title: Sempervivum davisii: phytochemical composition, antioxidant and lipase-inhibitory activities.
abstract: BACKGROUND
  Sempervivum davisii Muirhead (Crassulaceae) is a traditional medicinal herb from Eastern Anatolia. To date the composition of phytochemicals and physiological properties of this herb were not subjected to any research.
  
  
  OBJECTIVE
  This study identifies compounds in S. davisii hydrophilic extracts and evaluates their potential biological properties.
  
  
  METHODS
  Ethanol-based lyophilized extracts were obtained from aerial parts of plant (10 g of ground dry plant material in 200 mL of acidified aqueous ethanol, shaken for 2 h at 22 °C with supernatant collected and freeze-dried under vacuum). Phytochemical composition was investigated by liquid chromatography mass spectrometry (LC-MS/MS, phenolics) and gas chromatography mass spectrometry (GC-MS, volatiles). Phenolic compounds were quantified by high-performance liquid chromatography (HPLC) and the Folin-Ciocalteu assay. Subsequently, antioxidant capacity [ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC) assays] and enzyme inhibitory properties (isolated porcine pancreatic lipase) of the extracts were determined.
  
  
  RESULTS
  Polyphenolic compounds were the main constituents of lyophilized extracts, among which kaempferol glycosides and quercetin hexoside dominated. The extracts exhibited potent antioxidant (FRAP values of 1925.2-5973.3 μM Fe2+/g DW; ORAC values of 1858.5-4208.7 μM Trolox Eq./g DW) and moderate lipase inhibitory (IC50: 11.6-2.96 mg/mL) activities. Volatile compounds (nonanal, dehydroxylinalool oxide isomers, 2-decenal, 2-undecenal, 2,6-di-tetr-butylphenol) were also found.
  
  
  CONCLUSIONS
  Phenolic compounds with the dominating kaempferol and quercetin derivatives are the sources of potent antioxidant properties of S. davisii hydrophilic extracts. The extracts exhibit moderate inhibitory properties towards isolated pancreatic lipase.
authors.affiliation: a Department of Pharmaceutical Botany, Faculty of Pharmacy , Yuzuncu Yil University , Van , Turkey.
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Uzun
authors.affiliation: a Department of Pharmaceutical Botany, Faculty of Pharmacy , Yuzuncu Yil University , Van , Turkey.
authors.forename: Abdullah
authors.initials: A
authors.lastname: Dalar
authors.affiliation: b Food Science & Technology, School of Chemical Engineering , The University of New South Wales , Kensington , New South Wales , Australia.
authors.forename: Izabela
authors.initials: I
authors.lastname: Konczak
mesh_terms: D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D029627:Crassulaceae / Q000737:chemistry*; D004791:Enzyme Inhibitors / Q000302:isolation & purification / Q000494:pharmacology*; D000431:Ethanol / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D044949:Kaempferols / Q000302:isolation & purification / Q000494:pharmacology; D008049:Lipase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D064209:Phytochemicals / Q000302:isolation & purification / Q000494:pharmacology*; D008517:Phytotherapy; D035261:Plant Components, Aerial; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D010946:Plants, Medicinal; D011794:Quercetin / Q000302:isolation & purification / Q000494:pharmacology; D012997:Solvents / Q000737:chemistry; D053719:Tandem Mass Spectrometry
chemical_list: D000975:Antioxidants; D004791:Enzyme Inhibitors; D044949:Kaempferols; D064209:Phytochemicals; D010936:Plant Extracts; D012997:Solvents; D000431:Ethanol; D011794:Quercetin; D008049:Lipase
keywords: FRAP; Kaempferol; ORAC; enzyme inhibition; quercetin; volatile compounds