Chemotaxonomic significance

Reports of phytochemical studies on less than 50% of the total number of Magnolia species are available to date. The amount and composition of classes of compounds such as alkaloids, flavonoids, essential oils and many others are governed by the age of the plant or its parts, the geographical source of the plants investigated, and their general habitat (Hegnauer, 1986). Therefore, detailed information on these factors and comprehensive data on chemical variations among the plants are essential for chemotaxonomic evaluation. On the basis of the data available from published results, it is somewhat difficult to draw any conclusion on the chemotaxonomy of the genus Magnolia. However, it is fair to say that the phytochemistry of Magnolia looks similar to that of other allied genera, especially Liriodendron and Michelia, within the family Magnoliaceae. The presence or absence of different classes of plant secondary metabolites in different species of this genus is summarised in Table 3.2. It can be noted that some species of Magnolia predominantly produce alkaloids, whereas some others produce lignans/neolignans as the major class of secondary metabolite (Table 3.1). Only M. grandiflora has been found to produce all classes of compounds described in this chapter. All other species are lacking in one or more classes.

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