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Transcript
Amino Alkaloids
*phenylalkylamine= aromatic ring +alkyl chain +( N) amide.
alkyl chain : 1 carbon :benzyl amine derivative
 2 carbon: phenylethylamine derivative
3 carbon : B-amino-phenyl-propane.
*Adrenaline and nor adrenaline  catecholamine
to get benefit of this cmp  given parentrally
because they are inactive in GIT.
so you need step of isolation(extraction) to these cmp , therefore they are not
occuring naturally active , so there is no difference between lab preparation
and naturally modified.
Capsaicinoides
*Capsa=box ;empty from inside.
*warmer climate  more pungent taste.
*Fruit also contain  Vit. C
-capsaicine="amide " grp.
capsaicine most pungent taste.
Benzylamine = acid moeity + Amine moiety.
SAP (phenylalanine) desaminationcinnamic acid methoxylationferulic
acid  beta-oxidation vanillic acid reduced vanilline  transamination
vanillyamine.
10 C :1 decenoic acid " must be straight FA"
isodecenoic acid not straight
8-methyl-6-nonanefatty acid =Isodecenoic acid.
1
In the last lecture, we started to discuss Derivatives of aromatic amino acids ;
Phenylalanine & Tyrosine. And we classified these alkaloids as Alkaloidal
amines (Amino Alkaloids),because :1) The nitrogen is not a part of the heterocyclic ring.
2) The nitrogen is originating from a Trans-amination reaction.
The Phenylalkylamines
They are subclassified depending on the number of carbons of the side chain.
Either we'll have Capsaicinoids ,or Benzylamine derivatives, or
Phenylethylamine derivatives, or β-amino-phenylpropane derivatives.
Phenylethylamine derivatives
Already it's a very indicating name : There's an aromatic ring and the side
chain ; an ethyl amine (with 2 carbons & amino group )
and here we are talking again about the precursors Phenylalanine & Tyrosine.
In fact, both amino acids proceed into two important reactions :1) Decarboxylation : to obtain corresponding amines.
2) Modification :
What are the modifications?!
a) Hydroxylation (oxidation ) on the aromatic ring .
b) Hydroxylation( oxidation ) of side chain.
c) Methylation .
These are basically important reactions to obtain different closely related
phenylethylamine derivatives .
The amino acid Tyrosine
para-hydroxyphenylalanine, it can be easily decarboxylated to its biogenic
amine : Tyramine.
It's in fact with this chapter ,we are entering a very important chapter of the
pharmacology ( the chapter of Catecholamines )
2
Catecholamines
They are important neurotransmitters of the mammalian organisms ,and they
are derivatives of this group of amino acids ( Amino acid derivatives ). Obtained
by the simple reactions mentioned above :
a) Hydroxylation (oxidation ) on the aromatic ring .
b) Hydroxylation( oxidation ) of side chain.
c) Methylation
And these Catecholamines are : Adrenaline (Epinephrine), Noradrenaline
(Norepinephrine) ,& Dopamine.
There are many plants containing Adrenaline , Noradrenaline,& Dopamine ,but
as plant constituents of less importance because of their instability in GIT of
humans.
Catecholamines should be administered parenterally (injection ) in order to
observe their activity.
And when we talk about plant constituents ,our primary objective is to use
these plants as such after drying in form of infusion or in form of a Tea .
Isolation from the plant ; when we are using the pure isolated compounds then
there's no difference from the synthetic compounds. it follows the single entity
regulations ,like the cardiac glycoside Digoxin .
but as plant constituents ,if we them in form of simple preparations ,then we
are talking about Herpal Remedies.
Therefore, because of their instability in GIT ,none of these catecholamines are
of plant constituents of interest, unless we use these plants as a source of
more economical production of these compounds.
so we cannot use them to benefit as a Tea of Epinephrine or such.
But, there are other drug constituents structurally closely related to these
substances ,and stable in the GIT ; a Phenylethylamine derivative : Mescaline .
Mescalin
A phenyethylamine derivative; 3,4,5-trimethoxyphenethylamine ( as a
representative of GI stable derivative ).
It's the active principal obtained from the cactus Lophophora williamsii (
Cactaceae ) .
3
These cacti are growing mainly in Southern America and Northern Mexico.
And they became famous because the American Indians or the old inhabitants
of Mexico were using these plants in a dry form or in form of a tea as a means
of inducing hallucinations during religious ceremonies.
The crude drug is called " Mescal Buttons "; Flattened-shaped button-like
outgrowths on the stem of the cactus ,so they were taking either these mescal
buttons or they were making slices (transversal cuts) then they were drying
them and taking them in the mouth ( ingestion ) ,or in the form of a tea .
As a result of this ,they were experiencing certain hallucinations ,and they were
aiming to have these hallucinations in order to get a better connection with
their Gods (to become nearer to their Gods) when they were mentally
,somehow , exciting from the normal performance and entering in an outside
world; a transient world ; or an imaginary world .
Hallucinations were accompanied primarily by visual symptoms; observing
flashing lights ,bright colors (colored hallucinations) , distortion of the shapes (
or objects of their surroundings taking different shapes ), and they were
hearing non-existing music & sounds.
Mescaline is classified as one of the three important psychedelic agents ,these
are :1) Mescaline ( Natural )
2) Psilocybin ( Natural )
3) LSD ( Semi-synthetic ) - Lysergic acid Diethylamide : The most famous & the
most potent among the three.
The first two are not used commonly ,even in the experimental psychiatry
,because LSD has superseded them.
What is the Mescaline structurally ?
It's as we have seen in Adrenaline , Noradrenaline , & dopamine with a
difference; that there's a third hydroxylation in the aromatic part , and none of
the hydroxyl groups are occurring in the free form ; they are possessing methyl
groups.
Mescaline can be synthesized from tyrosine or a hydroxylated
phenylalanine,which is decarboxylated to tyramine then followed by oxidation (
Hydroxylation) to dopamine. Dopamine converts into mescaline in a
biosynthetic pathway involving m-O-methylation and aromatic hydroxylation.
4
so, it's a very structurally simple compound with buzzard effect on the mood of
human-beings (Hallucinations).
But, again, it's not a wide spread misused drug ( it's not used worldwide ).
 β-amino-phenylpropane derivatives
Indicating the β position of the amino carbon on the side chain
Most important derivative of this this group : Ephedrine
Ephedrine
A β-amino-phenylpropane derivative; 2-(methylamino)-1-phenylpropan-1-ol ,
which has adrenaline-like activities ( sympatho-mimetic ), but ephedrine is
orally-active ,and with longer duration of action than adrenaline.
It's obtained from Ephedra sinica ( Ephedraceae) and other related species.
It's one of the eldest medicinally reported plants.
E.sinica comes from China, has been used in traditional Chinese medicine for
thousands of years under the name " ma huang "
It was primarily used in the treatment of common cold ,but it's now claimed for
its vasoconstriction activity and possibilities to be used as a vasoconstrictor in
the treatment of rhinitis , and for its bronchodilator activity in the treatment of
allergic asthma.
Ephedrine and ephedrine based compounds are banned by FDA, In response to
accumulating evidence of adverse effects and deaths related to ephedra.
It's accompanied in the plant with its stereoisomer Pseudoephedrine , and
pseudoephedrine is used for its vasoconstriction activity ( α-adrenergic activity
) in the treatment of rhinitis . And all products based on ephedrine and
pseudoephedrine are banned from the Sport activities ,classified as a Doping
agent (The use of performance-enhancing drugs in human sport is commonly
referred to by the term doping )
In fact, until the late 70's ,ephedra preparations were widely used in weightreducing tablets;due to their activity on the fat consumption ,but nowadays it's
not permitted to use either ephedrine or pseudoephedrine in the weightreducing preparations ,because they get the user a mild high ,these plant
products are classified as "Uppers" ,so they are considered as "Ecstacy" (
entactogenic /psychoactive) ; because they have amphetamine-like activity.
5
Structure & Correlation of Ephedra alkaloids
Alkaloids do not occur in a single form . In the plant, we always have major
alkaloids & minor alkaloids ( (1)Major + (n) Minor ) , so mainly the major
alkaloid is accompanied with a number of minor alkaloids ,therefore, when we
say ephedrine and pseudoephedrine, then we'll expect there are other closelyrelated alkaloids that are occurring in the ephedra species ,and they have
correlations with one another.
Epherda alkaloids are derivatives of the amino acids ; phenylalanine ( mainly)
& tyrosine ,but the amino acid is not donating the nitrogen . The nitrogen is
intorduced by a Trans-amination reaction.
Different intermediates are converted into the Diketone ; the occurrence of the
diketone is an essential intermediate in the biosynthetic pathway ,otherwise,we
cannot continue with the trans-amination reaction.
And as as a result of the transamination ,we obtain a basic intermaediate
termed the Cathinone, that still possesses one of the carbonyl groups as a keto
group, and the other keto group has already changed versus the amino group.
Now, the next reaction is the Reduction ,the carbonyl group can be reduced
,then we obtain two isomeric compounds : Norephedrine &
Norpseudoephedrine.
* The prefix "nor-" indicates that there must be a closely-related compound
with an additional methyl (it indicates either a nor-methyl or a nor-methoxy)
So, when we say : norephedrine & norpseudoephedrine, then there must be
methylated derivatives ,and these methylated derivatives are : Ephedrine &
Pseudoephedrine.
Further methylation of this amino group ( there's still a hydrogen that can be
replaced with another methyl group ) will obtain :From ephedrine : N-methylephedrine.
& From pseudoephedrine : N-methylpseudoephedrine.
These substances ( Ephedrine & Pseudoephedrine ) have similar activities to
that of Amphetamine . Also basic similarities to the structure of Amphetamine
but the absence of hydroxyl group . There's also methamphetamine ; one of the
hydrogens is methylated .
Important Note
6
Norpseudoephedrine is also termed as "Cathine" , Structurally the same.
( Different researchers were working on Ephedra species and others on Catha
edulis ( Khat Tea ). Those working on Catha edulis isolated compound which
they termed as " Cathine " and those working on Ephedra species isolated the
same compound and termed it as "Norpseudoephedrine". So, two different
reserchers isolated the same compound ,named differently ).
Therefore, when we say "Khat leaves " ,we don't say it contains
Norpseudoephedrine , we say it contains Cathine .
But ,in fact, Cathine is structurally nothing else than Norpseudoephedrine.
Khat or Abyssinian Tea
Alkaloids found in the Khat are very closely-related to Ephedra alkaloids ,and
there are other secondary metabolites.
It's the leaf of Catha edulis ( Celastraceae ); a small tree which is cultivated in
Yemen, Somalia , and Ethiopia .
It's the primary plant for misused leaves of this tea.
The active principals are found in the leaves.
The major active compound is Cathinone ( not Cathine ).
It's preferred to use the cut leaves when they are young leaves ( why ?! )
Because during their development, the cathinone is reduced to cathine and
norehedrine. So, in the young leaves ,the major constituent is Cathinone , and
this ketone is the major active principal and has the major biological activity of
the cut leaves ( when we use older leaves ,we isolate cathine ).
*In general, It's rich in alkaloids.
* It contains complex alkaloids called Cathedulins.
*There are also flavonoids , tannins , volatile oils ...etc. ( rich in secondary
metabolites ).
* The effect of Cathinone is similar to that of Amphetamine.
Khat is classified in some countries of the Arabic world as a Social drug like in
Yemen. It's forbidden in Saudi Arabia . Black-listed in Soudan and Somalia .
It's not internationally used widely.
7
The misuse is restricted to Arabic World ; this is easily explained because the
activity is best observed in young fresh leaves ,which means if they want to
transfer the leaves from Yemen ( for example ) to the States or Europe, then
there will be complicated procedures, while the majority of other hallucinogenic
preparations like marihuana are already used as dried material. So, it's not
wide spread throughout the world like other addicted drugs.
* When young leaves are kept in banana leaves ,they keep their freshness for
24 hours.
* Usually , the leaves should be used within the first 24 hours of preparation.
* It's classified in Yemen as a Social drug ; because it increase the selfconfidence ,talkativeness, and alertness of the users . But main activity is
suppression the feeling of hunger , therefore , Anorexia is one of the adverse
effects seen in individuals who are using these leaves for long term.
Inflammation of the oral cavity is common. The plant also contains tannins
constipation is a common observation as a side effect .
* By chewing the leaves , the user will have a Constant mild high
* Long-term use is associated with impotency & female infertility .
Colchicine
Another class of derivatives of Penylalanine & Tyrosine .
Obtained from Colchicum autumnale ( Liliaceae ).
This is a small class of secondary metabolites and observed only primarily in
two families : Amaryllidaceae & Liliaceae .
Colchicine is representing the family Liliaceae as a derivative of the different
alkaloids which are originating from Phenylalanine & Tyrosine.
Colchicine is pharmacologically an important drug., available in the market (
Colchicine tablets are available in the Jordanian market ) ,and it's used
primarily for the control of Acute attacks of Gout.
Note : Ingredient of Colchicine table is natural ,not synthetic.
Colchicine isolated as a pure compound either from the seeds or from the
tuber-like underground parts of the plant Colchicum autumnale , so seeds and
corms are collected ,submitted to extraction , and then Colchicine is obtained .
It's not only Colchicine in the plant , there's also Demecolcine and other related
alkaloids .
8
Biosynthesis of Colchicine
Biosynthesis of Colchicine is one the most complex biosynthetic pathways ,
because it includes both amino acids together ( both Phenylalanine & Tyrosine
), but each amino acid has a different pathway
* Phenylalanine proceeds in Shikimic acid pathway, it will be dis-aminated (
lose the amino group ) and then formation of the shikimic acid ( Cinnamic acid
; C6-C3 derivatives )
* While Tyrosine will be decarboxylated and converted to its biogenic amine :
Tyramine , and the nitrogen of Tyramine is incorporated in the structure of
colchicine ( The nitrogen atom in Colchicine is Tyrosine-derived ).
So, in the biosynthesis of Colchicine ,there's no trans-amination reaction.
Structure of Colchicine
It has an aromatic ring ( ring A ) , a 7-membered ring ( ring B ) , a tropolone
ring ( ring C ) ; whis is a pseudo-aromatic 7-membered ring ).
Biosynthetically , ring A is derived from Phenylalanine ,which also contributes
carbon atoms 5,6,and 7 of ring B , while the rest is originating from the amino
acid Tyrosine.
Colchicine is not a true alkaloid because nitrogen is not part of the heterocyclic
ring, it's on the side chain .
There's an amide group ( nitrogen is part of the amide function ) , and its
presence indicates that Colchicine is non-basic neutral alkaloid.
*Colchicine has a potent anti-inflammatory activity .
* It's a cytotoxic agent ( Anti-tumor agent ) : But until now ,neither colchicine
nor any semi-synthetic derivative of colchicine is utilized pharmacologically as
anti-tumor agent, it's nit used because of its toxicity ; the cytotoxicity is
affecting the cancerous cells and the normal cells ( non-selective toxicity ) , so
it's not used despite its very potent anti-mitotic activity .
* Colchicine is highly poisonous , it's used in Europe primarily as a suicidal
agent.
------------------------------------------------------------------------------------
Pyridine and piperidine alkaloids
Alkaloids which are possessing either a pyridine or piperidine in their structure
9
are called pyridine-piperidine alkaloid,s allthough the origin of the pyridine and
piperdine can be of different amino acids. The first type we’ll talk about is
Coniine:
Coniine is an exceptional case where no amino acids are involved in providing
the N but the transamination rxn; the nature has no limits as you can see, as
we are used on the N not to be a part of a heterocyclic ring structure! , but
coniine is an exceptional case, its N is a result of transamination rxn and it’s
included in a heterocyclic ring.
You can always be surprised with the nature providing us with different toxic
and biologically active substances.
Coniine is the toxic principle of Conium maculatum plant which belong to the
Apiaceae family , its fruit is similar to anise fruits the same size and
appearance .
It exist in jordan in wadi shoaib , you can see the Conium maculatum next to
the anise plants they grow in the same climate conditions but the Conium is
the toxic plant in the family Apiacea .
As mentioned before ( hahahah 3a asas fe 7ad b7dar wela 3aref :p) a nonoxygenated substances are oily as in the case of Coniine .it’s an oily liquid as it
doesn’t have an oxygen in its structure ,it cause paralysis of the diaphragm (
interrupt respiration then death)
Again the N should be originated from an amino acid but this is an exceptional
case it comes from transamination and here the acetic pathway is involved in
the biosynthesis
We have 4 acetate units ---- polyketomethylene ----- transamination --
cyclisation.
10

Arecoline and Areca catechu
Arecoline
Arecaidine
Arecoline it’s from the family Arecaceae it’s called betel nut, the seeds contain
the active principle , it can occur as a single compound or with other closely
related alkaloids like its derivative Arecaidine .
It’s use is only important from the pharmacological point in the veterinary
medicine (‫ ) الطب البيطري‬it is used widly as a vermifuge ( ‫)مضاد للديدان‬
The precursor in its synthesis is the nicotinc acid which is formed by the rxn of
L-aspartic acid + 3-phosphoglycerylaldehyde and several intermediate
compounds are formed until nicotinc acid is formed then it is converted to
arecoline .
L-aspartic acid+ 3-phosphoglycerylaldehyde--- --- --- nicotinic acid-- - arecoline
In fact arecoline seeds are of importance for the veterinary medicine in south
Asia where the plant is growing in countries like India and Serilanka, but also
in these countries they chew the betel “betel chewing”, but they have to make
preparation of it to form chewing gum of it
Leaves of the betel+lime (as the alkaline media) + tannin + betel nut (which
contain Arecoline) -- they chew it through the day to achieve a refreshment
and relaxation but hallucinations do not occur .
This relaxation effect result from the ( ARECAIDINE ) msh ARECOLINE
Demethylation of arecoline results in Arecaidine formation and that happens in
alkaline media (that’s why the lime used for) by the addition of lime when the
person chew the betel gum, arecaidine is formed and the accumulation of it is
responsible for the relaxation effect .
11
Adverse effect : can cause inflammation ,yellow teeth caused by the tannin ,
and over years with continuous use it can cause cancer!
The betel leaves and tannine-- for aroma.
The betel nut- responsible for the relaxation effect due to the arecaidine
formed from the arecoline.

Nicotine and Nicotina tabacum
When we talk about the pyridine-piperidine derivatives, the most important
representative is the Nicotina tabacum ( people smoke it), it is the oldest one of
the eldest attitudes of human being and the most officially acceptable social
behavior ( smoking cigarette)
Nicotina tabacum is the representative of the family Solanaceae ,so far around
100 species have been identified ,some of them are wild others are widely
culturated to cover the need of the cigarette industry
We have many alkaloids in this plant ,some of them are liquid but the most
important alkaloids found in Nicotina tabacum are:
The diffrences between them that both the nicotine and nornicotine are based
on pyridine-pyrrolidine whereas the anabasine is based on the pyridinepiperidine .
NORnicotine : nor- here means that its missing a methyl group (CH3).
The damages and health effect are well known, starts with the nicotine which is
used as insecticide and it’s more stable in its sulphate form and can be used
out door ,it’s used in the agriculture .
As we mentioned in previous lectures the pyridien itself is used as indoor
insecticide because it gets degraded fast “not stable” .
12
In closed places like greenhouses, you can use the nicotine , just leave an open
bottle of nicotine and it will be enough to kill insects, but in open places you
should use its sulphate form as it’s more stable.
The lethal dose is ≈ 100 mg you can obtain that from smoking 5 cigarrates but
because the smoker exhales it he doesn’t get the whole amount so it won’t kill
IMMEDIATELY (but it will kill you eventually!!)
Tobacco has more than 3000 compounds in it, depending on the sensitivity of
the GCLS device used to indicate them , divided into 2 groups :
Particulate & gaseous (volatile)
The 3000 compounds are components of the tar! Which is the polycyclic
aromatic hydrocarbon , the most cancerous one!

Biosynthetic origins of tobacco alkaloids :
Heterocyclic structure found in the Nicotina tabacum alkaloids :
Pyridine
Piperidine
Pyrrolidine
Now the pyridine is formed from the nicotinic acid which is formed by the
aspartic acid the pyridine can be converted easily into piperidine but that’s not
what happens in nature it’s more complicated to form the piperidine and use it
to form the anabasine .
Instead of L-aspartic acid--nicotinic acid-- pyridine and conver it it to
piperidine ,what happens is that the plant uses another amino acid which is Llysine .
The pyrrolidine originate from L-ornithine .
13
L-lysine
L-ornithine
L-aspatic acid
-
5 important amino acids are involved in the synthesis of alkaloids :
tyrosine ,alanine,lysine,orthnithine,aspartic acid
3 of them are alphatic and 2 are aromatic
And then the condensation between the pyridine and pyrrolidine to form
nicotine and nornicotine and condensation of pyridine with piperidine to
form anabasine .

Tropane alkaloids :
Are also a very important as antispasmodic and anesthetic they are distributed
in few families :
1-Solanaceae: Atropa bellladona , Datura stramonim, Hyoscyamus niger,
H.muticus , Withania somnifera .
2-Erythroxylaceae: Erythroxylum coca.
Again different isoisermism of tropane alkaloids their structure are not very
complex because the nucleus of its alkaloid tropane is composed of 2 rings
structure :piperidine+pyrrolidine and what is important that two carbons and
N are common to the rings of the piperidine and pyrrolidine ; you can write the
structure in different ways :
14
All tropane alkaloids have a methyl group unless they are NOR-tropanes
The biosynthesis , nothing new in this case for the formation of piperidine ring.
But here we are using acetoacetate (small carbons) in order to complete the
carbons of the tropane ring and all the carbons of the 4 acetylacetate is used
for the formation of the Coca alkaloids and all the carbons of the 3
acetylacetate fused for the formation of the Solanaceae alkaloids .
The Coca and Solanaceae alkaloids are ester alkaloids and to form an ester
alkaloid we need an alchohol moiety and an acid moiety .in fact these
heterocyclic structures which are occurring in 2 stereoisomers has a hydroxyl
group which is always attached to the carbon no.3 of the tropane nucleus ,this
alcoholic hydroxyl group occur as an α or β ,the compound that has an α is
called α-tropine and the one that has the β is called pseudotropine ( β-tropine).
Example is the tropanol :
The α configuration attached to C no.3 is α-tropanol which occurs primaly in
the Solanaceae alkaloids and the β form is pseudotropanol .
* Acid moieties in natural and semisynthetic alkaloids :
In the case of Solanaceae, the acid moiety is tropic acid which possess an
asymmetric carbon so we’ll except to have an L- and D- configuration of the
tropic acid, and keep in mind they occur as a racemic mixture.
The biologically active tropic acid is the L-tropic acid this is why we keep saying
L-hyoscyamin and so on to indicate the precursor of it which is the L-tropic
15
acid, hyoscyamin is racemized to atropine ( atropine as racemate of D and L
isomer) , when we use atropine, we have to use the double dose of hyoscyamin
to achieve the same effect .
Atropine acid and apoatropine , (the prefix apo- is based on the prefix asometimes), and here it means losing an h2O molecule so (atropine – h2O =
apo-atropine).
The synthetic available marketed products are based on Mandelic acid
(homatropine).

Tropane alkaloids/ester formation :
These alkaloids as mentioned before are occurring in their ester form ( because
of the esterification of -OH group on carbon number 3 in case of tropanol with
the carboxyl group in case of the tropic acid
There are some other alcoholic moieties isolated such as alcoholic hyoscyamine
= scopolamine; it has an epoxy group between carbon no.6 and no.7, in its
biosynthesis an O is introduced to carbon no.6 ,with the presence of the
necessary enzymes,6-hydroxy tropanol will be converted to 6,7-epoxytropine
which is termed as Scopine and with the addition of tropic acid it will be
converted to Scopolamine .
The important plants of tropane alkaloids have been mentioned before : Atropa
belladonna ….. .

Atropine :pharmacological properties/uses:
-
Plz refere to ur sheet to memorize them
Alkaloids of atropine and related substances have been isolated as an
important anticholinergic substances , the difference between atropine and
scopolamine is that later is classified as an CNS depressant while atropine and
hyoscyamine are stimulants but other than that ,they posse the same
activities.
They are used to counter act the insecticides poisoning and nerve paralyzing
gases.
 Coca alkaloids :
In case of tropane alkaloid ,we said that’s it’s either produced using 3 acetyl
acetate or 4 acetate to give Ecgonine ( a tropane alkaloid) , the latter is
16
different, it has an additional carboxylic acid attached to carbon no.2 of the
tropane.
( the dr said carbon no.3 but I checked the internet, its carbon no 2 )
tropane + -COOH ----
In the case of Coca alkaloids ,we have 2 ester group; why? Because we have
ecgonine alkaloid which has a free –OH group which will be converted to ester
by an alcohol moiety an a free –COOH group which will be converted to ester by
an acid moiety .
The alcohol moiety is methanol to provide the –CH3 to the –COOH and convert
it to ester.
And the acid moiety is usually Benzoic acid.
Ecgonine + -CH3 (from the methanol) --- ( carbomethoxy-ψ-tropine) + benzoic
acid-- L-cocain .
17
Benzoic acid can be replaced by other acids such as :
1- cinnamic acid and the formed alkaloid is cinnamyl cocain.
2- Truxillic acid(dimmeric cinnamic acidsto have α and β-truxillins .
cinnamic acid .
truxillinic acid.

Cocain :
It’s a major alkaloid in Erythroxylum coca .
In the group of secondary metabolite of the tropane alkaloid ,two important
ones are mentioned :
1- The one used as anticholinergic .
2- the local anesthetic (Cocain), it’s advantage that until now it is not overcome
by any
synthetic local anesthetic because the cocain form a
vasoconstriction effect when used topically (in ophthalmic preparation for
example) while synthetic doesn’t! , so when we use a synthetic local
anesthetic we have to add a vasoconstrictive agent . we need the
vasconstriction effect to eliminate the sweating from the surrounding tissue
.
until 1910 cocain was legal in the coca-cola ! but then they started to use
different species of the coca that doesn’t contain cocain .
18