Candibirin A, a furanocoumarin dimer isolated from Heracleum candicans WALL.
Candibirin A [systematic name: 9,9'-(1,4-dioxane-2,5-diyldimethylenedioxy)di(7H-furo[3,2-g]chromen-7-one)], a new furanocoumarin dimer, was isolated from Heracleum candicans WALL. (1)H NMR and MS spectra had indicated that the title compound was a dimer of heraclenin or heraclenol, but the linkage structure and its chirality were undetermined. The dioxane linkage, having the R,R configuration, has now been elucidated from dimethyl sulfoxide-solvated crystals, C(32)H(28)O(10).2C(2)H(6)OS. Candibirin A is thus a dimerization product from heraclenin formed by reaction at the epoxy group. Dimethylformamide-solvated crystals, C(32)H(28)O(10).C(3)H(7)NO, adopt a different conformation, with a folded structure that differs from the extended structure in the dimethyl sulfoxide solvate. However, the puckering of the dioxane linker unit is very similar in the two conformers. This result shows that the rotation of the ether bonds, in the linker between the furanocoumarin and dioxane moieties, causes the conformational flexibility of (I).
Doi
Mitsunobu
M
Osaka University of Pharmaceutical Sciences, Nasahara, Takatsuki, Osaka 569-1094, Japan. doit@gly.oups.ac.jp
Nakamori
Terue
T
Shibano
Makio
M
Taniguchi
Masahiko
M
Wang
Nian He
NH
Baba
Kimiye
K
D018712:Analgesics, Non-Narcotic / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004121:Dimethyl Sulfoxide; D030002:Heracleum / Q000737:chemistry*; D029001:Herbal Medicine; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008958:Models, Molecular; D008968:Molecular Conformation; D012997:Solvents
D018712:Analgesics, Non-Narcotic; D012997:Solvents; D004121:Dimethyl Sulfoxide