Isolation and structure elucidation of two phosphorylated sterol sulfates, MT1-MMP inhibitors from a marine sponge Cribrochalina sp.: revision of the structures of haplosamates A and B

Two inhibitors of membrane-type matrix metalloproteinase (MT1-MMP) were isolated from a marine sponge Cribrochalina sp. Their structures were elucidated as unusual phosphorylated sterol sulfates by spectroscopic and chemical methods. One of the sterol sulfates was found to be identical to haplosamate A, whose structure was previously proposed to be a steroidal sulfamate ester, which led to structure revisions of both haplosamates A and B. The absolute stereochemistry of haplosamate A was determined by chemical transformation and the modified Mosherʹs method. The sterol sulfates inhibited MT1-MMP with IC50 values of 150 and 160 μg/mL, respectively.