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_s001494950514800.1 abies_alba Aalbaalba5_s001494950514800.1
Aalbaalba5_s001558340526890.1 abies_alba Aalbaalba5_s001558340526890.1
Aalbaalba5_s001629750540520.1 abies_alba Aalbaalba5_s001629750540520.1
Aalbaalba5_s001640050542460.1 abies_alba Aalbaalba5_s001640050542460.1
Aalbaalba5_s001789200567720.1 abies_alba Aalbaalba5_s001789200567720.1
Aalbaalba5_s001803920570250.1 abies_alba Aalbaalba5_s001803920570250.1
Aalbaalba5_s001994750600440.1 abies_alba Aalbaalba5_s001994750600440.1
Aalbaalba5_s002145560621770.1 abies_alba Aalbaalba5_s002145560621770.1
Aalbaalba5_s002147400622020.1 abies_alba Aalbaalba5_s002147400622020.1
Aalbaalba5_s002496350665320.1 abies_alba Aalbaalba5_s002496350665320.1
Aalbaalba5_s002820290699110.1 abies_alba Aalbaalba5_s002820290699110.1
Aalbaalba5_s002853770702480.1 abies_alba Aalbaalba5_s002853770702480.1
Aalbaalba5_s003040310718690.1 abies_alba Aalbaalba5_s003040310718690.1
Aalbaalba5_s003063950720710.1 abies_alba Aalbaalba5_s003063950720710.1
Aalbaalba5_s003325050741130.1 abies_alba Aalbaalba5_s003325050741130.1
Aalbaalba5_s003393950746010.1 abies_alba Aalbaalba5_s003393950746010.1
Aalbaalba5_s003982980781670.1 abies_alba Aalbaalba5_s003982980781670.1
Aalbaalba5_s004634890814090.1 abies_alba Aalbaalba5_s004634890814090.1
Aalbaalba5_s005272110838980.1 abies_alba Aalbaalba5_s005272110838980.1
Aalbaalba5_s005682860851810.1 abies_alba Aalbaalba5_s005682860851810.1
Aalbaalba5_s005833460855580.1 abies_alba Aalbaalba5_s005833460855580.1
Aalbaalba5_s005989980859330.1 abies_alba Aalbaalba5_s005989980859330.1
Aalbaalba5_s006071070861350.1 abies_alba Aalbaalba5_s006071070861350.1
Aalbaalba5_s007082870880990.1 abies_alba Aalbaalba5_s007082870880990.1
Aalbaalba5_s007145120882000.1 abies_alba Aalbaalba5_s007145120882000.1
Aalbaalba5_s007430200886340.1 abies_alba Aalbaalba5_s007430200886340.1
Aalbaalba5_s013145510928020.1 abies_alba Aalbaalba5_s013145510928020.1
Aalbaalba5_s025460610941850.1 abies_alba Aalbaalba5_s025460610941850.1
XP_027331608.1 abrus_precatorius XP_027331608.1
XP_027331609.1 abrus_precatorius XP_027331609.1