A-72363 A-1, A-2, and C, novel heparanase inhibitors from Streptomyces nobilis SANK 60192, II. Biological activities.

Inhibitory activities of A-72363 A-1, A-2, and C, the diastereomers of a neuraminidase inhibitor siastain B, against various glycosidases were tested in comparison to siastatin B. Despite these compounds differing only in their configuration, each compound showed strikingly different specificities towards the various glycosidases tested. A-72363 C inhibited bovine liver β-glucuronidase and tumor cell heparanase with IC50 values of 1.6 μM and 12 μM, respectively.