Triterpene saponins from the seeds of Erythrophleum fordii and their cytotoxic activities

Cassaine diterpenoids from the seeds of Erythrophleum fordii Oliv. and their antiangiogenic activity

Fourteen undescribed cassaine diterpenoids along with nine known ones were isolated from the seeds of Erythrophleum fordii Oliv. (Leguminosae). In addition, subsequent structural modification yielded ten derivatives. Their chemical structures were established by extensive spectroscopic methods and acid hydrolysis. All the diterpenoids were screened for their antiangiogenic activity using the human umbilical vein endothelial cell (HUVEC) model. Five compounds were active, of which three possessed excellent activity as their effect was better than that of the positive control (SU5416). The structure-activity relationship analysis revealed that the side chain at C-13 was the key part affecting the inhibitory effect. Further study demonstrated that 3β-hydroxynorerythrosuamine-3-O-β-D-glucopyranoside and the formate of 3β-hydroxynorerythrosuamine-3-O-β-D-glucopyranoside significantly inhibited a series of angiogenic processes including proliferation, migration and capillary-like structure formation of endothelial cells. These findings may provide a new type of antiangiogenic agent for future cancer drug development.

Triterpene saponins from the roots of Acacia senegal (L.) Willd

Six new triterpenoid saponins, named senegalosides A-F (1-6) were isolated from the seedpods and roots of Acacia senegal (Mimosaceae). Their structures were elucidated using 1D and 2D-NMR spectroscopic analysis and mass spectrometry. Compound 1 possesses an unusual sapogenin, 3β-hydroxy-21-oxo-olean-12-en-28-oic acid (machaeric acid), and was reported here in its natural form for the first time within the genus Acacia. Senegaloside A is the first example of a machaeric-type triterpenoid glycoside in the plant kingdom. The cytotoxic effect of isolated saponins was evaluated on the H4IIE rat hepatoma cell line. As a result, compounds 1, 3-6 were not significantly cytotoxic to H4IIE cells even at 200 μM. Compound 2 was suppressed cell viability at 50-200 μM.

Two new phenolic glucosides from marine-derived fungus Aspergillus sp

Two new phenolic glucosides, including a new O-glycoside (1) and a new C-glycoside (2), were isolated from a marine-derived fungus Aspergillus sp. The structures of new compounds were elucidated through interpretations of spectroscopic evidence and high-resolution electrospray ionization mass spectrometry. The hexose unit of 1 was identified as β-D-glucose by comparison with an authentic sample via HPLC after acid hydrolysis and derivatization. All compounds were evaluated for their ability to inhibit LPS-induced NO production in RAW264.7 macrophages, but none of them displayed significant activity.