ABSTRACT
The CDC25 phosphatases regulate the cell division cycle by controlling the activity of cyclin-dependent kinases. While screening for inhibitors of phosphatases among natural products we repeatedly found that some polyprenyl-hydroquinones and polyprenyl-furans (furanoterpenoids) (furospongins, furospinosulins) were potent CDC25 phosphatase inhibitors. These compounds were extracted, isolated and identified independently from three sponge species (Spongia officinalis, Ircinia spinulosa, Ircinia muscarum), collected at different locations in the Mediterranean Sea. The compounds were inactive on the Ser/Thr phosphatase PP2C-alpha and on three kinases (CDK1, CDK5, GSK-3), suggesting that some potent and selective CDC25 phosphatase might be designed from these initial structures.
Subject(s)
Cell Cycle/drug effects , Furans/pharmacology , Hydroquinones/pharmacology , Porifera/chemistry , cdc25 Phosphatases/drug effects , cdc25 Phosphatases/pharmacology , Animals , Escherichia coli , Furans/isolation & purification , Hydroquinones/isolation & purificationABSTRACT
Three new cytotoxic 3,6-disubstituted indoles (1-3) were isolated from the mycelium of a strain identified as Streptomyces sp. (BL-49-58-005), which was separated from a Mexican marine invertebrate, and their structures established by analysis of NMR and mass spectral data. GI(50) values for 1 and 2 in cytotoxic bioassays against a panel of 14 different tumor cell lines were estimated at micromolar range, while compound 3 showed no activity in the same assays.
