Evaluation of the Modulatory Effect of Annona muricata Extracts on the Activity of Some Selected Antibiotics against Biofilm-Forming MRSA

Table 2

Phytochemical screening tests of various extracts of A. muricata.

Phytochemical	Test	Observation
Alkaloid	Wagner’s reagent (I2/KI) was used. A minute amount of extract was dissolved in dilute HCl and filtered. Few drops of Wagner's reagent (I2/KI) were added to about 2 mL of the filtrate.	The formation of brownish/red precipitate confirmed the presence of alkaloid.
Flavonoids	Sulphuric acid (H2SO4) test was done by treating a fraction of the extract with concentrated H2SO4.	The formation of orange colour confirmed the presence of flavonoids.
Steroids	Liebermann-Buchard test was used. Four milligrams of the extracts was treated with 0.5 mL of acetic anhydride and 0.5 mL of acetic acid. Concentrated H2SO4 was slowly added.	The surfacing of a reddish/brown colour designating the presence of steroids.
Terpenoids	Liebermann-Buchard test was used. Four milligrams of the extracts was treated with 0.5 mL of acetic anhydride and 0.5 mL of acetic acid. Concentrated H2SO4 was slowly added.	The appearance of a blue-green colour proving the presence of terpenoids.
Saponins	Exactly 0.5 g of the plant extract was dissolved in 2.5 mL of distilled water. The mixture was shaken vigorously.	The presence of foam indicated the presence of saponins.
Tannins	An exact amount of 0.5 g of the extract was boiled in 20 mL of distilled water and filtered afterwards. Few drops of 0.1% of FeCl3 were added.	The presence of brownish-green, brownish-black, or blue-black colour confirmed the presence of tannins.
Glycosides	Benedict's test was used for the detection of glycosides. Precisely, 0.5 g of plant extract was dissolved in 5 mL of distilled water. Exactly 2 mL of benedict's solution was heated, and 8 drops of the dissolved sample were added and allowed to boil for 5 min.	The appearance of a brick red precipitate confirmed the presence of glycosides.