TY - JOUR T1 - In vitro Cytotoxic Pentacyclic Triterpenoids of Newbouldia laevis AU - Onocha, P.A. AU - Okorie, D.A. AU - Krebs, H.C. AU - Meier, B. JO - Research Journal of Medical Sciences VL - 5 IS - 6 SP - 330 EP - 335 PY - 2011 DA - 2001/08/19 SN - 1815-9346 DO - rjmsci.2011.330.335 UR - https://makhillpublications.co/view-article.php?doi=rjmsci.2011.330.335 KW - Bignoniaceae KW -fibroblasts KW -cytotoxicity KW -bioactivity KW -ursenoic acid KW -oleanenoic acid AB - Bioactivity directed fractionation afforded four cytotoxic constituents from the bioactive methanolic leaf extract (LD50 30 μg mLG1) of Newbouldia laevis (Bignoniaceae) collected from Ibadan, Nigeria. Four pentacyclic triterpenoids namely 2α, 3β, 19α-trihydroxy-12-ursen-28-oic acid, 3β, 19α-dihydroxy-12-ursen-28-oic acid, 3β-hydroxy-12-ursen-28-oic acid, 3β-hydroxy 12-oleanen-28-oic acid were found to be the cytotoxic principles. These compounds demonstrated significant cytotoxicity in vitro against ST-57 brain tumor transformed fibroblasts with LD50 ranging from 0.4 μg mLG1 (compound 1) to 4 μg mLG1 (compound 4). These ursene and oleanene type triterpenoids are encountered for the first time in this plant. The structures of these compounds were established by spectral data. ER -