Preparative mass-spectrometry profiling of bioactive metabolites in Saudi-Arabian propolis fractionated by high-speed countercurrent chromatography and off-line atmospheric pressure chemical ionization mass-spectrometry injection.
Propolis is a glue material collected by honeybees which is used to seal cracks in beehives and to protect the bee population from infections. Propolis resins have a long history in medicinal use as a natural remedy. The multiple biological properties are related to variations in their chemical compositions. Geographical settings and availability of plant sources are important factors for the occurrence of specific natural products in propolis. A propolis ethylacetate extract (800mg) from Saudi Arabia (Al-Baha region) was separated by preparative scale high-speed countercurrent chromatography (HSCCC) using a non-aqueous solvent system n-hexane-ACN (1:1, v/v). For multiple metabolite detection, the resulting HSCCC-fractions were sequentially injected off-line into an atmospheric pressure chemical ionization mass-spectrometry (APCI-MS/MS) device, and a reconstituted mass spectrometry profile of the preparative run was visualized by selected ion traces. Best ion-intensities for detected compounds were obtained in the negative APCI mode and monitored occurring co-elution effects. HSCCC and successive purification steps resulted in the isolation and characterization of various bioactive natural products such as (12E)- and (12Z)-communic acid, sandaracopimaric acid, (+)-ferruginol, (+)-totarol, and 3β-acetoxy-19(29)-taraxasten-20a-ol using EI-, APCI-MS and 1D/2D-NMR. Cycloartenol-derivatives and triterpene acetates were isolated in mixtures and elucidated by EI-MS and 1D-NMR. Free fatty acids, and two labdane fatty acid esters were identified by APCI-MS/MS. In total 19 metabolites have been identified. The novel combination of HSCCC fractionation, and APCI-MS-target-guided molecular mass profiling improve efficiency of lead-structure identification.
Institute of Food Chemistry, Technische Universität Braunschweig, Schleinitzstrasse 20, 38106 Braunschweig, Germany. Electronic address: g.jerz@tu-bs.de.
Gerold
G
Jerz
King Saud University, Department of Zoology, College of Science, Riyadh, Saudi Arabia; Helmholtz Centre for Infection Research, Chemical Biology, Inhoffenstrasse 7, 38124 Braunschweig, Germany. Electronic address: yelnakady@ksu.edu.sa.
Yasser A
YA
Elnakady
Institute of Food Chemistry, Technische Universität Braunschweig, Schleinitzstrasse 20, 38106 Braunschweig, Germany.
André
A
Braun
Institute of Food Chemistry, Technische Universität Braunschweig, Schleinitzstrasse 20, 38106 Braunschweig, Germany.
Kristin
K
Jäckel
Helmholtz Centre for Infection Research, Chemical Biology, Inhoffenstrasse 7, 38124 Braunschweig, Germany.
Florenz
F
Sasse
King Saud University, Chair of Engineer Abdullah Baqshan for Bee Research, College of Food and Agriculture Sciences, Riyadh, Saudi Arabia.
Ahmad A
AA
Al Ghamdi
King Saud University, Chair of Engineer Abdullah Baqshan for Bee Research, College of Food and Agriculture Sciences, Riyadh, Saudi Arabia.
Mohamed O M
MO
Omar
Institute of Food Chemistry, Technische Universität Braunschweig, Schleinitzstrasse 20, 38106 Braunschweig, Germany.
Peter
P
Winterhalter
D000085:Acetates; D000818:Animals; D001516:Bees; D005591:Chemical Fractionation; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003377:Countercurrent Distribution / Q000379:methods; D008970:Molecular Weight; D011429:Propolis / Q000737:chemistry* / Q000378:metabolism; D012529:Saudi Arabia; D012997:Solvents; D013237:Stereoisomerism; D053719:Tandem Mass Spectrometry / Q000379:methods
D000085:Acetates; D012997:Solvents; C007650:ethyl acetate; D011429:Propolis
1D/2D-NMR; Diterpene; Off-line APCI-MS/MS injection metabolite profiling; Preparative high-speed countercurrent chromatography; Saudi Arabian propolis; Triterpene