The genus Cinnamomum

104 U.M. Senanayake and R.O.B. Wijesekera
65–75% of the total volatiles, eugenol accounts for about 70–75% of leaf oil, while
70–90% of the root bark oil accounts for camphor.
Cassia produces only one type of oil, usually called bark oil, obtained by distilling leaves
and bark together. Almost 95% of the oil consists of cinnamic aldehyde. C. camphora is
not a spice, the oil of camphora usually contains only terpenes, camphor and cineole being
the major compounds.
Tracer studies indicate that phenylpropanoids, eugenol and cinnamic aldehydes are
synthesised via the Shikimic acid pathway. The phenylalanine skeleton is retained in
the cinnamic aldehyde biosynthesis. The end carbon of the alanine chain of phenylalanine
does not contribute to the eugenol biosynthesis. During the eugenol biosynthesis
the end carbon atom of the allyl branch is not derived from phenylalanine, but from
a methyl donor such as methionine.
The incorporation of labelled mevalonic acid into terpenes indicated that the normal
mevalonic acid pathway was operating in the cinnamon plant during the biosynthesis of
terpenoid compounds. Tracer studies also indicated that the leaf was the predominant
site of biosynthesis of these compounds.
References
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