2.1 Sample, Chemicals and reagents
Non-refined, organic PSO from pumpkin seeds roasted at
~110 °C (Bio-Zentrale Naturprodukte, Ulbering, Germany)
was purchased in a local supermarket in Stuttgart (Germany). Potassium
hydroxide, toluene (99.9%) and hydrochloric acid (concentrated, 32%)
were bought from Carl Roth (Karlsruhe, Germany). Methanol
(> 99.8%) and n -hexane (> 95%) were
ordered from VWR Chemicals (Darmstadt, Germany). Pyridine, ethyl acetate
(both distilled before use), trifluorotoluene (benzotrifluoride, BTF,
> 99%) and silica gel 60 were from Sigma-Aldrich
(Steinheim, Germany). Acetonitrile (99.9%) was bought from Th. Geyer
(Renningen, Germany). The trimethylsilylation reagent (99%
N,O-bis(trimethylsilyl) trifluoroacetamide and 1%
trimethylchlorosilane) was purchased from Supelco (Bellefonte, PA, USA).
The internal standard for GC/MS measurements, 5α-cholestane
(> 98%), was from Acros Organics (Geel, Belgium).
Deuterated chloroform (CDCl3, 99.8%) was ordered from
Deutero (Kastellaun, Germany).