The synthesis of triterpenic amides on the basis of 2,3-seco-1-cyano-19β,28-epoxy-18α-oleane-3-oic acid

Abstract

Novel 2,3-seco-triterpenic amides were prepared by the interaction of the chloride of 2,3-seco-l-cyano-19beta,28-epoxy-18alpha-oleane-3-oic acid with primary amines and synthetic and biogenic amino acids. A cytotoxic triterpenic conjugate with a residue of the ethyl ester of beta-alanine was found among the synthesized nitrogen-containing derivatives. Treatment with this conjugate in a concentration of 100 muM resulted in the 45.5% survival of melanoma cells in the medium.

Allobetulin and Its Derivatives: Synthesis and Biological Activity

“…Upon Schmidt reaction of methyl betulonate or Beckmann rearrangement (POCl 3 ) of its oxime, the 28-oxo derivatives 59b and 60b were formed after two consecutive rearrangements [ 98 ]. Other 2,3- seco -derivatives were prepared via Beckmann fragmentation of allobetulin derivatives ( Figure 16 ) [ 33 , 45 , 99 , 100 ].…”

Synthesis of 1-cyano-2,3-seco-derivatives of glycyrrhetic acid

“…Like glycyrrhizic acid, its triterpene aglycon and natural metabolite 18E-glycyrrhetic acid exhibits multifunctional pharmacological activity (including antiulcer, anti-inflammatory, immunomodulating, antiviral, and antitumor), is the active principle of many drugs, and is used as a base for preparing new biologically active derivatives [4,5].We synthesized previously from the available triterpenoid betulin C-3 O-and N-containing 2,3-seco-triterpene derivatives of the lupane and 19E,28-epoxy-18DH-oleanane series including some with antiviral, cytotoxic, and immunotropic activity [6][7][8][9][10][11]. The steroid chemistry method [12][13][14] that involves Beckmann fragmentation of the D-hydroxyoxime of glycyrrhetic acid was adapted to triterpenoids [5,6] during the preparation of 2,3-seco-derivatives of the 18EH-oleanane series.…”

“…We synthesized previously from the available triterpenoid betulin C-3 O-and N-containing 2,3-seco-triterpene derivatives of the lupane and 19E,28-epoxy-18DH-oleanane series including some with antiviral, cytotoxic, and immunotropic activity [6][7][8][9][10][11]. The steroid chemistry method [12][13][14] that involves Beckmann fragmentation of the D-hydroxyoxime of glycyrrhetic acid was adapted to triterpenoids [5,6] during the preparation of 2,3-seco-derivatives of the 18EH-oleanane series.…”