Protoalkaloids

Protoalkaloids are compounds, in which the N atom derived from an amino acid is not a part of the heterocyclic31. Such kinds of alkaloid include compounds derived from L-tyrosine and L-tryptophan (see Table 1). Protoalkaloids are those

Definition, Typology and Occurrence of Alkaloids Table 1 Main types of alkaloids and their chemical groups

Alkaloid Type

Precursor

Chemical Group of

Parent

Examples of

Compound

Alkaloids

Compounds

Alkaloids

True alkaloids

L-ornithine

Pyrrolidine alkaloids

Pyrrolidine

Cuscohygrine Hygrine

Tropane

Tropane

Atropine

alkaloids

Cocaine Hyoscyamine Scopolamine/ hyoscine

Pyrrolizidine

Pyrrolizidine

Acetyl-

alkaloids

lycopsamine Acetyl-intermedine Europine Homospermidine Ilamine

Indicine-N-oxide

Meteloidine

Retronecine

L-lysine

Piperidine alkaloids

Piperidine

Anaferine Lobelanine Lobeline N -methyl pelletierine Pelletierine Piperidine Piperine

Pseudopelletierine Sedamine

Quinolizidine

Quinolizidine

Cytisine

alkaloids

Lupanine Sparteine

Indolizidine

Indolizidine

Castanospermine

alkaloids

Swansonine

L-tyrosine

Phenylethyl-

Phenylethyl

Adrenaline

aminoalkaloids

amine

Anhalamine Dopamine Noradrealine Tyramine

Simple

Benzyltetra-

Codeine

tetrahydroiso-

hydro-iso-

Morphine

quinoline

quinoline

Norcoclaurine

alkaloids

Papaverine Tetrandrine Thebaine Tubocurarine

Alkaloid Type

Precursor Compound

Chemical Group of Alkaloids

Parent Compounds

Examples of Alkaloids

L-tyrosine or Phenethylisoquinoline Amaryllidaceae L-phenylanine alkaloids alkaloids

L-tryptophan

Indole alkaloids

Quinoline alkaloids

Pyrroloindole alkaloids

L-histidine

Ergot alkaloids

Imidazole alkaloids

Indole

Simple indole alkaloids

Simple

ß-carboline alkaloids

Terpenoid indole alkaloids

Quinoline

Indole

Imidazole

Autumnaline

Crinine

Floramultine

Galanthamine

Galanthine

Haemanthamine

Lycorine

Lycorenine

Maritidine

Oxomaritidine

Vittatine

Arundacine

Arundamine

Psilocin

Serotonin

Tryptamine

Zolmitriptan

Elaeagnine

Harmine

Ajmalicine Catharanthine Secologanin Tabersonine

Chloroquinine Cinchonidine Quinine Quinidine

A-yohimbine

Chimonantheine

Chimonantheine

Corynantheine

Corynantheidine

Dihydrocoryn-

antheine Corynanthine

Ergobine

Ergotamine

Ergocryptine

Histamine

Pilocarpine

Pilosine

Alkaloid Type

Precursor Compound

Chemical Group of Alkaloids

Parent Compounds

Examples of Alkaloids

L-arginine

Anthranilic acid

Nicotinic acid

Protoalkaloids L-tyrosine

L-tryptophan

Manzamine alkaloids

Marine alkaloids

Quinazoline alkaloids

Quinoline alkaloids

Xestomanz-amine

ß-carboline Quinazoline Quinoline

Acridone alkaloids

Pyridine alkaloids

Acridine

Pyridine/ Pyrrolidine

Phenylethylamino-alkaloids

Terpenoid indole alkaloids

Phenylethyl-

amine Indole

Xestomanz-amine A Xestomanz-amine B Saxitoxin Tetrodotoxin Peganine

Acetylfolidine

Acutine

Bucharine

Dictamnine

Dubunidine

Flindersine

Foliosidine

Glycoperine

Haplophyllidine

Haplopine

Helietidine

Kokusaginine

Maculosine

Perfamine

Perforine

Polifidine

Skimmianine

Acronycine Rutacridone

Anabasine

Cassinine

Celapanin

Evoline

Evonoline

Evorine

Maymyrsine

Nicotine

Regelidine

Wilforine

Hordenine Mescaline Yohimbine

Table 1 (Continued)

Alkaloid Type Precursor

Chemical Group

Parent

Examples of

Compound

of Alkaloids

Compounds

Alkaloids

L-ornithine

Pyrrolizidine

Pyrrolizidine

4-hydroxy-

alkaloids

stachydrine

Stachydrine

Pseudoalkaloids Acetate

Piperidine

Piperidine

Coniine

alkaloids

Coniceine

Pinidine

Sesquiterpene

Sesquiterpene

Cassinine

alkaloids

Celapanin

Evonine

Evonoline

Evorine

Maymyrsine

Regelidine

Wilforine

Pyruvic acid

Ephedra alkaloids

Phenyl C

Cathine

Cathinone

Ephedrine

Norephedrine

Ferulic acid

Aromatic

Phenyl

Capsaicin

alkaloids

Geraniol

Terpenoid

Terpenoid

Aconitine

alkaloids

Actinidine

Atisine

Gentianine

ß-skytanthine

Saponins

Steroid alkaloids

Cholestane

Conessine

Cyclopamine

Jervine

Pregnenolone

Protoveratrine A

Protoveratrine B

Solanidine

Solasodine

Squalamine

Tomatidine

Adenine/

Purine alkaloids

Purine

Caffeine

Guanine

Theobromine

Theophylline

Sources: Refs [7, 23, 28, 31, 32, 33, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58].

Usambarensine

Figure 4. An example of a true alkaloid. L-tyrosine-derived alkaloid usambarensine has strong anti-malarial potential. Usambarensine was extracted from the root bark of African Strychnos usambarensis, a small tree in East and South Africa, and a small bush in West Africa.

Usambarensine

Figure 4. An example of a true alkaloid. L-tyrosine-derived alkaloid usambarensine has strong anti-malarial potential. Usambarensine was extracted from the root bark of African Strychnos usambarensis, a small tree in East and South Africa, and a small bush in West Africa.

ch3o ch3o

Mescaline

0H2 0H2

Mescaline

ch3o

Figure 5. An example of protoalkaloids. Mescaline is the alkaloid derived from L-tyrosine and extracted from the Peyote cactus (Lophophora williamsii) belonging to the Cactus family (Cactaceae). Mescaline has strong psychoactive and hallucinogenic properties. Peyote cactus grows in the desert areas of northern Mexico and the southern parts of the USA. This plant was used in Pre-Columbian America in the shamanic practice of local tribes.

with a closed ring, being perfect but structurally simple alkaloids. They form a minority of all alkaloids. Hordenine, mescaline (Figure 5) and yohimbine are good examples of these kinds of alkaloid. Chini et al.33 have found new alkaloids, stachydrine and 4-hydroxystachydrine, derived from Boscia angustifolia, a plant belonging to the Capparidacea family. These alkaloids have a pyrroline nucleus and are basic alkaloids in the genus Boscia. The species from this genus have been used in folk medicine in East and South Africa. Boscia angustifolia is used for the treatment of mental illness, and occasionally to combat pain and neuralgia.

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Responses

  • jacob cabell
    What is protoalkaloids example?
    9 months ago
  • kaarle
    What are proto alkaloids?
    6 months ago

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