Tri- and diterpenoids from some species of Euphorbiaceae. Evaluation of their antiinflammatory and cytotoxic properties

The Euphorbiaceae family is one of the largest in the plant kingdom; it is widespread throughout the world and biosynthesizes a variety of bioactive metabolites [1, 2]. The aim of present study is the characterization and bioevaluation of the secondary metabolites from four Euphorbiaceae species, Sapium nitidum , Sebastiania longicuspis , Sapium macrocarpum and Croton glabellus . From the aerial parts of S. nitidum were characterized lupeyl palmitate ( 1 ), lupeyl acetate ( 2 ), 19βH-lupeol ( 3 ), β-amyrinyl palmitate ( 4 ), 1β,3β,11α-trihydroxy-olean-12-enyl-3-palmitate ( 5 ), 3β-hydroxy-11-oxo-olean-12-enyl-3-palmitate ( 6 ), cycloeucalenol ( 7 ), β-sitosterol, stigmasterol, β-sitosteryl-3- O -β-D-glucopyranoside and β-sitosteryl-3- O -β-D-glucopyranoside-6'- O -palmitate. From S. longicuspis were isolated 3-epi-taraxerol ( 8 ), 3β-taraxerol ( 9 ), 3-acetyl-aleuritolic acid ( 10 ), 3-oxo-21αH-hop-22(29)-ene ( 11 ), ent-kaurane-3-oxo-16α,17-diol ( 12 ) and 3 . Lupenone ( 13 ), sitostenone, β-sitosterol, tonantzitlolone ( 14 ) and 3 were isolated from the aerial parts of S. macrocarpum . From the leaves of C. glabellus were isolated austroinulin ( 15 ), 6- O -acetylaustroinulin ( 16 ) and phytosterols. Preliminary biological evaluation of some natural compounds indicated moderate activity. In order to explore the bioactivity, some semisynthetic compounds were prepared. Diindolylmethane derivative ( 17 ) was obtained from 30-oxo-lupeol, which was prepared from the oxidation of 3 with SeO 2 . Compound 17 displayed good selectivity against human leukemia-cancer cell lines. References: [1] García A, Ramírez-Apan MT, Cogordán A, Delgado G. Absolute configuration assignments by experimental and theoretical approaches of ent-labdane- and cis-ent-clerodane-type diterpenes isolated from Croton glabellus. Can J Chem 2006; 84: 1593 – 1602. [2] Reyes B, Ramírez-Apan MT, Toscano RA, Delgado G. Triterpenes from Garcia parviflora. Cytotoxic Evaluation of Natural and Semisynthetic Friedelanes. J Nat Prod 2010; 73: 1839 – 1845.