Planta Med 2013; 79 - PI9
DOI: 10.1055/s-0033-1352099

Microwave-assisted hydrodistillation and extraction of petals from Rosa damascena and Crocus sativus

E Dina 1, A Argyropoulou 1, N Xynos 1, G Papaefstathiou 1, N Aligiannis 1, P Polychronopoulos 1, A Skaltsounis 1
  • 1University of Athens, Department of Pharmacognosy and Natural Products Chemistry, Faculty of Pharmacy

The region of Kozani, in northern Greece, is known for the cultivation of two unique aromatic plants that yield valuable natural products: Rosa damascena (Rosaceae) is commercialized for its rose oil and rose water while Crocus sativus (Iridaceae) is renowned for its red stigmas, an exclusive aliment (saffron). Several pharmacological properties, including antibacterial, antioxidant, antitussive and anti-diabetic have been attributed to rose petals. Crocus petals have displayed antioxidant and antibacterial activity and were found to reduce blood pressure and be effective in the treatment of mild to moderate depression. The aim of this work was to investigate the phytochemical profile of extracts deriving from the petals of these two plants, obtained by microwave-assisted-hydrodistillation (MAHD) and -extraction (MAE) techniques. Fresh rose petals were distilled with MAHD using various extractions times for the recovery of the rose oil which was analyzed with GC-MS. Citronellol and geraniol were found to be the main components. The aqueous residue that remained inside the clevenger apparatus was fed continuously to macroporous resins (XAD-4) in order to study the remaining phenolic compounds. Dried crocus petals were extracted by applying various extraction times in MAE with ethanol or aqueous ethanol. The optimal extract, in terms of yield, was fed continuously to macroporous resins (XAD-4) for the recovery of the phenolic compounds. The extracts were analyzed, concerning their phenolic constituents with HPLC-DAD and UHPLC-UV. A Folin-Ciocalteau assay was used for the determination of their total phenolic content and their antioxidant potential was evaluated in a DPPH assay. Further chromatographic separation for the purification of the principal bioactive compounds indicated that the rose extract was rich in glycosides of quercetin and kaempferol while the crocus extract contained mostly kaempferol 7-O-glucopyanosyl-3-O-sophoroside and kaempferol 3-O-sophoroside.