Betulonic amides modified at cycle a by amino acids: Synthesis and inhibition of flu A virus reproduction
摘要:
The Beckman rearrangement of carboxy- and alkyloxycarbonylalkylamides of 3-hydroxyiminobetulonic acid led to derivatives of 3a-homo-4-aza-3-oxolup-20(29)-ene and 3,4-seco-2-cyanolupa-4(23),20(29)-diene. An X-ray analysis showed methyl 3-(N-acetoximino)lup-20(29)-enoate is the E-isomer. The compounds synthesized exhibited inhibiting activity toward the reproduction of flu A virus in cell culture.