Table 1 Preliminary phytochemical tests for plant extracts

1

Alkaloid

2 ml of extract + 2 ml of 2 N HCl + 2 drops of Wagner’s reagent

2 ml of extract + 2 ml of 2 N HCl + 2 drops of Mayer’s reagent

Reddish-brown precipitation validates the presence of alkaloid

Gelatinous white precipitation validates the presence of alkaloid

2

Tanins and phenol

2 ml of extract + 2 ml water + 2–3 drops of 5% FeCl₃

Green precipitate validates the presence of tannin. Purple solution validates presence of phenol.

3

Flavonoid

3 ml of extract + evaporated to dryness. Residue + 1–2 ml 50% CH₃CH₂OH, heat + 4–5 drops HCl + Mg ribbon

Red or orange color validates the presence of flavonoid.

4

Steroid (Salkowski Test)

2 ml extract + 2 ml CHCl₃ + 3 ml conc. H₂SO₄

● The reddish brown precipitate validates the presence of steroid.

5

Glycoside

2 ml extract + 2 ml CHCl₃ + 1–2 ml CH₃COOH

Formation of violet or blue to green coloration validates presence of glycoside.

6

Saponin

2 ml extract + evaporated to dryness. Residue + 1 ml water + shaken vigorously.

The persistent foam (1 cm in the test tube) validates the presence of saponin.

7

Emodol

2 ml extract + 1–2 ml 25% NH_{3 +} Shaken.

A cherries red color indicates the presence of emodol

8

Coumarin

2 ml extract + 3 ml (10%) NaOH

Yellow coloration validates presence of coumarin.

9

Anthocyanin

2 ml extract + 2 ml (2 N) HCl + 1 ml NH₃

Formation of pinkish red to bluish violet coloration validates presence of the anthocyanin.

10

Protein

2 ml extract + 1 ml (40%) NaOH + 1–2 drops 1% CuSO₄ solution.

Formation of violet color validates presence of protein.

11

Carbohydrate

Fehling’s test: 1 ml extract + 2 ml water + 1 ml Fehling solution (1 and 2) + heated in a water bath

Molisch’s test: 1 ml extract + 5 ml distilled water + 2 drops alcoholic α-naphthol

A brick red precipitate validates presence of reducing sugar.

violet ring at the junction validate the presence of carbohydrates

12

Terpenoids

2 ml extract + 2 ml CHCl₃ + 5 ml conc. H₂SO₄

Reddish-brown coloration validates the presence of terpenoids

13

Glucoside

2 ml extract + few drops conc. H₂SO₄

black coloration validates the presence of glucoside