PHA6117 LEC: Alkaloids Part 1

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

are of rare occurrence in other organisms

lysergic acid derivatives and sulfur-containing

In fungi, the _ alkaloids are best known

amphibians

True Alkaloids are also present in _ (many are antimicrobial)

Alkali

due to the universal presence of nitrogen

Amines

are often called the “organic bases”

acids

Alkaloids are nitrogenous compounds and unite with _ to form salts

crystalline

Most are _ (some amorphous) solids

free state

May exist in the _ as salts or N-oxides

oxygen

Most contain _; some that don’t are liquids at room

temperature (ex. sparteine, coniine, arecoline, and nicotine)

Alkaloids

Rarely have color

berberine

YELLOW

sanguinarine

RED

Free bases

sparingly soluble in H₂O, soluble in organic solvent

Free bases

Reversed when converted to alkaloidal salts

amine

Alkaloids can also be classified based on the type of _.

Primary

Mescaline

Primary

Secondary

Ephedrine; Most Basic

Secondary

Tertiary

Atropine; Least Basic

Tertiary

Quarternary

Tubocurarine

Quarternary

True Alkaloids

Almost all compounds considered to be alkaloids have their nitrogen atoms enclosed within a ring system, and are called

Pseudoalkaloids

Heterocyclic “alkaloids” that are not derived from amino acids

Protoalkaloids

Those which do not have nitrogenous heterocycles are called _

True Alkaloids

✓ NITROGENOUS HETEROCYCLE

✓ DERIVED FROM AMINO ACID

Pseudoalkaloids

✓ NITROGENOUS HETEROCYCLE

✘ DERIVED FROM AMINO ACID

Protoalkaloids

✘ NITROGENOUS HETEROCYCLE

✓ DERIVED FROM AMINO ACID

Lysine

Ornithine Aspartate

Ornithine

Tryptophane

Tyrosine

Purine (Aspartate. Glycline, Glutamine)

Process A

Powdered material is moistened with water, mixed with lime

Process A

Extraction is done with organic solvents like ether or petroleum spirit

Process A

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

Process A

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

Process B

Powdered material is extracted with water or aqueous alcohol containing dilute acid

Process B

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

Process B

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

“P” ALKALOIDS

Specifically, monocyclic structures

“P” ALKALOIDS

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

Pyridine

from ornithine/aspartate

Piperidine

from lysine

Pyrrolidine

from ornithine/aspartate

Pyrrolizidine

from ornithine

TOBACCO

Scientific Name

Nicotiana tabacum

TOBACCO

Family

Solanaceae

TOBACCO

Constituents

Nicotine

TOBACCO

Use	Smoking cessation

TOBACCO

Note	Can cause lung cancer

TOBACCO

TOBACCO

For smoking cessation

Neuromuscular stimulation

For spasmodic asthma and chronic bronchitis

TOBACCO

Antismoking preparations

TOBACCO

Resuscitation of newborn infants

INDIAN TOBACCO

In toxic doses, paralytic

BROOM

Scientific Name

Cytisus scoparius

BROOM

Family

Fabaceae

BROOM

Constituents

Sparteine, cytisine

BROOM

Use		Mild diuretic and cathartic

BROOM

Sparteine & Cytisine & Varenicline

Cytisine

• is an α4β2 partial agonist

  • Used for smoking cessation

Varenicline

Artificial alternative of Cytisine

POISON HEMLOCK

Scientific Name

Conium maculatum

POISON HEMLOCK

Family

Apiaceae

POISON HEMLOCK

Constituents

Coniine

POISON HEMLOCK

Use	Used by Geeks for preparing a draught by means of which criminals were put to death

POISON HEMLOCK

Note	With KOH (Potassium hydroxide), develops strong, mouse-like odor due to liberation of coniine

Coniine

BETEL NUT

Scientific Name

Areca catechu

BETEL NUT

Family

Arecaceae

BETEL NUT

Constituents

Arecoline, guavacine

BETEL NUT

Use	Taenicide in the east

Arecoline

POMEGRANATE

Scientific Name

Punica granatum

POMEGRANATE

Family

Punicaceae

POMEGRANATE

Constituents

Pelletierine, isopelletierine

POMEGRANATE

Use	Anthelminthic, for hemorrhoids

POMEGRANATE

Note	Pelletierine tannate
	Anthelminthic for tapeworms

Pelletierine

BLACK PEPPER

Scientific Name

Piper nigrum

BLACK PEPPER

Family

Piperaceae

BLACK PEPPER

Constituents

Piperine, piperettine

BLACK PEPPER

Use	Once employed in treatment of gonorrhea and chronic bronchitis

BLACK PEPPER

Pungency ascribed to piperine

Long pepper

• Piper retrofractum

• P. longum

Cubeb

Piper cubeba

Guineesine

• Acyl-CoA:cholesterol acyltransferase inhibitor

• Potential antihypercholesterolemic

Piperine

CLUBMOSS

Scientific Name

Lycopodium clavulatum

CLUBMOSS

Family

Lycopodiaceae

CLUBMOSS

Constituents

Lycopodiumoleic acid, lycopodine

CLUBMOSS

Limited extent in dusting powders and medicated snuffs, and as dusting powder for pills