11-Epi-azadirachtin H from Azadirachta indica

A new tetranortriterpenoid 11-epi-azadirachtin H has been isolated from the methanolic extracts of Azadirachta indica seeds. Its structure is proposed on the basis of various spectral analyses.

A natural compound, methyl angolensate, induces mitochondrial pathway of apoptosis in Daudi cells

Natural products discovered from medicinal plants have played an important role in the treatment of cancer. In an effort to identify novel small molecules which can affect the proliferation of lymphoma cells, we tested methyl angolensate (MA), a plant derived tetranortriterpenoid, purified from the crude extract of the root callus of Soymida febrifuga commonly known as Indian red wood tree. We have tested MA for its cytotoxic properties on Burkitt's lymphoma cell lines, using various cellular assays. We observed that MA induces cytotoxicity in Daudi cells in a dose-dependent manner using trypan blue, MTT and LDH assays. We find that the treatment with MA led to activation of DNA double-strand break repair proteins including KU70 and KU80, suggesting the activation of nonhomologous DNA end joining pathway in surviving cells. Further, we find that methyl angolensate could induce apoptosis by cell cycle analysis, annexin V-FITC staining, DNA fragmentation and PARP cleavage. Besides, MA treatment led to reactive oxygen species generation and loss of mitochondrial transmembrane potential. These results suggest the activation of mitochondrial pathway of apoptosis. Hence, we identify MA as a potential chemotherapeutic agent against Daudi cells.

Schilancidilactones A and B: two novel tetranortriterpenoids with an unprecedented skeleton from Schisandra lancifolia

Schilancidilactones A (1) and B (2). two novel tetranortriterpenoids possessing an unprecedented skeleton, have been isolated from the stems of Schisandra lancifolia. Their structures were elucidated on the basis of extensive spectroscopic analysis. The r

A New Triterpenoid from Amoora dasyclada

Five compounds were isolated from the EtOH extraction of the stem of Amoora dasyclada (How et T. Chen) C. Y. Wu (Meliaceae). On the basis of spectroscopic methods, their structures were elucidated as 24, 25-epoxy-tirucall-7-ene-3, 23-dione (1), 24, 25, 26, 27-tetranortirucall-7-ene-3-oxo-23(21)-lactone (2), taraxerone (3), taraxerol (4) and b-sitosterol (5). Among them, compound 1 was a new triterpenoid, compounds 3-5 were firstly obtained from this plant; compound 2, an tetranortriterpenoid, was firstly isolated from natural sources, and its NMR data were assigned for the first time. Moreover, the D7-bond and the Me-14 in compound 2 were never changed, which has never been found in other tetranortriterpenoids. And the biosynthetic pathway of tetranortriterpenoid was further discussed.