2.3. Extraction of plant

Method of extraction for AN includes extraction of the leaf powder by cold maceration. In the first set of experiments, the extraction was performed using different solvents. The suitable solvent which gives higher AN enrichment in the extracted phase was selected for further experiments. The leaves were ground to a powder (80 mesh size) and extracted at reflux temperature for 3 h. The extraction of AN from the ground powder was carried by mixing powder and solvent using Sox-let extraction technique. The powder to the different solvent ratio (w/v) used for all the studies. The solvent was removed and the process was repeated for one more time to remove the final traces of AN from the ground powder of leaves. The extracts were then combined and concentrated by recovering the solvent using Buchi rotavapour. The obtained brownish enriched extract of AN was used for further studies.

The airy parts of A. paniculata were collected from Guwahati, Assam in Aug-Sep 2010. The dried plant parts were successively extracted from different solvent such as petroleum ether, ethyl acetate and methanol. Methanol extracts was kept at (25 ± 2) °C for 3 d and following filtration; Methanol extract was vaporized in a low pressure to get sticky mass (Nugroho et al., 2012). The obtained semi-purified AN extract was kept in deep freezers at −30 °C for 24 h and vacuum dry at 40 psi in lyophilizer for 12 h. The dried semi-purified AN extract was kept in airtight container for analysis of various physicochemical parameters DSC, FTIR, TLC, HPLC and preparation of formulation.