Chemical composition and antioxidant activity of the essential oil and flavonoids of phlomis floccosa D. don

الملخص EN

The present study aimed to investigate the antioxidant activities of essential oils and different extracts from Phlomis floccosa parts.

Where the essential oil was detected in the leaves of Phlomis floccosa only, while it was absent in stem and flower parts.

The hydro-distillation of the leaves of Phlomis floccosa yielded 0.18% of clear yellowish liquid oil and it didn´t has antioxidants activity.

On the other hand, the methanol extracts of different parts of the plant (stems, leaves and flowers) showed high free radical scavenging activity.

The DPPH radical scavenging activity of methanol extracts probably related to their flavonoids contents.

Hence, methanol extract was analyzed by using HPLC, which revealed that, the plant contained 21 flavonoid compounds in different plant parts (stems, leaves and flowers).

The major detected compound of flavonoids was luteolin-6- glucose -8- arabinose with percentages of 1234.3 mg/100 g, 1098.2 mg/100 g and 440.17 mg/100 g for stems, leaves and flowers of Phlomis floccosa, respectively.

The second major compound detected in stems and flowers was luteolin-6- arabinose -8- glucose (144.47 mg/100 g and 375.3 mg/100 g, respectively).

On the other hand, the second major compound detected in leaves was naringenin (278.13 mg/100 g).

According to the obtained results, the methanolic extract of Phlomis floccosa can be considered as an interesting source of natural antioxidant