L. Nezbedova et al., Prelandrine, the key-step intermediate in the biosynthesis of the macrocyclic spermine alkaloid aphelandrine, HELV CHIM A, 84(1), 2001, pp. 172-179
By means of the high sensitive on-line-coupled high-performance liquid chro
matography and atmospheric-pressure chemical-ionization mass spectrometry (
HPLC/APCI-MS and HPLC/APCI-MS/MS) techniques, the new macrocyclic spermine
alkaloid prelandrine (5) was detected in the roots of Aphelandra squarrosa
(Acanthaceae), and its structure was elucidated as 4'-hydroxyprotoverbine (
=8-(4-hydroxyphenyl)-1,5,9,13-tetraazacycloheptadecan-6-one). It was furthe
r demonstrated that protoverbine (6) is enzymatically hydroxylated to prela
ndrine (5) in a reaction catalyzed by microsomes from the roots of A. squar
rosa. The chemical synthesis of (-)-(S)-prelandrine is also described. The
possible key role of prelandrine (5) as an intermediate in the biosynthesis
of aphelandrine (1) is discussed.