Chemodiversity, chemotaxonomy and chemoecology of Amaryllidaceae alkaloids

Recent Progress in Amaryllidaceae Biotechnology

“…According to Desgagne’-Penix [ 59 ], the biosynthetic pathway of Amaryllidaceae alkaloids could be provisionally divided into five stages: (1) Biosynthesis of the two aromatic amino acid L-phenylalanine and L-tyrosine, which are the building blocks of Amaryllidaceae alkaloids; (2) Formation of 3,4-dihydroxybenzaldehyde from phenylalanine, which is the aldehyde moiety of Amaryllidaceae alkaloids; (3) Formation of 4′- O -methylnorbelladine from norbelladine (a condensation product of tyramine with 3,4-dihydroxybenzaldehyde); (4) Formation of unstable intermediate products by specific phenol coupling of 4′- O -methylnorbelladine followed by a reduction step; (5) Biosynthesis of the different types of Amaryllidaceae alkaloids (galanthamine, lycorine, homolycorine, galasine, haemanthamine, plicamine, secoplicamine, narciclasine, pretazettine, crinine, cripowelline, graciline, montanine, ismine, cherylline and norbelladine types, as well as galanthindole, maritinamine and elwesine). The last stage involves very specialized enzymes which could be found in different plant species producing specific Amaryllidaceae alkaloids ( Figure 2 ) [ 59 , 60 ].…”

“…PAL is a very important enzyme, since it redirects the carbon flux in the plant cell from primary to secondary metabolism, in this particular case to Amaryllidaceae alkaloid biosynthesis [ 59 , 62 , 63 ]. Several genes encoding PAL have been identified and characterized from different Amaryllidaceae species [ 58 , 59 , 60 , 64 , 65 ]. Recent phylogenetic analysis of identified Amaryllidaceae PALs showed that they can be divided into two main clusters named “PAL1” and “PAL2”, which share between 80 and 83% amino acid identities [ 59 ].…”

“…It has been demonstrated that PAL1 is expressed at similar levels in all plant parts (root, bulb, stem, leaf, flower), whereas PAL2 is expressed in the bulb [ 59 , 65 , 66 ]. Another important gene from the phenylpropanoid pathway, cinnamate-4-hydroxylase (C4H), has been recently cloned and characterized to be present as a one single transcript in Amaryllidaceae alkaloid producing plants [ 59 , 60 , 64 , 65 , 67 ]. The transcript expression analyses of C4H showed that the expression was highest in the bulbs of dormant and early germination stages, and it was also high in the stems, roots and bulbs in flowering plants [ 59 , 64 , 65 , 66 ].…”

“…The fourth stage includes the specific reactions of phenol coupling of 4′- O -methylnorbelladine ( para-ortho’, ortho-para’ and para-para’ ), leading to formation of the main precursors of the different types Amaryllidaceae alkaloids [ 59 , 60 ]. Here, cytochrome P450 96T1 monooxygenase (CYP96T1) is the only known enzyme.…”

Amaryllidaceae alkaloids with anti-Trypanosoma cruzi activity

“…Lycorine 1, hippeastrine 2, crinine 3, haemanthamine 4, narciclasine 5, tazettine 6, montanine 7, sanguinine 8 and 1-O-acetylcaranine 9 alkaloids were isolated from extracts of different Narcissus species (16,18). The information of all the compounds studied can be found in the extensive chapter by Bastida et al (16).…”