PlantSME Plant secondary metabolism enzyme database
Alkaloid portable pathway

Alkaloid portable pathway

Category:Alkaloid pathway

Alkaloid pathway definition imported from the 2026-05-17 portable BLAST/HMM package.

Representative Alkaloid Reaction Route
BIA, MIA, nicotine/tropane, and purine branches. Alkaloid biosynthesis is not a single route; this page separates BIA, MIA, nicotine/tropane, and purine branches with entry substrates, key enzyme modules, and representative products.
6 curated steps/modules
BIA Benzylisoquinoline Branch
01
Substrate
L-Tyrosine/dopamine
C9H11NO3 / C8H11NO2
catechol-CH2-CH2-NH2
Substrate
4-Hydroxyphenylacetaldehyde
C8H8O2
4-HO-C6H4-CH2-CHO
Dopamine formation and norcoclaurine condensation
Product
(S)-Norcoclaurine
C16H17NO3
benzylisoquinoline tetrahydro core
TYDC/DDC provide aromatic amine substrates, and NCS forms the BIA core.
02
Substrate
Norcoclaurine/reticuline-like intermediates
C16-C19 BIA
benzylisoquinoline scaffold
Methylation, hydroxylation, and downstream BIA diversification
Product
BIA derivatives
benzylisoquinoline alkaloids
O-methylated/bridged BIA scaffolds
OMT/CYP/reductase combinations route norcoclaurine-like intermediates to diverse BIA products.
MIA Monoterpene Indole Alkaloid Branch
03
Substrate
GPP/geraniol
C10H20O7P2 / C10H18O
C10 prenyl-OPP / HO-CH2-C10 isoprenoid
Formation of the terpenoid seco-iridoid donor
Product
Secologanin
C17H24O10
seco-iridoid glucoside aldehyde
The terpenoid branch of MIA biosynthesis generates the secologanin donor from GPP/geraniol-derived intermediates.
04
Substrate
Tryptamine + secologanin
C10H12N2 + C17H24O10
indole-CH2-CH2-NH2 + seco-iridoid aldehyde
Tryptamine condensation and post-strictosidine tailoring
Product
Strictosidine/MIA derivatives
C27H34N2O9 and derivatives
indole-monoterpene alkaloid scaffold
STR couples tryptamine with secologanin; downstream hydrolysis and tailoring yield diverse MIA scaffolds.
Nicotine, Tropane, And Purine Branches
05
Substrate
Ornithine/arginine
C5H12N2O2 / C6H14N4O2
H2N-(CH2)n-CH(NH2)-COOH
Polyamine-derived nicotine/tropane scaffolds
Product
Nicotine/tropane intermediates
N-heterocyclic alkaloids
N-methylpyrrolinium / tropane ring
ODC/ADC/PMT/MPO and related enzymes generate N-methylpyrrolinium-type intermediates for nicotine or tropane directions.
06
Substrate
Xanthine/xanthosine
C5H4N4O2 / nucleoside
purine-2,6-dione ring
Purine methylation
Product
Methylxanthines/caffeine
C8H10N4O2
1,3,7-trimethyl-purine-2,6-dione
XMT/MXMT/DXMT methyltransferases catalyze stepwise methylation of the xanthine scaffold.
Lineage Distribution
Assignments under this module are distributed across the following plant lineages.
Module Gene List
GeneSpeciesProtein ID
Aalbaalba5_s002871380704320.1 abies_alba Aalbaalba5_s002871380704320.1
Aalbaalba5_s002888100705780.1 abies_alba Aalbaalba5_s002888100705780.1
Aalbaalba5_s002888940705870.1 abies_alba Aalbaalba5_s002888940705870.1
Aalbaalba5_s002894980706350.1 abies_alba Aalbaalba5_s002894980706350.1
Aalbaalba5_s002895800706440.1 abies_alba Aalbaalba5_s002895800706440.1
Aalbaalba5_s002920800708670.1 abies_alba Aalbaalba5_s002920800708670.1
Aalbaalba5_s002962410711880.1 abies_alba Aalbaalba5_s002962410711880.1
Aalbaalba5_s002978590713410.1 abies_alba Aalbaalba5_s002978590713410.1
Aalbaalba5_s002984470713910.1 abies_alba Aalbaalba5_s002984470713910.1
Aalbaalba5_s003022860717220.1 abies_alba Aalbaalba5_s003022860717220.1
Aalbaalba5_s003052760719880.1 abies_alba Aalbaalba5_s003052760719880.1
Aalbaalba5_s003108700724350.1 abies_alba Aalbaalba5_s003108700724350.1
Aalbaalba5_s003127700725950.1 abies_alba Aalbaalba5_s003127700725950.1
Aalbaalba5_s003129960726140.1 abies_alba Aalbaalba5_s003129960726140.1
Aalbaalba5_s003131520726220.1 abies_alba Aalbaalba5_s003131520726220.1
Aalbaalba5_s003183300730350.1 abies_alba Aalbaalba5_s003183300730350.1
Aalbaalba5_s003189240730810.1 abies_alba Aalbaalba5_s003189240730810.1
Aalbaalba5_s003190360730890.1 abies_alba Aalbaalba5_s003190360730890.1
Aalbaalba5_s003209870732320.1 abies_alba Aalbaalba5_s003209870732320.1
Aalbaalba5_s003218790733070.1 abies_alba Aalbaalba5_s003218790733070.1
Aalbaalba5_s003230670733920.1 abies_alba Aalbaalba5_s003230670733920.1
Aalbaalba5_s003273980737210.1 abies_alba Aalbaalba5_s003273980737210.1
Aalbaalba5_s003282660737830.1 abies_alba Aalbaalba5_s003282660737830.1
Aalbaalba5_s003283460737880.1 abies_alba Aalbaalba5_s003283460737880.1
Aalbaalba5_s003289770738360.1 abies_alba Aalbaalba5_s003289770738360.1
Aalbaalba5_s003329160741410.1 abies_alba Aalbaalba5_s003329160741410.1
Aalbaalba5_s003372250744330.1 abies_alba Aalbaalba5_s003372250744330.1
Aalbaalba5_s003432830748660.1 abies_alba Aalbaalba5_s003432830748660.1
Aalbaalba5_s003504370753140.1 abies_alba Aalbaalba5_s003504370753140.1
Aalbaalba5_s003519010754150.1 abies_alba Aalbaalba5_s003519010754150.1