*2.2. Preparation of Plant Extracts*

The plant was dried in shade followed by cutting into small pieces and grinding into fine powder. The dried powdered material of aerial and root parts were 1500 g and 300 g, respectively. The dried powdered material of the flower parts of *C. procera, C. gigantea*

and *C. gigantea ash* were 200 g each. The flower ash was obtained by burning the flowers in petroleum ether. The powder of *A. aspera* was soaked in methanol (10 times *w*/*v*) and the powders of *C. procera* and *C. gigantea* were soaked in methanol (5 times *w*/*v*), at room temperature, for 10 days and 5 days, respectively, depending upon the weight of the powders. The extracted content was first filtered by Whatman filter paper (150 mm) and then evaporated using a Heidolph rotary evaporator. The crude methanol extract was successively fractionated in various solvents, i.e., hexane, ethyl acetate, ethanol and water, in order of their increasing polarity [35,36]. Total yield of the extractable components (EC) from *A. aspera* (aerial and root parts), *C. procera* (flower), *C. gigantea* (flower) and *C. gigantea* (flower ash) in various solvents are shown in Table 1.


**Table 1.** Total yield of the extractable components (EC) from *A. aspera* (aerial and root parts) *C. procera* (flower), *C. gigantea* (flower) and *C. gigantea* (flower ash).
