configuration at C-3 and the A/B fusion mode. 3β-OH and A/B ring cis fusion are favoured by OleD (ASP). An epoxide ring at C-14 and C-15 further increases the bioconversion rate; while an acetyl group at C-16 and lactone ring type at C-17 did not influence the biotransformation. A high conversion rate corresponded to a low Km value. A molecular docking simulation showed that filling of hydrophobic pocket
A permissive steroid glycosyltransferase (UGT74AN1) from Asclepias curassavica exhibited robust capabilities for the regiospecific C3 glycosylation of cardiotonic steroids and C-21 steroid precursors, and unprecedented promiscuity toward 53 structurally diverse natural and unnatural compounds to form O-, N-, and S-glycosides, along with the catalytic reversibility for a one-pot transglycosylation reaction. These findings highlight UGT74AN1 as the first regiospecific catalyst for cardiotonic steroid C3 glycosylation and exhibit significant potential for glycosylation of diverse bioactive molecules in drug discovery.
Triple-Negative Breast Cancer Cells Exhibit Differential Sensitivity to Cardenolides from <i>Calotropis gigantea</i>
作者:Petra J. Pederson、Shengxin Cai、Chase Carver、Douglas R. Powell、April L. Risinger、Tanja Grkovic、Barry R. O’Keefe、Susan L. Mooberry、Robert H. Cichewicz
DOI:10.1021/acs.jnatprod.0c00423
日期:2020.7.24
yielded nine cardenolides responsible for the selective activity. These included eight known cardenolides and a new cardenolide glycoside. Structure–activity relationships among the cardenolides demonstrated a correlation between their relative potencies toward BT-549 cells and Na+/K+ ATPase inhibition. Calotropin, the compound with the highest degree of selectivity for BT-549 cells, increased intracellular