Axinellin A and B: Two New Pyrrolactam Alkaloids from Axinella sp.
Two new pyrrolactam alkaloids, axinelline A (1) and B (2), were isolated from the n-BuOH extract of marine sponge Axinella sp. The structures of these compounds were elucidated on the basis of spectroscopic methods (HR-ESI-MS, 1D and 2D NMR).
Sodwanone and yardenone triterpenes from a South African species of the marine sponge Axinella inhibit hypoxia-inducible factor-1 (HIF-1) activation in both breast and prostate tumor cells.
Hypoxia-inducible factor-1 (HIF-1) is a transcription factor that promotes tumor cell adaptation and survival under hypoxic conditions. HIF-1 is currently recognized as an important molecular target for anticancer drug discovery. A T47D breast tumor cell-based reporter assay was used to evaluate the NCI Open Repository of marine invertebrates and algae lipid extracts for HIF-1 inhibitory activity. Bioassay-guided fractionation and isolation of an active extract from Axinella sp. yielded seven new sodwanone triterpenoids [3-epi-sodwanone K (1), 3-epi-sodwanone K 3-acetate (2), 10,11-dihydrosodwanone B (4), sodwanones T-W (3, 7, 8, 9)], the new yardenone triterpene 12R-hydroxyyardenone (10), and the previously reported compounds sodwanone A (5), sodwanone B (6), and yardenone (11). The structures and relative configurations of these Axinella metabolites were determined spectroscopically. The absolute configuration of 1 was determined by the modified Mosher ester procedure. Sodwanone V (8) inhibited both hypoxia-induced and iron chelator (1,10-phenanthroline)-induced HIF-1 activation in T47D breast tumor cells (IC50 15 microM), and 8 was the only sodwanone that inhibited HIF-1 activation in PC-3 prostate tumor cells (IC50 15 microM). Compounds 1, 3, 4, and 5 inhibited hypoxia-induced HIF-1 activation in T47D cells (IC50 values 20-25 microM). Compound 2 was cytotoxic to T47D cells (IC50 22 microM), and 8 showed cytotoxicity to MDA-MB-231 breast tumor cells (IC50 23 microM).
Crossing Borders: Time, Memory, and the Construction of Identity in Song of the Exile
This article analyzes the construction of memory in Ann Hui's Song of the Exile as it intersects with issues of cultural identity, national allegory, and women's autobiographies.