Fig. 3.

A structurally novel acetal-functional anthracycline selectively targets leukemic blast cells and not nonmalignant lymphocytes within a human bone marrow biopsy. a Chromatographic arraying of Streptomyces specus was performed using split flow HPLC/UV/MS with polarity-switching mass scanning resulting in an array of highly characterized fractions from a crude extract of the baumycin producer S. specus. Primary cell preparations were prepared from AML patient biopsy. The metabolite array was incubated with heterogeneous cell samples, and the cells were then viability stained, fixed, barcoded, and stained with antibodies for biomarker and surface marker expression. Standard gating was performed using biaxial plots of CD45 expression vs. SSC was used to determine cell-type subsets (blue gate: lymphocytes, red gate: blasts) that were each individually analyzed for γH2AX and cCasp3 expression. b Structures of specumycin A1 and B1. c Biaxial plots of selected wells gated for lymphocytes and leukemia blasts. d Total ion current and selected extracted ion currents of metabolites within the metabolome of S. specus correlating to bioactive wells from assays against two patient samples. Bar graphs of percent of cells in the upper left quadrant of marker/viability gate (marker positive and viable cells). The solid red line is the arcsinh transformed median of the marker. For patient 015, the average cells collected per well were 3996 blasts (minimum 240) and 764 lymphocytes (minimum 66). For patient 001, the average collected per well was 1655 blasts (minimum 189) and 53 lymphocytes (minimum 17)