PHA6117 LEC ALKALOIDS

Derosne

Narcotine (1803)

Serturner

Morphine (1816)

Pelletier and Caventou

Strychnine, emetine, brucine, piperine, caffeine, quinine, colchicine, coniine (1817 -1826)

Coniine

first alkaloid with established structure (by Schiff).

True alkaloids

rare occurrence in other organisms

Fungi

lysergic acid derivatives and sulfurcontaining alkaloids are best known.

True Alkaloids

Also present in amphibians (many are antimicrobial)

Pteridophytes

Ephedra, Taxus

nitrogen

"Alkali" due to the universal presence of ________.

organic bases

Amines are often called the "___________"

acids

Nitrogenous compounds and unite with ________ to form salts.

T

(T/F) Most are crystalline (some amorphous) solids in alkaloids.

salts, N-oxides

Alkaloids may exist in the free state as ________ or ________.

T

(T/F) Most contain oxygen; some that don't are liquids at room temperature

sparteine, coniine, arecoline, and nicotine

Alkaloids that are liquid at room temp.

F

(T/F) Alkaloids are rarely colorless

Berberine

Yellow

Sanguinarine

Red

Free bases

Sparingly soluble in H2O, soluble in organic solvent

T

(T/F) Alkaloids are soluble in water when turned into salt.

Primary

Mescaline

Secondary

Ephedrine

Tertiary

Atropine

Quaternary

Tubocurarine

True Alkaloids

Have their nitrogen atoms enclosed within a ring system.

Pseudoalkaloids

Heterocyclic "alkaloids" that are not derived from amino acids.

Protoalkaloids

Those which do not have nitrogenous heterocycles.

Process A

Powdered material is moistened with water,

mixed with lime

o Extraction is done with organic solvents like ether or petroleum spirit

o Organic liquid is then shaken with aq. acid and allowed to separate

o Alkaloid salts now in aqueous liquid, impurities are in organic liquid

Process B

Powdered material is extracted with water or

aqueous

o Pigments and other unwanted materials are removed by shaking with chloroform or other organic solvents

o Free alkaloids are precipitated with sodium bicarbonate or ammonia and separated by filtration

"P" Alkaloids

Traditionally called pyridine-piperidine alkaloids, but other alkaloids have other rings.

Pyridine

ornithine/aspartate

Piperidine

lysine

Pyrrolidine

ornithine/aspartate

Pyrrolizidine

ornithine

"P" Alkaloids

Many come from plants, though some are found in insects, amphibians, and marine animals.

Tropane

bicyclo[3.2.1] structure

Ornithine, putrescine and acetate

Precursors of tropane

N-methyl group

from methionine

Tropic acid

from phenylalanine

Benzylisoquinoline

Consists most of the said isoquinolines listed.

Tetrahydroisoquinoline

Special class; ex. Ipecac

Benzylisoquinoline & Tetrahydroisoquinoline

Derived from dopamine which if you can recall, originated from tyrosine)

Quinoline

Results from Mannich reactions

Quinoline

Those involving alpha-carbon of the indole nucleus (from tryptophan) affords a beta-carboline derivative

indolenine

Reaction of quinoline with beta-position gives ________.

Quinoline

Beta-carbolines have psychomimetic properties

Quinolizidines

Extensive liver damage in animals using plants containing them as fodder.

Indoles

Derived from tryptophan

T

(T/F) Some indoles are embedded in a larger ring system.

Physostigmine

Always classified as a carbamate

hallucinogenic

Indole derivatives can sometimes be ________ (ex. amanitins, reserpine, strychnine, Mitragyna alkaloids)

C27 group

Solanum alkaloids, veratrum alkaloid

C21 group

Apocynaceae, Buxaceae

Jerveratrum alkaloids

Contain 1-3 oxygens. Ex. jervine, pseudojervine, veratrosine

Cerveratrum

Contain 7-9 oxygen atom. Ex. germine, protoverine, veracevine

Conessine

Desirable starting material for synthesis of some hormones.

Holaphylline

Little toxicity

Malouetine

Curare-type poison

Solanine

Toxic principles of potatoes and other Solanum plants

Alkaloidal Amines

Also known as protoalkaloids

Alkaloidal Amines

Do not have a nitrogen as part of their heterocyclic ring system, but are derived from amino acids.

Alkaloidal Amines

Often derived from phenylalanine

Alkaloidal Amines

Some are quaternary bases (ex. Protoberberine alkaloids).

Alkaloidal Amines

Antibacterial, antimalarial, and potential genotoxic properties.

Purine Bases/Xanthines

Also known as pseudoalkaloids

Methylxanthines

Potent bronchodilatory and stimulant molecules (due to increased cAMP via PDE inhibition).

Murexide test

Quantitative identification of Purine Bases/Xanthines

Caffeine

Central stimulant, diuretic, and content of several carbonated beverages

Theophylline

Widely used a bronchodilator in asthma

Theobromine

Preferred over caffeine in cases of cardiac edema and angina

Amaryllidaceae Alkaloids

From phe and tyramine. Represented by galantamine