ALKALOIDS

Question 1

very diverse group, only characteristic is presence of amine group or nitrogen containing group

Answer 1

alkaloids

Question 2

Four major groups of N-containing organic compounds in biological systems

Answer 2

✓ amino acids (peptides and proteins)
✓ nucleoside bases (DNA and RNA)
✓ porphyrins
✓ alkaloids

Question 3

cyclic organic compounds containing nitrogen in a negative state of oxidation with limited distribution among living organisms commonly found in medicinal plants.

Answer 3

alkaloids

Question 4

• first natural products to be purified, characterized and commercialized
• can be purified from crude extracts by acid-base extraction and recrystallization

Answer 4

alkaloids

Question 5

(5) classification of alkaloids

Answer 5

• Biosynthetic pathway
• Types of amines
• Basicity
• Chemical skeleton
• Botanical source

Question 6

Classification according to Biosynthetic pathway
______________- derived from amino acids and have N in a heterocyclic ring (e.g., atropine)
____________- derived from amino acids and do not have N in a heterocyclic ring (e.g., ephedrine)
_______________- not derived from amino acids but have N in a heterocyclic ring (e.g., caffeine)
______________- non alkaloids; give false positive reaction with alkaloidal reagents

Answer 6

true (typical) alkaloids
Protoalkaloids
Pseudo alkaloids
False alkaloids

Question 7

Classification according to Type of Amines

Answer 7

• alkyl amines (2°, 3°, 4°)
• heterocyclic amines

Question 8

Classification according to Basicity

Answer 8

weak bases
strong bases
amphoteric
✓ phenolic alkaloids
✓ alkaloids with carboxylic groups
neutral alkaloids

Question 9

Classification according to Chemical skeleton

Answer 9

phenylalkylamines
pyridine/piperidine
phenanthrene
quinoline
tropane
indole
terpenoid
imidazole
steroidal

Question 10

Just a note!
the powerful and immediate effects of alkaloids are thought to be due to the presence of the cationizable N-atom which gives it lipid- and water soluble characteristics, and enables it to cross membrane barriers more readily

Question 11

General Properties of Alkaloids

Answer 11

1. most are crystalline solids
2. bitter and exert physiological action
3. either insoluble or sparingly soluble in water
4. optically active, levorotatory
5. gives strong alkaline reaction
6. can be precipitated

Question 12

alkaloids are derived from the following:

Answer 12

1) aliphatic amino acids: lysine, glutamic acid, and ornithine
2) aromatic amino acids: phenylalanine, tyrosine, & tryptophan
3) others: secologanin: terpene-derived C10 unit

Question 13

ornithine is derived from

Answer 13

glutamic acid

Question 14

ornithine can be derived to what types

Answer 14

pyrrolidine, tropane, pyrrolizidine

Question 15

lysine is modified following an analogous pathway to ornithine.
The alkaloids produced are the 6-membered

Answer 15

piperidine, homotropane and quinolizidine structures.

Question 16

have the characteristic fused 6,6-bicyclic group and are derived from lysine.

Answer 16

Quinolizidine alkaloids

Question 17

Biosynthesis of this group involves simply loss of the carboxylic acid carbon. Some important members of this group are the
hallucinogenic compound mescaline and the drug epinephrine.

Answer 17

alkaloids from phenylalanine/ tyrosine:
Simple phenylethylamines.

Question 18

______________are important components of a number of culturally, historically and
commercially important plants, in particular coffee, cola (kolanut), tea and cacao (chocolate).
The active constituents are methyl xanthines, the best known of which are: caffeine, which
occurs in coffee (Coffea arabica); theophylline, which is found in tea (Camellia sinensis); and theobromine, which is found in cacao (Theobroma cacao).

Answer 18

Xanthine alkaloids

Question 19

_________ from hemlock (Conium maculatum) was used by the ancient Greeks for state executions. Its most famous victim was Socrates.

Answer 19

Coniine

Question 20

_______________-is an opiate produced by
Claviceps purpurea, a parasitic fungus that
grows on some grain crops. The unhygienic practices of medieval Europe caused outbreaks of convulsion which was called “St. Anthony’s Fire”.

Answer 20

Lysergic acid

Question 21

_______________- is the principal alkaloid in Nicotiana tabacum. It is addictive and has been recently classified as a drug.

Answer 21

Nicotine

Question 22

______________-was first purified in 1818 by Pelletier and Magendie from the seeds of Strychnos nux-vomica, a plant native to India. It is a deadly poison and was used for many centuries as a rodenticide and vermicide. It is so chemically and biologically stable that it has been found in bodies exhumed after several years (this makes it a bad choice for a poison!)
It was first synthesized in 1954.

Answer 22

Strychnine

Question 23

_____________ was first purified by Pelletier and Caventou in 1820. It is the major alkaloid from the bark of the Cinchona tree. Christened the “Jesuit bark,” the bark was traditionally used by Peruvian indians for fever due to malaria. It was the principal antimalarial drug up to WW II, after which it was supplanted by chloroquin.

Answer 23

Quinine

Question 24

_______________ is the chief alkaloid of the South American coca bush. It has anaesthetic properties but is very addictive.

Answer 24

Cocaine

Question 25

________________was first isolated by Sertürner in 1806 from Papaver somniferum. It is still valued up to this day for its pain-killing properties, although it is highly addictive. It was first synthesized in 1952. Codeine is the methyl derivative

Answer 25

Morphine

Question 26

________________- one of the world’s largest pharmaceutical companies, made its initial fortune from cocaine, morphine, and codeine.

Answer 26

Merck

Question 27

_____________is a well-known hallucinogenic compound extracted from the Indian peyote cactus, Laphophora williamsii.

Answer 27

Mescaline

Question 28

___________is perhaps one of the most widely consumed alkaloids in the world. It is a member of a group of xanthine alkaloids which is present in coffee. The other famous xanthines, theobromine and theophylline, are found in tea and cocoa, respectively.

Answer 28

Caffeine

Question 29

___________________ is the anticancer drug from Catharanthus roseus (locally known as chichirica). Because it occurs in very minute amounts in the plant, this plant has been the subject of intense biotechnology research to try to produce it in vitro using cell culture techniques.

Answer 29

Vinblastine