Plakevulin A induces apoptosis and suppresses IL-6-induced STAT3 activation in HL60 cells.

(+)-Plakevulin A (1), an oxylipin isolated from an Okinawan sponge Plakortis sp. inhibits enzymatic inhibition of DNA polymerases (pols) α and δ and exhibits cytotoxicity against murine leukemia (L1210) and human cervix carcinoma (KB) cell lines. However, the half-maximal inhibitory concentration (IC) value for cytotoxicity significantly differed from those observed for the enzymatic inhibition of pols α and β, indicating the presence of target protein(s) other than pols.

Synthesis and Antiviral Activities of Neoechinulin B and Its Derivatives.

We have previously reported that neoechinulin B (), a prenylated indole diketopiperazine alkaloid, shows antiviral activities against hepatitis C virus (HCV) via the inactivation of the liver X receptors (LXRs) and the resultant disruption of double-membrane vesicles. In this study, a two-step synthesis of the diketopiperazine scaffold of was achieved by the base-induced coupling of 1,4-diacetyl-3-{[-butyldimethylsilyl)oxy]methyl}piperazine-2,5-dione with aldehydes, followed by the treatment of the resultant coupling products with tetra--butylammonium fluoride. Compound and its 16 derivatives - were prepared using this method.

Epo-C12 inhibits peroxiredoxin 1 peroxidase activity.

Epo-C12 is a synthetic derivative of epolactaene, isolated from Penicillium sp. BM 1689-P. Epo-C12 induces apoptosis in human acute lymphoblastoid leukemia BALL-1 cells.

Synthesis and Cytotoxic Evaluation of -Alkyl-2-halophenazin-1-ones.

In this study, the synthesis of -alkyl-2-halophenazin-1-ones has been established. Six -alkyl-2-halophenazin-1-ones, including WS-9659 B and marinocyanins A and B, were synthesized by the direct oxidative condensation of 4-halo-1,2,3-benzenetriol with the corresponding -alkylbenzene-1,2-diamines. One of the most significant features of the present method is that it can be successfully applied to the synthesis of -alkyl-2-chlorophenazin-1-ones.