Page 81 - Phytochemistry -1 (PG404) / Clinical Pharmacy 2nd level students ( 2019 )

Clinical pharmacy PharmD program Third level Phytochemistry-1 (PG-504)

Preliminary qualitative chemical tests for herbal drug active
constituents (Scheme)

1) Molisch test (for carbohydrates and/or glycosides)

1 ml sample + 1 ml alc α-naphthol, shake è Carefully “on T.T.
wall” add 1ml C.H 2SO 4

è Violet ring “at the junction” between 2 layers.---

2) Alkali test (for Flavanoids, Anthraquinones or khellin)
1 ml sample + 1ml 5% NaOH shake è * Red (rose to blood red
color) = (Anthraquinone).

* Yellow (Or dark brown, but yellow on the T.T. wall) = (flavonoid).

# (Color Blank should be done “to

exclude extract color effect”) 1 ml

sample + 1 ml H 2O (instead of NaOH).

1 ml sample + KOH pellets è * Red (rose to blood red color)

= (Khellin bitter principle). --

3) Mayer’s test (for Alkaloids)

1 ml sample + dp. by dp. Mayer’s reagent, shake è Yellowish
white ppt.

# (ppt Blank should be done “to exclude extract (alcoholic)
+ H 2O precipitation effect” 1 ml sample + dp. by dp. H 2O

(instead of Mayer’s).--

4) Froth test (for saponins)

1 ml sample + 1 ml H 2O, shake VIGOROUSLY è Large,
Permanent froth.

--
5) FeCl3 (for tannins)

1ml sample + dps. FeCl 3, shake è Black color (blue on the
T.T. wall= Pyrogallol).

(Green on the T.T. wall= Catechol).

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