Hexane Extract of Echinops spinosissimus Turra subsp. spinosus from Tunisia: A Potential Source of Acetylated Sterols - Investigation of its Biological Activities

• Published in: Chemistry & biodiversity Vol. 13; no. 12; pp. 1674 - 1684
• Main Authors: Bouattour, Emna, Fakhfakh, Jawhar, Frikha Dammak, Donyez, Jabou, Khaled, Damak, Mohamed, Mezghani Jarraya, Raoudha
• Format: Journal Article
• Language: English
• Published: Switzerland Blackwell Publishing Ltd 01.12.2016; Wiley Subscription Services, Inc
• Subjects: Acetic acid; Acetylated sterols; Acetylation; Anti-Bacterial Agents - analysis; Anti-Bacterial Agents - pharmacology; Antibacterial activities; Antibacterial activity; Antifungal activities; Antifungal activity; Asteraceae - chemistry; Bacillus cereus; Bacillus cereus - drug effects; Dose-Response Relationship, Drug; Echinops; Echinops spinosissimus Turra subsp. spinosus; Fatty acids; Flowers - chemistry; Fungicides; Hexanes - analysis; Hexanes - pharmacology; Iodine; Microbial Sensitivity Tests; Micrococcus luteus; Micrococcus luteus - drug effects; Minimum inhibitory concentration; Peroxide; Physicochemical characteristics; Plant Extracts - analysis; Plant Extracts - pharmacology; Staphylococcus aureus; Staphylococcus aureus - drug effects; Sterol composition; Sterols; Sterols - chemistry; Structure-Activity Relationship; Terpenes; Tunisia; Antibacterial activities; Acetylated sterols; Echinops spinosissimus Turra subsp. spinosus; Physicochemical characteristics; Antifungal activities
• ISSN: 1612-1872; 1612-1880
• DOI: 10.1002/cbdv.201600118

The hexane extract of Echinops spinosissimus Turra subsp. spinosus flower heads was analyzed for its fatty acid and sterol composition. Its physicochemical characteristics were also studied. The saponification, iodine and peroxide values were determined as 255 mg KOH/g, 42.57 g I2/100 g and 110 m equiv. O2/kg of oil, respectively. The oleic (C18:1; 61.14%), palmitic (C16:0; 21.36%) and linoleic (C18:2; 10.45%) acids were the dominant fatty acids. This extract was also found to contain high levels of β‐sitosterol and stigmasterol (44.97% and 34.95% of total sterols, respectively). On the other hand, the identification of terpenoid compounds was investigated by using GC/MS, which revealed fourteen major terpenoids mainly taraxasterol, lupeol, pseudotaraxasterol, lup‐22(29)‐en‐3‐yl acetate, taraxasteryl acetate, α‐amyrin, β‐amyrin, pseudotaraxasteryl acetate, hop‐20(29)‐en3‐β‐ol, α‐amirenone, along with β‐sitosterol and stigmasterol. Moreover, we have evaluated the in vitro antibacterial and antifungal activities of the unsaponifiable matter and a fraction isolated from this extract. These activities were conducted using the diffusion disc methods and broth microdilution assay. The resulted fraction from this extract showed the highest antibacterial activity with significant minimum inhibitory concentrations (MIC) values 125.0 μg/ml against Staphylococcus aureus, Micrococcus luteus and Bacillus cereus. However, it did exhibit no substantial antifungal activity.