10.1021/np200411p.s001
George R. Pettit
George R.
Pettit
Ricardo F. Mendonça
Ricardo F.
Mendonça
John C. Knight
John C.
Knight
Robin K. Pettit
Robin K.
Pettit
The Cephalostatins. 21. Synthesis of Bis-steroidal Pyrazine Rhamnosides
American Chemical Society
2011
21 c
nosocomial pathogen Enterococcus faecalis
steroidal pyrazine 10
rhamnosides 17 b
Pyrazine 9
cancer cell growth
21. Synthesis
iodide
cancer cell line panel
boron triflouride etherate
orthoester
pyrazine 10
2011-09-23 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/The_Cephalostatins_21_Synthesis_of_Bis_steroidal_Pyrazine_Rhamnosides/2611681
The synthesis of bis-steroidal pyrazines derived from 3-oxo-11,21-dihydroxypregna-4,17(20)-diene (<b>4</b>) and glycosylation of a D-ring side chain with α-l-rhamnose have been summarized. Rearrangement of steroidal pyrazine <b>10</b> to <b>14</b> was found to occur with boron triflouride etherate. Glycosylation of pyrazine <b>10</b> using 2,3,4-tri-<i>O</i>-acetyl-α-l-rhamnose iodide led to 1,2-orthoester-α-l-rhamnose pyrazine <b>17b</b>. By use of a persilylated α-l-rhamnose iodide as donor, formation of the orthoester was avoided. Bis-steroidal pyrazine <b>10</b> and rhamnosides <b>17b</b> and <b>21c</b> were found to significantly inhibit cancer cell growth in a murine and human cancer cell line panel. Pyrazine <b>9</b> inhibited growth of the nosocomial pathogen <i>Enterococcus faecalis</i>.