Analysis of Metabolic Variation and Galanthamine Content in Narcissus Bulbs by 1H NMR

Introduction - Galanthamine is a benzazepine alkaloid used as a drug to relieve symptoms of Alzheimer's disease. For pharmaceutical use this natural product has been extracted from the plant Leucojum aestivum (Amaryllidaceae) or produced synthetically. Limited supply of the natural source and high cost of synthetic production has led to a search for alternative sources of galanthamine. The bulbs of Narcissus pseudonarcissus (Amaryllidaceae) have been identified as a potential source of raw material for galanthamine extraction. Since inconsistent chemical composition can be an issue with medicinal plant material, it is of interest to know whether large variations occur between Narcissus bulbs grown in different geographical locations. Objective - To evaluate whether large differences exist in the overall metabolic profiles of Narcissus bulbs grown in the two most important cultivation regions. Methodology - H-1 NMR and principal component analysis were used for an unbiased comparison of the bulb samples. Results - Overall metabolite profiles were quite similar, but galanthamine levels could slightly discriminate samples by geographical region. H-1 NMR was used for quantitation of galanthamine, and was found to be comparable to quantitation by HPLC. Compared with conventional chromatographic methods, sample preparation for H-1 NMR analysis is simple and rapid, and only a small amount of plant material is required. Conclusions - Since useful qualitative and quantitative information about the metabolic state of Narcissus bulbs can be obtained by H-1 NMR, this method is useful for agricultural applications, and for quality control of raw material used in the pharmaceutical industry. Copyright (C) 2009 John Wiley & Sons, Ltd.