Determination of phenolic compounds and antioxidant activity of a Mediterranean plant: The case of Satureja montana subsp. kitaibelii

• Determination of phenolics of Satureja montana subsp. kitaibelii by HPLC–DAD–MS.
• Identification of 42 new polyphenols out of 45 in Satureja montana subsp. kitaibelii.
• Chlorogenic acid and one dicaffeoylquinic acid isomer were the major phenolics found.
• Total phenolic contents by HPLC–DAD and Folin–Ciocalteu were in agreement.
• DPPH as EC50 was 116.36 ± 12.83 µg/mL and ABTS 106.59 ± 1.41 µmol equiv. trolox/g d.w.

Satureja montana subsp. kitaibelii extract was analyzed by HPLC–DAD–ESI–TOF–MS (high performance liquid chromatography–diode array detector–electrospray ionization–time of flight–mass spectroscopy). Forty five compounds were identified, 42 of which were identified for the first time in this plant. Quantification of the identified phenolic compounds by UV–vis (ultraviolet–visible) detection was done and chlorogenic acid was the most concentrated compound. Total phenolic content (TPC) by Folin–Ciocalteu method and antioxidant activity by DPPH and ABTS methods were also measured. TPC quantified by HPLC–DAD were 1958.44 mg/100 g dry sample. This is in agreement with TPC measured by Folin–Ciocalteu method. Antioxidant activity determined by the DPPH method expressed as EC50 was 116.36 ± 12.83 µg/mL and by the ABTS method was 106.59 ± 1.41 µmol trolox equivalents/g dry sample. These results reveal that Satureja montana subsp. kitaibelii could be a good functional food ingredient because its high content of natural antioxidants as demonstrated by quantification with HPLC–DAD.