Cyanogenic and non-cyanogenic pyridone glucosides from Acalypha indica (Euphorbiaceae).
Seven cyanopyridone derivatives and one corresponding seco compound have been isolated from a methanolic extract of the inflorescences and leaves of Acalypha indica L. (Euphorbiaceae). The absolute configuration of the main cyanogenic glucoside acalyphin, (-)-(5R,6S)-5-cyano-5-beta-d-glucopyranosyloxy-6-hydroxy-4-methoxy-1-methyl-2(5,6-dihydro)-pyridone, was deduced from an X-ray crystallographic study. In addition, the 6R-epimer of acalyphin, epiacalyphin, and the corresponding pair of N-demethyl derivatives were isolated. The corresponding amide of acalyphin and a 1',2'-glucosyl-fused epiacalyphin amide were isolated from air-dried material. Structural elucidation was performed by means of (1)H and (13)C NMR-spectra, chiroptical methods such as CD-spectroscopy and optical rotation. Two further corresponding derivatives, an aromatized compound and an open-chain structure, were isolated from the aqueous phase.
Hungeling
Monika
M
Institute of Pharmaceutical Biology and Phytochemistry, Westfälische Wilhelms-Universität, Hittorfstrasse 56, D-48149 Münster, Germany.
Lechtenberg
Matthias
M
Fronczek
Frank R
FR
Nahrstedt
Adolf
A
D000577:Amides / Q000737:chemistry; D018360:Crystallography, X-Ray; D019665:Euphorbiaceae / Q000737:chemistry*; D005960:Glucosides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009570:Nitriles / Q000737:chemistry*; D011728:Pyridones / Q000737:chemistry*
D000577:Amides; D005960:Glucosides; D009570:Nitriles; D011728:Pyridones; C011206:cyanogen