Advances in Agriculture and Agricultural Sciences

Advances in Agriculture and Agricultural Sciences ISSN 2756-326X Vol. 12 (2), pp. 001-008, February, 2026. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Characterization of Phenolic Compounds in Iranian Walnut (Juglans regia L.) Leaves

Amir Jalili*¹, Asra Sadeghzade²

1Department of Biology, Islamic Azad University, Urmia branch, Urmia, IRAN.
²Department of Biology, Islamic Azad University, Urmia branch, Urmia, IRAN.

Accepted 10 January, 2026

Walnut leaves constitute a good source of healthy compounds, namely phenolics, suggesting that it could be useful in the prevention of diseases in which free radicals are implicated. In this study walnut (Juglans regia L.) leaves from eleven different cultivars (Mayette, Fernor, Mellanaise, Elit, Orientis, Lara, Hartley, Franquette, Parisienne, Arco, Marbot) were studied for their phenolic compounds. The evolution of major phenolic compounds was monitored from May to September. Two extractive procedures were assayed and the best results were obtained using acidified water (pH 2) and a solid phase extraction column purification step. Qualitative analysis was performed by HPLC-DAD/MS and, in all samples; nine phenolic compounds were identified (3-caffeoylquinic, 3-p-coumaroylquinic and 4-p-coumaroylquinic acids, quercetin 3-galactoside, quercetin 3-arabinoside, quercetin 3-xyloside, quercetin 3-rhamnoside, quercetin 3-pentoside and kaempferol 3-pentoside). Quantification of phenolic compounds was performed by HPLC-DAD, which revealed that the highest content of phenolics was found in May and July the quercetin 3-galactoside was always the major compound while 4-p-coumaroylquinic acid was the minor one. In addition, Franquette cultivars total phenolic content was the highest among all cultivars.

Keywords: Juglans regia L., total phenolics content, Phenolic profile, Walnut leaf, HPLC-DAD, HPLC/DAD/ESI-MS