The book has been divided into three major parts. Part one describes the general importance of plants as medicines and a special focus has been given to Astragalus species. Second part tells the structure elucidation of various cycloartane triterpenoids by using modern spectroscopic techniques such as 1D and 2D-NMR, COSY, ROESY, HMQC, HMBC, etc. Similarly the techniques such as high- and low-resolution mass spectrometry (EI-MS, FAB-MS, ESI-QTOF-MS), UV, and IR spectrophotometery have also been discussed for structure elucidation. This part also describes the methodology adopted for their isolation and purification. Third part incldues in vitro assays of isolated compounds against the promastigotes of Leishmania major for leishmanicidal potential, screening against 3T3 fibroblast cells for cyctotoxcicity and antiglycation activity.