Download Iridoids and Valerian are not mentioned in the archive so please

Iridoids and Valerian are not mentioned in the archive so please refer to
the slides and your own notes concerning these two topics.
Irregular Monoterpenes:
In the last lecture, we were talking about regularity, and when we are
following roles of condensation DMAPP & IPP for the monoterpenoid
condensation, we will obtain by head to tail condensation 10 carbon unit
geranyl pyrophosphate (GPP) which is modified to form different acyclic,
monocyclic, bi cyclic ,…….etc, derivative of monoterpenoid .
In irregular monoterpenes we are not following this rule DMAPP & IPP,
and we can use either two IPP or two DMAPP units without following
head to tail condensation, and in this case we will obtain odd structures
different from the 10 carbon basic unit of GPP, which is obtained from
Tanacetum cinerariifolium which is containing substances widely used as
insecticide which is used in the household to get rid of flies or other
insects "Quik knock down ".
This insecticide structure based on pyrethrins & pyrethroid, pyrethroid is
an organic synthetic compound similar to the natural pyrethrins. The
natural compound obtained from species of Tanacetum cinerariifolium,
which is a plant in Europe but it's cultured in many countries, mainly in
Africa but Kenya also produces different insecticide substance from this
plant. The constituent of pyrethroid are monoterpenoid substances
different in their structure of our common nucleus of GPP, by this
condensation as IPP + DMAPP  GPP which is 10 carbons.
GPP + IPP  FPP is the backbone for the Sesquiterpenes, so in the
terpenoid chemistry to continue enlarging the molecule is based on the
formation of GPP, if we didn't obtain GPP we will not be able to form a
class of Sesquiterpenes substances either by head to tail or tail to tail
condensation.
In this plant by which we have the pyrethrins lacking GPP will obtain odd
structure with very distinct activity (insecticide), the monoterpenoid parts
of this substance are obtained from two DMAPP, either mono carbonic
acid which is Chrysanthemic Acid of methyl ester or di carbonic acid
which is Pyrethric Acid.
Pyrethrins which are possessing insecticidal activity are esters, because
what we obtain from monoterpenoid chemistry are the carboxylic acids,
mono carboxylic acids or di carboxylic acid, and these substances are
forming in fact a series of esters using different alcohol moieties.
In this plant we have also free alcohols, they are characterized by
possessing a 5 member unsaturated ring with carbonyl group, these
three alcohols (rethrolones) are:
1- Pyrethrolone
2- Cinerolone
3- Jasmolone
In the presence of this alcohol moiety as well as the acid moiety
(Carboxylic group), we can form a series of esters.
These esters are In fact the biological active compounds of expanded
flowers, and they do possess insecticidal activity and they are toxic to
cold blood animals, they have a low toxicity to the human being, also the
different series of the pyrethin, cinerin, jasmolin are formed using the
two acids: Chrysanthemic Acid and Pyrethric Acid, and the three
alcohols, so we have a series of esters which possess a certain degree of
insecticidal activity, and depending of the Chrysanthemic Acid or
Pyrethric Acid, we can obtain different series of insecticidal compounds,
and we will be able to kill the insect immediately, because they are very
potent agents.
Depending on series 1 or series 2, either by Chrysanthemic Acid or
Pyrethric Acid derivatives, we will obtain a different potency of the
insecticide killing capability, while pyrethrines are paralyzing
insecticides, there are different substance which are used as synergistic
agents, they only potentiate insecticidal activity, and one of them is
Piperonyl butoxides, they increase the toxic activity of pyrethrine, they
are used in Veterinary medicine because they are non-toxic to the warm
blood animal and they are non-toxic for human being, and the advantage
& disadvantage of this insecticide is being degraded by oxygen of the air
so they lose their biological effect .
End of Midterm material! Please refer to the slides and your notes along
with these sheets while studying.
Best of luck !!