New 19-acetoxyingol diterpenes from the latex of Euphorbia poisonii (Euphorbiaceae)

✍ Scribed by Majekodunmi O. Fatope; Lu Zeng; Joseph E. Ohayagha; Jerry L. McLaughlin

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 482 KB
• Volume: 4
• Category: Article
• ISSN: 0968-0896
• DOI: 10.1016/0968-0896(96)00157-5

✦ Synopsis

The poisonous latex of Euphorbia poisonii gave bioactive 3,12-diacetyl-8-nicotinyl-7-phenylacetyl 19-acetoxyingol (1) together with its less active congeners, 3,12-diacetyl-7-phenylacetyl 19-acetoxyingol (2) and 3-acetyl-7-phenylacetyl 19-acetoxyingol (3). The chemical structures of 1-3 were determined by spectroscopic methods including HRMS, DEPT, HETCOR, COSY, NOESY, HMQC and HMBC. The absolute configurations of the hydroxylated carbons in 2 and 3 were provisionally suggested by the Mosher ester method. Bioactivity-guided isolation, structure determination and cytotoxic activity of the new ingols are described.