A rapid high performance liquid chromatographic method for the separation of the alkaloid precursor L‐tyrosine and six tetrahydroisoquinoline alkaloids of Papaver somniferum

Abstract

A high performance liquid chromatographic (HPLC) method was developed for the qualitative and quantitative determination of L-tyrosine and six common tetrahydroisoquinoline alkaloids (papaverine, noscapine, sanguinarine, morphine, codeine and thebaine) of Pupuuer somniferum. The reversed phase HPLC method yields baseline separation of the alkaloids in 20 min and is achieved using a simple H,O: MeOH linear gradient. Silanol effects commonly associated with the separation of such strongly basic compounds were minimized by the addition of the amine modifier, triethylamine, to the mobile phase.

Phloem-Specific Expression of Tyrosine/Dopa Decarboxylase Genes and the Biosynthesis of Isoquinoline Alkaloids in Opium Poppy

“…Plates were dried at room temperature and photographed under ultraviolet illumination at 365 nm on Kodak RoyalGold 100 film. Extracts were separated by HPLC (600E HPLC and 991 photodiode array detector; Waters, Montreal, Canada) on a Waters Nova Pak C18 reverse phase (3.9 x 300 mm) column using an isocratic gradient of methanol/water (6:4) containing 0.1% triethanolamine (Kraml and DiCosmo, 1993). The retention time for sanguinarine in root extracts was 16.1 min and was identical with that obtained for the corresponding standard.…”

Determination of the five major opium alkaloids by reversed-phase high-performance liquid chromatography on a base-deactivated stationary phase

“…The organic modifiers used are acetonitrile [7,15] or methanol [13,14]. Because trials to achieve the separation of the alkaloids from accompanying substances with methanol-water-triethylamine mixtures [13] were not successful, we decided to use an eluent system similar to that used in the method recommended by the European Pharmacopoeia. As expected, isocratic conditions were not applicable; after isocratic elution for 9 min, however, a linear gradient provided excellent separation and resolution of the five alkaloids and the internal standard in only 20 min (Figures 1 and 2 and Table II).…”

“…The mobile phase in RP-H.PLC on C18 columns is usually a buffered system containing sodium acetate [7,14] or the sodium salt of octanesulfonic acid [15]. The organic modifiers used are acetonitrile [7,15] or methanol [13,14]. Because trials to achieve the separation of the alkaloids from accompanying substances with methanol-water-triethylamine mixtures [13] were not successful, we decided to use an eluent system similar to that used in the method recommended by the European Pharmacopoeia.…”

“…As C18 stationary phases are the most widely used for opium analysis [7,[13][14][15] we used a 5 lain Hypersil column for preliminary investigations. A slightly better separation was finally achieved with a 5 ~tm Inosil column, although both columns can, nevertheless, be used under the proposed conditions.…”