Quinoline alkaloids Flashcards
What are quinoline alkaloids?
Heterocyclic, aromatic organic compounds with molecular formula C9H7N
quinolines are derivatives of
tryptophan amino acids
In which solvents they are soluble
less soluble in cold water but readily soluble in hot water and other organic solvents
Classification of quinolines
Comprise of quinine, quinidines, cinchonine, cinchonidine, strychnine, brucine, etc.
Biosynthesis of quinolines
They are formed from the precursors anthranilic acid or tryptophane in plants, condensed with either hemiterpenes or monoterpenes.
Occurrence
rutaceae or rubiaceae family in plants, in microorganisms and animals.
Also found as partial redox structures in PQQ (pyrroloquinoline quinone) and quinoenzymes
What is cinchona
Cinchona is the dried stem and root bark obtained from various cinchona plants
Cinchona sources
C. succiruba (red cinchona)
C. ledgeriana
C. calisaya (yellow cinchona)
C. officinales (pale cinchona)
Isolation of alkaloids
Isolation is done on the basis of solubility of different alkaloids:
1. quinine monosulfate - sparingly soluble in water
2. Cinchonine - insoluble in ether
3. l-isomers tartarates (quninine and cinchonidine) - water insoluble while d-isomers tartarates (quinidine and cinchonine) - water soluble
quinine is
diacidic base
which sulfates are formed by quinine
3 sulfates:
quinine monosulfate (neutral and water insoluble)
quinine bisfulfate (acidic and water soluble)
quninine tetrasulfate (more water soluble)
quinine and cinchonidine are
levorotatory
quinidine and cinchonine are
dextrorotatory
quinine give quinidine
when warmed with KOH
Uses
- Simple extract is used as stomachic and astringent
- Quinine is used as anti-malarial, as tonic and for alopecia
- Quinidine is used as cardiac depressant
- Cinchonine and cinchonidine are used as anti-rheumatic
