Strepamrisides C and D: two new rhamnosides from <i>Streptomyces amritsarensis</i> 13-85

Two new rhamnosides, strepamrisides C and D (<b>1</b> and <b>2</b>), together with two known rhamnosides, maculosin-O-<i>α</i>-L-rhamnopyranoside (<b>3</b>) and 2-pyrrolylcarbonyl-<i>α</i>-L-rhamnopyranoside (<b>4</b>) were isolated from <i>Streptomyces amritsarensis</i> 13-85. Their structures were elucidated by comprehensive spectroscopic analyses, including nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), and chemical derivatization. Compounds <b>2</b> and <b>3</b> showed inhibitory activity against <i>α</i>-glucosidase.