Page 66 - phytochemistry II -pharmD general

2- Non-aqueous titration

Atropine, hyoscyamine and hyoscine and their medicinal preparations are
estimated potentiometrically and/or by non-aqueous titration.

Coca alkaloids

Coca leaves contain two types of alkaloids:

1- Tropane alkaloids: cocaine, cinnamyl cocaine, & truxillines and
tropacocaine.

2- Pyrrolidine alkaloids: hygrine and cuscohygrine.

Tropane coca alkaloids

Tropane coca alkaloids are obtained from the leaves and shrubs of family
Erythroxylaceae; namely Erythroxylon coca (Bolivian or Huanuco) and
Erythroxylon truxillense (Peruvian or Truxillo) cultivated in Peru, Bolivia and
Colombia.

Coca leaves contain about 0.7 to 2% of total alkaloids of which cocaine,
cinnamyl cocaine and α-truxilline are the most important. They occur in different
proportions in different commercial varieties. Javanese leaves are usually the
richest in total alkaloids, of which the chief is cinnamyl cocaine; while the Bolivian,
Peruvian and Ceylon leaves contain less total alkaloids but a higher proportion of
cocaine.

Coca alkaloids are di-esters of ecgonine base.

Ecgonine

Me

NH
COOH

OH

H
Ecgonine

65