Alkaloids

Question 1

low molecular weight nitrogen containing compounds found mainly in plants, but also to a
lesser extent in microorganisms and animals; over 27,000 different alkaloid structures have been
characterized, with 21,000 from plants.

Answer 1

K

Question 2

one or more nitrogen atoms, typically as primary, secondary, or tertiary amines, and this
usually places basicity on the alkaloid, facilitating isolation and purification, since water-soluble salts can be
formed in the presence of mineral acids.

Answer 2

K

Question 3

The biological activity of many alkaloids is
often dependent on the

Answer 3

K

Question 4

Pyrrolidine

Answer 4

K

Question 5

Simple pyrrolidine-containing alkaloid structures are illustrated by

Answer 5

I

Question 6

hygrine

Answer 6

I

Question 7

cuscohygrine

Answer 7

K

Question 8

The pyrrolidine ring system is formed initially as a

Answer 8

K

Question 9

Δ1-pyrrolinium cation.

Answer 9

I

Question 10

oxidative deamination of N-methylputrescine

Answer 10

J

Question 11

diamine oxidase

Answer 11

J

Question 12

The N-methyl-1-pyrrolinium cation is then generated via
…. formation.

Answer 12

L

Question 13

The extra carbon atoms required for hygrine formation are derived from acetate via

Answer 13

8

Question 14

the enolate anion from acetyl-CoA acts as nucleophile towards the ….

Answer 14

L

Question 15

Mannich-like reaction,

Answer 15

I

Question 16

Claisen condensation

Answer 16

O

Question 17

thioester group

Answer 17

I

Question 18

and most of the natural tropane alkaloids lack this particular carbon atom, which can be lost by
suitable hydrolysis/decarboxylation reactions.

Answer 18

J

Question 19

The bicyclic structure of the tropane skeleton in cocaine is achieved by a repeat

Answer 19

J

Question 20

the ester of tropine with (S)-tropic acid, which is derived from l-phenylalanine via
phenyl-lactic acid.

Answer 20

K

Question 21

The pathway is the same as for hyoscyamine, but must proceed through the S-enantiomer of the N-
methylpyrrolidineacetoacetyl-CoA.

Answer 21

L

Question 22

subsequently obtained from the
methoxycarbonyltropinone by stereospecific reduction of the carbonyl.

Answer 22

K

Question 23

Reduction of the carbonyl occurs from the opposite face to that noted with the

Answer 23

K

Question 24

diester of ecgonine,

Answer 24

U

Question 25

arising from phenylalanine via cinnamic acid
and benzoyl-CoA.

Answer 25

K

Question 26

found in Erythroxylum coca (coca) and is used medicinally as a local anesthetic
, and as an illicit drug for its euphoric properties.

Answer 26

K

Question 27

They began their synthesis
from cycloheptanone and,
in 23 steps, completed the
synthesis of (±)-cocaine.

Answer 27

K

Question 28

The key step is a
…… followed by an
intramolecular
transannular SN2 to form
the tropane skeleton (

Answer 28

.

Question 29

mixed with lime, thus liberating the principal alkaloid cocaine as the free base, and the
combination is then chewed

Answer 29

J

Question 30

are extracted from crushed leaf using alkali (lime) and petrol. The petrol extract is
then re-extracted with aqueous acid,

Answer 30

I

Question 31

he coca alkaloids are often diluted with

Answer 31

L

Question 32

Cocaine Derivatives

Answer 32

K

Question 33

Cocaine Derivatives

Answer 33

K

Question 34

Procaine

Answer 34

K

Question 35

Benzocaine

Answer 35

O

Question 36

Tetracaine

Answer 36

I

Question 37

Lidocaine

Answer 37

K

Question 38

Lidocaine

Answer 38

K

Question 39

ALKALOIDS DERIVED FROM TYROSINE

Answer 39

O

Question 40

dependent decarboxylation of l-tyrosine gives the simple phenylethylamine derivative
tyramine

Answer 40

J

Question 41

phenylethylamine

Answer 41

L

Question 42

tyramine

Answer 42

L

Question 43

tyramine

Answer 43

L

Question 44

which on di-N-methylation yields hordenine, a germination inhibitory alkaloid from barley

Answer 44

L

Question 45

relatively non-specific and can catalyse
decarboxylation of other aromatic amino acids, e.g. tryptophan and histidine.

Answer 45

K

Question 46

Pre-eminent amongst the simple phenylethylamine derivatives are the

Answer 46

O

Question 47

catecholamines

Answer 47

I

Question 48

These
compounds are synthesized by sucessive β-hydroxylation and N-methylation reactions on
dopamine.

Answer 48

K

Question 49

Aromatic hydroxylation and O-methylation reactions in the cactus Lophophora williamsii (Cactaceae
) convert dopamine into

Answer 49

K

Question 50

mescaline

Answer 50

K

Question 51

alkaloid with psychoactive and hallucinogenic properties.

Answer 51

U

Question 52

also found in other species of cactus, e.g. Trichocereus pachanoi, a substantially
larger columnar plant that can grow up to 20 feet tall and found mainly in the Andes.

Answer 52

U

Question 53

anhalamine, anhalonidine, and anhalonine.

Answer 53

U

Question 54

ALKALOIDS DERIVED FROM • Catecholamines: TYROSINE

Answer 54

U

Question 55

can act on both vascular α1 and cardiac β1 receptors, but also has its own receptors in
several other structures.

Answer 55

8

Question 56

but needs
to be administered with a DOPA-decarboxylase inhibitor, to prevent rapid decarboxylation in the
bloodstream.

Answer 56

8

Question 57

Parkinson’s disease, there is a deficiency of dopamine due to neural degeneration

Question 58

Parkinson’s disease, there is a deficiency of dopamine due to neural degeneration

Answer 58

L

Question 59

cardiac stimulants in cases of cardiogenic shock. These
agents act on β1 receptors.

Answer 59

I

Question 60

found in plants, e.g. Corydalis spp. (Papaveraceae), but can also be detected in the urine
of humans

Answer 60

M

Question 61

product from dopamine and acetaldehyde formed via a Pictet–Spengler reaction.

Answer 61

I

Question 62

are elaborated from (R)-reticuline.

Answer 62

I

Question 63

change in configuration is known to be achieved by an oxidation–reduction process through the intermediate 1,2-
dehydroreticulinium cation.

Answer 63

I

Question 64

S)-reticuline, a pivotal intermediate to
other alkaloids, is attained by ….

Answer 64

.

Question 65

only the phenylethylamine fragment of the
tetrahydroisoquinoline ring system is formed via DOPA,

Answer 65

K

Question 66

hydroxyphenylacetaldehyde

Answer 66

I

Question 67

benzylisoquinoline alkaloid found in opium,

Answer 67

K

Question 68

from N-nor-reticuline by
successive O-methylations and oxidation in the heterocyclic ring.

Answer 68

I

Question 69

the principal opium alkaloids, are derived by this type of
coupling, though the subsequent reduction of one aromatic ring.

Answer 69

I

Question 70

is the precursor of these morphinan alkaloids

Answer 70

I

Question 71

tetrahydroisoquinoline

Answer 71

I

Question 72

dienone salutaridine,

Answer 72

U

Question 73

The coupling enzyme salutaridine synthase is a

Answer 73

I

Question 74

P-450-dependent monooxygenase.

Answer 74

O

Question 75

Only the original ……. can be restored to aromaticity, since the
tetrahydroisoquinoline fragment is coupled para to the phenol function, a position which is already
substituted

Answer 75

.

Answer 76

K

Question 77

Ring closure to form the ether linkage in thebaine would be the result of nucleophilic attack
of the phenol group onto the dienol system and subsequent displacement of the hydroxyl.

Answer 77

K

Question 78

conversion of thebaine into codine and morphine, involves a process which modifies the
oxidation state of the diene ring, …… two O-methyl groups.

Answer 78

.

Question 79

which gives …… and then codeine by non-
enzymic keto–enol tautomerism and NADPH-dependent reduction.

Answer 79

L

Question 80

……. of the phenol ether codeine to the phenol morphine

Answer 80

.

Question 81

The enzymic demethylations of both the enol ether (in thebaine) and the phenol ether (in codeine)
involve ……… followed by loss of the methyl groups as ………

Answer 81

.

Question 82

withdrawal symptoms, including agitation, severe abdominal cramps,
diarrhoea, nausea, and vomiting, which may last for 10–14 days unless a further dose of morphine
is taken. This leads to physical dependence which is difficult to overcome, so that the major current
use of morphine is thus in the relief of terminal pain.

Answer 82

O

Question 83

withdrawal symptoms, including agitation, severe abdominal cramps,
diarrhoea, nausea, and vomiting, which may last for 10–14 days unless a further dose of morphine
is taken. This leads to physical dependence which is difficult to overcome, so that the major current
use of morphine is thus in the relief of terminal pain.

Answer 83

O

Question 84

dependent on partial demethylation in the liver to produce morphine, so it produces
morphine-like analgesic effects,

Answer 84

,

Question 85

structurally from morphine/codeine mainly by its possession of a conjugated diene ring system. It is almost
devoid of analgesic activity, but may be used as a morphine antagonist. Its main value is as substrate for the semi-synthesis of
other drugs.

Answer 85

K

Question 86

benzylisoquinoline alkaloid, and is structurally very different from the morphine, codeine, thebaine

Answer 86

J

Question 87

phthalideisoquinoline alkaloids and

Answer 87

K

Question 88

but no analgesic or narcotic
action.

Answer 88

L

Question 89

effective and reliable antitussive, can be obtained by alkylation with N-(chloroethyl)morpholine.
• Dihydrocodeine is a reduced form of codeine with similar analgesic properties.

Answer 89

I

Question 90

…… is a reduced form of codeine with similar analgesic properties.

Answer 90

.

Question 91

the double bond of morphine has been reduced, and in addition the 6-hydroxyl has been oxidized to a

Answer 91

O

Question 92

hydromorphone

Answer 92

I

Question 93

diacetate of morphine; i

Answer 93

O

Question 94

used for terminal care, e.g.

Answer 94

L

Question 95

common and extremely important precursor of
alkaloids, l-phenylalanine is less frequently utilized;

Answer 95

O

Question 96

Phenylalanine-derived Alkaloids

Answer 96

I

Question 97

the main alkaloid in species of Ephedra (Ephedraceae) and a valuable nasal
decongestant and bronchial dilator.

Answer 97

J

Question 98

major constituent of the leaves of khat (Catha edulis; Celastraceae),
chewed in African and Arab countries as a stimulant. Its traditional use alleviates hunger and fatigue

Answer 98

I

Question 99

major constituent of the leaves of khat (Catha edulis; Celastraceae),
chewed in African and Arab countries as a stimulant. Its traditional use alleviates hunger and fatigue

Answer 99

I

Question 100

Prolonged usage can lead to hypertension, insomnia, or even mania.

Answer 100

O

Question 101

caffeine

Answer 101

I

Question 102

theobromine

Answer 102

I

Question 103

theophylline

Answer 103

I

Question 104

PURINE ALKALOIDS

Answer 104

K

Question 105

important as a drug compound because of its muscle relaxant properties,
utilized in the relief of bronchial asthma.

Answer 105

K

Question 106

major constituent of cocoa and related chocolate products, it acts as a diuretic
and smooth muscle relaxant.

Answer 106

I

Question 107

Theobromine

Answer 107

L