Synthesis and cytotoxicity of 28-carboxymethoxy lupane triterpenoids.Preference of 28-O-acylation ov

• 作 者: Aye Aye Mar Ali Koohang Nathan D.Majewski Erika L.Szotek David A.Eiznhamer Michael T.Flavin
• 机 构: Advanced Life Sciences,Inc.,1440 Davey Road,Woodridge,IL 60517 USA,
• 出 处: Chinese Chemical Letters
• 发表日期: 2009年10期
• 关键词: betulin hydroxyethyl Preference elongation iodide cytotoxic cytotoxicity targete

28-Carboxymethoxy lupane tritepenoids 3 and 4 were synthesized by alkylation of betulin with the THP protected 2- hydroxyethyl iodide followed by oxidation and reduction.Direct reaction of betulin(5) or betulone(10) with ethyl bromoacetate led to 28-O-acylation,instead of 28-O-alkylation.The targeted compounds 3 and 4 were not cytotoxic at the highest concentration tested(75μmol/L),suggesting that elongation of the chain length at the 28-position in both betulinic acid(1) and betulonic acid(2) was detrimental to the cytotoxicity.The acylation products 28-O-bromoacetates(8a,8b and 11) and 28-O-methoxyacetate 13 exhibited cytotoxicity against several cancer cell lines tested.

28-Carboxymethoxy lupane tritepenoids 3 and 4 were synthesized by alkylation of betulin with the THP protected 2-hydroxyethyl iodide followed by oxidation and reduction. Direct reaction of betulin (5) or betulone (10) with ethyl bromoacetate led to 28-O-acylation , instead of 28-O-alkylation. The targeted compounds 3 and 4 were not cytotoxic at the highest concentration tested (75 μmol / L), suggesting that elongation of the chain length at the 28-position in both betulinic acid (1) and betulonic acid (2) was detrimental to the cytotoxicity.The acylation products 28-O-bromoacetates (8a, 8b and 11) and 28-O-methoxyacetate 13 exhibited cytotoxicity against several cancer cell lines tested.