity of these CGAs was confirmed by 1 H and 13 C NMR spectroscopy (24, 25). Water was treated in a Milli-Q water purification system (Millipore Academic).…”

“…In the present work, we optimized a suitable UHPLC method in order to quantify and evaluate seasonal variation of CGAs derivatives in walnut leaves as well as the presence of cis isomers, thanks to UV irradiation ad hoc experiment on standard solutions of CQAs and p CoQAs (23). Qualitative identification was performed using synthetized standards of FQAs and p CoQAs, not commercially available (24, 25). Quantitative analyses are expressed as 5-CQAs equivalents in order to assure reliable results (26).…”

Optimization of the Extraction of Bioactive Compounds from Walnut (Juglans major 209 x Juglans regia) Leaves: Antioxidant Capacity and Phenolic Profile

“…It is widely distributed in fruits, vegetables, and cereals and exhibits a broad number of chemoprotective effects both in vitro and in vivo, against oxidative stress, cancer, cardiovascular disorders, diabetes, and allergic reactions [24]. Chlorogenic acids are also present in many vegetables and fruits and some health benefits have been associated with them such as the prevention of cardiovascular diseases and types 2 diabetes [25] and also antioxidants, anticancer, anti-inflammatory, and immunomodulatory properties have been shown Finally, to identify and quantify the compounds responsible for the antioxidant activity of the optimum Juglans major 209 x Juglans regia leaf extract, it was analyzed by UPLC/ESI-QTOF-MS. Table 5 and Figure 7 show the phenolic profile determined. Fifteen phenolic compounds were identified and quantified, with the flavonoid quercetin 3-β-D-glucoside being the major compound, representing 49.35% of the total phenolic composition, followed by chlorogenic acid (29.16%), and neochlorogenic acid (18.34%).…”

“…It is widely distributed in fruits, vegetables, and cereals and exhibits a broad number of chemoprotective effects both in vitro and in vivo, against oxidative stress, cancer, cardiovascular disorders, diabetes, and allergic reactions [24]. Chlorogenic acids are also present in many vegetables and fruits and some health benefits have been associated with them such as the prevention of cardiovascular diseases and types 2 diabetes [25] and also antioxidants, anticancer, anti-inflammatory, and immunomodulatory properties have been shown [26]. The importance of these phenolic compounds for various industrial applications demonstrate the interest of the valorization of Juglans major 209 x Juglans regia leaves.…”