Extraction of Walnut Husks and Leaves Using Subcritical Water and Supercritical Carbon Dioxide Extraction Methods and Comparison the Antioxidant Activities of the Extracts

Anatolian Conference 4th on Organic Chemistry, Antalya, Türkiye, 4 - 07 Mart 2024, ss.75, (Özet Bildiri)

The genus Juglans (family Juglandaceae) is a plant with many varieties and has a wide

distribution throughout the world. Green husks, seeds, and dried leaves are used in the

pharmaceutical and cosmetic industry. Especially walnut leaves are used extensively in

traditional medicine in the treatment of venous insufficiency, hypoglycemia, hemorrhoids,

infections, diarrhea, microbial and fungal diseases. In this study, walnut husks and leaves

were collected from Hakkari province (Turkey) and extracted by subcritical water and

supercritical carbon dioxide extraction methods under various temperature and pressure. The

phytochemicals compositions of the extracts were determined by GC-MS. In all extracts five

main groups of phytochemicals were obtained with different amount. They are HCs and

squalene; fatty acids, fatty acid ester and phytol; tocopherols; tetralones. Additionally,

antioxidant activity of husks and leaves extracts were tested. The results shown taht the

antioxidant activities of the leaf extracts obtained by the subcritical water method were higher

than those obtained with supercritical carbon dioxide and the reference substance butylated

hydroxytoluene (Figure 1). The subcritical water extract which obtained at 160 ̊C and 60 atm

has the highest antioxidant activity. The main characteristic of this extract having the highest

amount of tetralones among the others.