Alkaloids

Question 1

most important and common feature of alkaloids

Answer 1

they contain an nitrogen atom in a heterocycle and bitter tasting and basic

Question 2

typical alkaloids are …

Answer 2

derived from plant sources
they are basic
contain one or more nitrogen atoms
have a physiological action on humans or other animals

Question 3

examples of common alkaloids

Answer 3

caffeine and nicotine

Question 4

important families of alkaloids

Answer 4

apocyanceae (Dogbane)
Papveraceae (Poppy)
Fabaceae (leguma, pea)
Ranunculaceae (Buttercup)
Rubiaceae (Coffee, Madder)
Rutaceae (Rue or Citrus)
Solonaceae (Nightshades)

Question 5

applications of alkaloids

Answer 5

medicinal - virtually every pharmaceutical applicaiton imaginable except antibiotic
agriculture - insectisides and veterinary
culturl/entheogenic - most often to idnuce an altered state of consiousness.
recreational - nicotine

Question 6

testing for alkaloids

Answer 6

mayer’s - cream colour
dragendorffs’s - orange
wagner’s reagent - red/brown
hager’s reagent - yellow

Question 7

physicochemical properties

Answer 7

most alkaloids that don’ contain oxygens are liquid at room temp
insoluble in water
soluble in polar or slightly polar organic solvents

Question 8

how are alkaloids classified

Answer 8

according to their origin
eg acontium, amaryllidaceae, ergot, opium etc

Question 9

chemical classification

Answer 9

True alkaloid
Proto alkaloid
Pseudoalkaloids
False Alkaloids

Question 10

what are true alkaloids

Answer 10

they are derived from an amino acid and have a nitrogen in a heterocyclic ring

Question 11

what are proto alkaloids

Answer 11

they are derived from an amino acid but their nitrogen atom is not in the heterocyclic ring

Question 12

what are pseudo alkaloids

Answer 12

they are not derived from amino acids but the nitrogen atom is in the heterocyclic ring

Question 13

what type of derived alkaloids are there

Answer 13

there is tryptophan, Phenylalanine/ tyroise

Question 14

what pathway and compound produce the precursor for the derived alkaloid pathway

Answer 14

the shikimata pathway with the compound chroismate.

Question 15

indole alkaloids

Answer 15

tryptophan poduct of tryptamine give rise to the indole alkaloids.
these contian 2 nitrogen, on is indolic nitrogen and the second is generally two carobons removed from the b-position of the indole ring.

Question 16

what determines the type of alkaloid produced for the tryptophan reactions

Answer 16

condensation between tryptamine and an aldehyde or a keto acid.
with the rection either occuring at the alpha or beta carbon.

Question 17

what terpene pathway is also used for alkaloids

Answer 17

the mevalonate pathway as it is used for non-trypotophan derived

Question 18

what families does a c10 monoterpenoid provide

Answer 18

the apocynaceae. loganiaceae and rubiaceae

Question 19

example of tryptophan derived alkaloid

Answer 19

physostigmine
used to treat glaucoma
originally used as a poison

Question 20

ergotamine

Answer 20

is a tryptophane derived alkaloid,
structural similiarity to several neurotransmitters
functions as a vasoconstrictor
used to treat acute migraine

Question 21

vinblastine

Answer 21

tryptophane derived,
obtianed from Catharanthus roseus (madagascar periwinkle)
a funsion of two alkaloid precursors
potent mitotic inhibitor used to treat a umber of types of cancer

Question 22

phenylalanine and tyrosine are ?

Answer 22

essential, aromatic amino acids

Question 23

benzylisoquinoline and opium are

Answer 23

well known derivatives of aromatic amino acids

Question 24

amaryllidaceae alkaloids

Answer 24

well known for toxic properties
derived from one phenylalanine and one tyramine
represented by haemanthamine, lycorine, galantamine
potential treatment of galanthamine

Question 25

Tetrahydroisoquinoline

Answer 25

derive from the condensation of dopamin with secologanin (c10 monoterpene) cephaelis gives ipecacuanha root

Question 26

emetine

Answer 26

earliest use of emtine is an emetic. antiprotozoal,

Question 27

Ornithine-derived alkaloid

Answer 27

the amino acid ornithine, makes the decarboxylation product putrescine, and proline constitute the basic unit of tropane, ecgonine, nicotine and others

Question 28

what are the two major ornithine-derived alkaloid groups

Answer 28

tropane and pyrrolizidine

Question 29

Tropane alkaloid

Answer 29

medical interest in atropine and hyoscine these are both contained to nightsades

Question 30

Atropine

Answer 30

comes from deadly nightshade, dilates the pupils, increase heart rrate, reduces salvation and other secreations used to treate nerve gas poisoning

Question 31

Hyoscine

Answer 31

antispasmodic used to prevent postoperative nausea and vomiting, treat gatrointestinal spasms,

Question 32

Pyrrolizidine alkaloids

Answer 32

constitute the natural biocides from plants of genus senecio. these are well known for their toxicity to livestock

Question 33

Piperine

Answer 33

used for cholera, dyspepsia

Question 34

Cytisine

Answer 34

also known as baptitoxine or sophorine currently used as an alternative to nioctine in replacement therapy

Question 35

Biosynthesis of Protoalkaloid

Answer 35

derived from amino acids but do not have the nitrogen in a heterocyclic ring are typically classified by what amino acid they came from

Question 36

Ephedra species

Answer 36

original source of ephedrine and pseudoephedrine

Question 37

Extraction methods for Alkaloids

Answer 37

Acidic or Basic choice depends on the chemical state of the particular alkaloid

Question 38

sample preparation

Answer 38

defatting using a non polar solvent which removes the interfering compounds

Question 39

Basic Extraction

Answer 39

Moistend with water and mixed with a base so alkaloid is released. organic solvents used for extraction by seperation. alkaloid salts igrate to teh aqueous phase.

Question 40

Acid Extraction

Answer 40

moistened with water or aqueous alcohol. unwatned materials removed with shaking with chloroform. free alkaloids are precipitated by the addition of excess sodium bicarbonate or ammonia and separated with filtration