Alkaloids are a broad class of naturally occurring organic compounds that contain at least one nitrogen atom.

Ferruginine is a naturally occurring tropane alkaloid isolated from rainforest tree species such as Darlingia ferruginea and Darlingia darlingiana.

1-Ethyl-β-carboline is an alkaloid of the β-carboline family found in tobacco smoke.

The 10-hydroxy Lycopodium alkaloids, which include 10-hydroxylycopodine, deacetylpaniculine, and paniculine, are a series of natural products isolated from a Chilean club moss Lycopodium confertum.

Alchorneine is an imidazopyrimidine alkaloid found in trees in the genus Alchornea such as Alchornea castaneifolia, Alchornea floribunda or Alchornea cordifolia.

Allocryptopine is a bioactive alkaloid found in plants of the Papaveraceae family, including Glaucium arabicum, Argemone mexicana, Eschscholtzia, Corydalis, Fumaria, Chelidonium, Hunnemannia fumariifolia, Eschscholzia lobbii and other Papaveraceae plants.

Allopumiliotoxins are a structural division in the pumiliotoxin-A class of alkaloids.

Allopumiliotoxin 267A is a toxin found in the skin of several poison frogs of the family Dendrobates.

Alschomine is an indole alkaloid first identified in the leaves of Alstonia scholaris in 1989.

Altemicidin is monoterpene alkaloid first identified in isolates from marine actinomycetes (specifically Streptomyces sioyaensis) in 1989.

Anatoxin-a, also known as Very Fast Death Factor (VFDF), is a secondary, bicyclic amine alkaloid and cyanotoxin with acute neurotoxicity.

Andrimid is an antibiotic natural product that is produced by the marine bacterium Vibrio coralliilyticus.

Aplysioviolin is a purple-colored molecule secreted by sea hares of the genera Aplysia and Dolabella to deter predators.

Apocynaceae alkaloids are natural products found in the plant family Apocynaceae.

Areca alkaloids are a group of tetrahydropyridine stimulant alkaloids found in the areca nut, the seeds of the areca palm (Areca catechu).

Arecoline is a cholinergic agent, stimulant, and naturally occurring alkaloid found in areca (betel) nuts of the areca palm (Areca catechu) found in South and Southeast Asia.

Substitution of the heterocycle isoquinoline at the C1 position by a benzyl group provides 1-benzylisoquinoline, the most widely examined of the numerous benzylisoquinoline structural isomers.

Bisbenzylisoquinoline alkaloids are natural products found primarily in the plant families of the barberry family, the Menispermaceae, the Monimiaceae, and the buttercup family.

The carbazole alkaloids are natural products of the indole alkaloid type, derived from carbazole.

Cassaine is a toxic compound found within the tree genus Erythrophleum.

Catharanthine is a terpene indole alkaloid produced by the medicinal plant Catharanthus roseus and Tabernaemontana divaricata.

Cephalotaxus alkaloids are natural products characterized by pentacyclic structure.

Clausenamide is an alkaloid found in Clausena lansium (wampee), an evergreen tree native to Southeast Asia and southern China.

Colchicine is a medication used to prevent and treat gout, familial Mediterranean fever and Behçet’s disease, and to reduce the risk of myocardial infarction.

Columbamine is an isoquinoline alkaloid made up of four rings, two of which contain nitrogen.

Conium alkaloids are natural products of the piperidine alkaloid type.

Coramsine (SBP002) was an experimental cancer drug that was evaluated in preliminary clinical trials but was abandoned after results were insufficient to continue development.

Cordycepin, or 3′-deoxyadenosine, is a derivative of the nucleoside adenosine, differing from it by replacement of the hydroxy group in the 3′ position with a hydrogen.

Coronaridine, also known as 18-carbomethoxyibogamine, is an alkaloid found in Tabernanthe iboga and related species, including Tabernaemontana divaricata.

Corydalis alkaloids are categorized as natural products of the isoquinoline alkaloid type.

Corymine, also known as NSC381080, is a natural alkaloid found in Hunteria zeylanica.

Crinine is an alkaloid found in a variety of plants including many species in the family Amaryllidaceae.

Cryogenine, also known as vertine, is a biphenylquinolizidine lactone alkaloid from the plants Sinicuichi (Heimia salicifolia) and H. myrtifolia.

Cryptopine is an opium alkaloid.

Cyclobuxine is an alkaloid found in Buxus sempervirens (family Buxaceae), the common boxwood, and is derived from the cholesterol skeleton.

Delphinine is a toxic diterpenoid alkaloid found in plants from the Delphinium and Atragene genera in the family Ranunculaceae.

Dendrobine is an alkaloid found in Dendrobium nobile at an average of 0.5% by weight.

Dendrobium alkaloids are natural products and so-called pseudoalkaloids.

Dioscorine is an alkaloid toxin isolated from the tubers of tropical yam on several continents.

Diterpene alkaloids are natural products of the terpene alkaloid type.

The duocarmycins are members of a series of related natural products first isolated from Streptomyces bacteria in 1978.

Eritadenine is a chemical compound found in shiitake mushrooms.

Erythrophleine is a complex alkaloid and ester of tricyclic diterpene acids derived from many plants in the genus Erythrophleum.

Ethocybin, also known as 4-phosphoryloxy-N,N-diethyltryptamine, is a psychedelic drug of the tryptamine and 4-hydroxytryptamine families related to the mushroom alkaloid psilocybin.

Fascaplysin is a marine alkaloid based on a 12H-pyrido[1–2-a:3,4-b′]diindole ring system.

Ferrugine (2α-benzoyltropane) is a tropane alkaloid discovered in the basic extract of the Australian rainforest tree Darlingia ferruginea.

In chemistry, a free base is the neutral form of an amine or other Lewis base.

Gentianine is a pyridine-derived alkaloid.

Guvacine is a tetrahydropyridine alkaloid found in areca nuts.

Hasubanonine is a member of the hasubanan family of alkaloids.

Histrionicotoxins are a group of related toxins found in the skin of poison frogs from the family Dendrobatidae, notably Oophaga histrionica.

Hodgkinsine is an alkaloid found in plants of the genus Psychotria, particularly Psychotria colorata.

Homolycorine is one of a number of toxic alkaloids found in various Amaryllidaceae species such as daffodils (Narcissus).

Imidazole is an organic compound with the formula (CH)2NHCHN and is a white or colourless solid soluble in water.

Imidazole alkaloids are a group of alkaloids whose basic structure contains the imidazole ring system.

Incarvillateine is a complex monoterpene alkaloid that is a derivative of α-truxillic acid.

Indolizidine alkaloids are natural products from various alkaloid groups whose structure can be derived from indolizidine.

KH-001 is an atypical serotonin reuptake inhibitor and phosphodiesterase inhibitor under development for the treatment of premature ejaculation.

Kifunensine is an alkaloid originally isolated from Kitasatosporia kifunense, an actinobacterium formerly called an actinomycete.

Lennoxamine is an isoindolobenzazepine alkaloid originally isolated from the Chilean barberry, Berberis darwinii.

Leonurine is a substituted guanidine isolated from several Leonotis and Leonurus species and other plants of the family Lamiaceae.

Liberine, also referred to as O(2),1,9-trimethyluric acid, is a purine alkaloid.

Lupine alkaloids are natural substances classified as quinolizidine alkaloids.

Lysergamides, also known as ergoamides or lysergic acid amides, are amides of lysergic acid.

(−)-Magellanine is a member of the Lycopodium alkaloid class of natural products.

Mayer’s reagent is an alkaloidal precipitating reagent used for the detection of alkaloids in natural products.

Melicopidine is an alkaloid.

Mesembranol is an alkaloid found in Sceletium tortuosum.

Methylliberine is an isolate of coffee beans, tea, cola nuts, guarana, cocoa, and yerba mate.

Midostaurin is a multi-targeted protein kinase inhibitor investigated for acute myeloid leukemia, myelodysplastic syndrome and advanced systemic mastocytosis.

Muscarine is a natural product found in certain mushrooms, particularly Inocybe and Clitocybe species.

Muscazone is an amino acid derivative found in Amanita muscaria (fly agaric) mushrooms.

Muscimol is a GABAA receptor agonist with sedative and hallucinogenic effects and the principal psychoactive constituent of Amanita mushrooms.

Necatorin is a highly mutagenic chemical compound with the molecular formula C15H8N2O3.

Neothiobinupharidine is a dimeric thiaspirane alkaloid isolated from the dwarf water lily Nuphar pumila.

Neurine is an alkaloid found in egg yolk, brain, bile and in cadavers.

Nicotelline is an alkaloid first identified in 1914 as a chemical constituent of tobacco plants of the genus Nicotiana.

Norharmine, also known as 7-methoxy-β-carboline, is an alkaloid of the β-carboline family naturally extracted from Peganum harmala.

Notoamides are bio-active isolates of marine Aspergillus.

Omacetaxine mepesuccinate is a pharmaceutical drug substance indicated for treatment of chronic myeloid leukemia.

Orellanine or orellanin is a toxin found in a group of mushrooms known as the Orellani within the family Cortinariaceae.

Palau’amine is a toxic chlorinated alkaloid compound synthesized naturally by certain species of sea sponges.

Phenylethylamine alkaloids are natural products with an open tetrahydroisoquinoline structure.

Physostigmine, also known as eserine, is a highly toxic parasympathomimetic alkaloid and reversible cholinesterase inhibitor.

Picrinine is a bioactive alkaloid from Alstonia boonei, a medicinal tree of West Africa.

Prajmaline (Neo-gilurythmal) is a class Ia antiarrhythmic agent available since the 1970s.

Precoccinelline is an alkaloid produced by the seven-spot ladybird, Coccinella septempunctata.

Prosopine is an alkaloid found in Prosopis africana.

Pseudopelletierine is the main alkaloid derived from the root-bark of the pomegranate tree (Punica granatum).

Psychotridine is an alkaloid found in some species of the genus Psychotria, including Psychotria colorata and related species.

Pumiliotoxin 251D is a toxic organic compound.

Pyonitrins are a family of unusual alkaloids discovered from an insect-associated Pseudomonas protegens strain.

Pyrrolidine alkaloids are natural products chemically derived from pyrrolidine.

Quinazoline alkaloids are natural products chemically derived from quinazoline.

Quinoline alkaloids are naturally occurring chemical compounds chemically derived from quinoline.

Rhazinilam is an alkaloid first isolated in 1965 from the Melodinus australis plant.

Rhoeadine (rheadine) is an alkaloid derived from the flowers of the corn poppy (Papaver rhoeas).

Ricinine is a toxic alkaloid found in the castor plant.

Samandaridine is an extremely toxic alkaloid produced by the skin glands of various salamanders.

Sanguinones A and B are blue alkaloid pigments found in the fruiting bodies of the mushroom Mycena sanguinolenta.

Scholaricine is an alkaloid isolated from Alstonia boonei, a tree of West Africa.

Sinapine is an alkaloidal amine found in some seeds, particularly oil seeds of plants in the family Brassicaceae.

Slaframine is a bicyclic alkaloid mycotoxin that causes salivation (slobbers) in most animals.

Spigiline is an alkaloid associated with Spigelia marilandica and is largely responsible for its hallucinogenic and medicinal actions.

Spirotryprostatin A is an indolic alkaloid from the 2,5-diketopiperazine class of natural products found in Aspergillus fumigatus.

Stachydrine, also known as proline betaine, is a naturally occurring alkaloid found in citrus, caper, chestnuts, alfalfa and several medicinal plants.

Staphidine is a bis-diterpene alkaloid of the atisane type found in Delphinium staphisagria.

Strychnos alkaloids are natural products primarily found in the seeds of the strychnine tree (Strychnos nux-vomica) and in the genus Catharanthus.

Tambjamines are a group of natural products structurally related to the prodiginines.

TAN-1057 A and TAN-1057 B are organic compounds found in the bacterium Flexibacter sp.

TAN-1057 C and TAN-1057 D are organic compounds found in the bacterium Flexibacter sp.

Theacrine, also known as 1,3,7,9-tetramethyluric acid, is a purine alkaloid found in cupuaçu and certain varieties of tea.

Trigonelline is an alkaloid with chemical formula C7H7NO2.

The Tscherniak-Einhorn reaction is an organic chemistry name reaction initiated in 1901 by Joseph Tscherniak.

Undecylprodigiosin is an alkaloid produced by some Actinomycetes bacteria.

Vasicine (peganine) is a quinazoline alkaloid.

Vasicinone is a quinazoline alkaloid.

Versicolamide B is a spiroindole alkaloid isolated from Aspergillus and belongs to a class of naturally occurring 2,5-diketopiperazines.