Abstract
Introduction: Hyssopus officinalis (L) (Hyssop, Family: Lamiaceae), one of the endemic Iranian perennial herb with a long history of medicinal use, was studied to detect some biologically active chemical constituents of the plant. Methods: The flavonoids of the hydromethanolic extract of the aerial parts of Hyssopus officinalis (L.) were studied by VLC and crystalisation of the major compound in subsequent fractions. Furthermore, the composition of its essential oil, total phenolic content and antioxidant activities were studied by GC-MS, Folin–Ciocalteau and DPPH reagents respectively. Results: Apigenin 7-O-β-D-glucuronide was isolated as the major flavonoid. All structural elucidation was performed by spectral means. A total of 20 compounds representing 99.97% of the oil have been identified. Myrtenylacetate , Camphor, Germacrene, Spathulenol were the main compounds The total phenol content of the n-butanol and ethylacetate extracts were determined spectrophotometrically according to the Folin–Ciocalteau procedure to be 246 mgGAE g-1 and 51 mgGAE g-1 in the aerial parts of Hyssopus officinalis. The antioxidant activities of apigenin 7-O-β-D-glucuronide, ethylacetate and n-butanol extracts were also determined by DPPH radical scavenging assay with IC50 values of 116×10_3, 103×10_3, 25×10_3 mg mL-1 respectively. The purified flavonoid showed weak radical scavenging activity (IC50 = 116×10_3mg mL_1). N-butanol extract, because of the highest content of total phenolic compounds (246 mgGAE100_1g) had the best antioxidant activity (IC50 = 25mg mL_1). Conclusion: On the whole, the findings of the study revealed that Hyssop possesses valuable antioxidant properties for culinary and possible medicinal use.