title: Antioxidant activity and chemical composition of three Tunisian Cistus: Cistus monspeliensis, Cistus villosus and Cistus libanotis.
abstract: The chemical composition of three rockrose Cistus species, Cistus monspeliensis, Cistus libanotis and Cistus villosus, collected in Tunisia, was studied by HPTLC, focusing on the terpenes and phenols constituents. Diterpenes of Cistus are important as the main constituents of the leaf sticky aromatic resin, known as labdanum, which are highly appreciated in perfumery. Polyphenols in the methanolic extracts of each species were identified, quantified as total and as flavonoids and tannins, and tested for antioxidant activity. Diterpenes were evident in C. libanotis and C. monspeliensis, whereas they were practically absent in C. villosus; C. libanotis had higher phenolic amount, whereas antioxidant activities were important, but different according to the following tests: DPPH radical scavenging, conversion of the Fe(3+/)ferricyanide complex and inhibition of β-carotene bleaching. The reported data confirm the validity of utilisation of Cistus sp. in marketed herbal products, as well as the relevant presence of diterpenes in species actually not used for labdanum production.
authors.affiliation: a Dipartimento di Biologia Ambientale , Università Sapienza di Roma , Rome , Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Nicoletti
authors.forename: Chiara
authors.initials: C
authors.lastname: Toniolo
authors.forename: Alessandro
authors.initials: A
authors.lastname: Venditti
authors.forename: Maurizio
authors.initials: M
authors.lastname: Bruno
authors.forename: Mariem
authors.initials: M
authors.lastname: Ben Jemia
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D029758:Cistus / Q000737:chemistry* / Q000145:classification; D004224:Diterpenes / Q000737:chemistry; D005419:Flavonoids / Q000737:chemistry; D010636:Phenols / Q000737:chemistry; D013634:Tannins / Q000737:chemistry; D014416:Tunisia
chemical_list: D000975:Antioxidants; D004224:Diterpenes; D005419:Flavonoids; D010636:Phenols; D013634:Tannins
keywords: Cistus; HPTLC; antioxidant activity; phenols; terpenes