Essential oil composition, free radical scavenging activity and polyphenolic content of <i>Gaillonia eriantha</i> Jaub. & Spach from Iran

<p><i>Gaillonia eriantha</i> is a member of family Paederieae (Rubiaceae). The essential oil of <i>G. eriantha</i> growing wild in south of Iran was obtained by hydrodistillation and analysed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). Antioxidante activity and polyphenolic content were identified by DPPH microplate method and HPLC-DAD, respectively. Twenty-two compounds were identified in the oil. The major volatile compounds were camphor (14.8%), octyl formate (14.7%), 1,8-cineole (10.9%), n-decane (8.1%), n-undecane (6.8%), n-dodecane (6.1%), n-nonane(5.4%) and α-agarofuran (5.2%). The antioxidant activity of the extract of <i>G. eriantha</i> was found to be 786.57 μg/mL. It was found that the predominant phenolic constituents were chlorogenic acid (2.23 mg/g), catechin (0.37 mg/g), hesperidin (0.13 mg/g), trans-ferulic acid (0.12 mg/g), caffeic acid (0.051 mg/g), carvacrol (0.028 mg/g) and vanillin (0.021 mg/g), respectively.</p>