Carboline AlkaloidsCarboline Alkaloids

NH

N

1- 1- RauwolfiaRauwolfia Alkaloids Alkaloids

Source:Source: RauwolfiaRauwolfia roots roots ( (Rauwolfia serpentina, Rauwolfia serpentina, Fam. ApocynaceaeFam. Apocynaceae))

Constituents:Constituents: The most important are Reserpine and The most important are Reserpine and Rescinnamine.Rescinnamine.

Properties:Properties: ReserpineReserpine and and related alkaloidsrelated alkaloids are are weakly basic diester, weakly basic diester,

tertiary alkaloidstertiary alkaloids and possess a carboxylic group on and possess a carboxylic group on ring "E".ring "E".

NH

NH3CO

H3COOC OR

R= 3,4,5-trimethoxybenzoic acid ReserpineR= 3,4,5-trimethoxycinnamic acid Recinnamine

E

Alkaline Hydrolysis:Alkaline Hydrolysis:1- 1- ReserpineReserpine → → reserpicreserpic acidacid + + trimethoxybenzoictrimethoxybenzoic acid + acid + methanol.methanol.

2- 2- RecinnamineRecinnamine → → reserpicreserpic acidacid + + trimethoxycinnamictrimethoxycinnamic acid + acid + methanolmethanol..

Its solution acquires a yellow color and a pronounced fluorescence Its solution acquires a yellow color and a pronounced fluorescence especially after the addition of acids or upon exposure to light.especially after the addition of acids or upon exposure to light.

Tests for reserpine:Tests for reserpine: Vanillin /HCl reagent: → violet color.Vanillin /HCl reagent: → violet color.

Sodium molybdate in HSodium molybdate in H22SOSO44 → Yellow → Blue in two minutes. → Yellow → Blue in two minutes.

Uses:Uses: ReserpineReserpine and the related alkaloidand the related alkaloid rescinnaminerescinnamine are mainly used as are mainly used as

antihypertensives (250-500 mg daily) and as tranquilizersantihypertensives (250-500 mg daily) and as tranquilizers (0.1- 1mg (0.1- 1mg or more daily).or more daily).

2- 2- YohimbeYohimbe Alkaloids Alkaloids Source:Source: Yohimbine occurs in the barks of the West Yohimbine occurs in the barks of the West

African tree African tree Pausinystalia yohimbe =Pausinystalia yohimbe = Coryanthe Coryanthe yohimba, yohimba, Fam. RubiaceaeFam. Rubiaceae..

Constituents:Constituents: About 6% total alkaloids, the major is YohimbineAbout 6% total alkaloids, the major is Yohimbine ..

Tests:Tests:1- 1- Yohimbine + HYohimbine + H22SOSO44 + crystals of K + crystals of K22CrCr22OO77 → violet → violet streaks → blue → green streaks → blue → green

2- Yohimbine + Mandalin's2- Yohimbine + Mandalin's reagent → blue color → greenreagent → blue color → green Uses:Uses:

Yohimbine is mainly used as an aphrodisiac drug.Yohimbine is mainly used as an aphrodisiac drug.

NH

N

OH

H3COOC